EP4624851A1

EP4624851A1 - A heat exchanger with multiple modes

Info

Publication number: EP4624851A1
Application number: EP24166189.1A
Authority: EP
Inventors: Michal BELZOWSKI; Damian JURKIEWICZ
Original assignee: Valeo Systemes Thermiques SAS
Current assignee: Valeo Electrification SAS
Priority date: 2024-03-26
Filing date: 2024-03-26
Publication date: 2025-10-01

Abstract

A heat exchanger (100) includes a housing (10), a first manifold (20), a second manifold (30, 130) and a core (40). The housing (10) defines an enclosure and comprises nozzles (14, 16) for ingress and egress of coolant inside the housing (10). The first manifold (20) includes ports (222) and channels (242) in fluidic communication with the corresponding ports (222). Each channel (242) includes different sets of apertures (244). The second manifold (30, 130) is disposed substantially opposite to the first manifold (20). The core (40) includes heat exchange tubes (42) in fluid communication with the first manifold (20) and the second manifold (30, 130). The different set of apertures (244) configure fluid communication between the channels (242) and the heat exchange tubes (42) based on operative configuration of the ports (222) controlled by a controller (60) to define the number of passes through the core (40).

Description

TECHNICAL FIELD

The present invention relates to heat exchanger, more specifically, a chiller for a battery pack of an electric or a hybrid vehicle.

BACKGROUND OF THE INVENTION

Vehicle electrification is a conscious step that automakers are taking towards a sustainable future. Conventional fuel vehicles such as petrol and diesel vehicles have advantage with respect to driving range, and there is constant consumer demand to increase the range of electric vehicles. To catch up with this demand, auto-manufacturers are opting for bigger, more powerful battery packs with higher energy densities.
Such battery packs generate heat due a variety of reasons such as internal resistance, enthalpy changes, etc. as they charge or discharge. The battery performs most efficiently in an optimum temperature range, roughly between 20-45ºC, depending on cell chemistry and packaging. Hence elevated temperatures, due to the heat generated by the battery can adversely impact efficiency, range, and battery health and in worse cases may lead to thermal runaway.
In another scenario, when the ambient conditions are cold, the battery temperature falls below the optimum temperature range, which again effects the operating efficiency, range and health of the battery.
As a result, depending on the scenario, it is important to effectively dissipate the heat generated during the operation of the battery, as well as to provide heat to the battery to raise the temperature of the battery when the battery temperature falls below an optimum temperature range.
Electric vehicles utilize a heat-exchanger, particularly, a chiller for heat dissipation from the battery pack to cool the battery pack. The chiller is used to cool a coolant (such as water) and the coolant is used to cool the battery. However, the chiller is bulky in size and commissioning a separate heat exchanger for heating of the battery requires a lot of space. Hence, it is necessary that the chiller assembly is utilized for both in cooling as well as heating the battery as necessary.
The chiller includes a housing and has inlet and outlet for coolant to ingress and egress the housing. The chiller also includes a core that further comprises a plurality of heat exchange tubes that carry refrigerant there through. The heat exchange tubes are configured for heat exchange between the refrigerant flowing there through and the coolant that is in fluidic contact with the heat exchange tubes.
The heat exchanger is configured so that refrigerant, after entering the chiller, makes multiple passes through the heat exchanging tubes. It can be appreciated that for better and more effective heat exchange higher number of passes are better. However, higher number of passes for the refrigerant is suitable when the chiller is used in a cooling mode i.e. the refrigerant passing through the heat exchanging tubes is in liquid state. In liquid state, the pressure drop of the refrigerant is low and a higher number of passes can be applied. However, if the chiller is intended for heating the coolant, the hot gaseous refrigerant is passed through heat exchanging tubes. If gaseous refrigerant is made to traverse a higher number of passes through the heat exchanging tubes, it suffers from large pressure drop. Thus, in the heating phase the number of passes need to be reduced.

OBJECT OF THE INVENTION

An object of the invention is to allow flexibility in changing the number of passes that the refrigerant takes through the heat exchanging tubes of the core, depending on the cooling/ heating requirement.
Another objective of the invention is to achieve changeability of the number of refrigerant passes without employing any movable parts in the chiller.

SUMMARY OF THE INVENTION

The present invention relates to a heat exchanger system that includes a housing, at least one first manifold, at least one second manifold and a core. The housing defines an enclosure and a plurality of nozzles in fluidic communication with an interior of the housing. The at least one first manifold includes a plurality of ports for ingress and egress of a refrigerant and a plurality of channels in fluidic communication with the corresponding ports. Each channel includes different sets of apertures in fluidic communication with the corresponding channels. The at least one second manifold is disposed substantially opposite to the first manifold. The core of the heat exchanger includes a plurality of heat exchange tubes fluidically connecting the first manifold and the second manifold allowing refrigerant to pass therein. The core is positioned in a fluidically sealed enclosure defined by the housing. Each of the apertures is in fluidic communication with at least one of the heat exchange tubes. The nozzles are configured to allow ingress and egress of a coolant in the housing. The coolant received inside the housing undergoes heat exchange with the heat exchange tubes by being in contact therewith. The plurality of ports includes least four ports and a controller is configured to selectively configure at least one of the ports as inlet and at least one of the ports as outlet, so as to define the number of passes through the core.
Generally, the first manifold includes at least one communication block, at least one first cover body, at least one first flow control plate and at least one first header. The second manifold generally includes at least one second cover body, a second flow control plate and a second header.
Particularly, the first flow control plate includes a first set of horizontal slots, a second set of horizontal slots and a set of vertical slots separating the first set of horizontal slots and the second set of horizontal slots.
Similarly, the second flow control plate includes at least one first set of vertical slits and at least one second set of vertical slits.
Particularly, the first set of vertical slits and the second set of vertical slits are separated by a horizontal separator adapted to block the flow of refrigerant between the at least one first set of vertical slits and the at least one second set of vertical slits.
Specifically, the heat exchanger is adapted to operate in at least a first mode and at least a second mode. In the first mode of operation, a first channel and a second channel are adapted to distribute and collect refrigerant with respect to the heat exchange tubes. The first cover body and the first flow control plate and the second flow control plate in conjunction are adapted to configure four passes with two U-turns at the second manifold and a single U-turn at the first manifold. Alternatively, in the second mode of operation, a third channel and a fourth channel are adapted to distribute and collect refrigerant with respect to the heat exchange tubes. The first cover body, the first flow control plate and the second flow control plate, in conjunction, are adapted to configure two passes with two U-turns at the second manifold and collection of the refrigerant from the two passes at the first manifold.
Generally, at least one of the vertical slots is aligned with at least one set of apertures and has dimension greater than or equal to the dimension of said one set of apertures.
Specifically, the number of passes of the refrigerant can be changed between an even number of passes based on selective operative configuration of the ports.
Additionally, the second manifold further includes at least one communication block.
Specifically, the communication block of the second manifold includes a plurality of ports adapted to be controlled by the controller to allow either ingress or egress of a refrigerant there-through based on operative configuration of the ports.
More specifically, the second cover body includes a plurality of channels that are aligned and in fluidic communication with the ports of the communication block. Each channel includes a plurality of apertures in fluidic communication with the channels of the second cover body.
Particularly, the first manifold and the second manifold are substantially similar.
Specifically, the number of passes of the refrigerant can be selectively changed between an even number of passes or an odd number of passes by configuring the communication block and cover body on one side and both sides of the core respectively.
Alternatively, the refrigerant can be configured to bypass the core.

BRIEF DESCRIPTION OF THE DRAWINGS

Other characteristics, details and advantages of the invention may be inferred from the description of the invention hereunder. A more complete appreciation of the invention and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying figures, wherein:

FIG. 1 illustrates a schematic representation depicting an arrangement of a heat exchanger in accordance with an embodiment of the present invention.
FIG. 2 illustrates an exploded view depicting elements of the heat exchanger of FIG. 1.
FIG. 3 illustrates an exploded view of a first manifold of the heat exchanger of FIG 1.
FIG. 4A illustrates an isometric view of a first cover body of the heat exchanger of FIG. 1
FIG. 4B illustrates the sectional view of the first cover body of the heat exchanger of FIG. 1 along a section line AA depicted in FIG. 4A.
FIG. 4C illustrates the sectional view of the first cover body of the heat exchanger of FIG. 1 along a section line BB depicted in FIG. 4A.
FIG. 5 illustrates an exploded view of a second manifold of the heat exchanger of FIG 1 in accordance with an embodiment of the present invention.
FIG. 6 illustrates an isometric view of a portion of the heat exchange tubes of the heat exchanger of FIG. 1.
FIG. 6A illustrates an isometric view of a core of the heat exchanger of FIG. 1 along with first and second flow control panels at extreme ends of the core.
FIG. 7A illustrates the sectional view of the he heat exchanger of FIG. 1 along a section line XX' depicted in FIG. 1.
FIG. 7B illustrates an enlarged view of a region depicted by a dotted line box in FIG. 7A of the heat exchanger of FIG. 1.
FIG. 8A illustrates the flow path of a refrigerant in a four-pass mode in the heat exchanger of FIG. 1
FIG. 8B illustrates the flow path of a refrigerant in a two-pass mode in the heat exchanger of FIG.1
FIG.9 illustrates a schematic representation depicting the heat exchanger in accordance with another embodiment of the present invention, wherein the heat exchanger is configured with two identical manifolds on either side.
FIG. 10 illustrates an exploded view of the second manifold of the heat exchanger of FIG 9.

DETAILED DESCRIPTION

It must be noted that the accompanying figures disclose the invention in a detailed enough way to be implemented, said figures helping to better define the invention, if need be. The invention should, however, not be limited to the embodiments disclosed in the description.
The present invention envisages a heat exchanger, more specifically an automotive chiller module for heating and cooling a coolant fluid, to overcome the challenges of conventional chillers in which significant pressure drop of the refrigerant occurs when the chiller operates in heating mode causing gaseous hot refrigerant to traverse the same number of passes through the chiller as the denser cold liquid refrigerant during cooling mode. The heat exchanger of the present invention is capable of switching between fewer pass configuration and multiple pass configuration, for example, between two pass configuration and four pass configuration to adapt to different requirements. More specifically, the chiller includes four ports for ingress/ egress of refrigerant. A controller selects a pair of ports (one of the ports as inlet and one other port as outlet) to enable the refrigerant to take four-pass fluid path through a core section of the heat exchanger (for cold liquid refrigerant), while the controller selects the other pair of ports for the refrigerant to take a two-pass fluid path through the core (hot gaseous refrigerant). The present invention is applicable to any heat exchanger system used in automotive or non-automotive applications that is required to be simple in construction and need to be operated in different modes.
FIG. 1 illustrates an isometric view of a heat exchanger 100 in an assembled configuration in accordance with an embodiment of the present invention.
In a preferred embodiment of the present invention, the heat exchanger 100 is functionally coupled to a controller 60 that controls operating configuration of the ports of the heat exchanger 100.
FIG. 2 illustrates an exploded view of the heat exchanger 100 depicting placement and interaction between various components thereof in accordance with an embodiment of the present invention. The figure depicts a housing 10 defining an enclosure. A first manifold 20 is disposed on one end of the housing 10 and a second manifold 30 is disposed on the substantially opposite end of the housing 10. A core 40 is disposed inside the housing 10 and is in fluidic communication with the first manifold 20 and the second manifold 30. Further, the housing 10 comprises a plurality of nozzles 14 and 16 configured to allow coolant ingress and egress to and from the enclosure defined by the housing 10. This way the coolant flows around a plurality of heat exchange tubes 42 of the core 40 for exchanging heat between the refrigerant flowing through the heat exchange tubes 42 and the coolant.
FIG. 3 illustrates an exploded view of the first manifold 20 in accordance an embodiment of the present invention depicting the components thereof. The first manifold 20 comprises a communication block 22. The communication block 22 comprises a plurality of ports 222 including a first port 222A, second port 222B, third port 222C, fourth port 222D selected to be operative for ingress and egress of a refrigerant by a controller (60). The communication block 22 further comprises a plurality of channels 242A, 242B, 242C, 242D in fluidic communication with the corresponding ports 222A, 222B, 222C, 222D. Each of the channels 242A, 242B, 242C, 242D comprises different sets of through apertures 244A, 244B, 244C, 244D in fluidic communication with the corresponding channels 242A, 242B, 242C, 242D. The first manifold 20 further comprises a first cover body 24, a first flow control plate 26 and a first header 28. The plurality of ports 222A, 222B, 222C, 222D are formed in the communication block 22 and the channels 242A, 242B, 242C, 242D are formed in the first cover body 24. Preferably, the number of ports 222A, 222B, 222C, 222D and channels 242A, 242B, 242C, 242D are equal. The communication block 22 is disposed orthogonal to the first cover body 24 and the ports 222A, 222B, 222C, 222D and the channels 242A, 242B, 242C, 242D are aligned about their respective longitudinal axes. The ports 222A, 222B, 222C, 222D are in fluidic communication with the channels 242A, 242B, 242C, 242D and thus the ports 222A, 222B, 222C, 222D allow fluid communication of refrigerant to and from the channels 242. The different sets of apertures 244 (244A, 244B, 244C, 244D) are formed in the first cover body 24 and are in fluidic communication with the channels 242. Each of the channels 242A, 242B, 242C, 242D is in fluid communication with at least one set of apertures 244. The flow control plate 26 is disposed abutting a flat face of the cover body 24 and comprises a first set of horizontal slots 262A, a second set of horizontal slots 262B and a set of vertical slots 264 separating the first set of horizontal slots 262A and the second set of horizontal slots 262B. The header plate 28 is disposed abutting the flow control plate 26. The header plate 28 acts to hold all the components of the first manifold 20 together, and also supports the core 40 of the heat exchanger 100 at one end. Such configuration of the flow control plate 26 and the header plate 28 define fluid communication between the apertures 244 and the heat exchange tubes 42.
In accordance with an embodiment, one of the vertical slots 264 that is aligned with the set of apertures 244D and has dimension such as a width greater than or equal to the dimension of said one set of apertures 244. Such a design allows unimpeded flow of refrigerant between the vertical slot 264 and the set of apertures 244D.
In a preferred embodiment, at least one of the channels 242C is in fluidic communication with two sets of apertures 244C. One set of apertures 244C is in fluidic communication with the top end of the third channel 242C and another set of apertures 244C is in fluidic communication with the bottom end of the third channel 242C of the cover body 24. This allows refrigerant fluid flow through two different points from the third channel 242C.
FIG. 4A illustrates an isometric view of the first cover body 24 in isolation while FIG. 4B and FIG. 4C illustrate the sectional view of the first cover body 24 of the heat exchanger 100 of FIG. 1 along a section line AA and BB, respectively as depicted in FIG. 4A to clearly depict the plurality of channels 242 (242A, 242B, 242C, 242D) and the apertures 244 (244A, 244B, 244C, 244D).
FIG. 5 illustrates an exploded view of the second manifold 30 as shown in FIG. 2. The second manifold 30 comprises a second cover body 34, a second flow control plate 36 and a second header 38.
In one embodiment, the second cover body 34 has a planar structure and is disposed at one extremity of the core 40 as part of the second manifold 30. The second flow control plate 36 abuts the second cover body 34. The second header 38 abuts the second flow control plate 36. Such configuration of the second flow control plate 36 and the second header plate 38 define u-flow between the heat exchange tubes 42.
The second header 38 is disposed on the opposite side of the second flow control plate 36 w.r.t the second cover body 34. The second header 38 thus acts to hold all the components of the second manifold 30 together, and also supports the core 40 of the heat exchanger 100 at an end substantially opposite to that of the first manifold.
In one embodiment of the invention, the second flow control plate 36 comprises a first set of vertical slits 362A and a second set of vertical slits 362B. The first set of vertical slits 362A and the second set of vertical slits 362B are separated by a horizontal separator 364. In one embodiment, the separator is a blank portion.
FIG. 6 illustrates an isometric view of an end portion of the heat exchange tubes 42. The core 40 of the heat exchanger 100 comprises plurality of such heat exchange tubes 42 stacked together in overlapping manner. Generally, each heat exchange tube 42 has numerous passages that allow the flow of refrigerant therein. Particularly, the heat exchange tube 42 is an extruded tube. More specifically, the heat exchange tube is a microchannel tube.
FIG. 6A illustrates a perspective view of the core 40 along with the first flow control plate 26 and the second flow control plate 36 on opposite sides of the core 40. The heat exchange tubes 42 of the core 40 are shown in four sets - a first set of heat exchange tubes 42A, a second set of heat exchange tubes 42B, a third set of heat exchange tubes 42C and a fourth set of heat exchange tubes 42D. The first set of heat exchange tubes 42A is in direct fluid communication with the first set of horizontal slots 262A of the first flow control plate 26. The fourth set of heat exchange tubes 42D is in direct fluid communication with the second set of horizontal slots 262B of the first flow control plate 26. The remaining sets of heat exchange tubes 42 that are located centrally and in direct fluid communication with the vertical slots 264 of the first flow control plate 26 are divided into two sets i.e. the second set of heat exchange tubes 42B and the third set of heat exchange tubes 42C. Set 42B is the set above the horizontal separator 364 and thus in direct fluid communication with the horizontal slits 362A of the second flow control plate 36. 42C is the set below the horizontal separator 364 and thus in direct fluid communication with the horizontal slits 362B of the second flow control plate 36. It is understood that the heat exchanger 100 may also have more than four or less than four sets of heat exchange tubes 42 without departing from the scope of the invention.
FIG. 7A illustrates a sectional view of the heat exchanger 100 along a section line XX' depicted in FIG. 1. FIG. 7B illustrates the connection of the heat exchange tubes 42 with the first manifold 20 and the second manifold 30.
In a preferred embodiment, the refrigerant enters the heat exchanger 100 through the ports 222, then the refrigerant passes through the channels 242, through the apertures 244 and then passes through the heat exchanging tubes 42 of the core 40 to the second manifold 30. More specifically, the channels 242 either distribute the refrigerant to the heat exchange tubes 42 or collect the refrigerant from the heat exchange tubes 42 through the apertures 244. The core 40 is positioned in the enclosure defined by the housing 10. The enclosure is fluidically sealed with the first manifold 20 and the second manifold 30 at both ends of the housing 10. As discussed earlier, the nozzles (14, 16) allow ingress and egress of a coolant to and from the enclosure defined by the housing 10. As the coolant enters the housing 10, it comes in contact with the heat exchange tubes 42 of the core 40 and thus heat exchange occurs between the coolant outside the heat exchange tubes 42 and the refrigerant flowing through the heat exchange tubes 42.
An enlarged sectional view of a portion of the heat exchanger 100 of FIG. 7A is illustrated in FIG. 7B. Particularly, FIG. 7B depicts in greater detail, the connection of the heat exchange tubes 42 with the first manifold 20, more specifically, with the apertures 244C formed on the channel 242 C and the connection between the apertures 244C and the third channel 242C. The figure also illustrates the internal structure of the third port 222C and its connection with the third channel 242C. It should be understood that the respective connections of the ports 222A, 222B and 222D with the respective channels 242A, 242B and 242D are obtained similarly. Similarly, it is understood that the connections of the channels 242A, 242B and 242D with the respective apertures 244A, 244B and 244D are obtained similarly. However, these are not described in detail considering the brevity of the present document.
In an embodiment, the heat exchanger 100 includes a controller 60 that can selectively adapted to configure at least one of the ports 222A, 222B, 222C, 222D as inlet and at least one of the ports 222A, 222B, 222C, 222D as outlet for the ingress and egress of the refrigerant, to change the number of passes that the refrigerant takes through the core section (40).
In another embodiment, the controller 60 may also be a separate system from the heat exchanger 100. It should be understood that a controller 60 disposed separately from the heat exchanger 100 or a controller 60 being a part of another system, and functionally connected to the heat exchanger 100 will have the same function as that of a controller that is comprised/embedded with the heat exchanger 100. Thus, such a configuration is well within the scope of the present invention.
By way of example and not limitation, the controller 60 can be an electronic or mechanical type controller capable of selectively enabling one or more of the ports 222A, 222B, 222C, 222D for fluid flow (such as the refrigerant). Such a controller may be an electronic controller including but not limited to BMS, ECU, BCM, PCM, TCM or the like. Such a controller may also be a mechanical type controller including but not limited to TCV, or the like. It should be appreciated that any suitable controller can be used without deviating from the scope of the invention.
FIG. 8A and FIG. 8B illustrate the flow path of the refrigerant in a four-pass and a two-pass modes.
In an exemplary embodiment of the present invention, when the heat exchanger 100 is operating in a first mode, the controller 60 configures the first port 222A to act as inlet port for ingress of refrigerant in to the heat exchanger 100 and the second port 222B as outlet port for egress of the refrigerant from the heat exchanger 100. When, the heat exchanger 100 is operating in the first mode, particularly, as a chiller, requiring more number of passes, the second and the third ports 222B and 222C are blocked to prevent refrigerant flow there through. In such a configuration, the refrigerant enters the heat exchanger 100 through the first port 222A. The refrigerant then flows through the first channel 242A, through the first set of apertures 244A and then to the first set of heat exchange tubes 42A. The first set of horizontal slots 262A aid in distributing the refrigerant entering through the aperture 244A throughout the width of the first set of heat exchange tubes 42A. Although the third set of apertures 244C are in fluidic communication with the horizontal slot 262A formed on the first control plate 26, however, the refrigerant does not flow through the apertures 244C as the third port 222C is blocked and not enabled for refrigerant flow. The refrigerant then flows through the length of the first set of heat exchange tubes 42A to the second manifold 30 completing a first pass. At the second manifold 30, the first set of vertical slits 362A of the second flow control plate 36 enables fluidic connection between the first set of heat exchange tubes 42A and heat exchange tubes set 42B configuring the first U-turn at the second manifold 30. The refrigerant flows from the first set heat exchange tubes 42A to the second set of heat exchange tubes 42B completing the first U-turn. After passing through the second set of heat exchange tubes 42B and reaching the first manifold 20, the refrigerant similarly follows a second U-turn at the first manifold flowing from the second set of heat exchange tubes 42B to the third set of heat exchange tubes 42C via the vertical slots 264 formed on the first control plate 26. After passing through the third set of heat exchange tubes 42C and completing the third pass and upon reaching the second manifold 30 again, the refrigerant follows a third U-turn at the second manifold 30 by flowing from the third set of heat exchange tubes 42C to the fourth set of heat exchange tubes 42D through the second set of vertical slits 362B. The refrigerant then reaches the first manifold 20 by flowing through the fourth set of heat exchange tubes 42D completing the fourth pass, then passes through the second set of apertures 244B, then through the second channel 242B and finally exiting the heat exchanger 100 through the second port 222B. Thus in such a configuration, the refrigerant undergoes two U-turns at the second manifold 30 and single U-turn at the first manifold 20 constituting a four-pass configuration. Further, the heat exchanger 100 can be configured with more than four passes by increasing the sets of heat exchange tubes and changing the configuration of the horizontal and vertical slots of the first control plate 26 and changing the placement of the apertures 244A, 244B, 244C, 244D associated with the channels 242A, 242B, 242C, 242D. The heat exchanger 100 with more than four passes fall well within the scope of this invention.
In an exemplary embodiment, the heat exchanger 100 is operating in a cooling mode and cold liquid refrigerant flows through the heat exchange tubes 42 of the core 40, particularly, the cold liquid refrigerant flows through four-passes. This allows the refrigerant flowing to heat exchanger 100 to have a more effective heat transfer with the coolant. Since the refrigerant is in liquid state, there is no significant pressure drop in it even when it takes a more number of passes (four or more passes in this case).
In an exemplary embodiment, the heat exchanger 100 operating in a second mode, the controller 60 configures the third port 222C to function as inlet port to distribute refrigerant to the heat exchange tubes 42 and the the controller 60 configures the fourth port 222D to function as outlet to collect refrigerant from the heat exchange tubes 42. When the heat exchanger 100 is operating in the second mode, the first and the second ports 222A and 222B are blocked to prevent refrigerant flow there through. In such a configuration, the refrigerant enters the heat exchange tubes 42 in two portions. Particularly, a first portion of the refrigerant stream enters the fourth set of heat exchange tubes 42D through the third set of apertures 244C, particularly, third set of apertures 244C formed on bottom of the third channel 242C. Also, another portion of the refrigerant stream enters the first set of heat exchange tubes 42A through the third set of apertures 244c, particularly, the third set of apertures 244C formed on top of the third channel 242C. The first cover body 24, the first flow control plate 26, the heat exchange tubes 42 and the second flow control plate 36 in conjunction adapted to configure two passes of the refrigerant with one U-turn of the first and second portions of the refrigerant streams at the second manifold 30. The first portion of the refrigerant stream flows through the channel 242C, through the third set of apertures 244C formed on the bottom of the third channel 242C and then through the fourth set of heat exchange tubes 42D. The second set of horizontal slots 262B aid in distributing the refrigerant entering through the third set of aperture 244C throughout the width of the fourth set of heat exchange tubes set 42D. Although the first set of apertures 244A are in fluidic communication with the horizontal slot 262A, however, the refrigerant does not flow through the first set of apertures 244A as the first port 222A is blocked to prevent the refrigerant flow there through. The refrigerant then flows through the length of the heat exchange tubes set 42D to the second manifold 30 completing the first pass. At the second manifold 30, the second set of vertical slits 362B formed on the second flow control plate 36 enables fluid communication between the fourth set of heat exchange tubes 42D and the third set of heat exchange tubes set 42C. The refrigerant thus flows from the fourth set of heat exchange tubes set 42D to the third set of heat exchange tubes set 42C after following the first U-turn. The refrigerant passes through the third set of the heat exchange tubes 42C constituting a second pass. Thereafter, upon reaching the first manifold 20 the refrigerant passes through the fourth set of apertures 244D, then through the fourth channel 242D and finally exits the heat exchanger 100 through the fourth port 222D. Similarly, the second portion of the refrigerant stream that enters the core 40 through the third set of apertures 244C formed on top of the third channel follows one U-turn at the second manifold 30 taking two passes through the core 40. Particularly, the second portion of the refrigerant stream enters the core 40 through the third set of apertures 244C 244C formed at the top of the third channel 242C and follows one U-turn at the second manifold 30 taking two passes through the core 40. Thus each of the two portions of the refrigerant stream entering through the third set of apertures 244C formed on top and bottom of the third channel 242C, after individually taking two passes through the core, collect at the fourth channel 242D through the fourth set of apertures 244D and finally exit the heat exchanger 100 through the fourth port 222D. Thus, each of the first and the second portions of the refrigerant stream is allowed to take two passes each and effectively, the whole flow of refrigerant is also subjected to only two passes through the core 40 of the heat exchanger 100.
In an exemplary embodiment, when the heat exchanger 100 functions in heating mode, hot gaseous refrigerant flows through the heat exchange tubes 42 of the core 40 and the second mode with two-pass configuration is activated. This allows the hot gaseous refrigerant to undergo heat exchange with the coolant, however, less number of passes (two passes in this case) prevents the gaseous refrigerant from experiencing large pressure drops, which would otherwise happen in case of more number of passes (such as four passes).
However, the four-pass configuration and two-pass configurations can each be used during both cooling and heating modes. During heating modes, when there is high heating requirement, the four pass mode can also be used for hot refrigerant without any limitation. Similarly, during cooling modes, when the cooling requirement is low (partial cooling), the two pass mode can also be used for cold refrigerant without any limitation.
In yet another embodiment, the ports 222A, 222B, 222C, 222D are adapted to cause the refrigerant to bypass the core 40. This can be achieved by the controller 60 selecting the first port 222A and the second port 222B as inlet ports and selecting the third port 222C as the outlet port. Since the first set of apertures 244A are in direct fluid communication with the apertures 244C at the top of the first manifold 20 via the first set of horizontal slots 262A of the flow control plate 26, the refrigerant that enters through the first port 222A conveniently exits through the third port 222C without passing through the core 40. Similarly, since the apertures 244B are in direct fluid communication with the apertures 244C at the bottom of the first manifold 20 via the second set of horizontal slots 262B of the flow control plate 26, the refrigerant that enters through the second port 222B conveniently exits through the third port 222C without passing through the core 40. Thus, the refrigerant can be made to bypass the core 40 when there is not requirement of heating or cooling.
In yet another embodiment, the heat exchanger 100 may be used to function in a partial cooling/heating mode by the controller selecting the first port 222A as inlet and the fourth port 222D as outlet for the refrigerant. The refrigerant enters the heat exchange tubes that are in fluid communication with the first set of apertures 244A, flows through the heat exchange tubes, takes a U-turn at the second manifold 30 utilizing the first set of vertical slits 362A, returns through another set of heat exchange tubes 42 in fluid communication with the first set of vertical slits 362A, enters through the apertures 244D in to the fourth channel 242D, and finally exits through the fourth port 222D. A similar flow configuration is achieved by selecting second port 222B as inlet and fourth port 222D as outlet.
Generally, when the heat exchanger 100 has inlet and outlet only through the first manifold 20 placed on the same side of the core 40, the refrigerant, after entering through the first manifold 20 may either bypass the core or must take at least one U-turn to return back to the first manifold 20 and thus only a bypass mode or an even number of passes are possible in such a configuration. Thus, the number of passes of the refrigerant can be switched between an even number of passes, based on selective operation of the ports 222.
FIG. 9 illustrates the heat exchanger 100 with the first manifold 20 and the second manifold 30 according to an alternate embodiment of the invention.
FIG. 10 illustrates an exploded view of the second manifold 30 according to an alternate embodiment of the current invention.
In an embodiment, the second manifold 130 is substantially similar to the first manifold 20 in structure, configuration and function. The second manifold 130 comprises a communication block 32, a second cover body 34, a second flow control plate 36 and a second header 38. The communication block 32 comprises a plurality of ports 322A, 322B, 322C, 322D for ingress and egress of a refrigerant and a plurality of channels 342A, 342B, 342C, 342D in fluidic communication with the corresponding ports 22A, 322B, 322C, 322D. Each channel 342A, 342B, 342C, 342D comprises corresponding different sets of through apertures 344A, 344B, 344C, 344D formed on the corresponding channels 342A, 342B, 342C, 342D. The plurality of ports 322A, 322B, 322C, 322D are formed in the communication block 32 and the channels 342A, 342B, 342C, 342D are formed in the second cover body 34. Preferably, the number of ports 322A, 322B, 322C, 322D and the channels 342A, 342B, 342C, 342D are equal. The ports 322A, 322B, 322C, 322D and the channels 342A, 342B, 342C, 342D are aligned about their respective longitudinal axes. The ports 322A, 322B, 322C, 322D are in fluidic communication with the channels 342A, 342B, 342C, 342D and thus the ports 322A, 322B, 322C, 322D allow communication of refrigerant to the channels 342A, 342B, 342C, 342D. The different sets of apertures 344A, 344B, 344C, 344D are formed in the second cover body 34 and are in fluidic communication with the channels 342A, 342B, 342C, 342D. Each of the channels 342A, 342B, 342C, 342D is configured with at least one set of apertures 344A, 344B, 344C, 344D. The second flow control plate 36 is disposed abutting a flat face of the cover body 34 and comprises a first set of horizontal slots 362A, a second set of horizontal slots 362B and a set of vertical slots 366 separating the first set of horizontal slots 362A and the second set of horizontal slots 362B. The header plate 38 is disposed abutting the second flow control plate 36. The header plate 38 acts to hold all the components of the second manifold 30 together, and also receives another end of the heat exchange tubes 42 of the core 40 of the heat exchanger 100 at one end. One of the vertical slots 366 that is aligned with the set of apertures 344D and has dimension such as a width greater than or equal to the dimension of said one set of apertures 344. Such a design allows unimpeded flow of refrigerant between the vertical slot 366 and the set of apertures 344D. At least one of the channels 342C is in fluidic communication with two sets of apertures 344C. One set of apertures 344C is in fluidic communication with the top end of the channel 342C and another set of apertures 344C is in fluidic communication with the bottom end of the channel 342C of the cover body 34. This allows refrigerant fluid flow through two different points from the channel 342C.
In the above embodiment, the first manifold 20 and the second manifold 30 both have ports 222 and 322 for ingress and egress of refrigerant. Thus, the ingress and egress of the refrigerant can be configured on either side of the core. Consequently, odd number of passes can also be implemented. By way of example and not limitation, the refrigerant can ingress through the first manifold 20 and egress through the second manifold 30 after taking a single pass through the core 40. Similarly, the refrigerant can ingress through the first manifold 20, take a U-turn at the second manifold, return to the first manifold 20, take a second U-turn, flow to the second manifold 30 and egress from the second manifold 30 executing three passes through the core. It should be understood that due to such an arrangement, both odd and even number of passes for the refrigerant can be executed. Any number of flow combinations are possible without departing from the scope of the invention.

Claims

A heat exchanger (100) comprising:
• a housing (10) defining an enclosure and a plurality of nozzles (14, 16) being in fluidic communication with an interior of the housing (10),

• at least one first manifold (20) comprising a plurality of ports (222) for ingress and egress of a refrigerant and a plurality of channels (242) in fluidic communication with the corresponding ports (222), each channel (242) configured with different sets of apertures (244)

• at least one second manifold (30, 130) disposed substantially opposite to the first manifold (20),

• a core (40) comprising a plurality of heat exchange tubes (42) fluidically connecting the first manifold (20) and the second manifold (30,130) allowing refrigerant to pass therein, wherein the core (40) is positioned in a fluidically sealed enclosure defined by the housing (10), each of the apertures (244) configured to allow fluidic communication between at least one channel (242) and at least one of the heat exchange tubes (42),
wherein, the nozzles (14, 16) are configured to allow ingress and egress of a coolant with respect to the housing (10),

characterized in that the plurality of ports (222) comprises at least a first port (222A), at least a second port (222B), at least a third port (222C) and at least a fourth port (222D), and a controller (60) is configured to selectively configure at least one of the ports (222) as inlet and at least one of the ports (222) as outlet, to define the number of passes through the core (40).
The heat exchanger (100) of claim 1, wherein the first manifold (20) comprises at least one communication block (22), at least one first cover body (24), at least one first flow control plate (26) and at least one first header (28).
The heat exchanger (100) of claim 1, wherein the second manifold (30, 130) comprises at least one second cover body (34), a second flow control plate (36) and a second header (38).
The heat exchanger (100) as claimed in claim 2, wherein the at least one first flow control plate (26) comprises a first set of horizontal slots (262A), a second set of horizontal slots (262B) and a set of vertical slots (264) separating the first set of horizontal slots (262A) and the second set of horizontal slots (262B).
The heat exchanger (100) as claimed in the claim 3, wherein the second flow control plate (36) comprises at least one first set of vertical slits (362A) and at least one second set of vertical slits (362B).
The heat exchanger 100 as claimed in claim 5 wherein, the at least one first set of vertical slits (362A) and the at least one second set of vertical slits (362B) are separated by a horizontal separator (364) adapted to block the flow of refrigerant between the at least one first set of vertical slits and the at least one second set of vertical slits.
The heat exchanger (100) of claim 1 being adapted to operate in at least a first mode and at least a second mode, wherein, in the first mode of operation, a first channel (242A) and a second channel (242B) are adapted to distribute and collect refrigerant with respect to the heat exchange tubes (42), the first cover body (24) and the first flow control plate (26) and the second flow control plate (36) in conjunction adapted to configure four passes with two U-turns at the second manifold (30,130) and a single U-turn at the first manifold (20),
and in the second mode of operation, a third channel (242C) and a fourth channel (242D) are adapted to distribute and collect refrigerant with respect to the heat exchange tubes (42), the first cover body (24), the first flow control plate (26) and the second flow control plate (36) in conjunction adapted to configure two passes with two U-turns at the second manifold (30, 130) and collection of the refrigerant from the two passes at the first manifold (20).
The heat exchanger (100) as claimed in claim 7 wherein, at least one of the vertical slots (264) is aligned with at least one set of apertures (244) and has dimension greater than or equal to the dimension of said one set of apertures (244).
The heat exchanger (100) as claimed in claim 1 wherein, the number of passes of the refrigerant can be changed between an even number of passes based on selective operative configuration of the ports (222).
The heat exchanger (100) as claimed in claim 1 wherein, the second manifold (130) is substantially similar to the first manifold (20).
The heat exchanger (100) as claimed in claim 1, wherein the second manifold (130) further comprises at least one communication block (32).
The heat exchanger as claimed in the previous claim, wherein the communication block (32) of the second manifold (130) comprises a plurality of ports (322) adapted to be controlled by the controller (60) to allow either ingress or egress of a refrigerant there-through based on operative configuration of the ports (3220.
The heat exchanger as claimed in the previous claim, wherein the second cover body (34) comprises a plurality of channels (342) that are aligned and in fluidic communication with the ports (322) of the communication block (32), each channel (342) having a plurality of apertures (344).
The heat exchanger (100) as claimed in claim 11, wherein the number of passes of the refrigerant can be selectively changed between an even number of passes or an odd number of passes by configuring the communication block (22, 32) and cover body (24, 34) on one side and both sides of the core respectively.
The heat exchanger (100) as claimed in claim 1, wherein the refrigerant can be configured to bypass the core (40).