Apparatus for vapourising a medium and separating droplets as well as for condensing the medium

Abstract

An apparatus for vaporizing a medium and separating droplets as well as for condensing, in which apparatus an evaporator (A) and a condenser (B) are arranged inside a single outer casing in such a manner that they are separated from each other by a partition wall.

Claims

1. An apparatus for vapourising a vapourisable medium, separating droplets therefrom and condensing the vapourisable medium when vapourized, wherein the apparatus comprises: an outer casing that comprises substantially vertical ends and a substantially horizontal cylindrical shell having an inner surface which defines a substantially horizontal interior space between the vertical ends, a substantially vertical partition wall that cross-sectionally divides the interior space of the cylindrical shell into separate horizontally oriented fluid-isolated functional spaces comprised of a first horizontally oriented subspace (A) and a second horizontally oriented subspace (B), an evaporator plate pack functioning as an evaporator which is arranged inside a lower region of the first horizontally oriented subspace (A) of the cylindrical shell, evaporator inlet and outlet connections for leading a heat exchange medium into and out from the evaporator plate pack, respectively, a gravitational droplet separator that is arranged inside the first horizontally oriented subspace (A) of the cylindrical shell I above the evaporator plate pack, an inlet connection for the vapourisable medium for leading the vapourisable medium into the first horizontally oriented subspace (A) of the cylindrical shell to thereby form a vapourised medium, and an outlet connection for leading the vapourised medium out from an upper region of the first horizontally oriented subspace (A) of the cylindrical shell, a condenser plate pack functioning as a condenser which is arranged inside the second horizontally oriented subspace (B) of the cylindrical shell, condenser inlet and outlet connections for leading the heat exchange medium into and out from the condenser plate pack, respectively, a vapourised medium inlet connection for leading the vapourised medium into the second horizontally oriented subspace (B) of the cylindrical shell, and a condensed medium outlet connection for leading the condensed medium out from the second horizontally oriented subspace (B) of the cylindrical shell.

2. The apparatus according to claim 1, wherein each of the evaporator plate pack and the condenser plate pack includes an arrangement of circular heat exchange plates on top of each other, wherein heat exchange plates are attached to each other as plate pairs at openings in the plates and/or at perimeters of the plates, and wherein inner parts of the plate pairs are arranged in connection with the evaporator inlet and outlet connections and the condenser inlet and outlet connections of the evaporator and condenser plate packs, respectively.

3. The apparatus according to claim 1, wherein the evaporator plate pack has an outer diameter that is 30-70% of an inner diameter of the cylindrical shell.

4. The apparatus according to claim 1, wherein the condenser plate pack has an outer diameter that is 100-200 mm larger than an outer diameter of the evaporator plate pack.

5. The apparatus according to claim 1, wherein the partition wall has a thickness of 5-20 mm.

6. The apparatus according to claim 1, wherein the partition wall comprises first and second metal plates and a layer of insulating material that is arranged between the first and second metal plates.

7. The apparatus according to claim 1, wherein the first horizontally oriented subspace (A) is about 50-70% of the substantially horizontal interior space of the cylindrical shell.

8. The apparatus according to claim 1, wherein the evaporator and condenser inlet and outlet connections a are arranged through a respective one of the vertical ends of the outer casing adjacent the evaporate and condenser plate packs.

9. The apparatus according to claim 1, which further comprises a connecting tube for leading the vapourisable medium from the second horizontal subspace (B) which includes the condenser plate pack to the first horizontal subspace (A) which includes the evaporator plate pack, and an expansion valve provided in the connecting tube.

10. The apparatus according to claim 1, which further comprises at least one filler unit arranged in the first horizontal subspace (A) between the inner surface of the cylindrical shell and the evaporator plate pack, the at least one filler unit being arranged to decrease liquid volume of the vapourisable medium inside the outer casing.

11. The apparatus according to claim 1, wherein the first horizontal subspace (A) further comprises a demister droplet separator which is arranged inside the outer casing at the upper region of the first horizontal subspace (A) beneath the outlet connection for the vaporised medium.

12. The apparatus according to claim 1, which further comprises a superheater arranged in the first horizontal subspace (A) above the evaporator plate pack.

13. The apparatus according to claim 1, which further comprises a condensation supercooler in the second horizontal subspace (B) adjacent to the condenser plate pack.

14. A system comprising: an evaporator, a compressor, a condenser, conduits for leading a medium circulating in the system from the evaporator to the compressor, from the compressor to the condenser and from the condenser to the evaporator, and an expansion valve, through which the medium circulating in the system is lead from the condenser to the evaporator, wherein the evaporator and the condenser are arranged in the system inside a single outer casing as an apparatus according to claim 1.

Description

SHORT DESCRIPTION OF THE DRAWINGS

(1) In the following, the invention will be described in more detail with reference to the appended drawings, in which

(2) FIG. 1 shows a system according to the invention, in which a compressor is arranged above an evaporator-condenser,

(3) FIG. 2 shows the process flow in a system according to the invention,

(4) FIG. 3 shows a cross-section of an apparatus according to the invention,

(5) FIG. 4 shows a cross-section of an evaporator part in an apparatus according to the invention, and

(6) FIG. 5 shows a cross-section of a condenser part in an apparatus according to the invention.

DETAILED DESCRIPTION OF THE INVENTION

(7) Same reference signs have been used in the Figures for parts corresponding to each other.

(8) In FIGS. 1-5 some apparatuses according to the invention are shown, in which inside one outer casing functioning as a frame, that is for example into a flat-ended cylinder 8 as shown in FIGS. 2 and 3, a Plate&Shell™-type plate pack 10 functioning as an evaporator, a gravitational droplet separator 13 and a second Plate&Shell™-type plate pack 11 functioning as a condenser have been arranged.

(9) FIG. 1 shows a system 1 according to the invention, which comprises a compressor 2 and an apparatus 3 according to the invention, in which apparatus both an evaporator and a condenser have been arranged inside one same outer casing. In the system of the Figure, a compressor 2 is arranged above an evaporator-condenser 3 according to the invention, whereby the evaporator-condenser 3 functions as a frame into which the compressor can be secured. The tube 4 underneath the evaporator-condenser 3 is arranged to extend from the condenser to the evaporator and is equipped with an expansion valve 5, by which the process of the system is controlled. FIG. 1 also shows a connecting tube 6 from the evaporator according to the invention to the compressor 2 and a connecting tube 7 from the compressor 2 to the condenser according to the invention.

(10) FIG. 2 shows schematically the process flow in a system 1 according to the invention and in FIG. 3 is shown an evaporator-condenser 3 according to an embodiment of the invention as a cross-section. Temperature values have been added to FIG. 2, which are meant only to illustrate the process flow in the system, the given temperatures thus not limiting the invention. An apparatus 3 according to the invention that comprises an evaporator (part A) and a condenser (part B) inside one same outer casing, is shown in the Figure as a cross-section. In a system according to the invention, the medium to be vapourised, for example a refrigerant, is evaporated in an evaporator (part A), the heat exchange medium flowing through the plate pack 10 functioning as an evaporator heats the medium to be vapourised, while at the same time cools down itself. The evaporated and heated medium is led from the evaporator A to the compressor 2. After the compressor 2 the compressed medium is led to the condenser (part B), which is arranged to cool the medium and to condensate it to liquid. The released heat heats up the heat exchange medium such as water or air flowing through the plate pack 11 functioning as a condenser. Thereafter the medium circulating in the system flows through the expansion valve 5 back to the evaporator A and a new round of the medium circulating in the system starts from the beginning.

(11) As in shown in FIGS. 2 and 3, the outer casing of the apparatus 3 is formed of a substantially horizontal cylindrical shell 8 and substantially vertical ends 9, 9′. The evaporator part A and the condenser part B of the apparatus 3 are separated from each other by a partition wall 12. The evaporator part A inside the cylindrical shell 8 comprises a plate pack 10, a so-called evaporator plate pack, and a droplet separator 13. The condenser part B comprises a plate pack 11, a so-called condenser plate pack.

(12) The medium to be vapourised, for example a refrigerant, is lead from the condenser part B of the apparatus 3 to the evaporator part A via a connecting tube 4, into which connecting tube 4 an expansion valve 5 has been arranged. The medium to be vapourised is led to the evaporator A typically through an inlet connection 15 arranged on the bottom part of the cylindrical shell 8. The evaporated medium exits the evaporator part A through an outlet connection 14 at the upper part of the outer casing. A heating medium is led to the evaporator part A through the end 9 of the outer casing into the plate pack 10 with the inlet connection 18 and removed from the plate pack 10 through the end 9 of the outer casing with the outlet connection 19. The inlet connection 18 and the outlet connection 19 extend through the plate pack 10 to evenly distribute the flow of the heating medium to the whole plate pack 10.

(13) The condenser part B of the apparatus 3 comprises an inlet connection 16 for leading the medium from the compressor 2 to the condenser B, the inlet 16 connection is typically arranged on the upper part of the cylindrical shell 8. The condenser part B comprises also an outlet connection 17 for the medium to be vapourised, typically on the lower part of the cylindrical shell 8. An inlet connection 20 and an outlet connection 21 have been arranged in connection with the inner parts of the plate pack 11 of the condenser part B.

(14) In the evaporator part A the vapour formed from the liquid surface (not shown in the Figure) of the medium to be vapourised rises up through the gravitational droplet separator 13 in the upper part of the cylindrical shell of the apparatus. The droplet separator may comprise a demister, such as for example a layer of steel wool that separates the finely divided droplets from the vapour. After passing through the demister, the vapour can exist through the outlet connection 14 at the upper part of the outer casing. From thereon, the evaporated refrigerant is lead further, for example to a compressor 2 of a refrigerating apparatus.

(15) FIG. 4 shows an evaporator part A in an apparatus 3 according to the invention as a cross-section. The evaporator part A of the apparatus 3 is arranged inside a cylindrical shell 8. The evaporator part comprises a plate pack 10 that is typically arranged in the lower part of the cylindrical shell and a droplet separator 13 that is arranged above the plate pack at the upper part of the cylindrical shell. The outer surfaces of the plate pack 10 function as heat exchange surfaces of the evaporator. FIG. 4 shows also filler units 22 and 22′ arranged between the outer casing of the cylindrical shell 8 and the plate pack 10 in one embodiment of the invention. The liquid volume of the evaporator part has been reduced by arranging longitudinal filler units 22 and 22′ to both sides between the cylindrical shell 8 and the plate pack 10. The filler units 22, 22′ are designed such that they reduce the liquid volume of the evaporator part as much as possible. The filler units are attached in place for example with plates or collars which have their shape. Typically flow channels 24, 24′ are arranged between the filler unit and the cylindrical shell 8, and typically flow channels 23, 23′ are arranged between the filler unit and the plate pack 10. Along the flow channels the liquid to be vapourised can sink and the generated vapour can rise.

(16) The casing of the filler units 22, 22′ is substantially tight to liquids. It can be manufactured for example from metal plate or plastic. A filler material is arranged inside the filler units, for example sand, concrete or plastic such as expanded polystyrene or another material suitable for the purpose.

(17) In FIG. 4, the inlet connection 15 of the medium to be vapourised is arranged at the bottom of the cylindrical shell 8 and the outlet connection 14 of the vapourised medium is arranged at the upper part of the cylindrical shell 8 above the droplet separator 13.

(18) The level of the medium to be vapourised, such as the refrigerant or other liquid to be vapourised, is advantageously adjusted to the level of the diameter of the cylindrical shell (not shown in the Figure), whereby the surface area of the medium to be vapourised is as large as possible and the production of vapour per surface area is as small as possible. The ascension speed of the vapour is thus also as small as possible, whereby the generated droplets travelling with the vapour more easily fall back down. Thus the gravitational droplet separation is made more efficient.

(19) FIG. 5 shows a condenser part B in an apparatus 3 according to the invention as a cross-section. A plate pack 11 is arranged inside a cylindrical shell 8. The vapourised medium is led to the condenser B through an inlet connection 16 and the cooled medium is let out from the condenser through an outlet connection 17. The inlet connection 16 and the outlet connection 17 are arranged into the cylindrical shell, whereby the circuit of the medium to be condensed is formed on the shell side of the plate pack 11. A connecting tube 4 has been arranged to the inlet connection 17, whereby the medium to be vapourised is led to the evaporator.

(20) The invention is not intended to be limited to the above-presented exemplary embodiments, but the intention is to apply the invention widely within the inventive idea defined by the claims defined below.