Plate-Type Heat Exchanger

The present application claims priority to Korean Patent Application No. 10-2024-0049333, filed on Apr. 12, 2024, the entire contents of which are incorporated herein for all purposes by this reference.

The present invention relates to a plate-type heat exchanger, and more particularly, to a plate-type heat exchanger designed to adjust performance to suit a utilization field.

In general, a heat exchanger includes a pair of header tanks into or from which a heat exchange medium is introduced or discharged, and a tube configured to connect the header tanks and allow the heat exchange medium to perform heat exchange while flowing in the tube. In this case, depending on the shapes of the heat exchangers, the heat exchangers may be broadly classified into two types including a tube-tank-type heat exchanger having a shape in which a plurality of tubes are inserted into a tank, and a plate-type heat exchanger in which a plurality of plates are stacked to configure a tube part and a tank part. Among the heat exchangers, the plate-type heat exchanger is widely used because the plate-type heat exchanger has various advantages in that the plate-type heat exchanger may be conveniently assembled in comparison with the tube-tank-type heat exchanger, has a small number of required components, and thus has improved productivity, a volume of the plate-type heat exchanger may be reduced, and the plate-type heat exchanger may be advantageous in ensuring a space of an engine room. In particular, in the case of the plate-type heat exchanger, a flow path, which is more complex and diversified in comparison with a pin-tube type heat exchanger, may be designed by changing a shape of the plate. Therefore, the plate-type heat exchanger is often used as a heat exchanger for different types of fluids such as a coolant/refrigerant, a coolant/oil, a high-temperature coolant/low-temperature coolant, and a high-temperature refrigerant/low-temperature refrigerant. In various preceding documents such as Korean Patent Laid-Open No. 2023-0111896 (“Plate-Type Heat Exchanger”, Jul. 26, 2023), configurations of the plate-type heat exchangers are disclosed in detail.

Meanwhile, an air conditioning system for a vehicle includes various cooling cycles, and various cooling cycles sometimes share a refrigerant route and a heat exchanger. Some of various cooling cycles are selectively performed in accordance with various air conditioning modes such as cooling, heating, and dehumidifying modes. Therefore, various operations, such as an operation of changing and adjusting the refrigerant route and an operation of changing the function of the heat exchanger, are performed. Some of the heat exchangers included in the air conditioning system for a vehicle are called internal heat exchangers (IHX). The internal heat exchanger serves to allow a high-pressure, high-temperature refrigerant, which has passed through a condenser, and a low-pressure, low-temperature refrigerant, which has passed through an evaporator, to exchange heat with each other. When the refrigerants in different states exchange heat with each other in the internal heat exchanger as described above, a difference in enthalpy of the evaporator may increase, thereby obtaining an effect of improving cooling performance.

In the related art, a separate heat exchanger, such as the tube-tank-type heat exchanger or the plate-type heat exchanger, is not used as the internal heat exchanger. That is, the internal heat exchanger is provided in a shape in which a pipe through which a high-pressure, high-temperature refrigerant flows and a pipe through which a low-pressure, low-temperature refrigerant flows are simply tangled, and the pipes exchange heat with each other, such that the function of the above-mentioned “internal heat exchanger” is implemented.is a view for explaining a shape of the internal heat exchanger in the related art and a shape of the recent internal heat exchanger. The upper view inillustrates a shape of an “internal heat exchanger′” in the related art. As illustrated, a pipe through which Refrigerantflows is disposed to be tightly attached to a periphery of a pipe through which Refrigerantflows, such that Refrigerantand Refrigerantmay exchange heat with each other. The heat exchange is performed to some extent only by the configuration in which the pipes are disposed to be tightly attached to each other. However, it is difficult to significantly improve the effect of improving the cooling performance by means of the heat exchange only by using the configuration. Therefore, a shape in which one pipe is wound around another pipe, like a coil, is applied to increase a heat exchange area.

However, the shape of the internal heat exchanger is sometimes changed during a process of variously changing the configurations of the conditioning system for a vehicle air to suit the recent introduction of electric vehicles and the like. The lower view inillustrates the shape of the recent internal heat exchanger. As illustrated in the lower view in, the recent internal heat exchanger is sometimes provided in the form of a plate-type heat exchangerand integrated with the other heat exchanger. This is to ensure a spatial utilization of an engine room and a convenience for a system configuration. As described above, the internal heat exchanger is a so-called additional device in which pipes are simply disposed densely without a separate heat exchanger device in the related art. In consideration of this configuration, a position, a standard, and the like of the other heat exchanger, which more directly performs the function in the cooling cycle, needs to be preferentially designed even though the internal heat exchanger is provided in the form of the plate-type heat exchanger. A position, a standard, and the like of the plate-type heat exchangerused as the internal heat exchanger is designed to follow the design, such as the position and the standard, of the other heat exchanger. In other words, there is a limitation in optionally changing and designing the position, the standard, and the like of the internal heat exchanger.

is a PH diagram for comparing the heat exchange performance of the internal heat exchanger in the related art and the heat exchange performance of the recent internal heat exchanger. A cooling cycle in a case in which the internal heat exchanger (IHX) is not applied is indicated by a dark-colored quadrangle, and a cooling cycle in a case in which the internal heat exchanger (IHX) is applied is indicated by a light-colored quadrangle. As described above with reference to the configuration in which the cooling performance is improved by applying the internal heat exchanger, the enthalpy at a high-pressure/high-temperature side is further lowered and the enthalpy at a low-pressure/low-temperature side is further raised when the internal heat exchanger is applied, such that the quadrangle, which defines the cooling cycle, is further increased.

In general, the improvement of the cooling performance is a good thing, but there may occur a problem in case that the improvement exceeds the limitation of the device that performs the cooling cycle. As illustrated in, a vertex at a right lower end of the quadrangle indicating the cooling cycle indicates an inlet of a compressor, a vertex at a right upper end of the quadrangle indicates an outlet of the compressor. In this case, in case that the performance of the internal heat exchanger is excessive, a temperature of the low-pressure, low-temperature refrigerant discharged from the evaporator may be raised above a designed level. Therefore, the temperature of the inlet of the compressor is raised, and the temperature of the outlet of the compressor is also naturally raised. However, when the temperature of the outlet of the compressor is excessively raised, there is a problem in that a risk of the occurrence of a problem with the durability of the compressor is increased. That is, it is necessary to prevent the performance of the internal heat exchanger from being excessively increased. As illustrated in the upper view in, the excessive performance does not need to be taken into account in the related art in which the heat exchange is performed by means of the simply tangled pipes. However, as illustrated in the lower view in, in case that the plate-type heat exchanger is introduced as the internal heat exchanger, there occurs a problem in that the compressor is damaged by the excessive performance, and the system cannot be operated because of the damage to the compressor. That is, there is a need for a design capable of appropriately adjusting the performance of the internal heat exchanger to prevent the performance of the internal heat exchanger from being excessively increased.

The present invention is proposed to solve these problems and aims to provide a plate-type heat exchanger used as an internal heat exchanger in which a dead zone is intentionally formed by changing an arrangement of flow ports or additionally installing a barrier to adjust performance in order to prevent a problem in which an operating temperature of a compressor is raised and durability is degraded because of excessive performance of the internal heat exchanger.

In order to achieve the above-mentioned object, the present invention provides a plate-type heat exchangerincluding: a plurality of platesstacked to alternately define a first medium space through which a first medium flows, and a second medium space through which a second medium flows, in which the platesincludes two types of plates including: a first platehaving a first medium inletand a first medium outletconfigured to allow the first medium to flow in the first medium space; and a second platehaving a second medium inletand a second medium outletconfigured to allow the second medium to flow in the second medium space, in which the plate has a rectangular shape having a pair of short sides and a pair of long sides, in which through-ports including the first and second medium inlets and outlets,,, andformed on the plateto allow the media to flow are collectively called flow ports, and in which a dead zone is formed by restricting the flow of the media in a partial zone on the plate.

In a first embodiment, the dead zone may be formed in the plate-type heat exchangerby arrangement positions of the flow ports, and when a pair of flow ports selected from the flow portsare disposed spaced apart from each other in parallel with a long side extension direction or a short side extension direction of the plateand define a row of flow ports, the remaining flow ports, except for the row of flow ports, may be disposed adjacent to the long side and the short side of the plate, the row of flow ports may be disposed at a middle position of the plate, and the row of flow ports and the remaining flow portsmay be disposed to be biased to a partial region on the plate, such that the remaining partial region is formed as the dead zone.

More specifically, in the plate-type heat exchanger, the flow portsmay be disposed to be biased to one long side selected from the pair of long sides of the platesuch that the remaining partial region at one long side is formed as the dead zone, or the flow portsmay be disposed to be biased to one short side selected from the pair of short sides of the platesuch that the remaining partial region at one short side is formed as the dead zone.

In a second embodiment, the dead zone may be formed in the plate-type heat exchangerby a barrierprovided in a medium flow path between the flow ports.

In this case, when a pair of flow ports of the flow portsare formed to allow the medium to flow in the plate, one of the pair of flow ports is an inlet port through which the medium is introduced, and the other of the pair of flow ports is an outlet port through which the medium is discharged, the inlet port may be disposed adjacent to any one of four vertices of the plate, the outlet port may be disposed to be spaced apart from the inlet port in a diagonal direction, and the barriermay extend in parallel with a short side extension direction of the plateand be disposed in parallel with the outlet port in the short side extension direction.

In addition, in this case, the outlet port may be disposed, in the short side extension direction of the plate, at a position adjacent to the long side different from the long side to which the inlet port is disposed adjacent, the outlet port may be disposed, in a long side extension direction, at a middle position of the short side different from the short side to which the inlet port is disposed adjacent, the outlet port may be disposed to be spaced apart from the inlet port in the diagonal direction, and a region between the barrierand the other short side may be formed as the dead zone by the barrierwhen viewed in the long side extension direction.

Alternatively, when a pair of flow ports of the flow portsare formed to allow the medium to flow in the plate, one of the pair of flow ports is an inlet port through which the medium is introduced, and the other of the pair of flow ports is an outlet port through which the medium is discharged, the inlet port may be disposed adjacent to any one of four vertices of the plate, the outlet port may be disposed to be spaced apart from the inlet port in a short side extension direction, and the barriermay extend in parallel with the short side extension direction of the plateand disposed to be spaced apart from a row of flow ports, which includes the inlet port and the outlet port, in a long side extension direction.

In addition, in this case, the outlet port may be disposed adjacent to another vertex connected, by moving short side, to the vertex of the plateto which the inlet port is disposed adjacent, the row of flow ports including the inlet port and the outlet port may extend in parallel with one short side of the plateand be disposed adjacent to one short side of the plate, and a region between the barrierand the other short side may be formed as the dead zone by the barrierwhen viewed in the long side extension direction.

In a third embodiment, the first medium inletand the first medium outleton the first platemay be disposed to be spaced apart from each other in parallel with a short side extension direction to constitute a first row of flow ports, the second medium inletand the second medium outleton the second platemay be disposed to be spaced apart from each other in parallel with the short side extension direction to constitute a second row of flow ports, one of the first and second rows of flow ports may be disposed adjacent to one short side selected from the pair of short sides, and the other of the first and second rows of flow ports may be disposed at a middle position of the pair of short sides.

In this case, the first row of flow ports may be disposed adjacent to one short side selected from the pair of short sides, and the second row of flow ports may be disposed at the middle position of the pair of short sides.

In addition, a flow direction of the first medium flowing from the first medium inletto the first medium outletand a flow direction of the second medium flowing from the second medium inletto the second medium outletmay be opposite to each other.

In addition, the plate-type heat exchangermay be configured to allow a relatively high-pressure, high-temperature refrigerant discharged from a condenser and a relatively low-pressure, low-temperature refrigerant discharged from an evaporator to exchange heat with each other.

In this case, the first medium may be a relatively low-pressure, low-temperature refrigerant discharged from the evaporator, and the second medium may be a relatively high-pressure, high-temperature refrigerant discharged from the condenser.

In addition, the plate-type heat exchangermay be integrated with the other heat exchangerand configured to receive a low-pressure, low-temperature refrigerant from the other heat exchanger.

In addition, the other medium flow portmay be formed on the plateof the plate-type heat exchanger, and the other medium, except for the first and second media to exchange heat with each other in the plate-type heat exchanger, may pass through the other medium flow port.

In addition, the other medium flow portmay be disposed in a dead zone region in the plate-type heat exchanger.

Hereinafter, a plate-type heat exchanger according to the present invention configured as described above will be described in detail with reference to the accompanying drawings.

Basically, a plate-type heat exchangerof the present invention is a heat exchanger that serves to allow different types of fluids to exchange heat with each other. Therefore, basically, the plate-type heat exchangeris formed in a shape in which a plurality of platesare stacked so that a first medium space through in a first medium flows and a second medium space in which a second medium flows are alternately formed. More specifically, the platesincludes two types of plates including a first plateconfigured to define the first medium space, and a second plateconfigured to define the second medium space. A first medium inletand a first medium outlet, which allow the first medium to flow through the first medium space, are formed in the first plate, and a second medium inletand a second medium outlet, which allow the second medium to flow through the second medium space, are formed in the second plate.

In addition, the plateis generally formed in a rectangular shape including a pair of short sides and a pair of long sides, more particularly, a rectangular shape in which vertices are rounded in consideration of flow properties. Hereinafter, in order to concisely describe the present invention, all the through-ports, which include the first/second medium inlets/outlets,,, andand are formed on the platesto allow the media to flow, will be collectively called flow portsin case that the flow portsdo not need to be distinguished from one another.

In general, when the configuration of a heat exchanger is improved, the design is changed to improve the heat exchange performance. However, as explained above, the present invention is intended to prevent problems such as system performance deterioration or device durability degradation caused by excessive heat exchange performance of the plate-type heat exchanger used as an internal heat exchanger. That is, the present invention proposes a design that intentionally reduces the heat exchange performance of the plate-type heat exchanger. More specifically, the plate-type heat exchangerof the present invention has a dead zone formed by restricting a flow of the medium in a partial zone on the plate. Therefore, the plate-type heat exchangerof the present invention may intentionally reduce heat exchange performance.

The use of the plate-type heat exchangerof the present invention is briefly described again as follows. The plate-type heat exchangermay be used as an “internal heat exchanger” (IHX) that allows a relatively high-pressure, high-temperature refrigerant discharged from a condenser, and a relatively low-pressure, low-temperature refrigerant discharged from an evaporator to exchange heat with each other. Depending on a configuration of a system, the internal heat exchanger may be used as a single heat exchanger or integrated with the other heat exchangerillustrated in. As illustrated in, in case that the plate-type heat exchangeris integrated with the other heat exchanger, the plate-type heat exchangermay receive a low-pressure, low-temperature refrigerant from the other heat exchanger. In particular, in this case, in order to ensure a flow route for the medium flowing through the other heat exchanger, the other medium flow portmay be formed on the plate, and the other medium, except for the first and second media to exchange heat with each other in the plate-type heat exchanger, passes through the other medium flow port. In this case, the other medium flow portmay be disposed in a dead zone region. However, the other medium flow portmay not be disposed in the dead zone region in accordance with the configuration and design of the flow path.

Hereinafter, various embodiments of the configuration for forming the dead zone in the plate-type heat exchanger of the present invention will be described more specifically.

A first embodiment of the configuration for forming the dead zone in the present invention uses arrangement positions of the flow ports. More specifically, the flow portsare disposed to be concentrated in a partial region on the plate, such that the dead zone is naturally formed in a region except for the region in which the flow portsare concentrated.illustrates the first embodiment of the configuration for forming the dead zone in the plate-type heat exchanger of the present invention. The first embodiment will be described below in more detail with reference to. In the first embodiment, a pair of flow portsselected from the flow portsare disposed to be spaced apart from each other in parallel in a long side extension direction or a short side extension direction of the plateto define a row of flow ports. The remaining flow ports, except for the row of flow ports, are disposed adjacent to the long and short sides of the plate, and the row of flow ports is disposed at a middle position of the plate. Therefore, in the first embodiment, the row of flow ports and the remaining flow portsare disposed to be biased to the partial region on the plate, and the remaining partial region is formed as the dead zone.

In this case, as illustrated in the upper view in, the flow portsis disposed to be biased to one long side selected from the pair of long sides of the plate, such that the partial region at the other long side may be formed as the dead zone. Alternatively, as illustrated in the lower view in, the flow portsis disposed to be biased to one short side selected from the pair of short sides of the plate, such that the partial region at the other short side may be formed as the dead zone. In both the two cases in, positions at which the row of flow ports is originally disposed are indicated by the dotted lines, and intervals and directions in which the row of flow ports is moved and disposed at the positions proposed by the present invention are indicated by the arrows. If the row of flow ports is disposed at the positions indicated by the dotted lines, the medium more uniformly flows in the entire region of the plate, and the heat exchange area is increased, such that the heat exchange performance is further improved. However, in the present invention, the row of flow ports is disposed at the middle position on the plate, the medium does not appropriately flow to the partial region behind the row of flow ports. Therefore, the corresponding region is not substantially used for heat exchange. As a result, the plate-type heat exchangermay achieve the heat exchange performance lower than the heat exchange performance expected based on the entire region of the plate. That is, excessively high heat exchange performance may be appropriately reduced.

The configuration for forming the dead zone second embodiment in the present invention uses a separate barrier. The barrierrefers to a structure provided on a medium flow path between the flow ports. The intended dead zone is formed by appropriately restricting the flow of the medium by using the barrier.

is a view illustrating a second embodiment of the configuration for forming the dead zone in the plate-type heat exchanger of the present invention. The configuration for forming the dead zone by using the barrierwill be described in more detail with reference to. In, the thick arrows indicate medium flow paths. As illustrated, among the flow ports, a pair of flow portsare formed to allow the medium to flow in the plate. In this case, one of the pair of flow portis an inlet port through which the medium is introduced, and the other of the pair of flow portis an outlet port through which the medium is discharged.illustrates two examples of the barrierin accordance with the positions of the inlet port and the outlet port. In both the two cases, the inlet port is disposed adjacent to any one of four vertices of the plate.

In the example illustrated in the upper view in, the outlet port is disposed to be spaced apart from the inlet port in a diagonal direction. That is, the flow port positioned at a start point of the arrow inindicates the inlet port, and the flow port positioned at an end point of the arrow indicates the outlet port. The medium introduced into the inlet port may of course flow a shortest distance toward the outlet port along the arrow in the diagonal direction. However, the medium may flow in another direction.

In the general plate-type heat exchanger, the flow of the medium flowing in another direction is further activated so that the medium is distributed to a large area, if possible, to improve the heat exchange performance. However, as described above multiple times, the plate-type heat exchangerof the present invention is designed to intentionally reduce the heat exchange performance. Therefore, the barrierneeds to be provided to prevent the medium from being distributed widely. In the example illustrated in the upper view in, the barrierextends in parallel with the short side extension direction of the plate. In addition, the barrieris disposed in parallel with the outlet port in the short side extension direction.

In this case, the outlet port is disposed, in the short side extension direction of the plate, at a position adjacent to the other long side different from one long side to which the inlet port is disposed adjacent, and the outlet port is disposed, in the long side extension direction, is disposed at one short side to which the inlet port is disposed adjacent and a middle position of the other short side, such that the outlet port is disposed to be spaced apart from the inlet port in the diagonal direction. With this configuration, almost no medium flows to the region behind the barrier. Therefore, as illustrated in, the region behind the barrier, i.e., the region between the barrierand the other short side when viewed in the long side extension direction is formed as the dead zone by the barrier.

In the example illustrated in the lower view in, the outlet port is disposed to be spaced apart from the inlet port in the short side extension direction. That is, in this case, the inlet port and the outlet port constitute the row of flow ports extending in parallel with the short side extension direction of the plate. More specifically, the outlet port is disposed adjacent to another vertex connected to, through the short side, to the vertex of the platedisposed adjacent to the inlet port, and the row of flow ports, which includes the inlet port and the outlet port, extends in parallel with one short side of the plateand is disposed adjacent to one short side of the plate.

With this arrangement, as indicated by the arrow illustrated in the lower view in, the medium flows directly from the inlet port to the outlet port, and almost no medium is distributed to another region only by the flow. Further, the barrierextends in parallel with the short side extension direction of the plate. When the barrieris disposed to be spaced apart from the row of flow ports in the long side extension direction, the discharge of the medium to another region is completely blocked. That is, in this case, when viewed in the long side extension direction, the significantly large region between the barrierand the other short side is formed as the dead zone by the barrier, such that the heat exchange performance may be very effectively reduced.

As in the first embodiment, a third embodiment of the configuration for forming the dead zone in the present invention uses the arrangement positions of the flow portsand is configured in consideration of the flow direction of the medium as well as the positions of the flow ports.

First, an example of the plate-type heat exchanger in which no clear dead zone is formed will be described specifically with reference to.specifically illustrates the arrangement of the flow ports and the flow direction of the medium in the plate-type heat exchanger in which the clear dead zone is not formed, i.e., the general plate-type heat exchanger in the related art. With reference to, in the related art, when a first medium (=low-temperature refrigerant) flows on a first plate′, a first medium inlet′ is disposed adjacent to a left lower end vertex, and a first medium outlet′ is disposed adjacent to a right upper end vertex, such that the first medium flows in the diagonal direction over the entire region of the first plate′. Meanwhile, when a second medium (=high-temperature refrigerant) flows on a second plate′, the second medium inlet′ is disposed adjacent to a left upper end vertex, and the second medium outlet′ is disposed adjacent to a middle lower end, such that the second medium also flows in an approximately diagonal direction over the most region of the second plate′. However, in this case, as described above, in case that the plate-type heat exchanger integrated with the other heat exchanger, the other medium flow port′ may be formed on the plate of the plate-type heat exchanger. In this case, the second medium outlet′ is disposed at the middle lower end while avoiding the other medium flow port′, and the second medium cannot smoothly flow to the region behind the second medium outlet′, i.e., the region in which the other medium flow port′ is present, such that the dead zone may be slightly formed. However, because the first medium flows appropriately over the entire region in the case of the first plate′, the heat exchange performance is not significantly decreased.

In the present invention, the dead zone is intentionally formed by adjusting the flow direction of the medium by changing the positions of the inlet and the outlet for the medium.illustrates the third embodiment of the configuration for forming the dead zone in the plate-type heat exchanger of the present invention. In the embodiment in, first, from the point of view of the flow port arrangement position, the first medium inletand the first medium outleton the first plateare disposed to be spaced apart from each other in parallel with the short side extension direction to constitute a first row of flow ports, and the second medium inletand the second medium outleton the second plateare disposed to be spaced apart from each other in parallel with the short side extension direction to constitute a second row of flow ports, such that one of the first and second rows of flow ports is disposed adjacent to one short side selected from the pair of short sides, and the other of the first and second rows of flow ports is disposed at the middle position of the pair of short sides. With reference to, the first row of flow ports may be disposed adjacent to one short side selected from the pair of short sides, and the second row of flow ports may be disposed at the middle position of the pair of short sides.

When only the arrangement position is simply taken into account when the configuration in which the medium is introduced or discharged through the flow ports is ignored, the above-mentioned embodiment may look similar to the first embodiment, in particular, the lower view in. However, the third embodiment differs from the first embodiment in that the inlet and the outlet for the medium are arranged in parallel with the short side extension direction, and the medium flow direction is a direction parallel to the short side extension direction, instead of the diagonal direction. In this arrangement state, as well illustrated in, the first medium (=low-temperature refrigerant) flows in a vertical direction while being almost attached to the left end side of the first plate, and the second medium (=high-temperature refrigerant) also flows in the vertical direction at the middle position on the second plate. In particular, the first and second medium inlets and outlets,,, andare disposed to be spaced apart from one another in the short side extension direction, such that the length of the flow path for the medium is short, and the medium is not appropriately distributed in another direction. That is, by setting the arrangement of the flow ports and the medium flow path, the clear dead zones may be formed on both the first and second platesand, as well illustrated in.

In addition, a flow direction of the first medium flowing from the first medium inletto the first medium outletand a flow direction of the second medium flowing from the second medium inletto the second medium outletmay be opposite to each other. The first medium (=low-temperature refrigerant) may have a lowest temperature in the first medium inletand have a middle temperature in the first medium outlet(because the temperature is raised as the first medium exchanges heat with the high-temperature refrigerant). The second medium (=high-temperature refrigerant) may have a highest temperature in the second medium inletand have a middle temperature in the second medium outlet(because the temperature is lowered as the second medium exchanges heat with the low-temperature refrigerant). It can be seen that the heat exchange cannot be actively performed because the above-mentioned arrangement decreases a temperature difference in consideration of the fact that the heat exchange is actively performed as a temperature difference between the media increases.

is a view illustrating an example of a dead zone formed by the configuration for forming the dead zone in. The upper view inillustrates an external shape of the plate-type heat exchangeridentical to the shape illustrated in the lower view in. In this case, because the plate-type heat exchangeris integrated with the other heat exchangerand receives the low-temperature refrigerant, i.e., the first medium from the other heat exchanger, the first medium inletis not visible from the external shape of the plate-type heat exchanger. The lower view inillustrates a flow simulation on the first platein the plate-type heat exchangerin the upper view in. The first medium inlet and outletandare filled with the refrigerant, and the second medium inlet and outletandand the other medium flow portare clogged, and the refrigerant does not flow. It can be ascertained that in the temperature distribution in the lower view in, the temperature is lowest in the vicinity of the first medium inlet, and the temperature is slightly increased toward the first medium outlet. Meanwhile, based on a boundary in the vicinity of the second row of flow ports including the second medium inlet and outletand, there is almost no change in temperature in the right region. That is, there is almost no effect of the temperature drop caused by the low-temperature refrigerant, i.e. the first medium, which well indicates that the first medium rarely flows in that direction. In other words, the portion in the lower view in, which is indicated by the white dotted quadrangular region, is clearly formed as the dead zone.

According to the present invention, it is possible to intentionally form the dead zone in the plate-type heat exchanger to adjust the performance to the desired degree. The description will be more specific as follows. There are cases in which the plate-type heat exchanger is introduced as the internal heat exchanger that performs heat exchange between the high-pressure, high-temperature refrigerant that has passed through the condenser and the low-pressure, low-temperature refrigerant that has passed through the evaporator. If the performance of the internal heat exchanger is excessively good at this time, the temperature of the refrigerant discharged from the internal heat exchanger and flowing into the compressor may become excessively high, which may increase the operating temperature of the compressor to a level that adversely affects the durability. In order to solve the problem, in the present invention, the dead zone is intentionally formed by changing the arrangement of the flow ports or additionally installing the barrier to adjust the performance in order to prevent the problem in which the operating temperature of the compressor is raised and the durability is degraded because of excessive performance of the internal heat exchanger, thereby appropriately adjusting the heat exchange performance to prevent the heat exchange performance from being excessive. As a result, the problem of degrading compressor durability is resolved, and the effect of improving the operational stability of the system including the compressor is achieved.

The present invention is not limited to the above embodiments, and the scope of application is diverse. Of course, various modifications and implementations made by any person skilled in the art to which the present invention pertains without departing from the subject matter of the present invention claimed in the claims.