JP2006519350A - Refrigeration system with integrated bypass system - Google Patents

Abstract

Compressor, condenser, main expansion device and evaporator connected to form a closed circuit through which the refrigerant is circulated, and the supercooling function rather than in the downstream part of the conventional condenser There is provided a heat transfer system that can be used for an air conditioner, a heat pump, or the like of a device having such a bypass device. The supercooling device has a single integrated structure, and has an inner tube that can be connected to the main refrigerant passage at the outlet of the condenser, and a concentric shape having an end sealed outside the inner tube. An outer tube, an inlet orifice connecting the inner tube to the upstream end of the outer tube, allowing a portion of the refrigerant flowing in the inner tube to be diverted at a reduced temperature and pressure, and a downstream end of the outer tube. And an exit orifice. The supercooling device is further communicated with the outlet orifice and is connectable to the main refrigerant passage, so that the bypassed refrigerant flows in the chamber and flows in the inner tube. It is possible to provide cooling and return to the main refrigerant flow path. The outlet orifice can also be sized to cause a pressure drop in the refrigerant as it exits the chamber so that the refrigerant in the bypass device and the main refrigerant passage at the point where the refrigerant re-enters. The differential pressure between is adjusted.

Description

  The present invention relates generally to high efficiency heat transfer systems, and more specifically, heat that optimizes the size of components including condensers, compressors and evaporators, thereby increasing overall system efficiency. Relates to the transmission system. For convenience, the present invention has been described in the context of a “refrigeration system”, but the present invention is directly applicable to pure refrigeration systems and to similar systems such as heat pumps. It should be understood that is also applicable.

  FIG. 1 shows a block diagram of a conventional refrigeration system, generally designated by the reference numeral 10. This system includes a compressor 12, a condenser 14, an expansion device 16, and an evaporator 18. These components are typically connected together by a copper tube as indicated by reference numeral 19, and a refrigerant such as R12, R22, R134a, R407c, R410a, ammonia, carbon dioxide or natural gas is circulated therein. This constitutes a closed loop.

  The main steps of the refrigeration cycle are to compress the refrigerant by the compressor 12, heat is taken away from the refrigerant by the condenser 14, the refrigerant flow is throttled by the expansion device 16, and the evaporator 18 is to be cooled. Heat is absorbed from the space by the refrigerant. This process is sometimes referred to as a vapor compression refrigeration cycle, which cools and dehumidifies air in living spaces, transportation means (eg automobiles, aircraft, trains, etc.), refrigeration equipment, heat pumps and other applications. It will be appreciated that the system configuration of FIG. 1 generally represents all these systems.

  Heat is removed from the refrigerant in the condenser 14 so that the superheated refrigerant from the compressor 12 becomes a liquid refrigerant before reaching the outlet of the condenser. In FIG. 1, the condenser 14 is divided into two parts 14a and 14b. In the first part of the condenser, shown as reference 14b, the superheated refrigerant becomes saturated steam, this process is called desuperheating, which causes the phase change from steam to liquid refrigerant. Wake up. In the second part of the condenser, indicated by reference numeral 14a, the liquid refrigerant is further cooled below the saturation temperature at the condenser pressure and this process is known as subcooling.

  The international publication No. 04/44503 (international application US03 / 36424, hereinafter referred to as 424 application) filed in November 2003 under the name of “REFRIGERATION SYSTEM WITH BYPASS SUBCOOLING AND COMPONENT SIZE DE-OPTIMIZATION” by the present applicant. ) Discloses that the supercooling is performed not in the condenser but in the second refrigeration passage partially bypassing the main refrigeration passage.

  This type of system is shown in FIG. In this figure, the main refrigeration passage is the same as that of the system shown in FIG. 1, but a bypass line 27 for bypassing a part of the refrigerant from the main refrigeration passage is also provided. The system includes a second expansion device 23 and a heat exchanger 22 that is thermally coupled to the main refrigeration passage between the condenser 14 and the main expansion device 16. A portion of the bypassed refrigerant exiting the condenser 14 passes through the second expansion device 23 and the pressure and temperature of this refrigerant is reduced until it is substantially below the pressure and temperature at the outlet of the condenser.

  The cold refrigerant mixture exiting the second expansion device 23 then flows into the heat exchanger 22 where heat is taken away from the liquid refrigerant flowing from the condenser 14 resulting in additional supercooling of the liquid refrigerant. The additional supercooling resulting from this bypass technique eliminates the need for a supercooling process in the condenser. This is illustrated in FIG. 2 by a small condenser where the supercooling section 14a has been removed and shown in outline.

  The pressure of the refrigerant in the bypass line 27 at the outlet of the heat exchanger is higher than the pressure at the outlet of the evaporator 18, and a PDAD (pressure differential accommodating device) 38 connects the outlet of the bypass line with the refrigerant. Used to connect to the main line. This differential pressure adjusting device can be either a vacuum generator or a pressure reducing device, as disclosed in the 424 application.

  Other information regarding the benefits of flowing refrigerant using a bypass passage for subcooling is also disclosed in the 424 application, the entire contents of which are incorporated herein by reference.

Although the use of bypass subcooling provides a significant improvement over conventional systems that produce supercooling in the condenser, there is a need for means to further reduce cost and size, especially in small systems. is doing.
US Pat. No. 6,651,451 US Pat. No. 5,095,712

  Accordingly, it is an object of the present invention to improve bypass subcooling for refrigeration systems, heat pumps and similar systems.

  Another object of the present invention is to provide a supercooling bypass device that employs components that can be manufactured at lower cost than conventional components.

  Another object of the present invention is to provide a subcooling bypass line that employs components that can be manufactured more compactly than conventional components.

  An additional object of the present invention is to provide improved components that can be employed to provide bypass subcooling in refrigeration systems or heat pump systems.

  It is a further object of the present invention to provide such an improved component with bypass subcooling that can be provided at a lower cost than with conventional components.

  Another object of the present invention is to provide such an improved component that allows refrigeration in a heat pump system employing bypass subcooling, which is more compact than when conventional components are employed in the bypass passage. It is in.

  According to the first aspect of the present invention, the bypass device including means for bypassing a part of the liquid refrigerant that exits the condenser and flows into the bypass passage in the main refrigerant passage, and the pressure of the bypassed refrigerant and A refrigerant flow comprising expansion means for reducing temperature and the bypassed refrigerant at the reduced temperature and pressure is thermally coupled to a portion of the main refrigerant passage downstream of the condenser means. A heat exchanger means for extracting sufficient heat from the internal refrigerant to provide supercooling; and the heat for returning the bypassed refrigerant to the main refrigerant passage downstream of the heat exchanger means. Supercooling is provided by outlet means connected to the exchanger means.

  According to the first aspect of the present invention, the outlet means may include a differential pressure adjusting means.

  Further according to the first aspect of the invention, all of the aforementioned functions of the bypass line are performed by a single mechanical component.

  According to the second aspect of the present invention, the first orifice for diverting a part of the liquid refrigerant exiting the condenser and flowing into the bypass passage from the main refrigerant passage is provided, and the pressure of the bypassed refrigerant and A heat exchanger having an integral structure for lowering the temperature and a first flow path, the upstream end of the heat exchanger being in communication with the opening, and the heat exchanger is connected to the condenser A heat exchanger that is thermally joined to a portion of the main refrigerant flow passageway at the downstream end thereof so that heat can be extracted from the refrigerant leaving the condenser to provide supercooling; Supercooling is provided by a second orifice in communication with the downstream end of the first flow path and returning the bypassed refrigerant to the main refrigerant path.

  According to the second aspect of the present invention, the second opening further includes a differential pressure adjusting device for adjusting a differential pressure between the refrigerant in the main flow path and the bypass passage. It doesn't matter.

  Also according to the second aspect of the invention, all of the above-described functions of the bypass line are performed by a single mechanical component.

  According to a third aspect of the present invention, a detour device function for a portion of the refrigerant exiting the condenser and for significantly reducing the temperature of the bypassed refrigerant relative to the temperature of the refrigerant exiting the condenser. An expansion device function, a heat exchanger function that uses the cooled bypass refrigerant to supercool the refrigerant flowing into the main expansion device from the condenser, and the bypassed refrigerant is for supercooling. Provided is a bypass subcooling component in a single integrated structure for a refrigeration system or heat pump system that performs a combined device function for returning this bypassed refrigerant back to the main refrigerant passage after use Is done.

  According to the third aspect of the present invention, the coupling device can also function as a differential pressure adjusting device.

  According to the fourth aspect of the present invention, the supercooling component can be composed of first and second concentric tubes. An inner tube is coupled to the outlet of the condenser and is designed to serve as part of the main refrigerant flow passage. A first orifice is provided between the inner tube and the outer tube at the upstream end of the outer tube. The first orifice serves to bypass a part of the refrigerant that exits the condenser and flows into the bypass passage and cools the bypassed refrigerant. As the cooled refrigerant flows through the outer tube, the cooled refrigerant extracts heat from the refrigerant flowing through the inner tube, thereby providing supercooling for the refrigerant in the main flow path. A second orifice provided at the downstream end of the outer tube connects the bypass passage to the return tube so that the bypassed refrigerant is returned to the main flow path downstream of the evaporator. It has been entered. By appropriately selecting the size of the second orifice, the differential pressure between the main refrigerant channel and the bypass channel can be adjusted.

  The described integrated configuration can greatly simplify the manufacture and assembly of the bypass passage and thus provide a significant cost reduction. In addition, instead of providing a separate second expansion device, a first small orifice is provided between the inner heat exchanger tube and the outer heat exchanger tube, and instead of providing a separate PDAD, the outer heat exchanger By providing the second small hole in the wall, the size of the supercooling device can be substantially reduced. This is particularly beneficial for small air conditioning systems or heat pump systems.

  According to a fifth aspect of the present invention, the integrated subcooling device described herein can be used in the various configurations described in the 424 application. In addition, the supercooling device described in this specification is disclosed in US Pat. No. 6,662,576 filed by the applicant under the name “REFRIGERATION SYSTEM WITH DESUPERHEATING BYPASS” (the entire contents of which are hereby incorporated by reference). It can be seen that the present invention is also useful in other aspects of modern heat transfer techniques such as those disclosed in US Pat.

The above and other objects of the present invention, as well as various features of the present invention, will be fully understood from the following description and the accompanying drawings.
Other features and advantages of the present invention will become apparent from the following description with reference to the accompanying drawings.
Note that the same reference numerals are used for similar members throughout the drawings.

  For purposes of illustrating the present invention, FIG. 2 can be considered as a representative example of a refrigeration system and heat pump that employs bypass supercooling as disclosed in the 424 application. According to the present invention, the component including the bypass passage 27 is replaced with an integrated configuration, and this integrated configuration exhibits all the functions of the replaced component. Such an integrated configuration is shown in FIG.

  Here, the supercooler to which reference numeral 40 is attached as a whole includes an inner tube 42 and an outer tube 44 provided concentrically therewith. The inner tube 42 is connected to the outside of the condenser 14 (see FIG. 2) at its upstream end 46 and is connected to the inlet of the main expansion device 16 at its downstream end 48. Accordingly, the tube 42 replaces the conduit for the main refrigerant flow through the bypass heat exchanger 22.

  Referring back to FIG. 3, the outer tube 44 includes a closed end 52 and a closed end 54 formed with an opening 56 and an opening 58 for receiving the inner tube 42, respectively. As described below, the opening 56 and the opening 58 are appropriately sealed with respect to the respective end portions 46 and 48 of the inner tube 42 in order to prevent refrigerant leakage.

  The inner space of the inner tube 42 and the chamber 60 are communicated by a small orifice 64 provided at the upstream end 46 of the inner tube 42. The orifice 64 is sized so as to function as an expansion orifice for a part of the refrigerant that leaves the condenser 14 and flows into the inner tube 42. The second orifice 66 is provided so as to communicate with the outlet tube 68 at the downstream end of the outer tube 44. Accordingly, referring again to FIG. 2, the chamber 60 replaces the conduit for refrigerant flow through the bypass heat exchanger 22.

  Still referring to FIG. 2, it will be recalled that in the illustrated system, there is a differential pressure between the refrigerant exiting the heat exchanger 22 and the refrigerant exiting the evaporator 18 in the bypass passage. Accordingly, the PDAD 38 is employed to mix the refrigerant bypassed in the bypass line 27 with the refrigerant exiting the evaporator and return it to the compressor 12. The 424 application discloses several possible configurations for PDAD 38.

  However, according to the present invention, as shown in FIG. 4, it is possible to integrate the function of the PDAD into the bypass subcooling device itself. Here, a discharge orifice 70 sized so as to cause a pressure drop when the refrigerant exiting the chamber 60 flows into the return line 68 is provided (see FIG. 2). Accordingly, the discharge orifice 70 can be employed to provide the function of the PDAD 38.

  3 and 4, an inlet orifice 64 for the chamber 60 is provided at the upstream end of each inner tube 42. Similarly, outlet orifices 66 and 70 for the chamber 60 are provided at the downstream end of the inner tube 42. As a result, a parallel flow of refrigerant occurs in the heat exchanger. That is, the refrigerant in the tube 42 and the refrigerant in the chamber 60 flow in the same direction.

  However, in the embodiment of FIG. 5, the bypass subcooler 40 a includes an inlet orifice 80 for the chamber 82 provided at the downstream end 88 of the inner tube 84 and an outlet orifice provided at the upstream end 90 of the inner tube 84. 86. Thus, for the embodiment of FIG. 5, counter flow occurs in the heat exchanger. That is, the refrigerant in the tube 84 and the refrigerant in the chamber 82 are flowing in opposite directions. As in the embodiment of FIG. 4, the functionality of the PDAD 38 can be provided by appropriately sizing the exit orifice 86.

  FIG. 6 shows a system as shown in FIG. 2 using a bypass subcooling device as shown in FIG. Here, the inlet end 90 of the inner tube 84 is connected to the outlet of the condenser 14 b, and the outlet end 88 of the inner tube 84 is connected to the inlet of the expansion device 16. The downstream end 92 of the outer heat exchanger 82 is connected to a return line 96 through a discharge orifice 80, which returns the outlet of the evaporator 18 to return the bypassed refrigerant to the compressor 12 inlet. It is connected to the main channel at the end.

  In describing the present invention, specific terminology is used for the sake of clarity. However, the present invention is not intended to be limited to specific descriptive terms, and each specific term includes all technical equivalents that operate in a similar manner to accomplish a similar purpose. It should be understood that it also encompasses objects.

  Similarly, the embodiments described and illustrated are intended to be illustrative, and various modifications and other embodiments belonging to the scope of the present invention will be apparent to those skilled in the art in light of this disclosure. Let's go.

The block diagram of the conventional refrigeration system is shown. 1 is a block diagram of a refrigeration system employing bypass supercooling. It is the schematic which shows the principle of the 1st Example of this invention, Comprising: The flow of the bypassed refrigerant | coolant which flows through a heat exchanger is made into the same direction as the flow of the main refrigerant | coolant. Although it is the same as that of FIG. 3, the schematic of the Example of this invention by which the differential pressure regulation apparatus is provided between the main freezing passage and the bypass passage is shown. It is the schematic which shows the principle of 1st Example, Comprising: The flow of the bypassed refrigerant | coolant which flows through a heat exchanger is made into the reverse direction with the flow of the main refrigerant | coolant. FIG. 6 is a schematic view of an embodiment of the present invention that is similar to FIG. 2 but employs the bypass subcooling device shown in FIG. 5.

Explanation of symbols

12 Compressor 14, 14a, 14b Condenser 16 Expansion device 18 Evaporator 22 Bypass heat exchanger 27 Bypass passage 38 PDAD
40, 40a Subcooler 42, 84 Inner tube 44 Outer tube 46, 90 Inner tube upstream end 48, 88 Inner tube downstream end 56, 58 Opening 60, 82 Chamber 64, 66, 70, 80, 86 Orifice 68 Outlet tube 96 return line

Claims (11)

The main refrigerant passage,
A first inlet such that the main refrigerant passage is connectable to an outlet of a condenser in the first refrigerant passage of the refrigeration system;
A first outlet such that the main refrigerant passage is connectable to an inlet of an expansion device in the first refrigerant passage;
A bypass passage,
A second inlet that acts to divert a portion of the refrigerant flowing through the bypass passage from the condenser and flowing into the supercooling device, and to reduce the pressure and temperature of the diverted refrigerant;
A second outlet such that the bypass passage is connectable to the first refrigerant passage downstream of the evaporator;
A subcooling device for a heat transfer system in the form of a single integrated structure comprising:
The bypass passage is thermally coupled to the main refrigerant passage, thereby forming a heat exchanger that acts to transfer heat from the refrigerant in the main refrigerant passage to the refrigerant in the bypass passage. A supercooling device characterized by comprising:   The second outlet further includes a device for adjusting a differential pressure of the refrigerant pressure in the bypass passage with respect to the refrigerant pressure in the first refrigerant passage as part of the integrated structure. The supercooling device according to claim 1. The main refrigerant passage comprises a first tube connectable between an outlet of the condenser and an inlet of the expansion device;
The bypass passage surrounds the first tube and has an end sealed to the outside of the first tube, thereby forming a second tube forming a chamber surrounding the first tube Consisting of
The second inlet comprises an orifice connecting the first tube to an upstream end of the second tube;
With this configuration, when the refrigerant flows through the first tube and the second tube, heat is generated from the relatively warm refrigerant in the first tube to the relatively cold refrigerant in the second tube. The supercooling device according to claim 1, wherein the supercooling device is absorbed.   The subcooling device according to claim 3, wherein the second outlet includes an orifice at a downstream end of the second tube that is connectable to the main refrigerant passage.   The supercooling device according to claim 3 or 4, wherein the second outlet gives a pressure drop of the refrigerant flowing through the second outlet.   The said 2nd inlet_port | entrance is provided in the upstream end of the said 1st tube, and the said 2nd exit is provided in the downstream end of the said 1st tube, The Claim 4 or 5 characterized by the above-mentioned. Supercooling device.   The said 2nd inlet_port | entrance is provided in the downstream end of the said 1st tube, and the said 2nd exit is provided in the upstream end of the said 1st tube, The Claim 4 or 5 characterized by the above-mentioned. Supercooling device. A compressor, a condenser, an expansion device, and an evaporator, which are connected to each other to form a closed loop system, and a main refrigerant passage through which refrigerant is circulated in the closed loop system;
The first inlet is connected to the outlet of the condenser, the first outlet is connected to the inlet of the first expansion device, and the second outlet is downstream of the evaporator and the first outlet is connected to the outlet of the condenser. The supercooling device according to any one of claims 1 to 7, which is connected to return the bypassed refrigerant to a refrigerant passage.
A heat transfer system comprising: Inlet means for diverting a portion of the liquid refrigerant exiting the condenser means in the main refrigerant passage of the refrigeration system;
Expansion means for reducing the pressure and temperature of the bypassed refrigerant;
Heat exchanger means for thermally coupling the bypassed refrigerant to a portion of the main refrigerant passage downstream of the condenser means at the reduced temperature and pressure, wherein the heat exchanger means Heat exchanger means for extracting sufficient heat to provide supercooling from the refrigerant within,
Outlet means connected to the heat exchanger means to return the bypassed refrigerant back to the main refrigerant path downstream of the evaporator means in the main refrigerant path;
A supercooling device for a heat transfer system having a single structure.   The subcooling device according to claim 9, wherein the outlet means acts so as to reduce the pressure of the refrigerant when the refrigerant passes through the inside. A compressor means, a condenser means, an expansion device means, and an evaporator means, which are connected to each other to form a closed loop system, and a main refrigerant passage through which refrigerant is circulated in the closed loop system;
10. The inlet means is connected to the outlet of the condenser means, and the outlet means is connected to return the bypassed refrigerant to the first refrigerant passage downstream of the evaporator means. A supercooling device according to claim 10,
A heat transfer system comprising:

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