EP1938027A1

EP1938027A1 - Apparatus and system for refrigerant compressor with liquid-suction heat exchanger

Info

Publication number: EP1938027A1
Application number: EP05802950A
Authority: EP
Inventors: Alexander Lifson; Michael F. Taras
Original assignee: Carrier Corp
Current assignee: Carrier Corp
Priority date: 2005-09-29
Filing date: 2005-09-29
Publication date: 2008-07-02
Also published as: WO2007040519A1; US20100132402A1; CN101443607A; EP1938027A4

Abstract

There is provided a refrigeration apparatus (100). The refrigeration apparatus (100) includes a liquid suction heat exchanger (LSHX) (110) and a compressor (120). The LSHX (110) and the compressor (120) are formed as an integral module (150). Disclosed combinations include tandem compressors (151, 152) and multiple integral module configurations (185, 186).

Description

APPARATUS AND SYSTEM FOR

REFRIGERANT COMPRESSOR WITH LIQUID-SUCTION HEAT EXCHANGER

BACKGROUND OF THE INVENTION

1. Field of the Invention

[0001] The present invention relates to a refrigerant system. More particularly, the present invention relates to an integral module including a refrigerant compressor and a liquid-suction heat exchanger. '

2. Description of the Related Art

[0002] In many refrigerant systems, performance enhancement demands dictate implementation of additional components for a capacity and/or efficiency boost. Employment of a liquid-suction heat exchanger (LSHX) is one of the choices to satisfy such requirements in many operating environments. Generally, a LSHX provides for extra subcooling of a liquid refrigerant leaving a condenser by superheating of a refrigerant vapor entering a compressor suction port (or ports). Accordingly, although refrigerant vapor density entering the compressor is reduced, the enthalpy boost resulting from subcooling of the liquid refrigerant often leads to an overall refrigerant system performance augmentation. Additionally, employment of a LSHX helps in reducing the possibility and severity of compressor flooding that could cause permanent damage to the internal compressor components. In particular, a LSHX can be useful in applications with long suction lines leading to the compressor, wherein additional preheating of the refrigerant in the LSHX would take place to potentially eliminate or reduce flooding. Further, a LSHX assures subcooling conditions at the entrance to the expansion device and consequently eliminates its malfunctioning. [0003] However, inclusion of a LSHX increases refrigerant system costs to the point that the benefits obtained by the LSHX performance enhancement become economically prohibitive. On the other hand, in determining costs, it is a common practice to consider "applied" costs, which include both the component costs (i.e., the costs of the individual LSHX and compressor components), as well as the cost of on-site labor and installation and other associated costs to assemble these components into a working system at the factory or in the field. In particular, these labor and installation costs can be a disincentive in using the LSHX in a refrigerant system and should be carefully evaluated.

[0004] Therefore, there is a need for a refrigerant apparatus and system that has a LSHX that does not have the same level of labor and associated costs as conventional LSHX/compressor apparatuses and systems.

SUMMARY OF THE INVENTION

[0005] In one embodiment, the present invention provides for a refrigerant apparatus that incorporates a liquid suction heat exchanger (LSHX) and a compressor, and the LSHX and the compressor are formed as an integral module.

[0006] In another embodiment, the present invention provides for a refrigerant system with the integral module that incorporates a compressor and a LSHX secured to the compressor.

[0007] In still yet another embodiment, the present invention provides for an integral module preferably positioned on a common base and including a compression system and a single LSHX, wherein the compression system consists of a plurality of compressors connected in tandem all connected to a single LSHX.

[0008] In another embodiment, the present invention provides for an integral module, preferably positioned on a common base and consisting of a plurality of compressors and a plurality of LSHX' s, each compressor connected to its own LSHX.

[0009] It is an object of the present invention to provide for a modular assembly of a LSHX and compressor, thereby reducing installation costs.

BRIEF DESCRIPTION OF THE DRAWINGS

[0010] FIG. 1 is a single, integral module comprising a LSHX connected to a side of a compressor.

[0011] FIG. 2 is a single, integral module comprising a LSHX connected to a top of a compressor.

[0012] FIG. 3 is a single, integral module comprising a LSHX connected to a bottom of a compressor.

[0013] FIG. 4 is a single, integral module comprising a plurality of compressors connected to a single LSHX.

[0014] FIG. 5 is an integral module comprising a plurality of compressors and a plurality of LSHX' s, each compressor connected to its own LSHX.

[0015] FIG. 6 illustrates a refrigerant system that has an integral module comprising a compressor and LSHX.

DESCRIPTION OF THE INVENTION

[0016] Referring to the drawings and, in particular, FIGURE 1, there is illustrated an integral module generally expressed by reference number 150. Integral module 150 includes a LSHX 110 connected to a compressor 120. An integral module can be generally defined as a subassembly of at least two closely connected non- removable components that have distinctly defined interfaces to the rest of the system. LSHX 110 and compressor 120 are connected so as to be integral module 150 and are permanently secured to each other during manufacturing. Within integral module 150, inlet 115 of LSHX 110 for refrigerant vapor leaving an evaporator is part of a vapor refrigerant interface. A discharge port 135 of compressor 120 is another part of the vapor refrigerant interface. LSHX 110 has two connections for a liquid refrigerant interface as well. One is connection 130 for liquid refrigerant leaving a condenser and the other is connection 131 for a line leading to an expansion device.

[0017] Compressor 120 has suction port 125 and discharge port 135. Suction port 125 is located at compressor 120 and downstream of LSHX 110. Discharge port 135 represents another vapor refrigerant interface of integral module 150 for compressed refrigerant vapor delivered by the compressor 120 to a discharge line.

[0018] In one embodiment, shown in FIG. 1, suction port 125 is associated with a single unitary pipe 127. Single unitary pipe 127 is connected to both LSHX 110 and compressor 120 of integral module 150. Single unitary pipe 127 is secured to both an outlet of LSHX 110 and suction port 125 of compressor 120.

[0019] As mentioned above, integral module 150 has two well-defined interfaces. The vapor refrigerant interface includes two connections, inlet 115 of LSHX 110 and discharge port 135 of compressor 120, and a liquid refrigerant interface, which includes connections 130 and 131 to an outlet of a condenser and inlet of an expansion device respectively. Use of integral module 150 allows employment of a modular design philosophy to reduce applied compressor costs (i.e., costs in installation, storage, shipping, etc.), in systems where the use of LSHX 110 is demanded by the performance requirements. Additionally, reduction of a number of connections and component mismatch reduces potential reliability problems.

[0020] By having LSHX 110 and compressor 120 manufactured, marketed and sold as integral module 150, manufacturing costs and complexities can be reduced. This is because, among other things, various module interfaces, such as vapor refrigerant interfaces (inlet 115 of LSHX 110 and discharge port 135 of compressor 120) and liquid refrigerant interfaces (connections 130 and 131 to an outlet of a condenser and inlet of an expansion device respectively) can be precisely defined, since there are no further components to be inserted between LSHX 110 and compressor 120. Implementation of these precisely defined interfaces typically reduces installation costs. In FIG 1, LSHX 110 is positioned to a side of compressor 120. In a further embodiment, LSHX 110 and compressor 120 are secured (e.g., bolted) together.

[0021] In FIGS. 2 and 3, other examples of connections between LSHX 110 and compressor 120 are illustrated. In FIG. 2, LSHX 110 is positioned on a top of compressor 120. LSHX 110 is connected to compressor 120 through single unitary pipe 127. LSHX 110 is secured to compressor 120 and supported by brackets 135. Obviously, other types of supports are also feasible.

[0022] In FIG. 3, LSHX 110 is located at a bottom of compressor 120. LSHX 110 and compressor 120 are connected by single unitary pipe 127. Preferably, LSHX 110 is housed or at least partially housed within base 111 that also supports compressor 120. Base 111 facilitates the assembly process and provides protection from damage to various components of integral module 150. For instance, as shown in FIG. 3, a thermal insulation 113 may be required for LSHX 110 to improve its performance. Insulation 113 will be better protected while having less exposure to various external factors. Additionally, locating LSHXI lO on a top or at a bottom of compressor 120 may provide better balanced position for the center of gravity for integral module 150. This could be beneficial during assembly and may eliminate extra brackets or a supporting structure. These examples are meant to be illustrative of the various connections that can be made between LSHX 110 and compressor 120 in forming integral module 150.

[0023] In further embodiments, integral module 150 can include a plurality of compressors 120 and LSHXs 110, if a specific configuration is demanded by refrigerant system design requirements. Consequently, during design time of a given refrigerant system, space for module 150, which comprises a combination of LSHXs 110 and compressors 120, is to be appropriately allocated.

[0024] Turning now to FIGURE 4, illustrated is an integral module 177 including a compression system comprising two compressors 151 and 152 connected in tandem and a single LSHX 110. Each compressor has suction port 125 and discharge port 135. Suction ports 125 are connected to a suction manifold (or unitary pipe) 127 leading from LSHX 110. Discharge ports 135 are connected into a discharge manifold 136, now representing a part of a vapor refrigerant interface. Obviously, more than two compressors can be connected in tandem within integral module 177. Also, as described below in FIG. 5, individual components of integral module 177, and compressors 151 and 152 in particular, are preferably positioned on a common base.

[0025] Turning now to FIGURE 5, illustrated is an integral module 187, preferably positioned on a common base 194 and consisting of two sub-modules 185 and 186. Each sub-module has its own combination of a compressor and LSHX. In particular, sub-module 185 includes compressor 191 and LSHX 181 and sub-module 186 comprises compressor 193 and LSHX 183. In other words, within module 187 each compressor is connected to its own LSHX. It has to be noted that vapor and liquid refrigerant interfaces each consist of four pairs of connections. In particular, a liquid refrigerant interface comprises a pair of connections 130 to a condenser outlet (or outlets) and a pair of connections 131 to an expansion device inlet (or inlets). Further, a vapor refrigerant interface comprises a pair of connections 115 to an evaporator outlet (or outlets) and a pair of discharge ports 135 associated with compressors 191 and 193. Each compressor-LSHX sub-module has its own interconnecting unitary pipe 127. Also, it has to be noted that sub-modules 185 and 186 within integral module 187 can be connected differently, depending on the overall refrigerant system configuration. In case, the refrigerant system has two-circuit configuration, each sub-module is interfaced with its own condenser, evaporator and expansion device. On the contrary, if the refrigerant system comprises a single circuit, sub- modules 185 and 186 are manifolded together, similar to a FIG4 exhibit. A particular piping arrangement can be performed at the factory during manufacturing of integral module 187 or an entire refrigerant system or in the field during refrigerant system installation. Obviously, integral module 187 can include more than two sub-modules.

[0026] Turning to FIGURE 6, illustrated is one embodiment of a refrigerant system 200 that employs integral module 150. Refrigerant system 200 includes integral module 150, a first refrigerant heat exchanger 205, an expansion device 210, and a second refrigerant heat exchanger 215. In this illustrated embodiment, first refrigerant heat exchanger 205 is an evaporator, and second refrigerant heat exchanger 215 is a condenser.

[0027] Expansion device 210 is connected through connection 131 of a liquid refrigerant interface to module 150. First refrigerant heat exchanger 205 is connected through connection 115 of the vapor refrigerant interface to integral module 150. First refrigerant heat exchanger 205 is also connected to an outlet of expansion valve 210.

[0028] Second refrigerant heat exchanger 215 is connected through connection 130 to module 150. Second refrigerant heat exchanger 215 is also connected through discharge port 135 of the vapor refrigerant interface to integral module 150.

[0029] By having LSHX 110 and compressor 120 connected as integral module 150 that is a separate module within system 200, installation cost and upkeep (e.g., storage and shipping costs) can be reduced. Also, a number of manufacturing defects during assembly can be decreased. This becomes possible, since the vapor refrigerant interface (connections 115 and 135) and the liquid refrigerant interface (connections 130 and 131) can be precisely defined, since there are no further components to be inserted between LSHX 110 and compressor 120. Therefore, there is an easier and more straightforward installation when coupling first heat exchanger 205, expansion valve 210, and second heat exchanger 215.

[0030] It should be understood that various alternatives, combinations and modifications of the teachings described herein could be devised by those skilled in the art. The present invention is intended to embrace all such alternatives, modifications and variances that fall within the scope of the appended claims.

Claims

WHAT IS CLAIMED IS:

1. A refrigeration apparatus (100), comprising: a liquid suction heat exchanger (LSHX) (110); and a compressor (120), wherein said LSHX (110) and said compressor (120) comprise an integral module (150).

2. The refrigeration apparatus (100) of claim 1, wherein said integral module (150) has a vapor refrigerant interface (115).

3. The refrigeration apparatus (100) of claim 1, wherein said integral module (150) has a liquid refrigerant interface (130, 131).

4. The refrigeration apparatus (100) of claim 2, wherein said vapor refrigerant interface (115, 135) has a plurality of connections (115, 135).

5. The refrigeration apparatus (100) of claim 3, wherein said liquid refrigerant interface (130, 131) has multiple connections (130, 131).

6. The refrigeration apparatus (100) of claim 1, further comprising a suction port connection (125) interposed between said LSHX (110) and said compressor (120).

7. The refrigeration apparatus (100) of claim 6, wherein said suction port connection (125) is defined at least in part by a single unitary pipe (127), said unitary pipe (127) connected to both said LSHX (110) and said compressor (120).

8. The refrigeration apparatus (100) of claim 7, wherein said single unitary pipe (117) contains said suction port connection (125) at a time of manufacture of said integral module (150).

9 The refrigeration apparatus (100) of claim 1, wherein said LSHX (110) is secured to said compressor (120).

10. The refrigeration apparatus (100) of claim 1, wherein said LSHX (110) is permanently connected to a surface selected from the group consisting of a side of said compressor (120), a bottom of said compressor (120), and a top of said compressor (120).

11. A refrigeration system (200), comprising: a condenser (215); an evaporator (205); an expansion device (210); and an integral module (150), comprising: a liquid suction heat exchanger (LSHX) (110); and a compressor (120) secured to said LSHX (110), wherein said integral module (150) is connected to said condenser (215), said evaporator (205) and said expansion device (210).

12. The refrigeration system (200) of claim 11, wherein said integral module (150) has a vapor refrigerant interface (115, 135).

13. The refrigeration system (200) of claim 11, wherein said integral module (150) has a liquid refrigerant interface (130, 131).

14. The refrigeration system (200) of claim 11, wherein said compressor (120) is secured to said LSHX (110) by a unitary pipe (127) that is secured to both an outlet of said LSHX (110) and an inlet of said compressor (120).

15. The refrigerant system (200) of claim 11, wherein said LSHX (110) of said integral module (150) is bolted to said compressor (120) of said integral module (150).

16. The refrigeration system (200) of claim 11, wherein said integral module (150) further comprises a base (111) connected to a bottom of said compressor (120), and wherein said LSHX (110) is connected to said bottom of said compressor (120) and at least partially housed by said base (111).

17. The refrigeration system (200) of claim 11, wherein said integral module (150, 177) further comprises a plurality of compressors (151, 152) connected in tandem.

18. The refrigeration system (200) of claim 11, wherein said integral module (187) is positioned on a base (194), and wherein said integral module (187) comprises a plurality of sub-modules (185, 186).

19. The refrigeration system (200) of claim 18, wherein each of said plurality of sub-modules (185, 186) comprises a compressor (191, 193) and a LSHX (181, 183).

20. A refrigerant system (100, 200) as herein before described with reference to any one of Figures 1 through 6 of the accompanying drawings.