JP2008528943A - A heat exchanger that expands the fluid in the header - Google Patents

Abstract

The heat exchanger includes a plurality of flat multi-channel heat transfer tubes extending between spaced headers. Each heat transfer tube has a plurality of flow paths extending in the longitudinal direction parallel to each other from the inlet end to the outlet end. A plurality of connectors are disposed between the inlet header and the heat transfer tube, and the inlet end of the connector is in fluid flow communication with the header through an opening having a relatively small channel cross-sectional area, and the outlet end of the connector is the inlet end of the heat transfer tube Adapted to accept. The connector defines a fluid flow path that extends from an opening of a relatively small channel cross-sectional area at the inlet end of the connector to an outlet opening at the outlet end of the connector, the outlet opening of the connector being the outlet end of the connector Opened in the flow path of the heat transfer tube received in

Description

  The present invention generally relates to a heat exchanger having a plurality of parallel tubes extending between a first header and a second header, also referred to as a manifold, and more particularly, such as a heat exchanger of a refrigerant compression system, etc. In order to improve the distribution of two-phase flow through the parallel tubes of the heat exchanger, it relates to expanding the fluid within the header of the heat exchanger.

  This application refers to US Provisional Application No. 60 / 649,269 “Small Channel Heat Exchanger with Expansion Connector” filed on Feb. 2, 2005, with the priority and benefit of the application. Alleged and incorporated herein in its entirety.

  A refrigerant vapor compression system is a technique well known in the art. Air conditioners and heat pumps that employ a refrigerant vapor compression cycle are used to cool or cool / heat air supplied to a comfortable space where the temperature and humidity are controlled in a residence, office building, hospital, school, restaurant, or other facility. Often used. Refrigerant vapor compression systems are also often used to cool air or other secondary fluids, and include food and beverages in display cases in supermarkets, convenience stores, grocery stores, cafeterias, restaurants, and other food service facilities. Provide a refrigerated environment for products.

  Conventionally, these refrigerant vapor compression systems include a compressor, a condenser, an expansion device and an evaporator connected in refrigerant flow communication. The basic refrigerant system components described above are interconnected by a refrigerant line of a closed refrigerant circuit and arranged according to the employed vapor compression cycle. The expansion device is usually an expansion valve or a metering device with a constant diameter, such as an orifice or a capillary, and is arranged in the refrigerant line in the refrigerant circuit at a position upstream of the evaporator and downstream of the condenser with respect to the refrigerant flow. Is done. The expansion device operates to expand the liquid refrigerant that passes through the refrigerant line from the condenser to the evaporator to bring the liquid refrigerant to a low pressure and low temperature. As a result, part of the liquid refrigerant passing through the expansion device expands into vapor. As a result, in this conventional type of refrigerant vapor compression system, the refrigerant stream entering the evaporator is composed of a two-phase mixture. The specific ratio of liquid refrigerant to vapor refrigerant is used with the particular expansion device employed, such as R12, R22, R134a, R404A, R410A, R407C, R717, R7, or other compressible fluids, etc. It depends on the refrigerant.

  In some refrigerant vapor compression systems, the evaporator is a parallel tube heat exchanger. Such a heat exchanger has a plurality of parallel refrigerant flow paths provided to a plurality of tubes extending parallel to each other between an inlet header and an outlet header. The inlet header receives the refrigerant flow from the refrigerant circuit and distributes the refrigerant flow to a plurality of flow paths through the heat exchanger. The outlet header collects the refrigerant flow as the refrigerant flow exits each flow path, and in a single-pass heat exchanger, this collected refrigerant flow is returned to the refrigerant line back to the compressor, and the multi-pass heat exchanger Is guided through other heat transfer tube groups.

  Conventionally, parallel tube heat exchangers used in such refrigerant compression systems typically have a 1/2 inch (about 12.7 mm), 3/8 inch (about 9.5 mm), or 7 mm circular tube. Has been used. Recently, flat rectangular or oval multi-channel tubes are used in heat exchangers for refrigerant vapor compression systems. Each multi-channel tube has a plurality of channels extending longitudinally parallel to each other over the length of the tube, each channel providing a refrigerant path with a small channel cross-sectional area. Thus, a heat exchanger having multi-channel tubes extending parallel to each other between the inlet header and outlet header of the heat exchanger has a refrigerant path with a small channel cross-sectional area extending between the two headers. You will have a relatively large number. In contrast, a parallel tube heat exchanger having a conventional circular tube will have a relatively small number of flow paths with a large flow area extending between the inlet header and the outlet header.

  The non-uniform distribution, also called the unbalanced distribution of the two-phase refrigerant flow, is a common problem with parallel tube heat exchangers and adversely affects the efficiency of the heat exchanger. The problem with the two-phase imbalance distribution is due to the difference in density that occurs between the vapor phase liquid and the liquid phase refrigerant present in the inlet header as the refrigerant expands through the upstream expansion device.

  One solution for controlling the distribution of refrigerant flow through the parallel tubes of an evaporative heat exchanger is disclosed by Repice et al. In US Pat. No. 6,502,413. In the refrigerant vapor compression system disclosed therein, the high pressure liquid refrigerant from the condenser is partially expanded with an expansion device in a conventional refrigerant line upstream of the inlet header of the heat exchanger, Use a low-pressure refrigerant. In addition, each pipe connected to the inlet header downstream of the pipe inlet is provided with an aperture stop such as an internal orifice plate disposed inside the pipe simply by narrowing the pipe, and then expanded after entering the pipe. Complete to a low pressure liquid / vapor refrigerant mixture.

  Another method for controlling the distribution of refrigerant flow through the parallel tubes of an evaporative heat exchanger is disclosed in Japanese Patent No. 4080575 by Kanzaki et al. Also in the refrigerant vapor compression system disclosed in the publication, the high-pressure liquid refrigerant coming out of the condenser is partially expanded in an expansion device in a conventional refrigerant line, and is low-pressure upstream of the distribution chamber of the heat exchanger. It becomes a refrigerant. A plate having a plurality of orifices extends across the chamber into the distribution chamber. The low pressure refrigerant expands as it passes through the orifice, resulting in a low pressure liquid / vapor mixture downstream of the plate and upstream of the inlet to each tube opening into the chamber.

  In Japanese Patent No. 6241682, Massaki et al. Disclosed a parallel tube heat exchanger for a heat pump. In the disclosed heat exchanger, the inlet end of each multi-channel pipe connected to the inlet header is Squeezed to form a partial throttle restriction on each tube just downstream of each tube inlet. In Japanese Patent No. 8233409, Hiroaki et al. Disclosed a parallel tube heat exchanger, and in the disclosed heat exchanger, a plurality of flat multi-channel tubes are connected by a pair of header tubes. Each pipe has an interior in which the flow path area decreases in the direction of the refrigerant flow as means for uniformly distributing the refrigerant to each pipe. In Japanese Patent No. 20020222313, Yasushi discloses a parallel tube heat exchanger, and in the disclosed heat exchanger, the refrigerant is finished before the end of the header along the header axis. Is supplied to the header through an inlet pipe extending to Thereby, the two-phase refrigerant flow does not separate from the inlet pipe because it enters the annular flow path between the outer surface of the inlet pipe and the inner surface of the header. Thereafter, the two-phase refrigerant flow enters each pipe that is open to the annular flow path.

  Evenly distributing the refrigerant flow to a relatively large number of refrigerant flow paths having a small channel cross-sectional area is more difficult than conventional circular tube heat exchangers and can significantly reduce the efficiency of the heat exchanger. is there.

  A general object of the present invention is to reduce the fluid flow imbalance distribution of a heat exchanger having a plurality of multi-channel tubes extending between a first header and a second header.

  An object of one aspect of the present invention is to reduce an unbalanced distribution of refrigerant flow in a heat exchanger of a refrigerant vapor compression system having a plurality of multi-channel pipes extending between a first header and a second header. That is.

  An object of one aspect of the present invention is to distribute the refrigerant in a relatively uniform manner to the individual channels of the multi-channel tube row.

  Another object of the present invention is to provide a heat exchanger of a refrigerant vapor compression system having a plurality of multi-channel pipes, and when the refrigerant flow enters the individual channels of the multi-channel pipe row from the header, Providing distribution and expansion.

  In one aspect of the invention, a header defining a chamber for receiving fluid, a plurality of fluid flow paths opening from an inlet end to an outlet end of the tube, and an inlet opening to the plurality of fluid flow paths. And a heat exchanger having at least one heat transfer tube. A connector is also provided having an inlet end in fluid communication with the header chamber through the first opening and an outlet end in fluid communication with the inlet opening of the at least one heat transfer tube through the second opening. The connector defines a fluid flow path that extends from its inlet end to its outlet end. In certain embodiments, the flow path through the connector may diverge in the direction of fluid flow through the connector. The first opening has a relatively small flow area to provide flow restriction, and fluid flows from the header chamber through the first opening to the flow path of the heat transfer tube.

  In another aspect of the invention, a refrigerant vapor compression system includes a compressor, a condenser, and an evaporative heat exchanger connected in refrigerant flow communication, whereby high pressure refrigerant vapor is transferred to the compressor by refrigerant flow communication. The high-pressure refrigerant liquid moves from the condenser to the evaporating heat exchanger, and the low-pressure refrigerant vapor moves from the evaporating heat exchanger to the compressor. The evaporative heat exchanger includes an inlet header, an outlet header, and a plurality of heat transfer tubes extending between the inlet header and the outlet header. The inlet header defines a chamber that receives liquid refrigerant from the refrigerant circuit. Each heat transfer tube has an inlet end, an outlet end, and a plurality of fluid flow paths extending from the inlet opening at the inlet end of the tube to the outlet opening at the outlet end. The connector has an inlet end in fluid flow communication with the inlet header chamber through the first opening and an outlet end in fluid flow communication with the inlet opening of the heat transfer tube through the second opening. The connector defines a fluid flow path that extends from the inlet end to the outlet end. In certain embodiments, the flow path through the connector may diverge in the direction of fluid flow through the connector. The first opening has a relatively small channel cross-sectional area to provide flow restriction, through which fluid flows from the header chamber to the heat transfer tube flow path.

  Herein, the heat exchanger 10 of the present invention will be described with respect to an exemplary single-pass parallel tube embodiment of the multi-channel tube heat exchanger shown in FIG. In the exemplary embodiment of the heat exchanger 10 shown in FIG. 1, heat transfer tubes 40 are disposed parallel to each other between an inlet header 20 that extends substantially horizontally and an outlet header 30 that extends substantially horizontally. Has been extended almost vertically. However, the illustrated embodiment is illustrative and not limiting. The invention described herein can be implemented with various other configurations of heat exchanger 10. For example, the heat transfer tubes may be arranged between the inlet header extending substantially vertically and the outlet header extending substantially vertical so that the heat transfer tubes extend parallel to each other and substantially horizontally. In yet another example, the heat exchanger has a toroidal inlet header and a toroidal outlet header of a different diameter, between which the heat transfer tubes are radially inward or radially It may extend somewhat outward in the direction. The heat transfer tubes may be arranged in a multi-pass parallel tube embodiment, as will be described in detail in FIGS.

  With particular reference to FIGS. 1-5, the heat exchanger 10 includes an inlet header 20, an outlet header 30, and a plurality of longitudinally extending multi-channel heat transfer tubes 40, whereby the inlet header. A plurality of fluid flow paths are provided between 20 and the outlet header 30. Each heat transfer tube 40 has an inlet 43 in fluid communication with the inlet header 20 via a connector 50 at one end and an outlet in fluid communication with the outlet header 30 at the other end. Each heat transfer tube 40 has a plurality of parallel flow passages 42 extending longitudinally, i.e., along the tube axis and over the length of the tube, between the tube inlet and the tube outlet. Provides a number of independent parallel flow paths. Each multi-channel heat transfer tube 40 is, for example, a “flat” tube having a rectangular or oval cross section that defines an interior, and the interior is further divided so that independent channels 42 are arranged adjacent to each other. ing. Compared to the prior art circular tubes having a diameter of 1/2 inch (12.7 mm), 3/8 inch (9.5 mm), or 7 mm, the flat multi-channel tube 40 of the present invention is For example, the width is 50 mm or less, typically 12 mm to 25 mm, and the height is about 2 mm or less. For simplicity of illustration, the tube 40 is shown as having twelve channels 42 that define a flow path having a circular cross section. However, in commercial applications such as refrigerant vapor compression systems, for example, each multi-channel tube 40 generally has about 10-20 channels 42, but has a desired number of channels around it. Please understand that you may. Usually, the hydraulic diameter of each channel 42 defined as four times the number obtained by dividing the channel area by the circumference is in the range of about 200 μm to about 3 mm. In the drawing, a circular cross section is shown. However, the cross section of the channel 42 may be a rectangular, triangular, or trapezoidal cross section, or may be a desired cross section other than a circular cross section.

  Each of the plurality of heat transfer tubes 40 of the heat exchanger 10 has an inlet end 43 and is not inserted directly into the chamber 25 defined in the inlet header 20 but is inserted into each connector 50. The Each connector 50 has an inlet end 52 and an outlet end 54 and defines a fluid flow path 55 that extends from the inlet end 52 to the outlet end 54. The inlet end 52 is in fluid flow communication with the chamber 25 of the inlet header 20 through the first opening 51. The outlet end 54 is in fluid communication with the inlet opening 41 of the flow path 42 at the inlet end of the received corresponding heat transfer tube 40 via the second opening 53. The first opening 51 of the inlet end 52 of each connector 50 has a relatively small flow path cross-sectional area. Accordingly, the connector 50 has a plurality of flow path restrictors (at least one corresponding to each heat transfer tube 40) that uniformize the pressure drop in the fluid flowing from the chamber 25 of the header 20 into the fluid flow path 55 in the connector 50. I will provide a. This ensures that the fluid is distributed relatively evenly among the individual tubes 40 operatively associated with the header 20.

  In the embodiment shown in FIGS. 1, 2 and 3, the inlet header 20 comprises a cylinder having a circular cross section, extending in the longitudinal direction and having a closed end. The inlet end 52 of each connector 50 is inserted into and mated with a corresponding slot 26 that extends through the wall of the inlet header 20. Each connector is secured to a corresponding mating slot in the header 20 wall by brazing, welding, soldering, adhesive bonding, diffusion bonding, or otherwise. However, the inlet header 20 is not limited to the configuration shown in the figure. For example, the header 20 may be a cylinder having an elliptical cross section and extending in the longitudinal direction with a hollow closed end, having a square, rectangular, hexagonal, octagonal, or other cross section and having a longitudinal direction. It may be a hollow pipe having a closed end extending to the pipe.

  In the embodiment shown in FIGS. 6, 7, and 8, the inlet header 20 is brazed to a semi-cylindrical shell having a generally semi-circular cross-section and extending longitudinally with a closed end and a semi-cylindrical shell opening. , An insert 58, such as a block that is secured by welding, adhesive bonding or otherwise. In this embodiment, instead of a plurality of connectors 50, longitudinally extending block-like inserts 58 form a single connector 50. A plurality of parallel flow paths 55 are formed in the block-like structure of the connector 50 at intervals in the longitudinal direction. Each flow path 55 is in fluid communication with a fluid chamber 25 defined in the header 20 and has an inlet end 52 with an inlet opening 51 having at least one relatively small flow area, and an inlet of the heat transfer tube 40. And an outlet end 54 adapted to receive the end 42. Accordingly, in this embodiment, the plurality of heat transfer tubes 40 are connected to the header using a single block-like connector 50. The block-like insert 58 provides a connector 50 having a plurality of flow restrictors such that at least one relatively small channel area opening 51 cooperates with each heat transfer tube 40, wherein the plurality of flow restrictors is a header. By equalizing the pressure drop of the fluid flowing from the twenty chambers 25 to the fluid flow path 55 in the connector 50, the fluid is distributed relatively evenly to the individual tubes 40 that cooperate with the header 20.

  In the embodiment shown in FIGS. 2, 3, and 5, one first opening 51 having a relatively small flow path area is provided at the inlet end 52 of each connector 50. However, it should be understood that a plurality of first openings having a relatively small flow area may be provided at the inlet end 52 of the connector 50 if desired. For example, if the heat transfer tube is relatively wide and / or has a relatively large number of channels, a comparison of two, three, or more numbers as shown in FIGS. A first opening having a relatively small flow area is disposed at the inlet end 52 of the connector 50 at an interval, and the fluid flows to the multiple flow paths 42 of the tube 40 inserted into the outlet end 54 of the connector 50. It is desirable to ensure uniform distribution.

  A fluid flow path 55 extending from the inlet opening 51 at the inlet end 52 of the connector 50 to the outlet opening 53 at the outlet end 54 of the connector 50 is best illustrated in FIGS. Toward the outlet opening 53 from the end toward the outlet opening 53. This diverging flow path helps to evenly distribute the fluid flowing through the flow path 55 to the individual flow paths 42 of the heat transfer tubes 40 inserted into the outlet end 54 of the connector 50. This is particularly true when the fluid is a mixture of liquid and vapor refrigerants, or the fluid expands into the liquid / vapor refrigerant mixture via the opening (s) 51 having a relatively small flow area. This is particularly effective in the refrigerant flow application.

  The medium vapor compression system 100 schematically shown in FIGS. 9 and 10 includes a compressor 60, a heat exchanger 10A that functions as a condenser, and a heat exchanger 10B that functions as an evaporator. Are connected by a refrigerant line 12, 14, 16 as a closed loop refrigerant circuit. Like a conventional refrigerant vapor compression system, the compressor 60 circulates high-temperature and high-pressure refrigerant vapor through the refrigerant line 12 to the inlet header 120 of the condenser 10A. Thereafter, when the high-temperature refrigerant vapor passes through the heat transfer tube 140 of the condenser 10A, it is condensed by exchanging heat with a cooling fluid such as ambient air sent onto the heat transfer tube 140 by the condenser fan 70 to become a liquid. . The high pressure liquid refrigerant collects at the outlet header 130 of the condenser 10A and then enters the inlet header 20 of the evaporator 10B through the refrigerant line 14. The refrigerant then passes through the heat transfer tube 40 of the evaporator 10B. At this time, the refrigerant is heated by exchanging heat with the cooled air sent onto the heat transfer tube 40 by the evaporator fan 80. The refrigerant vapor collects at the outlet header 30 of the evaporator 10B, passes through the refrigerant line 16 from the header, and returns from the suction port of the compressor 60 to the compressor 60. Although the exemplary refrigerant vapor compression cycle of FIGS. 9 and 10 is a simplified air conditioning cycle, the heat exchanger of the present invention can be applied to various designs of refrigerant vapor compression systems, including heat pump cycles, economizer cycles, and refrigeration cycles. Can be adopted.

  In the embodiment shown in FIG. 9, the condensed refrigerant liquid moves directly from the condenser 10A to the evaporator 10B without passing through the expansion device. Thus, in this embodiment, the refrigerant generally enters the inlet header 20 of the evaporative heat exchanger 10B as a high pressure liquid refrigerant rather than a fully expanded low pressure refrigerant liquid / vapor mixture as in a conventional refrigerant compression system. . Accordingly, in this embodiment, the refrigerant in the evaporator 10B of the present invention as it enters the flow path 55 of the connector 50 through the relatively small area opening (s) 51 in the inlet end 52. Expansion occurs. In this way, expansion occurs reliably after distribution is achieved in a substantially uniform manner.

  In the embodiment shown in FIG. 10, the condensed refrigerant liquid flows through the expansion valve 50 provided in the refrigerant line 14 so as to be operable when moving from the condenser 10A to the evaporator 10B. The high-pressure liquid refrigerant partially expands into a low-pressure / low-temperature liquid refrigerant or a liquid / vapor refrigerant mixture in the expansion valve 50. In this embodiment, as the refrigerant enters the flow path 55 of the connector 50 through the relatively small channel area opening (s) 51 in the inlet end 52, the final refrigerant in the evaporator 10B. Complete expansion. When the flow passage cross-sectional area of the opening 51 cannot be sufficiently reduced to complete the reliable expansion of the liquid as it passes through the opening 51, or when the expansion valve is used as a flow control device, the inlet header 20 of the evaporator 10B. It is advantageous to partially expand the refrigerant by means of an upstream expansion valve.

  Referring to FIG. 11, the heat exchanger 10 of the present invention is shown in a multi-pass evaporator embodiment. In the illustrated multi-pass embodiment, the inlet header 20 is partitioned into a first chamber 20A and a second chamber 20B, the outlet header is also partitioned into a first chamber 30A and a second chamber 30B, and the heat transfer tube 40 is Divided into three groups 40A, 40B and 40C. The pipes of the first tube group 40A are inserted into the respective connectors 50A whose inlet ends are opened into the first chamber 20A of the inlet header 20, and the outlet ends are connected to the first chamber 30A of the outlet header 30. It is open. The pipes of the second tube group 40B are inserted into the respective connectors 50B whose inlet ends are opened into the first chamber 30A of the outlet header 30, and the outlet ends are connected to the second chamber 20B of the inlet header 20. It is open. The pipes of the third tube group 40C are inserted into the respective connectors 50C whose inlet ends are opened into the second chamber 20B of the inlet header 20, and the outlet ends are connected to the second chamber 30B of the outlet header 30. It is open. In such a configuration, the refrigerant entering the heat exchanger from the refrigerant line 14 flows so as to exchange heat three times with the air covering the outside of the heat transfer tube 40 instead of once as in the single-pass heat exchanger. According to the present invention, the inlet end 43 of each tube of the first tube group 40A, the second tube group 40B, and the third tube group 40C is inserted into the outlet end portion 54 of the corresponding connector 50, thereby the tube 40. Each flow path 42 receives an expanded refrigerant liquid / vapor mixture that is relatively evenly distributed. When the refrigerant enters the connector 50 from the header through the opening 51 having a relatively small channel cross-sectional area, the refrigerant is distributed and expanded, not only when the refrigerant enters the first tube group 40A, It also occurs when entering the second tube group 40B and the third tube group 40C. Thus, a more uniform distribution of the refrigerant liquid / vapor is ensured when entering the tube flow path of each tube group.

  Referring to FIG. 12, the heat exchanger 10 of the present invention is shown in a multi-pass condenser embodiment. In the illustrated multi-pass embodiment, the inlet header 120 is partitioned into a first chamber 120A and a second chamber 120B, the outlet header 130 is also partitioned into a first chamber 130A and a second chamber 130B, and the heat transfer tube 140 is It is divided into three tube groups 140A, 140B, 140C. The tubes of the first tube group 140A have an inlet end opening that opens into the first chamber 120A of the inlet header 120 and an outlet end opening that opens into the first chamber 130A of the outlet header 130. Have. The tubes of the second tube group 140B include an inlet end inserted into each connector 50B that opens into the first chamber 130A of the outlet header 130, and an outlet that opens into the second chamber 120B of the inlet header 120. And an end portion. The tubes of the third tube group 140C are inserted into the respective connectors 50C whose inlet ends are opened into the second chamber 120B of the inlet header 120, and the outlet ends are connected to the second chamber 130B of the outlet header 130. It is open. In such a configuration, the refrigerant entering the condenser from the refrigerant line 12 flows so as to exchange heat three times with the air covering the outside of the heat transfer tube 140 instead of once as in the single-pass heat exchanger. All of the refrigerant entering the first chamber 120A of the inlet header 120 from the compressor outlet via the refrigerant line 14 is high-pressure refrigerant vapor. However, since the refrigerant partially condenses as it passes through the first tube group and the second tube group, the refrigerant entering the second tube group and the third tube group is typically a liquid / vapor mixture. According to the present invention, the inlet ends of the tubes of the second tube group 140B and the third tube group 140C are inserted into the outlet ends of the corresponding connectors 50B and 50C, respectively, and the flow paths 42 of the tubes are expanded. The refrigerant liquid / vapor mixture will be distributed relatively uniformly. In condenser applications, it should be noted that the pressure drop through opening 51 is limited so as not to exceed a predetermined threshold in order not to reduce the heat exchange efficiency. Those skilled in the art will also appreciate that other multi-pass arrangements for condensers and evaporators are within the scope of the present invention.

  Although the invention has been described in detail with reference to the preferred embodiments illustrated in the figures, those skilled in the art can make various changes in detail without departing from the spirit and scope of the invention as defined in the claims. I want you to understand.

The perspective view of the embodiment of the heat exchanger by the present invention. Partial cross-sectional perspective view with respect to line 2-2 in FIG. FIG. 3 is a cross-sectional front view with respect to line 3-3 in FIG. 2. FIG. 4 is a cross-sectional view taken along line 4-4 of FIG. Sectional drawing regarding the line 5-5 of FIG. The partial cross-section perspective view of another embodiment of the heat exchanger by this invention. Sectional drawing regarding line 7-7 of FIG. FIG. 8 is a cross-sectional view taken along line 8-8 of FIG. The schematic of the refrigerant vapor compression system incorporating the heat exchanger of the present invention. The schematic of another refrigerant | coolant vapor compression system incorporating the heat exchanger of this invention. 1 is a partial cross-sectional front view of an embodiment of a multi-pass evaporator according to the present invention. 1 is a partial cross-sectional front view of an embodiment of a multipass condenser according to the present invention. FIG.

Claims (25)

A header defining a chamber for collecting fluid;
At least one heat transfer tube defining therein a plurality of individual fluid flow paths and having an inlet opening open to the plurality of fluid flow paths;
And having an inlet end and an outlet end and defining a fluid flow path extending from the inlet end to the outlet end, the inlet end being connected to the chamber of the header through a first opening. A connector in fluid communication, wherein the outlet end is in fluid communication with the inlet opening of the at least one heat transfer tube via a second opening, the first opening having a relatively small channel cross-sectional area;
A heat exchanger comprising:   The heat exchanger according to claim 1, wherein the first opening of the connector is an expansion orifice.   2. The fluid flow path of the connector comprises a divergent fluid flow path whose cross-section becomes wider in the direction of the fluid flowing through the first opening to the second opening. The described heat exchanger.   The heat exchanger according to claim 3, wherein the first opening of the connector is an expansion orifice.   The heat exchanger of claim 1, wherein the at least one heat transfer tube has a flat, non-circular cross section.   The heat exchanger according to claim 5, wherein the at least one heat transfer tube has a flat rectangular cross section.   6. A heat exchanger according to claim 5, wherein the at least one heat transfer tube has a flat, generally oval cross section.   The heat exchanger according to claim 1, wherein each of the plurality of flow paths defines a flow path having a cross section other than circular.   9. The heat exchanger of claim 8, wherein each of the plurality of flow paths defines a flow path selected from the group of a rectangular cross section, a triangular cross section, or a trapezoidal cross section.   The heat exchanger of claim 1, wherein each of the plurality of flow paths defines a flow path having a circular cross section.   The heat exchanger according to claim 1, wherein the first opening includes a plurality of openings. A compressor, a condenser and an evaporative heat exchanger connected in fluid flow communication in a refrigerant circuit, wherein the high pressure refrigerant vapor moves from the compressor to the condenser by the fluid flow communication; In the refrigerant vapor compression system, the low-pressure refrigerant vapor moves from the condenser to the evaporation heat exchanger, and the low-pressure refrigerant vapor moves from the evaporation heat exchanger to the compressor.
The evaporative heat exchanger is
An inlet header in fluid communication with the refrigerant circuit and defining a chamber for receiving refrigerant from the refrigerant circuit; and an outlet header in fluid flow communication with the refrigerant circuit;
At least one heat transfer tube having an inlet opening and an outlet opening, and having a plurality of individual fluid flow paths extending from the inlet opening to the outlet opening, the outlet opening being in fluid flow communication with the outlet header When,
An inlet end and an outlet end define a fluid flow path extending from the inlet end to the outlet end, the inlet end being in fluid flow communication with the chamber of the header through a first opening. The outlet end is in fluid communication with the inlet opening of the at least one heat transfer tube through a second opening, the first opening having a relatively small channel area; and
A refrigerant vapor compression system comprising:   The refrigerant vapor compression system according to claim 12, wherein the first opening of the connector comprises an expansion orifice.   13. The fluid flow path of the connector is a divergent fluid flow path in which the direction and cross section of the fluid flowing through the first opening to the second opening are widened. Refrigerant refrigerant compression system.   The refrigerant vapor compression system according to claim 14, wherein the first opening of the connector comprises an expansion orifice.   The refrigerant vapor compression system according to claim 12, wherein the at least one heat transfer tube has a cross section other than a flat circular shape.   The refrigerant vapor compression system of claim 16, wherein the at least one heat transfer tube has a flat rectangular cross section.   The refrigerant vapor compression system of claim 16, wherein the at least one heat transfer tube has a flat, generally oval cross section.   The refrigerant vapor compression system according to claim 12, wherein each of the plurality of flow paths defines a flow path having a cross section other than a circular shape.   The refrigerant vapor compression system of claim 12, wherein each of the plurality of flow paths defines a flow path selected from the group of rectangular, triangular, or trapezoidal cross sections.   The refrigerant vapor compression system of claim 12, wherein each of the plurality of flow paths defines a flow path having a circular cross section.   The refrigerant vapor compression system according to claim 12, wherein the heat exchanger comprises a single-pass heat exchanger.   The refrigerant vapor compression system according to claim 12, wherein the heat exchanger comprises a multi-pass heat exchanger.   The refrigerant vapor compression system according to claim 12, wherein the heat exchanger comprises a condenser.   The refrigerant vapor compression system according to claim 12, wherein the heat exchanger comprises an evaporator.

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