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:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    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. 
         [0003]    2. Description of the Related Art 
         [0004]    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. 
         [0005]    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. 
         [0006]    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 
       [0007]    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. 
         [0008]    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. 
         [0009]    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. 
         [0010]    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 LSHXs, each compressor connected to its own LSHX. 
         [0011]    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 
         [0012]      FIG. 1  is a single, integral module comprising a LSHX connected to a side of a compressor. 
           [0013]      FIG. 2  is a single, integral module comprising a LSHX connected to a top of a compressor. 
           [0014]      FIG. 3  is a single, integral module comprising a LSHX connected to a bottom of a compressor. 
           [0015]      FIG. 4  is a single, integral module comprising a plurality of compressors connected to a single LSHX. 
           [0016]      FIG. 5  is an integral module comprising a plurality of compressors and a plurality of LSHX&#39;s, each compressor connected to its own LSHX. 
           [0017]      FIG. 6  illustrates a refrigerant system that has an integral module comprising a compressor and LSHX. 
       
    
    
     DESCRIPTION OF THE INVENTION 
       [0018]    Referring to the drawings and, in particular,  FIG. 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. 
         [0019]    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. 
         [0020]    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 . 
         [0021]    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. 
         [0022]    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. 
         [0023]    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. 
         [0024]    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 LSHX 110  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 . 
         [0025]    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. 
         [0026]    Turning now to  FIG. 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. 
         [0027]    Turning now to  FIG. 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  FIG. 4  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. 
         [0028]    Turning to  FIG. 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. 
         [0029]    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 . 
         [0030]    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 . 
         [0031]    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 . 
         [0032]    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.