A refrigeration cycle for lowering the temperature of liquid refrigerant stored in a receiver using a plate heat exchanger

Abstract

The present invention relates to a refrigeration cycle for lowering the temperature of a liquid refrigerant stored in a receiver using a plate heat exchanger. A refrigeration cycle of a first embodiment using a plate heat exchanger comprises: a compressor provided in the middle of a refrigerant circulation circuit configured to form a closed circuit; a condenser that condenses and liquefies a high-temperature, high-pressure gaseous refrigerant compressed and discharged from the compressor; a receiver that temporarily stores a room-temperature liquid refrigerant discharged after condensation and liquefaction from the condenser; a first solenoid valve for controlling the circulation operation of the liquid refrigerant discharged from the receiver; a main expansion valve for rapidly expanding the liquid refrigerant passing through the first solenoid valve; and an evaporator configured to allow the mist-state refrigerant rapidly expanded from the main expansion valve to flow into a second inlet / outlet line, thereby causing the incoming mist-state refrigerant to evaporate through a heat exchange action that removes heat from a surrounding heat exchange medium, and thereby absorbing surrounding heat to convert it into a low-temperature gaseous state. In a refrigeration cycle configured to repeat the operation of introducing refrigerant into a compressor, A plate exchanger having a liquid refrigerant circulation passage and a gaseous refrigerant circulation passage installed in parallel is configured to be connected between the second inlet / outlet line of the condenser and the inlet of the receiver, The invention is characterized by a means in which the inlet and outlet of a liquid refrigerant circulation passage installed in conjunction with the plate heat exchanger are configured to be connected to the second inlet / outlet line of a condenser and the inlet of a receiver, respectively, and the inlet and outlet of a gaseous refrigerant circulation passage installed in conjunction with the plate heat exchanger are configured to be connected to the first inlet / outlet line of an evaporator and the inlet line of a compressor, respectively, such that the ambient temperature liquid refrigerant, which is condensed and liquefied in the condenser and discharged through the second inlet / outlet line, is introduced into the inlet of the liquid refrigerant circulation passage installed in conjunction with the plate heat exchanger and circulates toward the outlet, and is then cooled to a low temperature through a heat exchange action in which heat is removed from the low temperature gaseous refrigerant that is discharged through the first inlet / outlet line of the evaporator and introduced into the inlet of the gaseous refrigerant circulation passage installed in conjunction with the plate heat exchanger and circulates toward the outlet, and is then introduced and stored in the receiver in a state where it is cooled to a low temperature.

Description

Technology Field

[0001] The present invention relates to a refrigeration cycle for lowering the temperature of a liquid refrigerant stored in a receiver using a plate heat exchanger, and more specifically, to a refrigeration cycle configured such that the liquid refrigerant discharged after condensing and liquefying in a condenser is cooled to a lower temperature using a plate heat exchanger before being stored in the receiver, thereby enabling the liquid refrigerant to be stored in the receiver. By configuring the liquid refrigerant at room temperature, discharged after condensing and liquefying in the condenser, to circulate smoothly to the receiver side where the refrigerant cooled to a lower temperature is stored, the circulation operation of the refrigerant is performed well. Furthermore, the invention relates to a refrigeration cycle configured to improve the compression efficiency of the compressor and reduce the power required by the compressor, thereby saving electrical energy and increasing the cooling performance of the refrigeration cycle. Background Technology

[0002] Generally, refrigeration cycle systems are known to be used in appliances such as refrigerators and freezers for storing food or beverages at low temperatures for extended periods, and air conditioners for maintaining a comfortable indoor temperature against high external temperatures.

[0003] Furthermore, refrigeration cycle systems used for the aforementioned purposes face problems such as increased compressor discharge pressure due to reduced performance of condensers installed outdoors caused by fine dust generated by global warming. This not only increases the power consumption of the compressor but also lowers the efficiency of the refrigeration cycle, leading to longer operating times. Consequently, this results in high costs for electrical energy required to operate the refrigeration cycle and increases maintenance costs for the compressor of the refrigeration cycle system.

[0004] Considering the above-mentioned problems, the cost of electricity required to operate the refrigeration cycle can be reduced, and as a means to save on the maintenance costs of the compressor of the refrigeration cycle, an example of a technical configuration for lowering the temperature of the liquid refrigerant stored in the receiver in the prior art is illustrated in FIG. 1 as follows.

[0005] The above-mentioned illustration of FIG. 1 relates to a conventional refrigeration cycle currently in use to control the temperature of a liquid refrigerant stored in a receiver to be lowered. The outlet line (210) of a compressor (200) provided in the middle of a refrigerant circulation circuit (100) configured to form a closed circuit is connected to the inlet line (310) of a condenser (300), the outlet line (320) of the condenser (300) is configured to be connected to the inlet (410) of a receiver (400), and the outlet (420) of the receiver (400) is configured to be connected to the inlet line (510) of an evaporator (500).

[0006] And between the outlet (420) of the receiver (400) and the inlet line (510) of the evaporator (500), an electronic valve (600) and an expansion valve (700) are connected in sequence, and the outlet line (520) of the evaporator (500) is connected to the inlet (810) of a liquid separator (800) that is inserted and installed inside the receiver (400), and the outlet (820) of the liquid separator (800) is configured to be connected to the inlet line (220) of the compressor (200).

[0007] In the conventional refrigeration cycle configured as described above, high-temperature, high-pressure gaseous refrigerant compressed in the compressor (200) and discharged through the outlet line (210) flows into the condenser (300), and ambient temperature liquid refrigerant, which is condensed and liquefied through heat exchange with an external heat exchange medium (air, water, etc.), is discharged through the outlet line (320) and flows into the inlet (410) of the receiver (400) for storage. At this time, low-temperature gaseous refrigerant evaporated through heat exchange in the evaporator (500) flows into the inlet (810) of the liquid separator (800) installed inside the receiver (400). Therefore, the low-temperature gaseous refrigerant flowing into the inlet (810) of the liquid separator (800) performs a heat exchange operation that removes heat from the ambient temperature liquid refrigerant stored in the receiver (400) while moving toward the outlet (820), and is then discharged through the outlet (820) to the compressor The operation of flowing into the compressor (200) through the inlet line (220) is repeated.

[0008] As seen above, the high-temperature, high-pressure gaseous refrigerant discharged through the outlet line (210) of the compressor (200) is condensed and liquefied through heat exchange with an external heat exchange medium in the condenser (300) and discharged through the outlet line (320). Since the ambient temperature liquid refrigerant is stored in the receiver (400) at the same time, the low-temperature gaseous refrigerant discharged through the outlet line (520) of the evaporator (500) is introduced into and circulated in the liquid separator (800) installed in the receiver (400). Consequently, the ambient temperature liquid refrigerant stored in the receiver (400) and the low-temperature gaseous refrigerant flowing into the inlet (810) of the liquid separator (800) and moving toward the outlet (820) perform a heat exchange operation in which they exchange heat with each other. Therefore, the ambient temperature liquid refrigerant stored in the receiver (400) flows into the inlet (810) of the liquid separator (800). While the temperature is lowered by a heat exchange action in which heat is taken from the low-temperature gaseous refrigerant that moves to the outlet (820) and is discharged, the low-temperature gaseous refrigerant flowing into the liquid separator (800) is heated and dried by a heat exchange action in which heat is taken from the ambient temperature liquid refrigerant stored in the receiver (400), changing into a dry vapor state, and is discharged to the outlet (820) and flows into the compressor (200).

[0009] Therefore, the temperature of the liquid refrigerant stored in the receiver (400) is lowered, so the liquid refrigerant condensed and liquefied in the condenser (300) circulates smoothly to the receiver (400) at a low temperature, and at the same time, the low-temperature gaseous refrigerant that has been heated and changed into a dry vapor state while circulating through the liquid separator (800) is introduced into the compressor (200), so that effects such as improved compression efficiency can be expected, and thus the conventional refrigeration cycle shown in FIG. 1 is still widely used.

[0010] However, it has been pointed out that the refrigeration cycle of the conventional technology described above is problematic because it requires a high cost to manufacture the receiver (400) and the liquid separator (800), and it is difficult to install the liquid separator (800) inside the receiver (400). Furthermore, it is pointed out that the biggest problem is that the heat exchange between the ambient temperature liquid refrigerant stored in the receiver (400) and the low temperature gaseous refrigerant flowing into and moving into the liquid separator (800) is not actively carried out.

[0011] In addition, it should be noted that the prior art proposed by the applicant of the present invention in Public Patent Publication No. 10-2024-0138139 utilizes a plate heat exchanger, but the liquid refrigerant stored in the receiver is in a state where the liquid refrigerant at room temperature discharged from the condenser and the liquid refrigerant at a low temperature that is cooled and discharged while circulating through the liquid refrigerant circulation passage of the plate heat exchanger are stored together. Therefore, the biggest problem is that the liquid refrigerant stored in the receiver cannot be cooled to a temperature that is about 3 to 4°C lower than the liquid refrigerant at room temperature discharged from the condenser, and thus it has not been used until now. Prior art literature

[0012] Published Patent Application No. 10-2023-0150445 (Published Oct. 31, 2023) Published Patent Application No. 10-2024-0138139 (Published Sep. 20, 2024) The problem to be solved

[0013] The present invention is proposed in consideration of the various problems arising from the prior art described above. It is configured such that the high-temperature, high-pressure gaseous refrigerant compressed and discharged from the compressor of the refrigeration cycle is not condensed and liquefied into a room-temperature liquid refrigerant through heat exchange with an external heat exchange medium in the condenser, but rather the room-temperature liquid refrigerant discharged from the condenser is sufficiently cooled through heat exchange with the low-temperature gaseous refrigerant discharged from the evaporator, allowing the liquid refrigerant to be introduced and stored in the receiver. This configuration enables the room-temperature liquid refrigerant condensed and discharged from the condenser to smoothly circulate and be introduced into the receiver side where a liquid refrigerant at a lower temperature is stored. At the same time, the invention is configured such that gaseous refrigerant that has been heated and dried to evaporate into a dry vapor state is introduced into the compressor, thereby improving the compression efficiency of the compressor and reducing the power required by the compressor, thus enabling the saving of electrical energy. It was invented with the purpose of providing. means of solving the problem

[0014] The present invention, as a means to pursue the above-mentioned purpose, comprises a refrigeration cycle of a first embodiment using a plate heat exchanger, wherein the refrigeration cycle comprises: a compressor provided in the middle of a refrigerant circulation circuit configured to form a closed circuit; a condenser that condenses and liquefies high-temperature, high-pressure gaseous refrigerant compressed and discharged from the compressor; a receiver that temporarily stores ambient temperature liquid refrigerant condensed and liquefied and discharged from the condenser; a first solenoid valve for controlling the circulation operation of the liquid refrigerant discharged from the receiver; a main expansion valve for rapidly expanding the liquid refrigerant passing through the first solenoid valve; and an evaporator configured to allow the mist-state refrigerant rapidly expanded from the main expansion valve to flow into a second inlet / outlet line, thereby causing the incoming mist-state refrigerant to evaporate through a heat exchange action that removes heat from a surrounding heat exchange medium, and thereby absorbing surrounding heat to convert it into a low-temperature gaseous state; and a refrigeration cycle configured to repeat the operation of introducing the refrigerant discharged from the first inlet / outlet line of the evaporator into the compressor. Because,

[0015] A plate exchanger having a liquid refrigerant circulation passage and a gaseous refrigerant circulation passage installed in parallel is configured to be connected between the second inlet / outlet line of the condenser and the inlet of the receiver,

[0016] The means are configured such that the inlet and outlet of the liquid refrigerant circulation passage installed in conjunction with the plate heat exchanger are connected to the second inlet / outlet line of the condenser and the inlet of the receiver, respectively, while the inlet and outlet of the gaseous refrigerant circulation passage installed in conjunction with the plate heat exchanger are connected to the first inlet / outlet line of the evaporator and the inlet line of the compressor, respectively. In this configuration, the ambient temperature liquid refrigerant, which is condensed and liquefied in the condenser and discharged through the second inlet / outlet line, is introduced into the inlet of the liquid refrigerant circulation passage installed in conjunction with the plate heat exchanger and circulates toward the outlet. During this process, the liquid refrigerant is discharged through the first inlet / outlet line of the evaporator and is introduced into the inlet of the gaseous refrigerant circulation passage installed in conjunction with the plate heat exchanger, thereby losing heat to the low temperature gaseous refrigerant that is circulating toward the outlet. This cooling process occurs through a heat exchange action, allowing the liquid refrigerant to be introduced and stored in the receiver in a state where it is cooled to a low temperature.

[0017] In addition, the refrigeration cycle of the first embodiment is provided with a bypass line to connect the inlet of a gaseous refrigerant circulation passage installed in conjunction with a plate heat exchanger and the outlet of a receiver, and is characterized in that a second solenoid valve and an auxiliary expansion valve are respectively installed in the bypass line.

[0018] In addition, the refrigeration cycle of the second embodiment using the plate heat exchanger of the present invention comprises: a compressor provided in the middle of a refrigerant circulation circuit configured to form a closed circuit; a four-way solenoid valve having a main inlet connected to an outlet line that discharges high-temperature, high-pressure gaseous refrigerant compressed by the compressor; a condenser having a first inlet / outlet line connected to the upper inlet / outlet of the four-way solenoid valve to condense and liquefy the high-temperature, high-pressure gaseous refrigerant discharged from the compressor through a heat exchange action with an external heat exchange medium; a receiver for temporarily storing the ambient temperature liquid refrigerant condensed and liquefied in the condenser and discharged through a second inlet / outlet line; a main expansion valve for rapidly expanding the liquid refrigerant discharged from the receiver; first and second solenoid valves that open and close to control the circulation operation of the mist-state refrigerant rapidly expanding from the main expansion valve; and a process in which the mist-state refrigerant rapidly expanding from the main expansion valve evaporates through a heat exchange action that absorbs heat from the surrounding heat exchange medium. In a refrigeration cycle configured to repeatedly operate by absorbing ambient heat and converting it into a low-temperature gaseous state through an evaporator, and introducing a refrigerant discharged through a first inlet / outlet line of the evaporator into a compressor,

[0019] The refrigeration cycle of the second embodiment above is configured such that a plate heat exchanger is connected between the second inlet / outlet line of the condenser and the inlet of the receiver, wherein a liquid refrigerant circulation passage and a gaseous refrigerant circulation passage are installed in parallel.

[0020] When operating the refrigeration cycle of the second embodiment above in a cooling operation state, the ambient temperature liquid refrigerant discharged through the second inlet / outlet line of the condenser is configured to flow into the inlet of the liquid refrigerant circulation passage installed in conjunction with the plate heat exchanger, circulate, and then be discharged through the outlet, and then flow into the receiver through the inlet formed in the receiver and be stored, while the low temperature gaseous refrigerant discharged through the second inlet / outlet line of the evaporator is configured to flow into the inlet of the gaseous refrigerant circulation passage installed in conjunction with the plate heat exchanger, circulate, and then be discharged through the outlet.

[0021] The above-mentioned plate heat exchanger is characterized by being configured such that the ambient temperature liquid refrigerant flowing into the inlet of the liquid refrigerant circulation passage is cooled to a low temperature through a heat exchange action in which it loses heat from the low temperature gaseous refrigerant flowing into the inlet of the gaseous refrigerant circulation passage and circulating, and then flows into and is stored in the receiver.

[0022] In addition, the refrigeration cycle of the second embodiment is characterized by having a bypass line formed connecting the outlet of the receiver and the inlet of the gaseous refrigerant circulation passage installed in parallel with the plate heat exchanger, and by the bypass line being configured such that a third solenoid valve and an auxiliary expansion valve are installed sequentially at regular intervals.

[0023] In addition, when the refrigeration cycle of the second embodiment is operated in a heating state, the high-temperature, high-pressure gaseous refrigerant discharged through the outlet line of the compressor flows into the main inlet of the four-way solenoid valve, is discharged through the lower inlet / outlet, and flows into the evaporator through the first inlet / outlet line formed in the evaporator; the ambient temperature liquid refrigerant discharged through the second inlet / outlet line of the evaporator flows into the inlet of the liquid refrigerant circulation passage installed in conjunction with the plate heat exchanger, circulates, and is then discharged through the outlet to be supplied and stored in the receiver. The liquid refrigerant flowing into the inlet of the liquid refrigerant circulation passage installed in conjunction with the plate heat exchanger and moving and circulating toward the outlet is cooled to a low temperature by a heat exchange action in which heat is removed from the low-temperature gaseous refrigerant circulating in the gaseous refrigerant circulation passage installed in conjunction with the plate heat exchanger, and is supplied and stored in the receiver.

[0024] In addition, the refrigeration cycle of the third embodiment using the plate heat exchanger of the present invention comprises: a compressor provided in the middle of a refrigerant circulation circuit configured to form a closed circuit; a four-way solenoid valve having a main inlet connected to an outlet line that discharges high-temperature, high-pressure gaseous refrigerant compressed by the compressor; a condenser having a first inlet / outlet line connected to the upper inlet / outlet of the four-way solenoid valve to condense and liquefy the high-temperature, high-pressure gaseous refrigerant discharged from the compressor through a heat exchange action with an external heat exchange medium; a receiver for temporarily storing the ambient temperature liquid refrigerant condensed and liquefied in the condenser and discharged through a second inlet / outlet line; a main expansion valve for rapidly expanding the liquid refrigerant discharged from the receiver; first and second solenoid valves that open and close to control the circulation operation of the mist-state refrigerant rapidly expanding in the main expansion valve; and a process in which the mist-state refrigerant rapidly expanding in the main expansion valve is evaporated through a heat exchange action that absorbs heat from the surrounding heat exchange medium. In a refrigeration cycle configured to repeatedly operate by absorbing ambient heat and converting it into a low-temperature gaseous state through an evaporator, and introducing a refrigerant discharged through a first inlet / outlet line of the evaporator into a compressor,

[0025] The refrigeration cycle of the third embodiment above is configured such that a plate heat exchanger is connected between the second inlet / outlet line of the condenser and the inlet of the receiver, wherein a liquid refrigerant circulation passage and a gaseous refrigerant circulation passage are installed in parallel.

[0026] When the refrigeration cycle of the third embodiment is operated in a cooling state, the high-temperature, high-pressure gaseous refrigerant compressed and discharged from the compressor flows into the condenser and is condensed and liquefied through heat exchange with an external heat exchange medium. The ambient temperature liquid refrigerant, which is discharged through the second inlet / outlet line, flows into the inlet of the liquid refrigerant circulation passage installed in conjunction with the plate heat exchanger and circulates toward the outlet. During this process, the liquid refrigerant is cooled to a low temperature through a heat exchange process in which heat is removed from the mist-state refrigerant circulating in the gaseous refrigerant circulation passage installed in conjunction with the plate heat exchanger, and is then supplied from a small auxiliary refrigeration cycle and stored in the receiver.

[0027] In addition, when the refrigeration cycle of the third embodiment is operated in a heating state, the high-temperature, high-pressure gaseous refrigerant compressed and discharged from the compressor is introduced into the evaporator and condensed and liquefied through heat exchange with an external heat exchange medium, and the ambient temperature liquid refrigerant discharged through the second inlet / outlet line is introduced into the inlet of the liquid refrigerant circulation passage installed in conjunction with the plate heat exchanger and circulated to the outlet side, and is cooled to a low temperature through a heat exchange action in which heat is removed from the mist-state refrigerant circulating in the gaseous refrigerant circulation passage installed in conjunction with the plate heat exchanger, and is then introduced and stored in the receiver.

[0028] In addition, the small auxiliary refrigeration cycle of the refrigeration cycle of the third embodiment is configured such that the liquid refrigerant discharged from the outlet of the receiver passes through an open small electronic valve and the mist-state refrigerant rapidly expanded in a small auxiliary expansion valve is introduced into the inlet of a gaseous refrigerant circulation passage installed in conjunction with a plate heat exchanger and circulated. Furthermore, the mist-state refrigerant introduced into and circulating at the inlet of the gaseous refrigerant circulation passage evaporates through a heat exchange action that removes heat from the ambient temperature liquid refrigerant circulating in the liquid refrigerant circulation passage, is discharged through the outlet of the gaseous refrigerant circulation passage, and is compressed to high temperature and high pressure in a small compressor. The high temperature and high pressure gaseous refrigerant compressed and discharged from the small compressor is condensed and liquefied in a small condenser, stored in a small receiver, and then discharged through the outlet, repeating this operation.

[0029] In addition, the refrigeration cycle of the fourth embodiment using the plate heat exchanger of the present invention comprises: a compressor provided in the middle of a refrigerant circulation circuit configured to form a closed circuit; a condenser that condenses and liquefies a high-temperature, high-pressure gaseous refrigerant compressed and discharged from the compressor; a receiver that temporarily stores a room-temperature liquid refrigerant discharged after condensing and liquefying from the condenser; a first solenoid valve for controlling the circulation operation of the liquid refrigerant discharged from the receiver; a main expansion valve for rapidly expanding the liquid refrigerant passing through the first solenoid valve; and an evaporator configured to allow the mist-state refrigerant rapidly expanded from the main expansion valve to flow into a second inlet / outlet line, thereby causing the incoming mist-state refrigerant to evaporate through a heat exchange action that removes heat from a surrounding heat exchange medium, and thereby absorbing surrounding heat to convert it into a low-temperature gaseous state; and further configured to repeat the operation of introducing the refrigerant discharged from the first inlet / outlet line of the evaporator into the compressor.

[0030] A plate exchanger having a liquid refrigerant circulation passage and a gaseous refrigerant circulation passage installed in parallel is configured to be connected between the second outlet line of the condenser and the inlet of the receiver,

[0031] When operating the refrigeration cycle of the above-mentioned fourth embodiment in a cooling state, the inlet and outlet of the liquid refrigerant circulation passage installed in conjunction with the plate heat exchanger are configured to be connected to the second inlet / outlet line of the condenser and the inlet of the receiver, respectively, so that the liquid refrigerant flowing into the inlet of the liquid refrigerant circulation passage is cooled to a low temperature by a heat exchange action in which heat is removed from the mist-state refrigerant flowing into the inlet of the gaseous refrigerant circulation passage installed in conjunction with the plate heat exchanger and circulating to the outlet side while moving towards the outlet side, and is then supplied to and stored in the receiver.

[0032] In addition, when the refrigeration cycle of the fourth embodiment is operated in a pre-cooling state, the compressor is temporarily stopped and the refrigerant pump installed at the outlet side of the receiver is operated to circulate the refrigerant. In this case, the liquid refrigerant discharged through the second inlet / outlet line of the condenser by the pumping operation of the refrigerant pump is cooled by a heat exchange action in which heat is removed from the mist-state refrigerant supplied from the small auxiliary refrigeration cycle and circulated through the inlet of the gaseous refrigerant circulation passage installed in the plate heat exchanger while it is moving and circulating to the outlet side, and is then supplied to the receiver and stored. Effects of the invention

[0033] According to the present invention, by controlling the liquid refrigerant circulating in the refrigeration cycle so that the temperature of the liquid refrigerant temporarily stored in the receiver is lowered, the liquid refrigerant at room temperature that condenses and liquefies in the condenser is smoothly discharged to the receiver side where a refrigerant at a lower temperature is stored. This improves the compression efficiency of the compressor, thereby reducing the power required by the compressor and reducing the electrical energy required to operate the refrigeration cycle, while simultaneously increasing the refrigeration performance of the refrigeration cycle. Brief explanation of the drawing

[0034] FIG. 1 is a circuit diagram showing the refrigerant circulation state of a conventional refrigeration cycle. FIG. 2 is a circuit diagram showing a refrigerant circulation state configured to store a low-temperature liquid refrigerant in a receiver forming a refrigeration cycle of the first embodiment of the present invention. FIG. 3 is another embodiment of the refrigeration cycle of the first embodiment of the present invention. FIG. 4 is a circuit diagram showing the refrigeration cycle of the second embodiment of the present invention, illustrating the refrigerant circulation state when operating in a cooling state using a four-way electronic valve. FIG. 5 is another embodiment of the refrigeration cycle of the second embodiment of the present invention when operated in a cooling operation state. FIG. 6 is a circuit diagram showing the refrigerant circulation state when the refrigeration cycle of the second embodiment of the present invention is operated in a heating operation state. FIG. 7 is a circuit diagram showing the refrigeration cycle of the third embodiment of the present invention, illustrating the refrigerant circulation state when operating in a cooling state using a four-way battery valve. FIG. 8 is a circuit diagram showing the refrigeration cycle of the third embodiment of the present invention, illustrating the refrigerant circulation state when operating in a heating state using a four-way electronic valve. FIG. 9 is a circuit diagram showing a refrigeration cycle of the fourth embodiment of the present invention, in which a liquid refrigerant cooled to a low temperature is stored in a receiver using a separately configured small auxiliary refrigeration cycle. FIG. 10 is a circuit diagram showing a refrigerant circulation state in which liquid refrigerant cooled to a low temperature is stored in a receiver using a separately configured small auxiliary refrigeration cycle when the refrigeration cycle of the fourth embodiment of the present invention is operated in a pre-cooling operating state. Specific details for implementing the invention

[0035] Specific embodiments of a refrigeration cycle for lowering the temperature of a liquid refrigerant stored in a receiver using a plate heat exchanger according to the present invention will be described in detail below with reference to the attached drawings.

[0036] First, we will examine the refrigeration cycle of the first embodiment of the present invention.

[0037] FIG. 2 illustrates a refrigeration cycle of the first embodiment of the present invention. The refrigeration cycle (1A) of the first embodiment is configured such that the outlet line (21) of the compressor (2), which is provided in the middle of the refrigerant circulation circuit (1) configured to form a closed circuit, is connected to the first inlet / outlet line (31) of the condenser (3), and the second inlet / outlet line (32) of the condenser (3) and the inlet (41) of the receiver (4) are connected by a liquid refrigerant circulation passage (7a) which is installed in conjunction with the plate heat exchanger (7) described later.

[0038] The outlet (42) of the above receiver (4) is configured to be connected to the second inlet / outlet line (52) of the evaporator (5), and a main electronic valve (6a) and a main expansion valve (6) are installed in sequence between the outlet (42) of the receiver (4) and the second inlet / outlet line (52) of the evaporator (5).

[0039] Meanwhile, a plate heat exchanger (7) formed between the second inlet / outlet line (32) of the condenser (3) and the inlet (41) of the receiver (4) has a liquid refrigerant circulation passage (7a) and a gaseous refrigerant circulation passage (7b) installed in parallel. The inlet (71) of the liquid refrigerant circulation passage (7a) installed in the plate heat exchanger (7) is connected to the second outlet line (32) of the condenser (3), and the outlet (72) of the liquid refrigerant circulation passage (7a) is connected to the inlet (41) of the receiver (4).

[0040] Additionally, the first inlet / outlet line (51) of the evaporator (5) is connected to the inlet (73) of the gaseous refrigerant circulation passage (7b) which is installed in conjunction with the plate heat exchanger (7), and the inlet line (22) of the compressor (2) is connected to the outlet (74) of the gaseous refrigerant circulation passage (7b).

[0041] In the refrigeration cycle (1A) of the first embodiment configured as described above, the high-temperature, high-pressure gaseous refrigerant, which is compressed at high temperature and high pressure in the compressor (2) and discharged through the outlet line (21), is introduced into the condenser (3) through the first outlet line (31) of the condenser (3) and condensed and liquefied through heat exchange with an external heat exchange medium (air, water, etc.) while circulating. The ambient temperature liquid refrigerant condensed and liquefied in the condenser (3) is discharged through the second inlet / outlet line (32) and introduced into the inlet (71) of the liquid refrigerant circulation passage (7a) installed in the plate heat exchanger (7), circulates, and is discharged through the outlet (72). At this time, the low-temperature gaseous refrigerant, which is introduced into the second inlet / outlet line (52) of the evaporator (5) and evaporates during the process of performing heat exchange with an external heat exchange medium (in the room where the evaporator is installed), is discharged through the first inlet / outlet line (51) and installed in the plate heat exchanger (7). As the liquid refrigerant circulating in the liquid refrigerant circulation passage (7a) flows into the inlet (73) of the gaseous refrigerant circulation passage (7b) and moves and circulates toward the outlet (74), it performs a heat exchange action that removes heat from the liquid refrigerant. Accordingly, the liquid refrigerant flowing into and circulating through the inlet (71) of the liquid refrigerant circulation passage (7a) installed in conjunction with the plate heat exchanger (7) is cooled to a lower temperature due to the heat exchange action of removing heat, discharged through the outlet (72), and then flows into and is stored at the inlet (41) of the receiver (4). Consequently, the liquid refrigerant flowing into and stored in the receiver (4) is a liquid refrigerant cooled to a temperature approximately 3 to 4°C lower than the ambient temperature liquid refrigerant condensed and liquefied in the condenser (3) and discharged through the second inlet / outlet line (32). Therefore, the ambient temperature liquid refrigerant condensed and liquefied in the condenser (3) and discharged through the second inlet / outlet line (32) is lower than It is smoothly circulated to the receiver (4) side, which maintains a low temperature and low pressure of about 3~4℃, and accordingly, not only is the compression efficiency of the compressor (2) improved, but the refrigeration performance of the refrigeration cycle (1A) can also be increased.

[0042] In addition, the illustration in FIG. 3 illustrates another embodiment of the refrigeration cycle (1A) of the first embodiment. When compared to the refrigeration cycle (1A) of the first embodiment described in FIG. 2, the configuration is substantially the same in that the high-temperature, high-pressure gaseous refrigerant, which is compressed in the compressor (2) and discharged to the outlet line (21), flows into the first inlet / outlet line (31) of the condenser (3), condenses and liquefies through heat exchange with an external heat exchange medium, is discharged to the second inlet / outlet line (32), flows into the inlet (71) of the liquid refrigerant circulation passage (7a) installed in conjunction with the plate heat exchanger (7), circulates, and is then discharged to the outlet (72). However, a bypass line (61) connecting the outlet (42) of the receiver (4) and the inlet (73) of the gaseous refrigerant circulation passage (7b) installed in conjunction with the plate heat exchanger (7) is additionally formed, and a second... The electronic valve (6b) and the auxiliary expansion valve (6) are configured to be installed in sequence, and the first inlet / outlet line (51) of the evaporator (5) and the outlet (74) of the gaseous refrigerant circulation passage (7b) installed in parallel with the plate heat exchanger (7) are each configured to be connected to the inlet line (22) of the compressor (2).

[0043] In addition, when operating another embodiment of the refrigeration cycle (1A) shown in FIG. 3, the first solenoid valve (6a) formed between the outlet (42) of the receiver (4) and the second inlet / outlet line (52) of the evaporator (5) and the second solenoid valve (6b) formed in the bypass line (61) are each opened. When operating the refrigeration cycle (1A) of the other embodiment shown in FIG. 3, the liquid refrigerant discharged from the outlet (42) of the receiver (4) is divided, with a portion circulating toward the first solenoid valve (6a) and supplied to the main expansion valve (6), while the remaining portion passes through the second solenoid valve (6b) installed in the bypass line (61) and is supplied to the auxiliary expansion valve (60).Accordingly, a portion of the liquid refrigerant passing through the first solenoid valve (6a) is rapidly expanded in the main expansion valve (6) and changes into a mist-like refrigerant. The mist-like refrigerant rapidly expanded in the main expansion valve (6) flows into the second inlet / outlet line (52) of the evaporator (5), circulates through the evaporator (5), evaporates through heat exchange with an external heat exchange medium, is discharged through the first inlet / outlet line (51), and circulates toward the compressor (2). At the same time, a portion of the liquid refrigerant discharged through the outlet (42) of the receiver (4) passes through the second solenoid valve (6b) installed in the bypass line (61) and rapidly expands in the auxiliary expansion valve (60). The mist-like refrigerant rapidly expanded in the auxiliary expansion valve (60) flows into the inlet (73) of the gaseous refrigerant circulation passage (7b) installed in parallel with the plate heat exchanger (7) and circulates toward the outlet (74). In the process of performing a heat exchange operation that removes heat from the liquid refrigerant circulating in the liquid refrigerant circulation passage (7a), the operation of being heated and dried and flowing into the inlet line (22) of the compressor (2) is repeated. Meanwhile, the liquid refrigerant circulating in the liquid refrigerant circulation passage (7a) installed in conjunction with the plate heat exchanger (7) is cooled to a low temperature due to a heat exchange operation in which heat is removed from the mist-state refrigerant circulating in the gaseous refrigerant circulation passage (7b) and flows into the inlet (41) of the receiver (4). Consequently, the ambient temperature liquid refrigerant that is condensed and liquefied in the condenser (3) and discharged through the second inlet / outlet line (32) is cooled to a low temperature due to a heat exchange operation in which heat is removed from the mist-state refrigerant circulating in the gaseous refrigerant circulation passage (7b) while circulating in the liquid refrigerant circulation passage (7a) installed in conjunction with the plate heat exchanger (7) and stored in the receiver (4). Therefore, in the condenser (3) The liquid refrigerant at room temperature, which is condensed and liquefied and discharged through the second inlet / outlet line (32), is smoothly moved and circulated to the receiver (4) side, which maintains a temperature about 3 to 4°C lower than that, and is stored therein. This ensures that the circulation of the refrigerant is well carried out, and also improves the compression efficiency of the compressor (2).

[0044] Next, we will examine the refrigeration cycle of the second embodiment of the present invention.

[0045] In describing the refrigeration cycle (1B) of the second embodiment of the present invention, components identical to those of the refrigeration cycle (1A) of the first embodiment described above will be described using the same names and reference numerals.

[0046] FIG. 4 illustrates a refrigeration cycle of a second embodiment of the present invention. The refrigeration cycle (1B) of the second embodiment is configured such that the outlet line (21) of the compressor (2), which is provided in the middle of a refrigerant circulation circuit (1) configured to form a closed circuit, is connected to the main inlet (81) of a four-way solenoid valve (8). The four-way solenoid valve (8) has a main inlet (81) protruding from the center of one side of the valve body (80), and an upper inlet / outlet (82), a middle inlet / outlet (83), a lower inlet / outlet (84), etc., protruding from the other side of the valve body (80). Additionally, the valve body (80) is configured with a variable connection passage (35) that allows the main inlet (81) to be selectively connected to the upper inlet / outlet (82) or the lower inlet / outlet (84), respectively, and the middle inlet / outlet (83) to be selectively connected to the upper inlet / outlet (82) or the lower inlet / outlet (84), respectively. A U-shaped connecting passage (86) is formed to allow for connection.

[0047] In addition, when the refrigeration cycle (1B) of the second embodiment is to be operated in a cooling state, the four-way solenoid valve (8) is adjusted to a cooling state as shown in FIG. 4. In this case, the outlet line (21) of the compressor (2) is connected to the main inlet (81) of the four-way solenoid valve (8), the upper inlet / outlet (82) of the four-way solenoid valve (8) is connected to the first inlet / outlet line (31) of the condenser (3), the lower inlet / outlet (84) of the four-way solenoid valve (8) is connected to the first inlet / outlet line (51) of the evaporator (5), and the middle inlet / outlet (83) of the four-way solenoid valve (8) is configured to be connected to the inlet (73) of the gaseous refrigerant circulation passage (7b) installed in conjunction with the plate heat exchanger (7).

[0048] The second inlet / outlet line (32) of the condenser (3) of the refrigeration cycle (1B) of the second embodiment is connected to the inlet (71) of the liquid refrigerant circulation passage (7a) which is installed in parallel with the plate heat exchanger (7), and the outlet (72) of the liquid refrigerant circulation passage (7a) is connected to the inlet (41) of the receiver (4). The outlet (42) of the receiver (4) is configured to be connected to a connecting line (40) in which the main expansion valve (6) and the first and second solenoid valves (6a) and (6b) are respectively installed. Both ends of the connecting line (40) are configured to be connected to the second inlet / outlet line (32) of the condenser (3) and the second inlet / outlet line (52) of the evaporator (5), respectively. Additionally, the outlet (42) of the receiver (4) is connected to a first connecting line (40) installed at a certain interval while the main expansion valve (6) is installed. It is configured to be connected between the electronic valve (6a) and the second electronic valve (6b), so as to selectively control the supply of the liquid refrigerant discharged from the outlet (42) of the receiver (4) to the second inlet / outlet line (52) of the evaporator (5) or to the second inlet / outlet line (32) of the condenser (3), in a mist state that is rapidly expanded at the main expansion valve (6).

[0049] In addition, the refrigeration cycle (1B) of the second embodiment is configured such that the inlet (71) of the liquid refrigerant circulation passage (7a) installed in conjunction with the plate heat exchanger (7) is simultaneously connected to the second inlet / outlet line (32) of the condenser (3) and the second inlet / outlet line (52) of the evaporator (5), and the outlet (72) of the liquid refrigerant circulation passage (7a) is connected to the inlet (41) of the receiver (4).

[0050] In addition, the inlet (73) of the gaseous refrigerant circulation passage (7b) installed in conjunction with the plate heat exchanger (7) is connected to the intermediate inlet / outlet (83) of the four-way solenoid valve (8), and the outlet (74) of the gaseous refrigerant circulation passage (7b) is configured to be connected to the inlet line (22) of the compressor (2).

[0051] When the refrigeration cycle (1B) of the second embodiment configured as described above is operated in a refrigeration operating state, the high-temperature, high-pressure gaseous refrigerant compressed in the compressor (2) and discharged to the outlet line (21) flows into the main inlet (81) of the four-way electronic valve (8), is discharged to the upper inlet / outlet (82) through the variable connection passage (85), and flows into the first inlet / outlet line (31) of the condenser (3). The high-temperature, high-pressure gaseous refrigerant flowing into the condenser (3) through the first inlet / outlet line (31) is condensed and liquefied through heat exchange with an external heat exchange medium. The ambient temperature liquid refrigerant condensed and liquefied in the condenser (3) is discharged to the second inlet / outlet line (32), flows into the inlet (71) of the liquid refrigerant circulation passage (7a) installed in parallel with the plate heat exchanger (7), and circulates toward the outlet (72). At this time, the low-temperature gaseous refrigerant discharged through the first inlet / outlet line (51) after performing heat exchange in the evaporator (5) sequentially circulates through the lower inlet / outlet (84) of the four-way solenoid valve (8), the U-shaped connecting passage (86), and the intermediate inlet / outlet (83), and flows into the inlet (73) of the gaseous refrigerant circulation passage (7b) installed in conjunction with the plate heat exchanger (7). While moving and circulating toward the outlet (74), it becomes dry and evaporates through a heat exchange action that removes heat from the liquid refrigerant circulating in the liquid refrigerant circulation passage (7a), and flows into the inlet line (22) of the compressor (2). In contrast, the liquid refrigerant circulating in the liquid refrigerant circulation passage (7a) installed in conjunction with the plate heat exchanger (7) is cooled to a low temperature through a heat exchange action that removes heat from the low-temperature gaseous refrigerant circulating in the gaseous refrigerant circulation passage (7b), and the receiver (4) It is stored by flowing into the inlet (41).

[0052] Accordingly, in the receiver (4) of the refrigeration cycle (1B) of the second embodiment, a liquid refrigerant that is cooled to a low temperature while circulating through the liquid refrigerant circulation passage (7a) installed in conjunction with the plate heat exchanger (7) is stored. In this way, the low-temperature liquid refrigerant that is cooled by heat exchange with the low-temperature gaseous refrigerant circulating through the gaseous refrigerant circulation passage (7b) while circulating through the liquid refrigerant circulation passage (7a) of the plate heat exchanger (7) and is then introduced and stored in the receiver (4) maintains a temperature approximately 3 to 4°C lower than the temperature of the ambient temperature liquid refrigerant that is condensed and liquefied in the condenser (3) and discharged through the second inlet / outlet line (32). Consequently, the ambient temperature liquid refrigerant that is condensed and liquefied in the condenser (3) and discharged through the second inlet / outlet line (32) circulates smoothly toward the receiver (4), thereby ensuring that the refrigerant circulation operation is performed well, as well as the compressor (2) The effect of improved compression efficiency can be expected.

[0053] Additionally, the illustration in FIG. 5 illustrates another embodiment of the refrigeration cycle (1B) of the second embodiment of the present invention. In this other embodiment of the refrigeration cycle (1B) of the second embodiment, the opening and closing operation of the first and second solenoid valves (6a) (6b) can be selectively controlled to supply the mist-state refrigerant rapidly expanding from the main expansion valve (6) mounted at the outlet (42) of the receiver (4) to the second inlet / outlet line (52) of the evaporator (5) or to the second inlet / outlet line (32) of the condenser (3) in order to form the refrigerant circulation circuit (1) as a closed circuit. At the same time, a bypass line (61) that guides the liquid refrigerant discharged from the outlet (42) of the receiver (4) to the inlet (73) of the gaseous refrigerant circulation passage (7b) installed in parallel with the plate heat exchanger (7) and a third solenoid valve (6c) formed at a certain interval thereon and an auxiliary It is configured by adding expansion valves (60) to each.

[0054] That is, in another embodiment of the refrigeration cycle (1b) of the second embodiment above, when operating in a cooling state, the first solenoid valve (6a) and the third solenoid valve (6c), each formed at regular intervals in the connection line (40), are operated in an open state, while the second solenoid valve (6b) is operated in a closed state. At this time, the ambient temperature liquid refrigerant, which is condensed and liquefied in the condenser (3) and discharged through the second inlet / outlet line (32), flows into the inlet (71) of the liquid refrigerant circulation passage (7a) installed in conjunction with the plate heat exchanger (7), circulates, is discharged through the outlet (72), flows into the inlet (41) of the receiver (4), and is stored therein. It then circulates toward the main expansion valve (6) which is discharged through the outlet (42) of the receiver (4). At this time, a portion of the liquid refrigerant discharged through the outlet (42) of the receiver (4) is directed toward the main expansion valve (6). The remaining liquid refrigerant is circulated through the bypass line (61), passes through the opened third solenoid valve (6c), rapidly expands into a mist state in the auxiliary expansion valve (60), flows into the inlet (73) of the gaseous refrigerant circulation passage (7b) which is installed in conjunction with the plate heat exchanger (7), and is dried and evaporated by a heat exchange action that removes heat from the liquid refrigerant circulating in the liquid refrigerant circulation passage (7a) while circulating toward the outlet (74), and is transferred toward the compressor (2) and flows into the compressor (2) through the inlet line (22), repeating the operation.

[0055] Meanwhile, a portion of the liquid refrigerant discharged from the outlet (42) of the receiver (4) is rapidly expanded into a mist-like refrigerant at the main expansion valve (6), passes through the opened first solenoid valve (6a), and joins with the low-temperature gaseous refrigerant discharged to the second inlet / outlet line (52) of the evaporator (5). In this way, the mist-like refrigerant rapidly expanded at the main expansion valve (6) and circulating through the connection line (40) joins with the low-temperature gaseous refrigerant discharged to the second inlet / outlet line (52) of the evaporator (5) and flows into the inlet (73) of the gaseous refrigerant circulation passage (7b) installed in conjunction with the plate heat exchanger (7). As it circulates, it removes heat from the liquid refrigerant circulating through the liquid refrigerant circulation passage (7a) through a heat exchange action, thereby cooling the liquid refrigerant circulating through the liquid refrigerant circulation passage (7a) and discharged to the outlet (72) to a low temperature, and consequently, the In the receiver (4), liquid refrigerant cooled to a temperature about 3 to 4° lower than the liquid refrigerant at room temperature that is condensed and discharged from the condenser (3) is introduced and stored.

[0056] Accordingly, in another embodiment of the refrigeration cycle (1B) of the second embodiment shown in FIG. 5, the liquid refrigerant that flows into and is stored in the receiver (4) is a liquid refrigerant that is cooled to a temperature about 3 to 4°C lower than the ambient temperature liquid refrigerant that is condensed and liquefied in the condenser (3) and discharged. Therefore, the ambient temperature liquid refrigerant that is condensed and converted in the condenser (3) can flow well toward the receiver (4), and thus, effects such as improved compression efficiency of the compressor (2) can be expected.

[0057] The illustration in FIG. 6 illustrates the refrigerant circulation state when the refrigeration cycle (1B) of the second embodiment of the present invention is operated in a heating state, and the circuit configuration state of the refrigeration cycle (1B) of the second embodiment is the same or similar as that in FIG. 4. However, when the refrigeration cycle (1B) of the second embodiment is operated in a heating state, the variable connecting passage (85) formed in the valve body (80) of the four-way solenoid valve (8) is variably operated to connect the main inlet (81) and the lower inlet / outlet (84), and at the same time, the U-shaped connecting passage (86) is variably operated to connect the middle inlet / outlet (83) and the upper inlet / outlet (82).

[0058] Meanwhile, the effect of the liquid refrigerant stored in the receiver (4) being cooled to a low temperature due to heat exchange with the low-temperature gaseous refrigerant circulating in the gaseous refrigerant circulation passage (7b) while circulating in the liquid refrigerant circulation passage (7a) installed in the plate heat exchanger (7) is similar, but the difference is that the mist-state refrigerant discharged from the outlet (42) of the receiver (4) and rapidly expanded in the main expansion valve (6) does not circulate to the second inlet / outlet line (52) of the evaporator (5) but circulates to the second inlet / outlet line (32) of the condenser (3).

[0059] That is, as shown in FIG. 5, when the refrigeration cycle (1B) of the second embodiment is operated in a heating state, the high-temperature, high-pressure gaseous refrigerant compressed by the compressor (2) and discharged through the outlet line (21) flows into the main inlet (81) of the four-way solenoid valve (8), passes through the variable connection passage (85), and is discharged through the lower inlet / outlet (84). The high-temperature, high-pressure gaseous refrigerant discharged through the lower inlet / outlet (84) flows into the first inlet / outlet line (51) of the evaporator (5). At this time, since the evaporator (5) operates as a "condenser," the high-temperature, high-pressure gaseous refrigerant flowing into the first inlet / outlet line (51) is condensed and liquefied through a heat exchange action (heat release action) with an external heat exchange medium (a space where the evaporator is installed). A liquid refrigerant at room temperature is discharged through the second inlet / outlet line (52) and flows into the inlet (71) of the liquid refrigerant circulation passage (7a) installed in conjunction with the plate heat exchanger (7), circulates toward the outlet (72), and flows into and is stored at the inlet (41) of the receiver (4). Meanwhile, the mist-state refrigerant, which is discharged through the outlet (42) of the receiver (4) and rapidly expands at the main expansion valve (6), circulates toward the second inlet / outlet line (32) of the condenser (3). At this time, when the refrigeration cycle (1B) of the second embodiment is operated in a heating state, the condenser (3) operates as an "evaporator." Accordingly, the mist-state refrigerant flowing into the second inlet / outlet line (32) of the condenser (3), which operates as a "condenser," absorbs heat and evaporates through heat exchange with an external heat exchange medium (space where the condenser is installed). In this way, the "evaporator's The low-temperature gaseous refrigerant evaporating from the condenser (3) operating as a "function" is discharged through the first inlet / outlet line (31).

[0060] As described above, the low-temperature gaseous refrigerant discharged through the first inlet / outlet line (31) of the condenser (3) which operates as the "function of the evaporator," flows into the upper inlet / outlet (82) of the four-way electronic valve (8), passes through the U-shaped connecting passage (86), and is discharged to the intermediate inlet / outlet (83). It then flows into the inlet (73) of the gaseous refrigerant circulation passage (7b) which is installed in conjunction with the plate heat exchanger (7) and performs a heat exchange operation that removes heat from the liquid refrigerant circulating in the liquid refrigerant circulation passage (7a) while circulating toward the outlet (74). Accordingly, the liquid refrigerant circulating in the liquid refrigerant circulation passage (7a) installed in conjunction with the plate heat exchanger (7) is cooled to a low temperature and stored through the inlet (41) of the receiver (4).

[0061] Meanwhile, the dried gaseous refrigerant, which is discharged through the first inlet / outlet line (31) of the condenser (3) operating as the "function of the evaporator" and sequentially passes through the upper inlet / outlet (82) → U-shaped connecting passage (86) → lower inlet / outlet (84) of the four-way electronic valve (8), flows into the inlet (73) of the gaseous refrigerant circulation passage (7b) installed in the plate heat exchanger (7), and is discharged through the outlet (74), circulates toward the compressor (2) and repeats the operation of flowing into the compressor (2) through the inlet line (22).

[0062] Therefore, even when the refrigeration cycle (1B) of the second embodiment is operated in a heating state, the liquid refrigerant stored in the inlet (41) of the receiver (4) is cooled to a low temperature, so the liquid refrigerant discharged through the second inlet / outlet line (52) of the evaporator (5), which operates as a "condenser function," circulates smoothly to the receiver (4), and since the dried gaseous refrigerant is introduced into the inlet line (22) of the compressor (2), the effect of improving the compression efficiency of the compressor (2) can be expected.

[0063] Next, the refrigeration cycle of the third embodiment of the present invention is described as follows.

[0064] In describing the refrigeration cycle (1C) of the third embodiment of the present invention, components identical to those of the refrigeration cycles (1A) and (1B) of the first and second embodiments described above will be described using the same names and reference numerals.

[0065] In addition, the refrigeration cycle (1C) of the third embodiment of the present invention is composed of two types of refrigeration cycles. For example, the refrigeration cycle (1C) of the third embodiment is completed by adding a small auxiliary refrigeration cycle (10) that is about one-tenth (1 / 10) smaller in size and capacity compared to the refrigeration cycle (1C) in order to rapidly expand and supply a mist-state refrigerant to a gaseous refrigerant circulation passage (7b) installed in conjunction with a plate heat exchanger (7) for cooling and heating the refrigerant stored in the receiver (4) among the various components constituting the refrigeration cycle (1C) to a low temperature.

[0066] In the refrigeration cycle (1C) of the third embodiment above, the outlet line (21) of the compressor (2), which is provided in the middle of the refrigerant circulation circuit (1) configured to form a closed circuit, is configured to be connected to the main inlet (81) of the four-way solenoid valve (8). The four-way solenoid valve (8) has a main inlet (81) formed protruding from the center of one side of the valve body (80), and an upper inlet / outlet (82), a middle inlet / outlet (83), a lower inlet / outlet (84), etc., are formed protruding from the other side of the valve body (80).

[0067] In addition, the valve body (80) is configured to have a variable connection passage (85) configured to allow the main inlet (81) to be selectively connected to the upper inlet / outlet (82) or the lower inlet / outlet (84), respectively, and a U-shaped connection passage (86) configured to allow the intermediate inlet / outlet (83) to be selectively connected to the upper inlet / outlet (82) or the lower inlet / outlet (84), respectively.

[0068] In addition, when the refrigeration cycle (1C) of the third embodiment is to be operated in a cooling state, the four-way solenoid valve (8) is adjusted to a cooling state as shown in FIG. 7 (see enlarged portion of FIG. 7). In this case, the outlet line (21) of the compressor (2) is connected to the main inlet (81) of the four-way solenoid valve (8), the upper inlet / outlet (82) of the four-way solenoid valve (8) is connected to the first inlet / outlet line (31) of the condenser (3), the lower inlet / outlet (84) of the four-way solenoid valve (8) is connected to the first inlet / outlet line (51) of the evaporator (5), and the middle inlet / outlet (83) of the four-way solenoid valve (8) is configured to be connected to the inlet (73) of the gaseous refrigerant circulation passage (7b) installed in conjunction with the plate heat exchanger (7).

[0069] The second inlet / outlet line (32) of the condenser (3) of the refrigeration cycle (1C) of the third embodiment is connected to the inlet (71) of the liquid refrigerant circulation passage (7a) which is installed in parallel with the plate heat exchanger (7), and the outlet (72) of the liquid refrigerant circulation passage (7a) is connected to the inlet (41) of the receiver (4). The outlet (42) of the receiver (4) is configured to be connected to a connecting line (40) in which the main expansion valve (6) and the first and second solenoid valves (6a) and (6b) are respectively installed. Both ends of the connecting line (40) are configured to be connected to the second inlet / outlet line (32) of the condenser (3) and the second inlet / outlet line (52) of the evaporator (5), respectively. Additionally, the outlet (42) of the receiver (4) is connected to a first connecting line (40) installed at a certain interval while the main expansion valve (6) is installed. It is configured to be connected between the electronic valve (6a) and the second electronic valve (6b), so as to selectively control the supply of the liquid refrigerant discharged from the outlet (42) of the receiver (4) to the second inlet / outlet line (52) of the evaporator (5) or to the second inlet / outlet line (32) of the condenser (3), in a mist state where the liquid refrigerant rapidly expands at the main expansion valve (6).

[0070] In addition, a small auxiliary refrigeration cycle (10) configured to a small size is formed in the refrigeration cycle (1C) of the third embodiment, and the small auxiliary refrigeration cycle (10) is configured such that components such as a compressor (11), a condenser (12), a receiver (13), an electronic valve (14), and an expansion valve (15) form a closed circuit.

[0071] The inlet (11a) of the compressor (11) formed in the above small auxiliary refrigeration cycle (10) is connected to the outlet (74) of the gaseous refrigerant circulation passage (7b) installed in conjunction with the plate heat exchanger (7) formed in the refrigeration cycle (1C), the outlet (11b) of the compressor (11) is connected to the inlet (12a) of the condenser (12), and the outlet (12b) of the condenser (12) is configured to be connected to the inlet (13a) of the receiver (13). An electronic valve (14) and an expansion valve (15) are installed in sequence at the outlet (13b) of the receiver (13), and the expansion valve (15) is configured to be connected to the inlet (73) of the gaseous refrigerant circulation passage (7b) installed in conjunction with the plate heat exchanger (7) formed in the refrigeration cycle (1C).

[0072] When the refrigeration cycle (1C) of the third embodiment configured as described above is operated in a refrigeration operating state, the high-temperature, high-pressure gaseous refrigerant compressed in the compressor (2) and discharged to the outlet line (21) flows into the main inlet (81) of the four-way electronic valve (8), is discharged to the upper inlet / outlet (82) through the variable connection passage (85), and flows into the first inlet / outlet line (31) of the condenser (3). The high-temperature, high-pressure gaseous refrigerant flowing into the condenser (3) through the first inlet / outlet line (31) is condensed and liquefied through heat exchange with an external heat exchange medium. The ambient temperature liquid refrigerant condensed and liquefied in the condenser (3) is discharged to the second inlet / outlet line (32), flows into the inlet (71) of the liquid refrigerant circulation passage (7a) installed in conjunction with the plate heat exchanger (7), and circulates toward the outlet (72). Meanwhile, the refrigerant circulating in the small auxiliary refrigeration cycle (10) As the mist-state refrigerant rapidly expanded and discharged from the expansion valve (15) flows into the inlet (73) of the gaseous refrigerant circulation passage (7b) installed in the plate heat exchanger (7) formed in the refrigeration cycle (1c) of the third embodiment and circulates toward the outlet (74), it performs a heat exchange action that removes heat from the liquid refrigerant circulating in the liquid refrigerant circulation passage (7a). Accordingly, the ambient temperature liquid refrigerant that is condensed and liquefied in the condenser (3) of the refrigeration cycle (1C) of the third embodiment and discharged through the second inlet / outlet line (32) flows into the inlet (71) of the liquid refrigerant circulation passage (7a) installed in the plate heat exchanger (7) and circulates toward the outlet (72), it is cooled by a heat exchange action that removes heat from the mist-state refrigerant circulating in the gaseous refrigerant circulation passage (7b) and is discharged toward the outlet (72). Accordingly, the liquid refrigerant flowing into and stored at the inlet (41) of the receiver (4) is cooled to a low temperature.

[0073] Meanwhile, the liquid refrigerant discharged from the outlet (42) of the receiver (4) is rapidly expanded in the main expansion valve (6), and the mist-like refrigerant rapidly expanded in the expansion valve (6) passes through the open first electronic valve (6a) and flows into the second inlet / outlet line (52) of the evaporator (5). At this time, the mist-like refrigerant flowing into the evaporator (5) through the second inlet / outlet line (52) evaporates through heat exchange with an external heat exchange medium (a state of absorbing heat) and is discharged through the first inlet / outlet line (51), and then circulates sequentially through the lower inlet / outlet (84) of the electronic valve (8) → U-shaped connecting passage (86) → middle inlet / outlet (83) and flows into the inlet line (22) of the compressor (2), repeating the operation.

[0074] When the refrigeration cycle (1c) of the third embodiment configured as described above is operated in a refrigeration operating state, the ambient temperature liquid refrigerant that is condensed and liquefied in the condenser (3) and discharged through the second inlet / outlet line (32) is cooled to a low temperature through a heat exchange action in which heat is taken from the mist-state refrigerant circulating through the gaseous refrigerant circulation passage (7b) while circulating through the liquid refrigerant circulation passage (7a) installed in conjunction with the plate heat exchanger (7), and is then supplied and stored in the receiver (4). Consequently, the liquid refrigerant stored in the receiver (4) maintains a temperature about 3 to 4°C lower than the ambient temperature liquid refrigerant that is condensed and liquefied in the condenser (3) and discharged, so the ambient temperature liquid refrigerant that is condensed and liquefied in the condenser (3) can circulate smoothly to the receiver (4).

[0075] The illustration in FIG. 8 illustrates the refrigerant circulation state when the refrigeration cycle (1C) of the third embodiment is operated in a heating state. In this case, the four-way solenoid valve (8) is converted to a heating state, and the high-temperature, high-pressure gaseous refrigerant discharged through the outlet line (21) of the compressor (2) flows into the main inlet (81) of the four-way solenoid valve (8), passes through the converted variable connection passage (85), and is discharged through the lower inlet / outlet (84). The high-temperature, high-pressure gaseous refrigerant discharged through the lower inlet / outlet (84) flows into the evaporator (5) through the first inlet / outlet line (51) of the evaporator (5). At this time, since the evaporator (5) operates in a state of "condenser function," the high-temperature, high-pressure gaseous refrigerant discharged from the compressor (2) and flowing into the first inlet / outlet line (51) of the evaporator (5) condenses and liquefies while performing a heat exchange action that releases heat. The liquid refrigerant at room temperature that is liquefied is discharged through the second inlet / outlet line (52) and flows into the inlet (71) of the liquid refrigerant circulation passage (7a) installed in conjunction with the plate heat exchanger (7) formed in the refrigeration cycle (1C) of the third embodiment, and circulates toward the outlet (72). At this time, the mist-state refrigerant discharged through the outlet (13b) of the receiver (13) formed in the small auxiliary refrigeration cycle (10) and rapidly expanded and discharged from the expansion valve (15) flows into the inlet (73) of the gaseous refrigerant circulation passage (7b) installed in conjunction with the plate heat exchanger (7) of the refrigeration cycle (1C) and circulates toward the outlet (74), performing a heat exchange operation that extracts heat from the liquid refrigerant circulating in the liquid refrigerant circulation passage (7a), and is dried and evaporated to become gaseous refrigerant, which is then discharged through the outlet (74) and flows into the compressor (11) of the small auxiliary refrigeration cycle (10). It ends up being repeated.

[0076] As seen above, even when the refrigeration cycle (1C) of the third embodiment is operated in a heating state, the liquid refrigerant discharged through the second inlet / outlet line (52) of the evaporator (5) operating as a "condenser function" flows into the inlet (71) of the liquid refrigerant circulation passage (7a) installed in conjunction with the plate heat exchanger (7) and, while circulating toward the outlet (72), is rapidly expanded at the expansion valve (15) of the small auxiliary refrigeration cycle (10) and is cooled by a heat exchange action in which heat is taken from the refrigerant in a mist state that flows into the inlet (73) of the gaseous refrigerant circulation passage (7b) installed in conjunction with the plate heat exchanger (7) and is discharged to the outlet (72) and then supplied to and stored in the receiver (4). Consequently, the liquid refrigerant cooled to a low temperature is stored in the receiver (4), so the ambient temperature liquid refrigerant discharged through the second inlet / outlet line (52) of the evaporator (5) operating as a "condenser function" The liquid refrigerant at a lower temperature can be smoothly circulated to the receiver (4) where it is stored.

[0077] Finally, the refrigeration cycle of the fourth embodiment of the present invention is described as follows.

[0078] In describing the refrigeration cycle (1D) of the fourth embodiment of the present invention, components identical to those of the refrigeration cycles (1A), (1B), and (1C) of the first to third embodiments described above will be described using the same names and reference numerals.

[0079] In addition, the refrigeration cycle (1D) of the fourth embodiment of the present invention is composed of two types of refrigeration cycles. For example, the refrigeration cycle (1D) of the fourth embodiment is completed by adding a small auxiliary refrigeration cycle (10) that is about one-tenth (1 / 10) smaller in size and capacity compared to the size and capacity of the refrigeration cycle (1D) for cooling and heating the indoor space and a gaseous refrigerant circulation passage (7b) installed in conjunction with a plate heat exchanger (7) for cooling the refrigerant stored in the receiver (4) among the various components constituting the refrigeration cycle (1D) to a low temperature, in order to rapidly expand and supply refrigerant in a mist state to the gaseous refrigerant circulation passage (7b).

[0080] Since the configuration of the small auxiliary refrigeration cycle (10) additionally configured in the refrigeration cycle (1D) of the fourth embodiment is described in detail in the refrigeration cycle (1C) of the third embodiment described above, a detailed description of the small auxiliary refrigeration cycle (10) additionally configured in the refrigeration cycle (1D) of the fourth embodiment will be omitted.

[0081] However, in the refrigeration cycle (1D) of the fourth embodiment above, a refrigerant pump (9) is installed in the middle of the refrigerant circulation circuit (1) that forms a closed circuit to increase and boost the refrigerant circulation operation.

[0082] In addition, the refrigeration cycle (1D) of the fourth embodiment is configured to circulate the refrigerant using the power of the compressor (2) as well as to circulate the refrigerant using the refrigerant pump (9).

[0083] The city of FIG. 9 shows a refrigerant circulation state for cooling the liquid refrigerant stored in the receiver (4) to a low temperature using a small auxiliary refrigerator (10) while circulating the refrigerant with the power of the compressor (2) of the refrigeration cycle (1D) of the fourth embodiment.

[0084] When the refrigeration cycle (1D) of the above-mentioned fourth embodiment is operated in a cooling state by simultaneously operating the compressor (2) and the refrigerant pump (9), the refrigerant circulates as shown in FIG. 9. At this time, the refrigeration cycle (1D) is operated with the first solenoid valve (6a) and the third solenoid valve (6c) each controlled to an open state, while the second and fourth solenoid valves (6b) and (6d) each controlled to a closed state.

[0085] That is, when the refrigeration cycle (1D) of the fourth embodiment is operated in a cooling state, the high-temperature, high-pressure gaseous refrigerant compressed by the compressor (2) and discharged to the outlet line (21) flows into the first inlet / outlet line (31) of the condenser (3). The high-temperature, high-pressure gaseous refrigerant flowing into the first inlet / outlet line (31) of the condenser (3) and circulating through the condenser (3) is condensed and liquefied through heat exchange with an external heat exchange medium and discharged to the second inlet / outlet line (32), then flows into the inlet (71) of the liquid refrigerant circulation passage (7a) installed in conjunction with the plate heat exchanger (7) and circulates toward the outlet (72). Meanwhile, the mist-state refrigerant rapidly expanded from the expansion valve (15) of the small auxiliary refrigeration cycle (10) flows into and circulates at the inlet (73) of the gaseous refrigerant circulation passage (7b) installed in conjunction with the plate heat exchanger (7).

[0086] As described above, the liquid refrigerant circulating in the liquid refrigerant circulation passage (7a) of the plate heat exchanger (7) and the gaseous refrigerant circulating in the gaseous refrigerant circulation passage (7b) perform heat exchange with each other. At this time, the liquid refrigerant circulating in the liquid refrigerant circulation passage (7a) is cooled to a low temperature through a heat exchange process in which heat is taken from the mist-state refrigerant circulating in the gaseous refrigerant circulation passage (7b), and is discharged through the outlet (72) and stored in the receiver (4). On the other hand, the mist-state refrigerant circulating in the gaseous refrigerant circulation passage (7b) is dried and evaporated through a heat exchange process in which heat is taken from the liquid refrigerant circulating in the liquid refrigerant circulation passage (7a), changes into a gaseous state, is discharged through the outlet (74), and flows into the compressor (11).

[0087] Accordingly, in the refrigeration cycle (1D) of the fourth embodiment, the liquid refrigerant circulating in the liquid refrigerant circulation passage (7) installed in conjunction with the plate heat exchanger (7) is cooled by a heat exchange action in which heat is taken from the mist-state refrigerant circulating in the gaseous refrigerant circulation passage (7b) of the plate heat exchanger (7), and thus the liquid refrigerant at room temperature that is condensed and liquefied in the condenser (3) is smoothly circulated to the receiver (4) where the liquid refrigerant cooled to a lower temperature is stored.

[0088] In addition, the refrigerant pump (9) installed on the outlet (42) side of the receiver (4) can pump the low-temperature liquid refrigerant stored in the receiver (4) and supply it to the main expansion valve (6), so the main expansion valve (6) can rapidly expand the low-temperature liquid refrigerant to supply the refrigerant in a mist state, and the mist state refrigerant rapidly expanded in the main expansion valve (6) flows into the evaporator (5), performs heat exchange with the external heat exchange medium (space where the evaporator is installed), is discharged through the first inlet / outlet line (51), passes through the third solenoid valve (6c) which is controlled to an open state, and then flows into the inlet line (22) of the compressor (2), repeating the operation.

[0089] Therefore, when the refrigeration cycle (1D) of the fourth embodiment is operated in a cooling state, the effect of enabling smooth circulation of the refrigerant and the effect of improving the compression efficiency of the compressor (2) can be expected.

[0090] Also, the city in Fig. 10 shows the refrigerant circulation state when the refrigeration cycle (1D) of the fourth embodiment is operated as a pre-cooling cycle.

[0091] When the refrigeration cycle (1D) of the above-mentioned fourth embodiment is operated in a pre-cooling state, the first solenoid valve (6a) and the third solenoid valve (6c) are each controlled to a closed state, and the second and fourth solenoid valves (6b) and (6d) are each controlled to an open state, the compressor (2) is stopped and only the refrigerant pump (9) is operated. Accordingly, the liquid refrigerant discharged through the second inlet / outlet line (32) of the condenser (3) flows into the inlet (71) of the liquid refrigerant circulation passage (7a) installed in conjunction with the plate heat exchanger (7) and circulates to the outlet (72), while the mist-like refrigerant rapidly expanding from the expansion valve (15) of the small auxiliary refrigeration cycle (10) flows into the inlet (73) of the gaseous refrigerant circulation passage (7b) installed in conjunction with the plate heat exchanger (7) and circulates to the outlet (74).

[0092] Accordingly, the liquid refrigerant circulating in the liquid refrigerant circulation passage (7a) and the mist refrigerant circulating in the gaseous refrigerant circulation passage (7b), which are installed in conjunction with the plate heat exchanger (7) of the refrigeration cycle (1D) of the fourth embodiment, perform heat exchange operations with each other. At this time, the liquid refrigerant circulating in the liquid refrigerant circulation passage (7) is cooled to a low temperature through a heat exchange operation in which heat is taken from the mist refrigerant circulating in the gaseous refrigerant circulation passage (7b) and is stored by flowing into the inlet (41) of the receiver (4), while the mist refrigerant circulating in the gaseous refrigerant circulation passage (7b) is dried and evaporated through a heat exchange operation in which heat is taken from the liquid refrigerant circulating in the liquid refrigerant circulation passage (7a) and is discharged through the outlet (74) and flows into the compressor (11), repeating the operation.

[0093] And, when the refrigeration cycle (1D) of the fourth embodiment is operated in a pre-cooling state, the liquid refrigerant discharged from the outlet (42) of the receiver (4) cannot move toward the first solenoid valve (6a) which is controlled to a closed state, but passes through the second solenoid valve (6b) which is controlled to an open state and flows into the second inlet / outlet line (52) of the evaporator (5). Additionally, the refrigerant discharged from the first inlet / outlet line (51) of the evaporator (5) cannot circulate toward the third solenoid valve (6c) which is controlled to a closed state, but circulates toward the fourth solenoid valve (6d) which is controlled to an open state, thereby repeating the operation of the condenser (3) flowing into the first inlet / outlet line (31).

[0094] As described above, in the refrigeration cycle (1D) of the fourth embodiment, the liquid refrigerant circulating in the liquid refrigerant circulation passage (7) installed in conjunction with the plate heat exchanger (7) is cooled by a heat exchange action in which heat is taken from the mist-state refrigerant circulating in the gaseous refrigerant circulation passage (7b) of the plate heat exchanger (7), and thus the liquid refrigerant at a lower temperature that is condensed and liquefied in the condenser (3) is stored in the receiver (4). Therefore, in the refrigeration cycle (1D) of the fourth embodiment, the liquid refrigerant at room temperature that is condensed and liquefied in the condenser (3) is smoothly circulated to the receiver (4) where the liquid refrigerant that is cooled to a lower temperature is stored.

[0095] Therefore, when the refrigeration cycle (1D) of the fourth embodiment is operated as a pre-cooling cycle, the refrigerant circulates smoothly, so there is an effect of enabling smooth refrigerant circulation operation.

[0096] As explained above, each of the refrigeration cycles (1A~1D) of the first to fourth embodiments of the present invention is configured such that, regardless of whether the high-temperature, high-pressure gaseous refrigerant compressed and discharged from the compressor (2) is condensed and liquefied in the condenser (3) and discharged as ambient temperature liquid refrigerant, it is not immediately fed into and stored in the receiver (4), but is cooled to a low temperature through heat exchange with the gaseous refrigerant (including refrigerant in a mist state) circulating in the gaseous refrigerant circulation passage (7b) while circulating in the liquid refrigerant circulation passage (7a) installed in conjunction with the plate-type heat exchanger (7). Therefore, the high-temperature, high-pressure gaseous refrigerant compressed and discharged from the compressor (2) can circulate smoothly to the receiver (4) after being condensed and liquefied in the condenser (3) or evaporator (5), and furthermore, the compressor (2) is not overloaded and the compression efficiency is improved. Since the power consumption can be reduced, there are effects such as saving electrical energy. Explanation of the symbols

[0097] 1A~1D: 1st~4th refrigeration cycles 10: Small auxiliary refrigeration cycle 1 : Refrigerant circulation circuit 2 : Compressor 21, 22: Outlet line and inlet line 3: Condenser 4 : IV fluid receiver 40 : Connection line 41,42: Inlet and Outlet 5: Evaporator 31,51: 1st Entrance / Exit Line 32,52: 2nd Entrance / Exit Line 6: Main expansion valve 6a to 6d: 1st to 4th solenoid valves 60: Auxiliary expansion valve 61: Bypass line 7 : Plate heat exchanger 7a : Liquid refrigerant circulation passage 7b: Gaseous refrigerant circulation passage 71, 73: Inlet 72,74 : Outlet 8 : Four-way solenoid valve 80 : Valve body 81 : Main inlet 82: Top Entrance / Exit 83: Middle Entrance / Exit 84: Bottom entrance / exit 85: Variable connecting passageway 86 : U-shaped connecting passage 9 : Refrigerant pump

Claims

Claim 1 delete Claim 2 delete Claim 3 delete Claim 4 delete Claim 5 delete Claim 6 delete Claim 7 delete Claim 8 A compressor (2) provided in the middle of a refrigerant circulation circuit (1) configured to form a closed circuit, a condenser (3) that condenses and liquefies high-temperature, high-pressure gaseous refrigerant compressed and discharged from the compressor, a receiver (4) that temporarily stores ambient temperature liquid refrigerant discharged after condensation and liquefaction from the condenser, a first solenoid valve (6a) for controlling the circulation operation of the liquid refrigerant discharged from the receiver, a main expansion valve (6) for rapidly expanding the liquid refrigerant passing through the first solenoid valve (6a), and an evaporator (5) configured to allow the mist-state refrigerant rapidly expanded from the main expansion valve to flow into a second inlet / outlet line (52), thereby causing the incoming mist-state refrigerant to evaporate through a heat exchange action that removes heat from the surrounding heat exchange medium, and thereby absorbing surrounding heat to convert it into a low-temperature gaseous state, and furthermore, discharged through the first inlet / outlet line (51) of the evaporator (5). A refrigeration cycle (1D) is configured to repeat the operation of introducing refrigerant into a compressor (2), and the refrigeration cycle (1D) is configured such that a plate heat exchanger (7) is connected between the second outlet line (32) of a condenser (3) and the inlet (41) of a receiver (4), wherein a liquid refrigerant circulation passage (7a) and a gaseous refrigerant circulation passage (7b) are installed in parallel. When the refrigeration cycle (1D) is operated in a cooling state, the inlet (71) and outlet (72) of the liquid refrigerant circulation passage (7a) installed in the plate heat exchanger (7) are configured to be connected to the second inlet / outlet line (32) of the condenser (3) and the inlet (41) of the receiver (4), respectively, so that while the liquid refrigerant flowing into the inlet (71) of the liquid refrigerant circulation passage (7a) moves and circulates toward the outlet (72), the gaseous refrigerant installed in the plate heat exchanger (7) In a refrigeration cycle configured to be cooled to a low temperature by a heat exchange action in which heat is removed from a mist-state refrigerant that flows into the inlet (73) of the circulation passage (7b) and moves and circulates toward the outlet (74), and can be supplied and stored in a receiver (4), when the refrigeration cycle (1D) is operated in a pre-cooling state,A refrigeration cycle for lowering the temperature of a liquid refrigerant stored in a receiver using a plate heat exchanger, characterized in that the compressor (2) is temporarily stopped, and the refrigerant pump (9) installed on the outlet (42) side of the receiver (4) is operated to circulate the refrigerant, and in this case, the liquid refrigerant discharged to the second inlet / outlet line (32) of the condenser (3) by the pumping operation of the refrigerant pump (9) flows into the liquid refrigerant circulation passage (7a) installed in conjunction with the plate heat exchanger (7) and, while moving and circulating toward the outlet (72) side, is cooled by a heat exchange action in which heat is removed from the refrigerant in a mist state supplied from the small auxiliary refrigeration cycle (10) and flowing into the inlet (73) of the gaseous refrigerant circulation passage (7b) installed in conjunction with the plate heat exchanger (7), and is then supplied from the small auxiliary refrigeration cycle (10) and circulated therein, and is stored in the receiver (4). Claim 9 delete Claim 10 In claim 8, a small auxiliary refrigeration cycle (10) separately configured in the above refrigeration cycle (1D) is configured to circulate the liquid refrigerant discharged from the outlet (42) of the receiver (4) through an open electronic valve (14) and the mist-state refrigerant rapidly expanded in the expansion valve (15) by introducing it into the inlet (73) of the gaseous refrigerant circulation passage (7b) installed in conjunction with the plate heat exchanger (7). Furthermore, the mist-state refrigerant circulating through the inlet (73) of the gaseous refrigerant circulation passage (7b) is evaporated and dried by a heat exchange action that removes heat from the ambient temperature liquid refrigerant circulating in the liquid refrigerant circulation passage (7a), and is discharged through the outlet (74) of the gaseous refrigerant circulation passage (7b) and compressed to high temperature and high pressure in the compressor (11). The high temperature and high pressure gaseous refrigerant compressed and discharged from the compressor (11) is condensed and liquefied in the condenser (12) and stored in the receiver (13). A refrigeration cycle for lowering the temperature of liquid refrigerant stored in a receiver using a plate heat exchanger characterized by being configured to repeat the operation of being discharged to the outlet (13b).

Images