ELECTRICITY GENERATION FROM A TEMPERATURE CONTROL SYSTEM

Abstract

A temperature control system includes: a compressor, a condenser, an expansion valve, and an evaporator all connected in series to form a refrigerant circuit. The system includes an electricity generating arrangement fluidly connected to the refrigerant circuit between the compressor and one of the condenser and the evaporator, the electricity generating arrangement comprising a solar thermal collector adapted to heat refrigerant leaving the compressor, and a fluid driven electricity generator adapted to receive refrigerant heated by the solar thermal collector.

Claims

1. A temperature control system comprising: a compressor, a condenser, an expansion valve, and an evaporator all connected in series to form a refrigerant circuit; and an electricity generating arrangement fluidly connected to the refrigerant circuit between the compressor and one of the condenser and the evaporator, the electricity generating arrangement comprising a solar thermal collector adapted to heat refrigerant leaving the compressor, and a fluid driven electricity generator adapted to receive refrigerant heated by the solar thermal collector.

2. A temperature control system as claimed in claim 1, the system being configured in a cooling cycle such that, in use, refrigerant is directed in sequence from the fluid driven electricity generator to the condenser and from the condenser through the expansion valve to the evaporator before being returned to the compressor.

3. A temperature control system as claimed in claim 1, the system being configured in a heating cycle such that, in use, refrigerant is directed in sequence from the fluid driven electricity generator to the evaporator and from the evaporator through the expansion valve to the condenser before being returned to the compressor.

4. A temperature control system as claimed in claim 1, the system being selectively configurable in a cooling cycle or a heating cycle, the system having a fluid flow control arrangement operative in use to direct refrigerant from the electricity generator to flow through the remainder of the refrigerant circuit back to the compressor in either a cooling cycle direction or a heating cycle direction.

5. A temperature control system as claimed in claim 1, the system incorporating a bypass arrangement selectively operable in use to direct some or all of the refrigerant from the compressor to said one of the condenser and evaporator bypassing at least the fluid driven electricity generator of the electricity generating arrangement.

6. A temperature control system as claimed in claim 5, wherein the bypass arrangement is operable in use to direct some or all of the refrigerant from the compressor to said one of the condenser and evaporator bypassing both the solar collector and the fluid driven electricity generator.

7. A temperature control system as claimed in claim 1, wherein the solar thermal collector comprises an array of two or more solar thermal collector units.

8. A temperature control system as claimed in claim 1, wherein the fluid driven electricity generator comprises an array of two or more fluid driven electricity generator units.

9. A temperature control system as claimed in claim 1, wherein the electricity generating arrangement comprises at least two solar thermal collector units fluidly connected to the compressor in parallel with one another, each of said at least two solar thermal collector units being connected in series with a respective fluid driven electricity generator unit.

10. A temperature control system as claimed in claim 7, wherein the system comprises a flow control arrangement operable to selectively vary the rate of flow of refrigerant through each solar collector unit in the array.

11. A temperature control system as claimed in claim 8, wherein the system comprises a flow control arrangement operable to selectively vary the rate of flow of refrigerant through each fluid driven electricity generator unit.

12. A temperature control system as claimed in claim 1, wherein each of the fluid driven electricity generator units comprises an electricity generating turbine.

13. A temperature control system as claimed in claim 1, the system comprising an electrical energy storage device adapted to store electrical energy generated by the fluid driven electricity generator.

14. A temperature control system as claimed in claim 13, wherein the electrical energy storage device comprises a battery.

15. A temperature control system as claimed in claim 1 the system comprising a flow control arrangement adapted to vary the rate at which refrigerant is passed to the solar thermal collector.

16. A temperature control system of claim 1, wherein the system is configured such that in use, the solar collector is operable to increase the velocity of refrigerant flowing from the compressor to the fluid driven electricity generator.

17. A temperature control system as claimed in claim 1, wherein the compressor comprises a first compressor and the system comprises at least one second compressor.

18. A temperature control system as claimed in claim 1, the system comprising an electronic control system adapted to regulate the flow of refrigerant about the circuit in use.

19. A temperature control system as claimed in claim 18, the system incorporating a bypass arrangement selectively operable in use to direct some or all of the refrigerant from the compressor to said one of the condenser and evaporator bypassing at least the fluid driven electricity generator of the electricity generating arrangement, the control system comprising a sensor arrangement adapted to determine the temperature of the refrigerant at one or more positions about the circuit and being operative in use to regulate the flow of the refrigerant through the electricity generating arrangement and the bypass arrangement in dependence on the measured temperature.

20. A temperature control system as claimed in claim 19, the control system comprising a sensor arrangement adapted to determine the temperature of the refrigerant leaving the compressor and the temperature inside the solar collector and being operative in use to regulate the flow of the refrigerant through the electricity generating arrangement and the bypass arrangement in dependence on the difference between the temperature of the refrigerant leaving the condenser and the temperature inside the solar collector.

21. (canceled)

22. A method of operating a temperature control system comprising: a compressor, a condenser, an expansion valve, and an evaporator all connected in series to form a refrigerant circuit; and an electricity generating arrangement fluidly connected in the circuit between the compressor and one of the condenser and the evaporator, the electricity generating arrangement comprising a solar thermal collector adapted to heat refrigerant from the compressor, and a fluid driven electricity generator adapted to receive refrigerant heated by the solar thermal collector; the method comprising: using the solar collector to increase the velocity of the refrigerant leaving the compressor; and using the increased velocity refrigerant to drive the fluid driven electricity generator in order to generate electricity.

23. A method as claimed in claim 22, the method comprising storing the electrical energy generated for later use.

24. A method as claimed in claim 22, wherein the method comprises selectively directing at least some of the refrigerant from the compressor to said one of the condenser or evaporator bypassing the electricity generating arrangement when the solar thermal collector is unable to increase the velocity of the refrigerant by a pre-determined amount.

25. (canceled)

Description

BRIEF DESCRIPTION OF THE INVENTION DRAWINGS

[0050] In order for the invention to be more clearly understood, embodiments thereof will now be described, by way of example only, with reference to the accompanying drawings, of which:

[0051] FIG. 1 is a schematic drawing illustrating a first embodiment of a temperature control system in accordance with an aspect of the invention, in which the system is configured in a cooling cycle;

[0052] FIG. 2 is a schematic drawing illustrating a second embodiment of a temperature control system in accordance with an aspect of the invention, in which the system is configured in a heating cycle;

[0053] FIG. 3 is a schematic drawing illustrating a further embodiment of a temperature control system in accordance with an aspect of the invention, in which the system is similar to that of FIG. 1 but incorporates a bypass arrangement to selectively allow refrigerant to be routed directly from the compressor to the condenser, bypassing the electricity generating arrangement; and

[0054] FIG. 4 is a schematic drawing illustrating a further embodiment of a temperature control system in accordance with an aspect of the invention which can be operated in either a cooling cycle or a heating cycle and which incorporates a bypass arrangement to selectively allow refrigerant to be routed directly from the compressor to either the condense or the evaporator depending on which cycle is in operation.

DETAILED DESCRIPTION

[0055] FIG. 1 illustrates schematically a temperature control system 12 incorporating an electricity generating arrangement 1, 2 in accordance with an aspect of the invention, the system being configured in a cooling cycle. The direction of flow of the refrigerant about the circuit being indicated by the arrows 14. The electricity generating arrangement 1, 2 is fluidly connected in the circuit directly after the compressor 8 and before the subsequent condenser 3 and is fluidly connected to the compressor 8 and condenser 3 through suited refrigerant pipes 5. The electricity generating arrangement includes a solar thermal collector 1 designed to heat the refrigerant and a fluid driven electricity generator 2 which is driven by the refrigerant after it has been heated by the solar collector and so is travelling at an increased velocity when compared with the refrigerant flowing from the compressor to the solar thermal collector. The refrigerant leaves the compressor in gaseous state and is then pushed through the solar collector 1, where it is absorbs heat energy thus creating increased velocity. The refrigerant gas then flows through the fluid driven electricity generator 2 under pressure to create electricity 10. The refrigerant then continues on into the condenser 3, to expansion valve 4, and finally to the evaporator 6, before returning to the compressor 8 in the usual way for a cooling cycle. The refrigerant as it is passed through the evaporator absorbs heat energy from surrounding air or other fluids which are passed about the evaporator thereby cooling them. The driven electricity generator 2 is connected to an electrical circuit by means of suitable cables 16. The electricity 10 generated can be used to charge a battery for later use and/or used as it is generated. The electricity could be used in a building in which the system is located or by the temperature control system itself or for any other suitable use.

[0056] The temperature control system 12 is has an electronic control system including a central control unit 7 to control the operation of at least some of the components of the temperature control system 12, such as the compressor 8, the electrical generating arrangement 1, 2, the condenser 3, the expansion valve 4, and/or the evaporator 6. The control unit 7 is an electronic control unit having an ICU and is connected to the various components under its control through transmission lines 9. The control unit 7 is configured to regulate the temperature control system 12 in accordance with predefined protocols and in dependence on various inputs which may be from sensors which monitor one or more parameters of the system, such as the temperature and/or pressure of the refrigerant at certain point within the system, and/or user inputs.

[0057] The temperature control system 12 in accordance with the invention makes use of available solar energy to increase the energy in the refrigerant and uses this to generate electricity which can be used, directly or indirectly, to off-set the power consumed by the system in operating the compressor and so increases the overall efficiency of the system.

[0058] FIG. 2 illustrates schematically a temperature control system incorporating an electricity generating arrangement 1, 2 in accordance with an aspect of the invention configured in a heat pump cycle. This embodiment is similar to the first embodiment except that the refrigerant leaving the fluid powered electricity generator is directed into the evaporator 6, then to expansion valve 4, then the condenser 3, before returning to the compressor 8 in order to operate as a heat pump in a known way. This embodiment can be used to generate electricity 10 in a similar manner to that described above in relation to the first embodiment by heating the refrigerant passing through the solar collector 1 to increase its velocity and using the increased velocity of the refrigerant to drive the electricity generator 2.

[0059] FIG. 3 illustrates a further embodiment of a temperature control system which is similar to that shown in FIG. 1 and as described above, in which the system is configured in a cooling cycle. The embodiment of FIG. 3 differs in that it includes a bypass arrangement with a diverter valve 11 to allow refrigerant to be routed directly from the compressor to the condenser, bypassing the electricity generating arrangement 1, 2. This may be useful, for example, when there is insufficient sunlight available to enable electricity to be generated cost effectively and/or without compromising the effectiveness of the system to cool a designated area. FIG. 3 shows the circuit with the bypass open so that all the refrigerant is routed through additional bypass pipes 5a from the compressor into the main flow path downstream of the generator 2 so as to flow directly to the condenser 3.

[0060] The diverter 11 is integrated in the circuit directly after the compressor 8 and before the solar collector 1 and connected to compressor 8, the solar collector 1, and the condenser 3 through suited refrigerant pipes 5, 5a. The bypass system is electronically controlled by electronic control; system 7 which includes sensors for measuring the temperature of the refrigerant leaving the compressor 8 and the temperature inside the solar collector 1. In normal operation wherein electricity 10 is being generated by the generator 2, the diverter 11 is switched to direct refrigerant from the compressor 8 through the solar collector 1 and the electricity generator 2 as previously described. In circumstances where If the solar collector 1 is not able to increase the velocity of the refrigerant by an amount sufficient to make generation of electricity viable, the diverter 11 can be switched as shown to allow the refrigerant to bypass the solar collector 1 and turbine 2 and to flow directly to the from the compressor 8 to condenser 3. The refrigerant then flows around the remaining circuit in the usually way, through the expansion valve 4 and to the evaporator 6, before returning to the compressor 8 as indicated by the arrows 14. The diverter 11 could also be operated to allow some of the refrigerant to bypass the electricity generating arrangement 1, 2 in circumstances where the temperature of the refrigerant may be raised so much when passing through the solar collector that it could give rise to a dangerous increase in pressure in the system. Thus the diverter 11, or a similar control arrangement, can be used to regulate and vary the flow of refrigerant through the solar collector 1. Typically, the diverter will be connected with the central control unit 7 by suitable transmission lines for automated control.

[0061] FIG. 4 illustrates a further embodiment of a temperature control system 12 in accordance with an aspect of the invention and which can be operated in either a cooling cycle or a heating cycle. The circuit includes a four-way valve (illustrated schematically at 18) in the circuit downstream of the electricity generator 2. The valve 18 is fluidly connected to the various components so that in one position of the valve the refrigerant is directed to flow in a first direction sequentially through the condenser 3, expansion valve 4, evaporator 6, and back to the compressor 8 in a cooling cycle and in a second position of the valve the refrigerant is directed to flow in the reverse direction sequentially through the evaporator 6, expansion valve 4, condenser and back to the compressor 8 in a heating cycle. FIG. 4 illustrates the valve 18 in the second position so that the circuit is configured to operate in a heating cycle.

[0062] The temperature control system 12 as shown in FIG. 4 also includes a bypass arrangement similar that shown in FIG. 3 and described above. The bypass pipes 5a from the diverter 11 are connected to the main fluid path downstream of the electricity generator 2 but upstream of the four way valve 18 so that the circuit can be configured in a cooling or heating cycle whether the bypass is operative or not. It will be appreciated that in alternative embodiments, the temperature control system as shown in FIG. 4 could omit the bypass arrangement and that a bypass arrangement could be included in a temperature control system 12 that is permanently configured to operate in a heat cycle, such as that shown in FIG. 2. The four-way valve is typically an electronic valve controlled by the electronic control 7.

[0063] In alternative embodiments of the temperature control system 12 incorporating a bypass arrangement, the diverter 11 could be located between the solar collector 1 and the electricity generator 2 so that only the electricity generator 2 is bypassed.

[0064] The solar collector 1 can be any suitable type of solar thermal collector for transferring solar energy obtained from the sun to the refrigerant. The solar collector 1 could include one or more solar panels through which the refrigerant is passed to absorb heat energy from the sun as it falls on the panel, for example. However, the solar collector 1 could comprise a fluid or other substance which is heated by solar energy from the sun and a heat exchanger arrangement for transferring heat energy from the fluid or substance into the refrigerant. In this type of arrangement, the solar collector could be used to heat a fluid, such as water, or other substance which is stored in a tank and the refrigerant passed through coils in the tank so as to be heated by the water or substance. This would enable electricity to be generated using energy from a previously heated and stored fluid to heat the refrigerant during periods where there may be insufficient sunlight to heat the refrigerant directly by a sufficient amount.

[0065] The solar collector 1 could include more than one solar collector unit arranged in an array. In this case, the solar collector units could be connected in parallel and/or in series and control means used to regulate the flow through the various solar collector units so as to regulate the amount of energy transferred into the refrigerant. For example, during periods of intense sunlight, only one or some of the available solar collector units may be used to prevent overheating of the refrigerant. Various flow control valves, which may be electronically controlled, can be used to regulate the flow of refrigerant through the various solar collector units.

[0066] The fluid powered electricity generator 2 can be of any suitable type and may be a fluid powered turbine.

[0067] The fluid powered electricity generator 2 may include more than one fluid powered electricity generator unit 2 arranged in array. In this case, the electricity generator units can be connected in parallel and/or in series.

[0068] The person skilled in the art will appreciate that there are numerous ways in which a number of solar collector units 1 and/or electricity generating units 2 can be incorporated into a temperature control system in accordance with an aspect of the invention. For example, two or more solar collector units 1 could be connected in series to have a cumulative effect on the refrigerant passing through them and these can be connected in series to one or more electricity generating units 2. Where there is more than one electricity generating unit, these may themselves be in parallel or series with one another. Alternatively, two or more solar collector units 1 could be connected to the compressor in parallel with one another, with each unit being connected in series with a respective electricity generator unit 2. Various combinations of parallel and series connected solar collector units 1 and electricity generator units could be adopted.

[0069] The above embodiments are described by way of example only. Many variations are possible without departing from the scope of the invention as defined in the appended claims. For example, whilst the embodiments as illustrated in the accompanying drawings are relatively simple, including only a single compressor 8 and evaporator 6 in the circuit, it will be appreciated that the concept of generating electricity by transferring energy captured from the sun, or indeed some other external source, into the refrigerant leaving the compressor in order to increase its pressure and velocity and using then refrigerant to drive a fluid powered electricity generator can be incorporated into a wide range of alternative temperature control systems utilizing a compression cycle. For example, such a temperature control system might include multiple evaporators 6 to enable the temperature in more than one area to be controlled and/or multiple compressors.