Heat recovery apparatus

Abstract

The present application relates to a heat recovery apparatus and method. According to the heat recovery apparatus and method, low-level heat sources at a temperature less than 100 C. discharged from industrial settings or various chemical processes, for example, a petrochemicals manufacturing process are not wasted but used to generate steam and the generated steam is used for various processes to reduce an amount of consumed high-temperature steam that is an external heat source to be used for a reactor or distillation column, thereby not only maximizing energy reduction efficiency but also autonomously producing power consumed by a compressor. Also, an evaporation phenomenon of a part of a refrigerant flow which passes through the compressor may be reduced, thereby recovering heat with excellent efficiency.

Claims

1. A heat recovery apparatus comprising: a first circulation loop which comprises an evaporator, a first compressor, a first condenser, and a control valve or a first turbine, fluidically connected through pipes through which a refrigerant flows; and a second circulation loop which shares the evaporator with the first circulation loop and comprises the evaporator, a second turbine, a second condenser, and a second compressor, fluidically connected through pipes through which the refrigerant flows, wherein a refrigerant flow discharged from the evaporator flows into a fluid distributor, wherein the refrigerant flow which flows into the fluid distributor is separated in the fluid distributor in such a way that one part of the refrigerant flow flows into the first compressor and another part flows into the second turbine, wherein a refrigerant flow discharged from the first compressor flows into the first condenser and heat-exchanged with a second fluid flow which flows into the first condenser, wherein the refrigerant flow discharged from the first condenser flows into the control valve or the first turbine of the first circulation loop, wherein the refrigerant flow discharged from the second turbine flows into the second condenser, wherein the refrigerant flow discharged from the second condenser flows into the second compressor, wherein the refrigerant flow discharged from the control valve or the first turbine of the first circulation loop and the refrigerant flow discharged from the second compressor flow into a fluid mixer and merge thereinto and then flow into the evaporator, and wherein the refrigerant flow which flows into the evaporator is heat-exchanged with a first fluid flow which flows into the evaporator, wherein the heat recovery apparatus further comprises: a first heat exchanger fluidically connected to a pipe between the evaporator and the fluid distributor and a pipe between the first condenser and the control valve or the first turbine of the first circulation loop, wherein the refrigerant flow discharged from the evaporator flows into the first heat exchanger and then flows into the fluid distributor, wherein the refrigerant flow discharged from the first condenser flows into the first heat exchanger and then flows into the control valve or the first turbine of the first circulation loop, wherein the refrigerant flow discharged from the evaporator and the refrigerant flow discharged from the first condenser are heat-exchanged in the first heat exchanger, a second heat exchanger fluidically connected to a pipe between the turbine and the second condenser and a pipe between the second compressor and the fluid mixer, wherein the refrigerant flow discharged from the second turbine flows into the second heat exchanger and then flows into the second condenser, wherein the refrigerant flow discharged from the second compressor flows into the second heat exchanger and then flows into the fluid mixer, and wherein the refrigerant flow discharged from the second turbine and the refrigerant flow discharged from the second compressor are heat-exchanged in the second heat exchanger, wherein a ratio of a flow rate of the refrigerant flow which is separated in the fluid distributor and flows into the first compressor to an entire flow rate of the refrigerant flow discharged from the evaporator satisfies following Equation 1:
0.3F.sub.c/F.sub.e0.5Equation 1 wherein F.sub.c is the flow rate of the refrigerant flow which is separated in the fluid distributor and flows into the first compressor and F.sub.e is the entire flow rate of the refrigerant flow discharged from the evaporator; wherein a ratio of a flow rate of the refrigerant flow which is separated in the fluid distributor and flows into the second turbine to an entire flow rate of the refrigerant flow discharged from the evaporator satisfies following Equation 2:
0.5<F.sub.t/F.sub.e0.7Equation 2 wherein F.sub.t is the flow rate of the refrigerant flow which is separated in the fluid distributor and flows into the second turbine and F.sub.e is the entire flow rate of the refrigerant flow discharged from the evaporator; wherein a temperature of the refrigerant flow discharged from the evaporator and a temperature of the first fluid flow which flows into the evaporator satisfy following Equation 3:
1 C.T.sub.EinT.sub.Eout20 C.Equation 3 wherein T.sub.Ein is the temperature of the first fluid flow which flows into the evaporator and is from 50 C. to 90 C., and T.sub.Eout is the temperature of the refrigerant flow discharged from the evaporator and is from 60 C. to 100 C.; wherein a ratio of a pressure of the refrigerant flow which is separated in the fluid distributor and flows into the first compressor to a pressure of the refrigerant flow discharged from the first compressor satisfies following Equation 4:
2P.sub.C1out/P.sub.C1in5Equation 4 wherein P.sub.C1out is the pressure (bar) of the refrigerant flow discharged from the first compressor and P.sub.C1in is the pressure (bar) of the refrigerant flow which is separated in the fluid distributor and flows into the first compressor; wherein a ratio of a pressure of the refrigerant flow which is discharged from the second condenser and flows into the second compressor to a pressure of the refrigerant flow discharged from the second compressor satisfies following Equation 5:
2P.sub.C2out/P.sub.C2in7Equation 5 wherein P.sub.C2out is the pressure (bar) of the refrigerant flow discharged from the second compressor and P.sub.C2in is the pressure (bar) of the refrigerant flow which is discharged from the second condenser and flows into the second compressor.

2. The heat recovery apparatus of claim 1, wherein the refrigerant is a refrigerant in which a slope of a tangent line of a saturated vapor curve of a temperature-entropy diagram has a positive slope.

3. The heat recovery apparatus of claim 1, wherein a temperature of the refrigerant flow which is discharged from the first condenser and flows into the first heat exchanger and a temperature of the refrigerant flow which is discharged from the first heat exchanger and flows into the fluid distributor satisfies following Equation 6:
1 C.T.sub.R1inT.sub.R1out50 C.Equation 6 wherein T.sub.R1in is the temperature of the refrigerant flow which is discharged from the first condenser and flows into the first heat exchanger and T.sub.R1out is the temperature of the refrigerant flow which is discharged from the first heat exchanger and flows into the fluid distributor.

4. A heat recovery method comprising: a refrigerant circulation step which comprises a first circulation step of allowing a refrigerant flow to flow into an evaporator, allowing one part of the refrigerant flow discharged from the evaporator to flow into a first compressor, allowing the refrigerant flow discharged from the first compressor to flow into a first condenser, allowing the refrigerant flow discharged from the first condenser to flow into a control valve or a first turbine, and allowing the refrigerant flow discharged from the control valve or the first turbine of the first circulation step to flow into the evaporator and a second circulation step of allowing another part of the refrigerant flow discharged from the evaporator to flow into a second turbine, allowing the refrigerant flow discharged from the second turbine to flow into a second condenser, allowing the refrigerant flow discharged from the second condenser to flow into a second compressor, and allowing the refrigerant flow discharged from the second compressor to flow into the evaporator; a first heat exchange step of heat-exchanging the refrigerant flow which flows into the evaporator with a first fluid flow which flows into the evaporator; and a second heat exchange step of heat-exchanging the refrigerant flow discharged from the first compressor with a second fluid flow which flows into the first condenser, wherein the first circulation step further comprises allowing the refrigerant flow discharged from the evaporator to flow into a first heat exchanger and then to flow into the first compressor and allowing the refrigerant flow discharged from the first condenser to flow into the first heat exchanger and then to flow into the control valve or the first turbine of the first circulation step, wherein the heat recovery method further comprises a third heat exchange step of heat-exchanging the refrigerant flow discharged from the evaporator and the refrigerant flow discharged from the first condenser in the first heat exchanger, wherein the second circulation step further comprises allowing the refrigerant flow discharged from the second turbine to flow into a second heat exchanger and then to flow into the second condenser and allowing the refrigerant flow discharged from the second compressor to flow into the second heat exchanger and then to flow into the evaporator, wherein the heat recovery method further comprises a fourth heat exchange stage of heat-exchanging the refrigerant flow discharged from the second turbine and the refrigerant flow discharged from the second compressor in the second heat exchanger, wherein a ratio of a flow rate of the refrigerant flow which flows into the first compressor to an entire flow rate of the refrigerant flow discharged from the evaporator satisfies following Equation 1:
0.3F.sub.c/F.sub.e0.5Equation 1 wherein F.sub.c is the flow rate of the refrigerant flow which flows into the first compressor and F.sub.e is the entire flow rate of the refrigerant flow discharged from the evaporator; wherein a ratio of a flow rate of the refrigerant flow which flows into the second turbine to an entire flow rate of the refrigerant flow discharged from the evaporator satisfies following Equation 2:
0.5F.sub.t/F.sub.e0.7Equation 2 wherein F.sub.t is the flow rate of the refrigerant flow which flows into the second turbine and F.sub.e is the entire flow rate of the refrigerant flow discharged from the evaporator; wherein a temperature of the refrigerant flow discharged from the evaporator and a temperature of the first fluid flow which flows into the evaporator satisfy following Equation 3:
1 C.T.sub.EinT.sub.Eout20 C.[Equation 3 wherein T.sub.Ein is the temperature of the first fluid flow which flows into the evaporator and is from 50 C. to 90 C., and T.sub.Eout is the temperature of the refrigerant flow discharged from the evaporator and is from 60 C. to 100 C.; wherein a ratio of a pressure of the refrigerant flow which flows into the first compressor to a pressure of the refrigerant flow discharged from the first compressor satisfies following Equation 4:
2P.sub.C1out/P.sub.C1in5Equation 4 wherein P.sub.C1out is the pressure (bar) of the refrigerant flow discharged from the first compressor and P.sub.C1in is the pressure (bar) of the refrigerant flow which flows into the first compressor; wherein a ratio of a pressure of the refrigerant flow which is discharged from the second condenser and flows into the second compressor to a pressure of the refrigerant flow discharged from the second compressor satisfies following Equation 5:
2P.sub.C2out/P.sub.C2in7Equation 5 wherein P.sub.C2out is the pressure (bar) of the refrigerant flow discharged from the second compressor and P.sub.C2in is the pressure (bar) of the refrigerant flow which is discharged from the second condenser and flows into the second compressor.

5. The heat recovery method of claim 4, wherein the refrigerant is a refrigerant in which a slope of a tangent line of a saturated vapor curve of a temperature-entropy diagram has a positive slope.

6. The heat recovery method of claim 4, wherein a temperature of the refrigerant flow which is discharged from the first condenser and flows into the first heat exchanger and a temperature of the refrigerant flow which is discharged from the first heat exchanger and flows into the fluid distributor satisfies following Equation 6:
1 C.T.sub.R1inT.sub.R1out50 C.Equation 6 wherein T.sub.R1in is the temperature of the refrigerant flow which is discharged from the first condenser and flows into the first heat exchanger and T.sub.R1out is the temperature of the refrigerant flow which is discharged from the first heat exchanger and flows into the fluid distributor.

Description

BRIEF DESCRIPTION OF DRAWINGS

(1) FIG. 1 is a schematic diagram of a conventional waste heat processing apparatus.

(2) FIG. 2 is a schematic diagram illustrating a heat recovery apparatus according to one embodiment of the present application.

(3) FIG. 3 is a schematic diagram of a heat recovery apparatus according to another embodiment of the present application.

(4) FIG. 4 is a graph illustrating a temperature entropy diagram of a refrigerant according to an exemplary embodiment of the present application.

(5) FIG. 5 is a schematic diagram of a heat recovery apparatus according to still another embodiment of the present application.

(6) FIG. 6 is a schematic diagram of a heat recovery apparatus according to yet another embodiment of the present application.

(7) FIG. 7 is a heat recovery apparatus according to an example of the present application.

MODE FOR INVENTION

(8) Hereinafter, experimental examples of the present application and comparative examples will be described in detail. However, the scope of the present application is not limited to following embodiments.

Example 1

(9) Steam was generated using a heat recovery apparatus of FIG. 5.

(10) A refrigerant 1,1,1,3,3-pentafluoropropane (R245fa) was allowed to flow into an evaporator and to circulate to allow one part of a refrigerant flow separated from the evaporator to sequentially pass through a compressor, a first condenser, and a pressure-dropping device. In detail, a refrigerant flow in a state of 69.6 C., 6.2 kgf/cm.sup.2 g (7.1 bar), and a gas volume fraction of 0.0 was allowed to flow into the evaporator at a flow rate of 50,000 kg/hr, and simultaneously, a waste heat flow in a state of 85.0 C., 1.0 kgf/cm.sup.2 g (1.96 bar), and a gas volume fraction of 0.0 was allowed to flow into the evaporator at a flow rate of 300,000 kg/hr to be heat-exchanged. After the heat-exchange, the waste heat flow was discharged in a state of 78.2 C., 1.0 kgf/cm.sup.2 g (1.96 bar), and a gas volume fraction of 0.0 at a flow rate of 300,000 kg/hr and the refrigerant flow was discharged in a state of 80.0 C., 6.2 kgf/cm.sup.2 g (7.1 bar), and a gas volume fraction of 1.0 and flowed into a fluid distributor. The refrigerant flow separated in the fluid distributor was allowed to flow into the compressor at a flow rate of 19,000 kg/hr, and the refrigerant flow compressed by the compressor was discharged from the compressor in a state of 125.0 C., 20.7 kgf/cm.sup.2 g (21.3 bar), and a gas volume fraction of 0.82. In this case, an amount of work used in the compressor was 135583.0 W. The refrigerant flow discharged from the compressor was allowed to flow into the first condenser, and simultaneously, water in a state of 115.0 C., 0.7 kgf/cm.sup.2 g (1.67 bar), and a gas volume fraction of 0.0 was allowed to flow into the first condenser at a flow rate of 1,000 kg/hr and heat-exchanged with the refrigerant flow. After the heat exchange, the water was discharged as steam in a state of 115.0 C., 0.7 kgf/cm.sup.2 g (1.67 bar), and a gas volume fraction of 0.75 and the refrigerant flow was condensed and discharged in a state of 125.0 C., 20.7 kgf/cm.sup.2 g (21.3 bar), and a gas volume fraction of 0.0 and then flowed into a control valve. Here, calories condensed in the first condenser were 463422.8 W. Also, the refrigerant flow which passed through the control valve was discharged from the control valve in a state of 75.4 C., 6.2 kgf/cm.sup.2 g (7.1 bar), and a gas volume fraction of 0.0 and was allowed to flow into a fluid mixer.

(11) Meanwhile, the other part of the refrigerant flow separated in the fluid distributor was circulated to sequentially pass through a turbine, a second heat exchanger, a second condenser, a pump, the second heat exchanger, and the fluid mixer. In detail, the other part of the refrigerant flow separated in the fluid distributor was allowed to flow into the turbine at a flow rate of 31,000 kg/hr and the refrigerant flow which was discharged from the turbine and flowed into the second heat exchanger was allowed to flow into the second condenser. Also, the refrigerant flow discharged from the second condenser was allowed to flow into the pump and the refrigerant flow compressed by the pump was allowed to flow again into the second heat exchanger to be heat-exchanged with the refrigerant flow which was discharged from the turbine and flowed into the second heat exchanger and then was allowed to flow into the fluid mixer. In detail, the refrigerant flow expanded by the turbine was discharged from the turbine in a state of 63.1 C., 1.5 kgf/cm.sup.2 g (2.45 bar), and a gas volume fraction of 1.0 and was allowed to flow into the second heat exchanger. In this case, an amount of work generated in the turbine was 137713.0 W. The refrigerant flow heat-exchanged with the refrigerant flow discharged from the pump in the second heat exchanger was discharged from the second heat exchanger in a state of 51.6 C., 1.5 kgf/cm.sup.2 g (2.45 bar), and a gas volume fraction of 1.0 and then flowed into the second condenser and was condensed. The refrigerant flow condensed by and discharged from the second condenser in a state of 39.6 C., 1.5 kgf/cm.sup.2 g (2.45 bar), and a gas volume fraction of 0.0 was allowed to flow into the pump and was compressed. The refrigerant flow which passed through the pump and was compressed was discharged from the pump in a state of 40.0 C., 6.2 kgf/cm.sup.2 g (7.1 bar), and a gas volume fraction of 0.0 and then was allowed to flow into the second heat exchanger and heat-exchanged with the refrigerant flow which was discharged from the turbine and flowed into the second heat exchanger. The refrigerant flow which was discharged from the pump and flowed into the second heat exchanger to be heat-exchanged was discharged from the second heat exchanger in a state of 46.6 C., 6.2 kgf/cm.sup.2 g (7.1 bar), and a gas volume fraction of 0.0 and was allowed to flow into the fluid mixer. The refrigerant flow discharged from the pump and the refrigerant flow discharged from the control valve were allowed to merge in the fluid mixer and to flow again into the evaporator at a flow rate of 50,000 kg/hr.

(12) In this case, a coefficient of performance of the heat recovery apparatus was calculated through following Equation 8 and shown in following Table 1. The coefficient of performance indicates calories absorbed by a heat exchange medium in comparison with energy input to the compressor, that is, means a rate of recovered energy to an input energy amount. For example, when the coefficient of performance is 3, it means that calories three times of input electricity are obtained.

(13) $\begin{array}{cc}\mathrm{COP}=\frac{Q}{W}& \left[\mathrm{Equation}8\right]\end{array}$

(14) In Equation 8, Q indicates calories condensed by the first condenser and W indicates a total amount of work performed by the compressor (an amount of work used by the compressoran amount of work generated by the turbine).

Example 2

(15) Steam was generated using a heat recovery apparatus of FIG. 7.

(16) A refrigerant 1,1,1,3,3-pentafluoropropane (R245fa) was allowed to flow into an evaporator and to circulate to allow one part of a refrigerant flow separated from the evaporator to sequentially pass through a first heat exchanger, a compressor, a first condenser, the first heat exchanger, and a pressure-dropping device. In detail, a refrigerant flow in a state of 69.6 C., 6.2 kgf/cm.sup.2 g (7.1 bar), and a gas volume fraction of 0.0 was allowed to flow into the evaporator at a flow rate of 50,000 kg/hr, and simultaneously, a waste heat flow in a state of 85.0 C., 1.0 kgf/cm.sup.2 g (1.96 bar), and a gas volume fraction of 0.0 was allowed to flow into the evaporator at a flow rate of 300,000 kg/hr to be heat-exchanged. After the heat-exchange, the waste heat flow was discharged in a state of 78.2 C., 1.0 kgf/cm.sup.2 g (1.96 bar), and a gas volume fraction of 0.0 at a flow rate of 300,000 kg/hr and the refrigerant flow was discharged in a state of 80.0 C., 6.2 kgf/cm.sup.2 g (7.1 bar), and a gas volume fraction of 1.0 and allowed to flow into the first heat exchanger. The refrigerant flow which was discharged from the evaporator and flowed into the first heat exchanger was allowed to flow into a fluid distributor to allow one part to flow into the compressor, and the refrigerant flow discharged from the compressor was allowed to flow into the first condenser to be heat-exchanged with a fluid flow which passed through the first condenser. Also, the refrigerant flow discharged from the first condenser was allowed to flow again into the first heat exchanger to be heat-exchanged with the refrigerant flow which was discharged from the evaporator and flowed into the first heat exchanger, and then allowed to flow into a control valve. In detail, the refrigerant flow which was discharged from the evaporator and flowed into the first heat exchanger and heat-exchanged was discharged from the first heat exchanger in a state of 115.0 C., 6.2 kgf/cm.sup.2 g (7.1 bar), and a gas volume fraction of 1.0 and then allowed to flow into the fluid distributor. After separating the refrigerant flow in the fluid distributor, the separated refrigerant flow was allowed to flow into the compressor at a flow rate of 19,000 kg/hr, and the refrigerant flow compressed by the compressor was discharged from the compressor in a state of 142.3 C., 20.6 kgf/cm.sup.2 g (21.3 bar), and a gas volume fraction of 1.0. In this case, an amount of work used in the compressor was 151682.0 W. The refrigerant flow discharged from the compressor was allowed to flow into the first condenser, and simultaneously, water in a state of 115.0 C., 0.7 kgf/cm.sup.2 g (1.67 bar), and a gas volume fraction of 0.0 was allowed to flow into the first condenser at a flow rate of 1,000 kg/hr and heat-exchanged with the refrigerant flow. After the heat exchange, the water was discharged as steam in a state of 120.0 C., 0.7 kgf/cm.sup.2 g (1.67 bar), and a gas volume fraction of 1.0 and the condensed refrigerant flow was discharged in a state of 124.9.0 C., 20.6 kgf/cm.sup.2 g (21.3 bar), and a gas volume fraction of 0.08 and then allowed to flow into the first heat exchanger. Here, calories condensed in the first condenser were 620779.0 W. The refrigerant flow discharged from the first condenser was heat-exchanged with the refrigerant flow discharged from the evaporator in the first heat exchanger and then discharged from the first heat exchanger in a state of 85.3 C., 20.6 kgf/cm.sup.2 g (21.3 bar), and a gas volume fraction of 0.0 and then flowed into the control valve. Also, the refrigerant flow was discharged from the control valve in a state of 75.4 C., 6.2 kgf/cm.sup.2 g (7.1 bar), and a gas volume fraction of 0.11 and was allowed to flow into a fluid mixer.

(17) Meanwhile, another part of the refrigerant flow separated in the fluid distributor was circulated to sequentially pass through a turbine, a second heat exchanger, a second condenser, a pump, the second heat exchanger, and the fluid mixer. In detail, the other part of the refrigerant flow separated in the fluid distributor was allowed to flow into the turbine at a flow rate of 31,000 kg/hr and the refrigerant flow which was discharged from the turbine and flowed into the second heat exchanger was allowed to flow into the second condenser. Also, the refrigerant flow discharged from the second condenser was allowed to flow into the pump and the refrigerant flow compressed by the pump was allowed to flow again into the second heat exchanger to be heat-exchanged with the refrigerant flow which was discharged from the turbine and flowed into the second heat exchanger and then was allowed to flow into the fluid mixer. In detail, the refrigerant flow expanded by the turbine was discharged from the turbine in a state of 97.6 C., 1.5 kgf/cm.sup.2 g (2.45 bar), and a gas volume fraction of 1.0 and was allowed to flow into the second heat exchanger. In this case, an amount of work generated in the turbine was 151682.0 W. The refrigerant flow which was discharged from the turbine and flowed into the second heat exchanger to be heat-exchanged with the refrigerant flow discharged from the pump was discharged from the second heat exchanger in a state of 64.5 C., 1.5 kgf/cm.sup.2 g (2.45 bar), and a gas volume fraction of 1.0 and then flowed into the second condenser and was condensed. The refrigerant flow condensed by and discharged from the second condenser in a state of 39.6 C., 1.5 kgf/cm.sup.2 g (2.45 bar), and a gas volume fraction of 0.0 was allowed to flow into the pump and was compressed. The refrigerant flow which passed through the pump and was compressed was discharged from the pump in a state of 40.0 C., 6.2 kgf/cm.sup.2 g (7.1 bar), and a gas volume fraction of 0.0 and then was allowed to flow into the second heat exchanger and heat-exchanged with the refrigerant flow which was discharged from the turbine and flowed into the second heat exchanger. The refrigerant flow which was discharged from the pump and flowed into the second heat exchanger to be heat-exchanged was discharged from the second heat exchanger in a state of 59.5 C., 6.2 kgf/cm.sup.2 g (7.1 bar), and a gas volume fraction of 0.0 and was allowed to flow into the fluid mixer. The refrigerant flow discharged from the pump and the refrigerant flow discharged from the control valve were allowed to merge in the fluid mixer and to flow again into the evaporator at a flow rate of 50,000 kg/hr.

(18) A coefficient of performance of the heat recovery apparatus in this case was shown in Table 1.

Example 3

(19) A refrigerant flow discharged from an evaporator was allowed to flow into a fluid distributor and separated. After separating the refrigerant flow in the fluid distributor, one part of the refrigerant flow separated in the fluid distributor was allowed to flow into a compressor at a flow rate of 25,000 kg/hr and another part of the refrigerant flow separated in the fluid distributor was allowed to flow into the turbine at a flow rate of 25,000 kg/hr. Also, water which flowed into a first condenser was allowed to flow thereinto at a flow rate of 3,000 kg/hr and the heat-exchanged water was discharged from the first condenser as steam in a state of 115.0 C., 0.7 kgf/cm.sup.2 g (1.67 bar), and a gas volume fraction of 0.33. Except those described above, the steam was generated through the same method as that of Experimental Example 1.

(20) A coefficient of performance of the heat recovery apparatus in this case was shown in Table 1.

Example 4

(21) A refrigerant flow discharged from an evaporator was allowed to flow into a fluid distributor and separated. After separating the refrigerant flow in the fluid distributor, one part of the refrigerant flow separated in the fluid distributor was allowed to flow into a compressor at a flow rate of 40,000 kg/hr and another part of the refrigerant flow separated in the fluid distributor was allowed to flow into a turbine at a flow rate of 10,000 kg/hr. Also, water which flowed into a first condenser was allowed to flow thereinto at a flow rate of 3,000 kg/hr and the heat-exchanged water was discharged from the first condenser as steam in a state of 115.0 C., 0.7 kgf/cm.sup.2 g (1.67 bar), and a gas volume fraction of 0.53. Except those described above, the steam was generated through the same method as that of Experimental Example 1.

(22) A coefficient of performance of the heat recovery apparatus in this case was shown in Table 2.

Example 5

(23) Steam was generated using the heat recovery apparatus of FIG. 7.

(24) A refrigerant 1,1,1,3,3-pentafluoropropane (R245fa) was allowed to flow into an evaporator and to circulate to allow one part of a refrigerant flow separated in the evaporator to sequentially pass through a first heat exchanger, a compressor, a first condenser, the first heat exchanger, and a pressure-dropping device. In detail, a refrigerant flow in a state of 69.6 C., 6.2 kgf/cm.sup.2 g (7.1 bar), and a gas volume fraction of 0.0 was allowed to flow into the evaporator at a flow rate of 50,000 kg/hr, and simultaneously, a waste heat flow in a state of 85.0 C., 1.0 kgf/cm.sup.2 g (1.96 bar), and a gas volume fraction of 0.0 was allowed to flow into the evaporator at a flow rate of 300,000 kg/hr to be heat-exchanged. After the heat-exchange, the waste heat flow was discharged in a state of 78.2 C., 1.0 kgf/cm.sup.2 g (1.96 bar), and a gas volume fraction of 0.0 at a flow rate of 300,000 kg/hr and the refrigerant flow was discharged in a state of 80.0 C., 6.2 kgf/cm.sup.2 g (7.1 bar), and a gas volume fraction of 1.0 and allowed to flow into the first heat exchanger. The refrigerant flow which was discharged from the evaporator and flowed into the first heat exchanger was allowed to flow into a fluid distributor to allow one part to flow into the compressor, and the refrigerant flow discharged from the compressor was allowed to flow into the first condenser to be heat-exchanged with a fluid flow which passed through the first condenser. Also, the refrigerant flow discharged from the first condenser was allowed to flow again into the first heat exchanger to be heat-exchanged with the refrigerant flow which was discharged from the evaporator and flowed into the first heat exchanger, and then allowed to flow into a control valve. In detail, the refrigerant flow which was discharged from the evaporator and flowed into the first heat exchanger and heat-exchanged was discharged from the first heat exchanger in a state of 110.0 C., 6.2 kgf/cm.sup.2 g (7.1 bar), and a gas volume fraction of 1.0 and then allowed to flow into the fluid distributor. After separating the refrigerant flow in the fluid distributor, the separated refrigerant flow was allowed to flow into the compressor at a flow rate of 19,000 kg/hr, and the refrigerant flow compressed by the compressor was discharged from the compressor in a state of 137.2 C., 20.7 kgf/cm.sup.2 g (21.3 bar), and a gas volume fraction of 1.0. In this case, an amount of work used in the compressor was 149916.0 W. The refrigerant flow discharged from the compressor was allowed to flow into the first condenser, and simultaneously, water in a state of 115.0 C., 0.7 kgf/cm.sup.2 g (1.67 bar), and a gas volume fraction of 0.0 was allowed to flow into the first condenser at a flow rate of 3,000 kg/hr and heat-exchanged with the refrigerant flow. After the heat exchange, the water was discharged as steam in a state of 115.0 C., 0.7 kgf/cm.sup.2 g (1.67 bar), and a gas volume fraction of 0.34 and the condensed refrigerant flow was discharged in a state of 125.0 C., 20.7 kgf/cm.sup.2 g (21.3 bar), and a gas volume fraction of 0.0 and then allowed to flow into the first heat exchanger. Here, calories condensed in the first condenser were 634524.0 W. The refrigerant flow discharged from the first condenser was heat-exchanged with the refrigerant flow discharged from the evaporator in the first heat exchanger and then discharged from the first heat exchanger in a state of 88.2 C., 20.7 kgf/cm.sup.2 g (21.3 bar), and a gas volume fraction of 0.0 and then flowed into the control valve. Also, the refrigerant flow was discharged from the control valve in a state of 75.4 C., 6.2 kgf/cm.sup.2 g (7.1 bar), and a gas volume fraction of 0.15 and was allowed to flow into a fluid mixer.

(25) Meanwhile, another part of the refrigerant flow separated in the fluid distributor was circulated to sequentially pass through a turbine, a second heat exchanger, a second condenser, a pump, the second heat exchanger, and the fluid mixer. In detail, the other part of the refrigerant flow separated in the fluid distributor was allowed to flow into the turbine at a flow rate of 31,000 kg/hr and the refrigerant flow which was discharged from the turbine and flowed into the second heat exchanger was allowed to flow into the second condenser. Also, the refrigerant flow discharged from the second condenser was allowed to flow into the pump and the refrigerant flow compressed by the pump was allowed to flow again into the second heat exchanger to be heat exchanged with the refrigerant flow which was discharged from the turbine and flowed into the second heat exchanger and then was allowed to flow into the fluid mixer. In detail, the refrigerant flow expanded by the turbine was discharged from the turbine in a state of 92.6 C., 1.5 kgf/cm.sup.2 g (2.45 bar), and a gas volume fraction of 1.0 and was allowed to flow into the second heat exchanger. In this case, an amount of work generated in the turbine was 149916.0 W. The refrigerant flow which was discharged from the turbine and flowed into the second heat exchanger to be heat-exchanged with the refrigerant flow discharged from the pump was discharged from the second heat exchanger in a state of 62.6 C., 1.5 kgf/cm.sup.2 g (2.45 bar), and a gas volume fraction of 1.0 and then flowed into the second condenser and was condensed. The refrigerant flow condensed by and discharged from the second condenser in a state of 39.6 C., 1.5 kgf/cm.sup.2 g (2.45 bar), and a gas volume fraction of 0.0 was allowed to flow into the pump and was compressed. The refrigerant flow which passed through the pump and was compressed was discharged from the pump in a state of 40.0 C., 6.2 kgf/cm.sup.2 g (7.1 bar), and a gas volume fraction of 0.0 and then was allowed to flow into the second heat exchanger to be heat-exchanged with the refrigerant flow which was discharged from the turbine and flowed into the second heat exchanger. The refrigerant flow which was discharged from the pump and flowed into the second heat exchanger to be heat-exchanged was discharged from the second heat exchanger in a state of 57.6 C., 6.2 kgf/cm.sup.2 g (7.1 bar), and a gas volume fraction of 0.0 and was allowed to flow into the fluid mixer. The refrigerant flow discharged from the pump and the refrigerant flow discharged from the control valve were allowed to merge in the fluid mixer and to flow again into the evaporator at a flow rate of 50,000 kg/hr.

(26) A coefficient of performance of the heat recovery apparatus in this case was shown in Table 2.

Example 6

(27) Steam was generated using the heat recovery apparatus of FIG. 7.

(28) A refrigerant 1,1,1,3,3-pentafluoropropane (R245fa) was allowed to flow into an evaporator and to circulate to allow one part of a refrigerant flow separated in the evaporator to sequentially pass through a first heat exchanger, a compressor, a first condenser, the first heat exchanger, and a pressure-dropping device. In detail, a refrigerant flow in a state of 69.6 C., 6.2 kgf/cm.sup.2 g (7.1 bar), and a gas volume fraction of 0.0 was allowed to flow into the evaporator at a flow rate of 50,000 kg/hr, and simultaneously, a waste heat flow in a state of 85.0 C., 1.0 kgf/cm.sup.2 g (1.96 bar), and a gas volume fraction of 0.0 was allowed to flow into the evaporator at a flow rate of 300,000 kg/hr to be heat-exchanged. After the heat-exchange, the waste heat flow was discharged in a state of 78.2 C., 1.0 kgf/cm.sup.2 g (1.96 bar), and a gas volume fraction of 0.0 at a flow rate of 300,000 kg/hr and the refrigerant flow was discharged in a state of 80.0 C., 6.2 kgf/cm.sup.2 g (7.1 bar), and a gas volume fraction of 1.0 and allowed to flow into the first heat exchanger. The refrigerant flow which was discharged from the evaporator and flowed into the first heat exchanger was allowed to flow into a fluid distributor to allow one part thereof to flow into the compressor, and the refrigerant flow discharged from the compressor was allowed to flow into the first condenser to be heat-exchanged with a fluid flow which passed through the first condenser. Also, the refrigerant flow discharged from the first condenser was allowed to flow again into the first heat exchanger to be heat-exchanged with the refrigerant flow which was discharged from the evaporator and flowed into the first heat exchanger, and then allowed to flow into a control valve. In detail, the refrigerant flow which was discharged from the evaporator and flowed into the first heat exchanger and heat-exchanged was discharged from the first heat exchanger in a state of 90.0 C., 6.2 kgf/cm.sup.2 g (7.1 bar), and a gas volume fraction of 1.0 and then allowed to flow into the fluid distributor. After separating the refrigerant flow in the fluid distributor, the separated refrigerant flow was allowed to flow into the compressor at a flow rate of 19,000 kg/hr, and the refrigerant flow compressed by the compressor was discharged from the compressor in a state of 125.0 C., 20.7 kgf/cm.sup.2 g (21.3 bar), and a gas volume fraction of 0.92. In this case, an amount of work used in the compressor was 141596.0 W. The refrigerant flow discharged from the compressor was allowed to flow into the first condenser, and simultaneously, water in a state of 115.0 C., 0.7 kgf/cm.sup.2 g (1.67 bar), and a gas volume fraction of 0.0 was allowed to flow into the first condenser at a flow rate of 3,000 kg/hr and heat-exchanged with the refrigerant flow. After the heat exchange, the water was discharged as steam in a state of 115.0 C., 0.7 kgf/cm.sup.2 g (1.67 bar), and a gas volume fraction of 0.28 and the condensed refrigerant flow was discharged in a state of 125.0 C., 20.7 kgf/cm.sup.2 g (21.3 bar), and a gas volume fraction of 0.0 and then allowed to flow into the first heat exchanger. Here, calories condensed in the first condenser were 520590.8 W. The refrigerant flow discharged from the first condenser was heat-exchanged with the refrigerant flow discharged from the evaporator in the first heat exchanger and then discharged from the first heat exchanger in a state of 114.0 C., 20.7 kgf/cm.sup.2 g (21.3 bar), and a gas volume fraction of 0.0 and then flowed into the control valve. Also, the refrigerant flow was discharged from the control valve in a state of 75.4 C., 6.2 kgf/cm.sup.2 g (7.1 bar), and a gas volume fraction of 0.0 and was allowed to flow into a fluid mixer.

(29) Meanwhile, another part of the refrigerant flow separated in the fluid distributor was circulated to sequentially pass through a turbine, a second heat exchanger, a second condenser, a pump, the second heat exchanger, and the fluid mixer. In detail, the other part of the refrigerant flow separated in the fluid distributor was allowed to flow into the turbine at a flow rate of 31,000 kg/hr and the refrigerant flow which was discharged from the turbine and flowed into the second heat exchanger was allowed to flow into the second condenser. Also, the refrigerant flow discharged from the second condenser was allowed to flow into the pump and the refrigerant flow compressed by the pump was allowed to flow again into the second heat exchanger to be heat exchanged with the refrigerant flow which was discharged from the turbine and flowed into the second heat exchanger and then was allowed to flow into the fluid mixer. In detail, the refrigerant flow expanded by the turbine was discharged from the turbine in a state of 72.9 C., 1.5 kgf/cm.sup.2 g (2.45 bar), and a gas volume fraction of 1.0 and was allowed to flow into the second heat exchanger. In this case, an amount of work generated in the turbine was 141686.0 W.

(30) The refrigerant flow which was discharged from the turbine and flowed into the second heat exchanger to be heat-exchanged with the refrigerant flow discharged from the pump was discharged from the second heat exchanger in a state of 55.2 C., 1.5 kgf/cm.sup.2 g (2.45 bar), and a gas volume fraction of 1.0 and then flowed into the second condenser and was condensed. The refrigerant flow condensed by and discharged from the second condenser in a state of 39.6 C., 1.5 kgf/cm.sup.2 g (2.45 bar), and a gas volume fraction of 0.0 was allowed to flow into the pump and was compressed. The refrigerant flow which passed through the pump and was compressed was discharged from the pump in a state of 40.0 C., 6.2 kgf/cm.sup.2 g (7.1 bar), and a gas volume fraction of 0.0 and then was allowed to flow into the second heat exchanger to be heat-exchanged with the refrigerant flow which was discharged from the turbine and flowed into the second heat exchanger. The refrigerant flow which was discharged from the pump and flowed into the second heat exchanger to be heat-exchanged was discharged from the second heat exchanger in a state of 50.2 C., 6.2 kgf/cm.sup.2 g (7.1 bar), and a gas volume fraction of 0.0 and was allowed to flow into the fluid mixer. The refrigerant flow discharged from the pump and the refrigerant flow discharged from the control valve were allowed to merge in the fluid mixer and to flow again into the evaporator at a flow rate of 50,000 kg/hr.

(31) A coefficient of performance of the heat recovery apparatus in this case was shown in Table 2.

Example 7

(32) Steam was generated using the heat recovery apparatus of FIG. 7.

(33) A refrigerant 1,1,1,3,3-pentafluoropropane (R245fa) was allowed to flow into an evaporator and to circulate to allow one part of a refrigerant flow separated in the evaporator to sequentially pass through a first heat exchanger, a compressor, a first condenser, the first heat exchanger, and a pressure-dropping device. In detail, a refrigerant flow in a state of 69.6 C., 6.2 kgf/cm.sup.2 g (7.1 bar), and a gas volume fraction of 0.0 was allowed to flow into the evaporator at a flow rate of 50,000 kg/hr, and simultaneously, a waste heat flow in a state of 85.0 C., 1.0 kgf/cm.sup.2 g (1.96 bar), and a gas volume fraction of 0.0 was allowed to flow into the evaporator at a flow rate of 300,000 kg/hr to be heat-exchanged. After the heat-exchange, the waste heat flow was discharged in a state of 78.4 C., 1.0 kgf/cm.sup.2 g (1.96 bar), and a gas volume fraction of 0.0 at a flow rate of 300,000 kg/hr and the refrigerant flow was discharged in a state of 77.0 C., 6.2 kgf/cm.sup.2 g (7.1 bar), and a gas volume fraction of 1.0 and allowed to flow into the first heat exchanger. The refrigerant flow which was discharged from the evaporator and flowed into the first heat exchanger was allowed to flow into a fluid distributor to allow one part thereof to flow into the compressor, and the refrigerant flow discharged from the compressor was allowed to flow into the first condenser to be heat-exchanged with a fluid flow which passed through the first condenser. Also, the refrigerant flow discharged from the first condenser was allowed to flow again into the first heat exchanger to be heat-exchanged with the refrigerant flow which was discharged from the evaporator and flowed into the first heat exchanger, and then allowed to flow into a control valve. In detail, the refrigerant flow which was discharged from the evaporator and flowed into the first heat exchanger and heat-exchanged was discharged from the first heat exchanger in a state of 108.2 C., 6.2 kgf/cm.sup.2 g (7.1 bar), and a gas volume fraction of 1.0 and then allowed to flow into the fluid distributor. After separating the refrigerant flow in the fluid distributor, the separated refrigerant flow was allowed to flow into the compressor at a flow rate of 19,000 kg/hr, and the refrigerant flow compressed by the compressor was discharged from the compressor in a state of 135.4 C., 20.7 kgf/cm.sup.2 g (21.3 bar), and a gas volume fraction of 1.0. In this case, an amount of work used in the compressor was 149260.0 W. The refrigerant flow discharged from the compressor was allowed to flow into the first condenser, and simultaneously, water in a state of 115.0 C., 0.7 kgf/cm.sup.2 g (1.67 bar), and a gas volume fraction of 0.0 was allowed to flow into the first condenser at a flow rate of 1,000 kg/hr and heat-exchanged with the refrigerant flow. After the heat exchange, the water was discharged as steam in a state of 120.0 C., 0.7 kgf/cm.sup.2 g (1.67 bar), and a gas volume fraction of 1.0 and the condensed refrigerant flow was discharged in a state of 125.0 C., 20.7 kgf/cm.sup.2 g (21.3 bar), and a gas volume fraction of 0.01 and then allowed to flow into the first heat exchanger. Here, calories condensed in the first condenser were 620779.0 W. The refrigerant flow discharged from the first condenser was heat-exchanged with the refrigerant flow discharged from the evaporator in the first heat exchanger and then discharged from the first heat exchanger in a state of 87.0 C., 20.7 kgf/cm.sup.2 g (21.3 bar), and a gas volume fraction of 0.0 and then flowed into the control valve. Also, the refrigerant flow was discharged from the control valve in a state of 75.4 C., 6.2 kgf/cm.sup.2 g (7.1 bar), and a gas volume fraction of 0.0 and was allowed to flow into a fluid mixer.

(34) Meanwhile, another part of the refrigerant flow separated in the fluid distributor was circulated to sequentially pass through a turbine, a second heat exchanger, a second condenser, a pump, the second heat exchanger, and the fluid mixer. In detail, the other part of the refrigerant flow separated in the fluid distributor was allowed to flow into the turbine at a flow rate of 31,000 kg/hr and the refrigerant flow which was discharged from the turbine and flowed into the second heat exchanger was allowed to flow into the second condenser. Also, the refrigerant flow discharged from the second condenser was allowed to flow into the pump and the refrigerant flow compressed by the pump was allowed to flow again into the second heat exchanger to be heat-exchanged with the refrigerant flow which was discharged from the turbine and flowed into the second heat exchanger and then was allowed to flow into the fluid mixer. In detail, the refrigerant flow expanded by the turbine was discharged from the turbine in a state of 90.9 C., 1.5 kgf/cm.sup.2 g (2.45 bar), and a gas volume fraction of 1.0 and was allowed to flow into the second heat exchanger. In this case, an amount of work generated in the turbine was 148985.0 W. The refrigerant flow which was discharged from the turbine and flowed into the second heat exchanger to be heat-exchanged with the refrigerant flow discharged from the pump was discharged from the second heat exchanger in a state of 62.0 C., 1.5 kgf/cm.sup.2 g (2.45 bar), and a gas volume fraction of 1.0 and then flowed into the second condenser and was condensed. The refrigerant flow condensed by and discharged from the second condenser in a state of 39.6 C., 1.5 kgf/cm.sup.2 g (2.45 bar), and a gas volume fraction of 0.0 was allowed to flow into the pump and was compressed. The refrigerant flow which passed through the pump and was compressed was discharged from the pump in a state of 40.0 C., 6.2 kgf/cm.sup.2 g (7.1 bar), and a gas volume fraction of 0.0 and then was allowed to flow into the second heat exchanger to be heat-exchanged with the refrigerant flow which was discharged from the turbine and flowed into the second heat exchanger. The refrigerant flow which was discharged from the pump and flowed into the second heat exchanger to be heat-exchanged was discharged from the second heat exchanger in a state of 57.0 C., 6.2 kgf/cm.sup.2 g (7.1 bar), and a gas volume fraction of 0.0 and was allowed to flow into the fluid mixer. The refrigerant flow discharged from the pump and the refrigerant flow discharged from the control valve were allowed to merge in the fluid mixer and to flow again into the evaporator at a flow rate of 50,000 kg/hr.

(35) A coefficient of performance of the heat recovery apparatus in this case was shown in Table 3.

Example 8

(36) Steam was generated using the heat recovery apparatus of FIG. 7.

(37) A refrigerant 1,1,1,3,3-pentafluoropropane (R245fa) was allowed to flow into an evaporator and to circulate to allow one part of a refrigerant flow separated in the evaporator to sequentially pass through a first heat exchanger, a compressor, a first condenser, the first heat exchanger, and a pressure-dropping device. In detail, a refrigerant flow in a state of 69.6 C., 6.2 kgf/cm.sup.2 g (7.1 bar), and a gas volume fraction of 0.0 was allowed to flow into the evaporator at a flow rate of 50,000 kg/hr, and simultaneously, a waste heat flow in a state of 85.0 C., 1.0 kgf/cm.sup.2 g (1.96 bar), and a gas volume fraction of 0.0 was allowed to flow into the evaporator at a flow rate of 300,000 kg/hr to be heat-exchanged. After the heat-exchange, the waste heat flow was discharged in a state of 78.2 C., 1.0 kgf/cm.sup.2 g (1.96 bar), and a gas volume fraction of 0.0 at a flow rate of 300,000 kg/hr and the refrigerant flow was discharged in a state of 80.0 C., 6.2 kgf/cm.sup.2 g (7.1 bar), and a gas volume fraction of 1.0 and allowed to flow into the first heat exchanger. The refrigerant flow which was discharged from the evaporator and flowed into the first heat exchanger was allowed to flow into a fluid distributor to allow one part thereof to flow into the compressor, and the refrigerant flow discharged from the compressor was allowed to flow into the first condenser to be heat-exchanged with a fluid flow which passed through the first condenser. Also, the refrigerant flow discharged from the first condenser was allowed to flow again into the first heat exchanger to be heat-exchanged with the refrigerant flow which was discharged from the evaporator and flowed into the first heat exchanger, and then allowed to flow into a control valve. In detail, the refrigerant flow which was discharged from the evaporator and flowed into the first heat exchanger and heat-exchanged was discharged from the first heat exchanger in a state of 127.7 C., 6.2 kgf/cm.sup.2 g (7.1 bar), and a gas volume fraction of 1.0 and then allowed to flow into the fluid distributor. After separating the refrigerant flow in the fluid distributor, the separated refrigerant flow was allowed to flow into the compressor at a flow rate of 19,000 kg/hr, and the refrigerant flow compressed by the compressor was discharged from the compressor in a state of 163.9 C., 29.3 kgf/cm.sup.2 g (29.7 bar), and a gas volume fraction of 1.0. In this case, an amount of work used in the compressor was 206685.2 W. The refrigerant flow discharged from the compressor was allowed to flow into the first condenser, and simultaneously, water in a state of 137.0 C., 2.3 kgf/cm.sup.2 g (3.24 bar), and a gas volume fraction of 0.0 was allowed to flow into the first condenser at a flow rate of 3,000 kg/hr and heat-exchanged with the refrigerant flow. After the heat exchange, the water was discharged as steam in a state of 137.0 C., 2.3 kgf/cm.sup.2 g (3.24 bar), and a gas volume fraction of 0.29 and the condensed refrigerant flow was discharged in a state of 142.9 C., 29.3 kgf/cm.sup.2 g (29.7 bar), and a gas volume fraction of 0.0 and then allowed to flow into the first heat exchanger. Here, calories condensed in the first condenser were 515418.0 W. The refrigerant flow discharged from the first condenser was heat-exchanged with the refrigerant flow discharged from the evaporator in the first heat exchanger and then discharged from the first heat exchanger in a state of 90.0 C., 29.3 kgf/cm.sup.2 g (29.7 bar), and a gas volume fraction of 0.0 and then flowed into the control valve. Also, the refrigerant flow was discharged from the control valve in a state of 75.4 C., 6.2 kgf/cm.sup.2 g (7.1 bar), and a gas volume fraction of 0.0 and was allowed to flow into a fluid mixer.

(38) Meanwhile, another part of the refrigerant flow separated in the fluid distributor was circulated to sequentially pass through a turbine, a second heat exchanger, a second condenser, a pump, the second heat exchanger, and the fluid mixer. In detail, the other part of the refrigerant flow separated in the fluid distributor was allowed to flow into the turbine at a flow rate of 31,000 kg/hr and the refrigerant flow which was discharged from the turbine and flowed into the second heat exchanger was allowed to flow into the second condenser. Also, the refrigerant flow discharged from the second condenser was allowed to flow into the pump, and the refrigerant flow compressed by the pump was allowed to flow again into the second heat exchanger to be heat-exchanged with the refrigerant flow which was discharged from the turbine and flowed into the second heat exchanger and then was allowed to flow into the fluid mixer. In detail, the refrigerant flow expanded by the turbine was discharged from the turbine in a state of 110.1 C., 1.5 kgf/cm.sup.2 g (2.45 bar), and a gas volume fraction of 1.0 and was allowed to flow into the second heat exchanger. In this case, an amount of work generated in the turbine was 156742.0 W. The refrigerant flow which was discharged from the turbine and flowed into the second heat exchanger to be heat-exchanged with the refrigerant flow discharged from the pump was discharged from the second heat exchanger in a state of 69.3 C., 1.5 kgf/cm.sup.2 g (2.45 bar), and a gas volume fraction of 1.0 and then flowed into the second condenser and was condensed. The refrigerant flow condensed by and discharged from the second condenser in a state of 39.6 C., 1.5 kgf/cm.sup.2 g (2.45 bar), and a gas volume fraction of 0.0 was allowed to flow into the pump and was compressed. The refrigerant flow which passed through the pump and was compressed was discharged from the pump in a state of 40.0 C., 6.2 kgf/cm.sup.2 g (7.1 bar), and a gas volume fraction of 0.0 and then was allowed to flow into the second heat exchanger to be heat-exchanged with the refrigerant flow which was discharged from the turbine and flowed into the second heat exchanger. The refrigerant flow which was discharged from the pump and flowed into the second heat exchanger to be heat-exchanged was discharged from the second heat exchanger in a state of 64.3 C., 6.2 kgf/cm.sup.2 g (7.1 bar), and a gas volume fraction of 0.0 and was allowed to flow into the fluid mixer. The refrigerant flow discharged from the pump and the refrigerant flow discharged from the control valve were allowed to merge in the fluid mixer and to flow again into the evaporator at a flow rate of 50,000 kg/hr.

(39) A coefficient of performance of the heat recovery apparatus in this case was shown in Table 3.

Comparative Example 1

(40) Steam was generated using the same method as that of Experimental Example 1 except that the whole refrigerant flow discharged from an evaporator was allowed to flow into a compressor without flowing into a fluid distributor.

(41) In detail, a refrigerant flow in a state of 75.4 C., 7.1 kgf/cm.sup.2 g, and a gas volume fraction of 0.0 was allowed to flow into the evaporator, and simultaneously, a waste heat flow in a state of 85.0 C., 1.0 kgf/cm.sup.2 g, and a gas volume fraction of 0.0 was allowed to flow into the evaporator at a flow rate of 300,000 kg/hr to be heat-exchanged. After the heat-exchange, the waste heat flow was discharged in a state of 81.2 C., 1.0 kgf/cm.sup.2 g, and a gas volume fraction of 0.0 at a flow rate of 300,000 kg/hr and the refrigerant flow was discharged in a state of 80.0 C., 7.1 kgf/cm.sup.2 g, and a gas volume fraction of 1.0 and flowed into a compressor. Also, the refrigerant flow compressed by the compressor was discharged from the compressor in a state of 125.0 C., 21.3 kgf/cm.sup.2 g, and a gas volume fraction of 0.82. In this case, an amount of work used in the compressor was 214078.6 W. The refrigerant flow discharged from the compressor was allowed to flow into the first condenser, and simultaneously, water in a state of 115.0 C., 0.7 kgf/cm.sup.2 g, and a gas volume fraction of 0.0 was allowed to flow into the first condenser at a flow rate of 1,800 kg/hr and heat-exchanged with the refrigerant flow. After the heat exchange, the water was discharged as steam in a state of 120.0 C., 0.7 kgf/cm.sup.2 g, and a gas volume fraction of 1.0 and the refrigerant flow was condensed and discharged in a state of 120.0 C., 21.3 kgf/cm.sup.2 g, and a gas volume fraction of 0.0 and then flowed into a control valve. Also, the refrigerant flow which passed through the control valve was discharged from the control valve in a state of 75.4 C., 7.1 kgf/cm.sup.2 g, and a gas volume fraction of 0.0 and was allowed to flow again into the evaporator.

(42) A coefficient of performance of the heat recovery apparatus in this case was calculated and shown in Table 4.

Comparative Example 2

(43) Steam was generated using the heat recovery apparatus of FIG. 7.

(44) A refrigerant 1,1,1,3,3-pentafluoropropane (R245fa) was allowed to flow into an evaporator and to circulate to allow one part of a refrigerant flow separated in the evaporator to sequentially pass through a first heat exchanger, a compressor, a first condenser, the first heat exchanger, and a pressure-dropping device. In detail, a refrigerant flow in a state of 47.1 C., 2.2 kgf/cm.sup.2 g (3.14 bar), and a gas volume fraction of 0.34 was allowed to flow into the evaporator at a flow rate of 50,000 kg/hr, and simultaneously, a waste heat flow in a state of 85.0 C., 1.0 kgf/cm.sup.2 g (1.96 bar), and a gas volume fraction of 0.0 was allowed to flow into the evaporator at a flow rate of 300,000 kg/hr to be heat-exchanged. After the heat-exchange, the waste heat flow was discharged in a state of 83.8 C., 1.0 kgf/cm.sup.2 g (1.96 bar), and a gas volume fraction of 0.0 at a flow rate of 300,000 kg/hr and the refrigerant flow was discharged in a state of 80.0 C., 2.2 kgf/cm.sup.2 g (3.14 bar), and a gas volume fraction of 1.0 and allowed to flow into the first heat exchanger. The refrigerant flow which was discharged from the evaporator and flowed into the first heat exchanger was allowed to flow into a fluid distributor to allow one part thereof to flow into the compressor, and the refrigerant flow discharged from the compressor was allowed to flow into the first condenser to be heat-exchanged with a fluid flow which passed through the first condenser. Also, the refrigerant flow discharged from the first condenser was allowed to flow again into the first heat exchanger to be heat-exchanged with the refrigerant flow which was discharged from the evaporator and flowed into the first heat exchanger, and then allowed to flow into a control valve. In detail, the refrigerant flow which was discharged from the evaporator and flowed into the first heat exchanger and heat-exchanged was discharged from the first heat exchanger in a state of 101.8 C., 2.2 kgf/cm.sup.2 g (3.14 bar), and a gas volume fraction of 1.0 and then allowed to flow into the fluid distributor. After separating the refrigerant flow in the fluid distributor, the separated refrigerant flow was allowed to flow into the compressor at a flow rate of 19,000 kg/hr, and the refrigerant flow compressed by the compressor was discharged from the compressor in a state of 149.1 C., 20.7 kgf/cm.sup.2 g (21.3 bar), and a gas volume fraction of 1.0. In this case, an amount of work used in the compressor was 260853.5 W. The refrigerant flow discharged from the compressor was allowed to flow into the first condenser, and simultaneously, water in a state of 115.0 C., 0.7 kgf/cm.sup.2 g (1.67 bar), and a gas volume fraction of 0.0 was allowed to flow into the first condenser at a flow rate of 1,000 kg/hr and heat-exchanged with the refrigerant flow. After the heat exchange, the water was discharged as steam in a state of 120.0 C., 0.7 kgf/cm.sup.2 g (1.67 bar), and a gas volume fraction of 1.0 and the condensed refrigerant flow was discharged in a state of 125.0 C., 20.7 kgf/cm.sup.2 g (21.3 bar), and a gas volume fraction of 0.14 and then allowed to flow into the first heat exchanger. Here, calories condensed in the first condenser were 620778.6 W. The refrigerant flow discharged from the first condenser was heat-exchanged with the refrigerant flow discharged from the evaporator in the first heat exchanger and then discharged from the first heat exchanger in a state of 106.8 C., 20.7 kgf/cm.sup.2 g (21.3 bar), and a gas volume fraction of 0.0 and then flowed into the control valve. Also, the refrigerant flow was discharged from the control valve in a state of 47.1 C., 2.2 kgf/cm.sup.2 g (3.14 bar), and a gas volume fraction of 0.60 and was allowed to flow into a fluid mixer.

(45) Meanwhile, another part of the refrigerant flow separated in the fluid distributor was circulated to sequentially pass through a turbine, a second heat exchanger, a second condenser, a pump, the second heat exchanger, and the fluid mixer. In detail, the other part of the refrigerant flow separated in the fluid distributor was allowed to flow into the turbine at a flow rate of 31,000 kg/hr and the refrigerant flow which was discharged from the turbine and flowed into the second heat exchanger was allowed to flow into the second condenser. Also, the refrigerant flow discharged from the second condenser was allowed to flow into the pump and the refrigerant flow compressed by the pump was allowed to flow again into the second heat exchanger to be heat exchanged with the refrigerant flow which was discharged from the turbine and flowed into the second heat exchanger and then was allowed to flow into the fluid mixer. In detail, the refrigerant flow expanded by the turbine was discharged from the turbine in a state of 97.8 C., 1.5 kgf/cm.sup.2 g (2.45 bar), and a gas volume fraction of 1.0 and was allowed to flow into the second heat exchanger. In this case, an amount of work generated in the turbine was 34916.2 W. The refrigerant flow which was discharged from the turbine and flowed into the second heat exchanger and heat-exchanged with the refrigerant flow discharged from the pump was discharged from the second heat exchanger in a state of 52.1 C., 1.5 kgf/cm.sup.2 g (2.45 bar), and a gas volume fraction of 1.0 and then flowed into the second condenser and was condensed. The refrigerant flow condensed by and discharged from the second condenser in a state of 39.6 C., 1.5 kgf/cm.sup.2 g (2.45 bar), and a gas volume fraction of 0.0 was allowed to flow into the pump and was compressed. The refrigerant flow which passed through the pump and was compressed was discharged from the pump in a state of 39.6 C., 2.2 kgf/cm.sup.2 g (3.14 bar), and a gas volume fraction of 0.0 and then was allowed to flow into the second heat exchanger and heat-exchanged with the refrigerant flow which was discharged from the turbine and flowed into the second heat exchanger. The refrigerant flow which was discharged from the pump and flowed into the second heat exchanger to be heat-exchanged was discharged from the second heat exchanger in a state of 47.1 C., 2.2 kgf/cm.sup.2 g (3.14 bar), and a gas volume fraction of 0.17 and was allowed to flow into the fluid mixer. The refrigerant flow discharged from the pump and the refrigerant flow discharged from the control valve were allowed to merge in the fluid mixer and to flow again into the evaporator at a flow rate of 50,000 kg/hr.

(46) A coefficient of performance of the heat recovery apparatus in this case was shown in Table 4.

(47) TABLE-US-00001 TABLE 1 Example 1 Example 2 Example 3 F.sub.c/F.sub.e 0.38 0.38 0.5 F.sub.t/F.sub.e 0.62 0.62 0.5 T.sub.Ein ( C.) T.sub.Eout( C.) 85 80 85 80 85 80 T.sub.Ein T.sub.Eout ( C.) 5 5 5 P.sub.C1in (bar) P.sub.C1out (bar) 7.1 21.3 7.1 21.3 7.1 21.3 P.sub.C1out/P.sub.C1in 3 3 3 P.sub.C2in (bar) P.sub.C2in (bar) 2.45 7.1 2.45 7.1 2.45 7.1 P.sub.C2out/P.sub.C2in 2.9 2.9 2.9 T.sub.R1in ( C.) T.sub.R1out ( C.) n/a n/a 124.9 115 n/a n/a T.sub.R1in T.sub.R1out ( C.) n/a 9.9 n/a Q (W) 463,422.8 620,779.0 609,766.8 Total W (W) 0 0 67,340 COP 9 n/a: not available

(48) TABLE-US-00002 TABLE 2 Example 4 Example 5 Example 6 F.sub.c/F.sub.e 0.8 0.38 0.38 F.sub.t/F.sub.e 0.2 0.62 0.62 T.sub.Ein ( C.) T.sub.Eout ( C.) 85 80 85 80 85 80 T.sub.Ein T.sub.Eout ( C.) 5 5 5 P.sub.C1in (bar) P.sub.C1out (bar) 7.1 21.3 7.1 21.3 7.1 21.3 P.sub.C1out/P.sub.C1in 3 3 3 P.sub.C2in (bar) P.sub.C2in (bar) 2.45 7.1 2.45 7.1 2.45 7.1 P.sub.C2out/P.sub.C2in 2.9 2.9 2.9 T.sub.R1in T.sub.R1out ( C.) n/a n/a 125 110 125 90 ( C.) T.sub.R1in T.sub.R1out ( C.) n/a 15 35 Q (W) 975,626.9 634,524.0 520,590.8 Total W (W) 241,014.5 0 0 COP 4.05

(49) TABLE-US-00003 TABLE 3 Example 7 Example 8 F.sub.c/F.sub.e 0.38 0.38 F.sub.t/F.sub.e 0.62 0.62 T.sub.Ein( C.) T.sub.Eout( C.) 85 77 85 80 T.sub.Ein T.sub.Eout( C.) 8 5 P.sub.C1in(bar) P.sub.C1out(bar) 7.1 21.3 7.1 29.7 P.sub.C1out/P.sub.C1in 3 4.2 P.sub.C2in(bar) P.sub.C2in(bar) 2.45 7.1 2.45 7.1 P.sub.C2out/P.sub.C2in 2.9 2.9 T.sub.R1in( C.) T.sub.R1out( C.) 125 108.2 142.9 127.7 T.sub.R1in T.sub.R1out( C.) 16.8 15.2 Q(W) 620,779.0 515,418.0 Total W(W) 275.0 49,943.2 COP 2257.4 10.32

(50) TABLE-US-00004 TABLE 4 Comparative Comparative Example 1 Example 2 F.sub.c/F.sub.e 1 0.38 F.sub.t/F.sub.e 0 0.62 T.sub.Ein( C.) T.sub.Eout( C.) 85 80 85 80 T.sub.Ein T.sub.Eout( C.) 5 5 P.sub.C1in(bar) P.sub.C1out(bar) 7.1 21.3 3.14 21.3 P.sub.C1out/P.sub.C1in 3 6.78 P.sub.C2in(bar) P.sub.C2in(bar) n/a n/a 2.45 3.14 P.sub.C2out/P.sub.C2in n/a 1.28 T.sub.R1in( C.) T.sub.R1out( C.) n/a n/a 125 101.8 T.sub.R1in T.sub.R1out( C.) n/a 23.2 Q(W) 830,573.0 620,778.6 Total W(W) 214,078.6 225,937.3 COP 3.88 2.75 n/a: not available