CN112771319A - Refrigeration cycle device - Google Patents
Refrigeration cycle device Download PDFInfo
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- CN112771319A CN112771319A CN201880097837.9A CN201880097837A CN112771319A CN 112771319 A CN112771319 A CN 112771319A CN 201880097837 A CN201880097837 A CN 201880097837A CN 112771319 A CN112771319 A CN 112771319A
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- pipe
- refrigerant
- circuit
- expansion valve
- pipe portion
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B41/00—Fluid-circulation arrangements
- F25B41/40—Fluid line arrangements
- F25B41/42—Arrangements for diverging or converging flows, e.g. branch lines or junctions
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B43/00—Arrangements for separating or purifying gases or liquids; Arrangements for vaporising the residuum of liquid refrigerant, e.g. by heat
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B2313/00—Compression machines, plants or systems with reversible cycle not otherwise provided for
- F25B2313/023—Compression machines, plants or systems with reversible cycle not otherwise provided for using multiple indoor units
- F25B2313/0233—Compression machines, plants or systems with reversible cycle not otherwise provided for using multiple indoor units in parallel arrangements
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B2400/00—General features or devices for refrigeration machines, plants or systems, combined heating and refrigeration systems or heat-pump systems, i.e. not limited to a particular subgroup of F25B
- F25B2400/02—Centrifugal separation of gas, liquid or oil
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B2400/00—General features or devices for refrigeration machines, plants or systems, combined heating and refrigeration systems or heat-pump systems, i.e. not limited to a particular subgroup of F25B
- F25B2400/13—Economisers
Abstract
The invention provides a refrigeration cycle device which can fully exert the performance of a supercooling circuit by a simple structure. A refrigeration cycle device (1) is provided with a refrigerant pipe (8) for connecting a compressor (2), an outdoor heat exchanger (3), a supercooling circuit (5), an indoor expansion valve (6), and an indoor heat exchanger (7) and allowing a refrigerant to flow therethrough. The refrigerant pipe (8) has: a main circuit pipe (31) for circulating the refrigerant through the compressor (2), the outdoor heat exchanger (3), the subcooling circuit (5), the indoor expansion valve (6), and the indoor heat exchanger (7); a bypass pipe (32) that branches from the middle of a main pipe (31) connecting the subcooling circuit (5) and the indoor expansion valve (6) and bypasses the refrigerant to the compressor (2); and a branching section (33) between the main loop pipe (31) and the bypass loop pipe (32). The branching section (33) has an upstream pipe section (51), a main circuit branching pipe section (52) that branches upward from the upstream pipe section (51) and that leads to the indoor expansion valve (6), and a bypass circuit branching pipe section (53) that branches downward from the upstream pipe section (51) and that leads to the subcooling circuit (5).
Description
Technical Field
Embodiments of the present invention relate to a refrigeration cycle apparatus.
Background
A refrigeration cycle apparatus including a subcooling circuit and a gas-liquid separator provided upstream of the subcooling circuit is known.
In a conventional refrigeration cycle apparatus, a gas-liquid two-layer refrigerant is separated into a gas refrigerant and a liquid refrigerant by a gas-liquid separator, and only the separated liquid refrigerant is made to flow into a subcooling circuit, and the separated gas refrigerant is made to bypass a compressor.
Documents of the prior art
Patent document
Patent document 1: japanese patent laid-open No. 2005-233551
Disclosure of Invention
Technical problem to be solved by the invention
The conventional refrigeration cycle apparatus requires a gas-liquid separator and a pipe for bypassing the separated gas refrigerant to the compressor. These gas-liquid separator and bypass pipe lead to an increase in the cost of the refrigeration cycle apparatus and complication of the piping system.
Therefore, the present invention provides a refrigeration cycle apparatus capable of sufficiently exhibiting the performance of the subcooling circuit with a simple configuration.
Technical scheme for solving technical problem
In order to solve the above problem, a refrigeration cycle apparatus according to an embodiment of the present invention includes: a compressor; a condenser; an indoor expansion valve; a supercooling circuit disposed between the condenser and the indoor expansion valve; an evaporator; and a refrigerant pipe connecting the compressor, the condenser, the supercooling circuit, the indoor expansion valve, and the evaporator and allowing a refrigerant to flow therethrough, the refrigerant pipe including: a main circuit pipe for circulating a refrigerant through the compressor, the condenser, the subcooling circuit, the indoor expansion valve, and the evaporator; a bypass pipe that branches from a middle of the main pipe connecting the subcooling circuit and the indoor expansion valve and bypasses the refrigerant to the compressor; and a branching portion between the main loop pipe and the bypass loop pipe, the branching portion having: an upstream pipe portion; a main circuit branch pipe portion that branches upward from the upstream pipe portion and that branches toward the indoor expansion valve; and a bypass circuit branch pipe portion branching downward from the upstream pipe portion and extending toward the subcooling circuit.
Preferably, in the refrigeration cycle apparatus according to the embodiment of the present invention, the main circuit branch pipe portion and the bypass circuit branch pipe portion are continuous straight pipes, and the upstream pipe portion is erected on the straight pipe.
Preferably, in the refrigeration cycle apparatus according to the embodiment of the present invention, a flow passage sectional area of the straight pipe is 2 times or more a flow passage sectional area of the upstream pipe portion.
Preferably, in the refrigeration cycle apparatus according to the embodiment of the present invention, the upstream pipe portion extends substantially in a horizontal direction, and the main circuit branch pipe portion and the bypass circuit branch pipe portion extend substantially in a vertical direction.
Preferably, in the refrigeration cycle apparatus according to the embodiment of the present invention, an extension line of a center line of the upstream pipe portion does not intersect with a center line of the main circuit branch pipe portion and a center line of the bypass circuit branch pipe portion.
Drawings
Fig. 1 is a schematic diagram of a refrigeration cycle apparatus according to an embodiment of the present invention.
Fig. 2 is a schematic diagram of a subcooling circuit of a refrigeration cycle apparatus according to an embodiment of the present invention.
Fig. 3 is a diagram obtained by comparing the heat exchange amount in the subcooling circuit of the refrigeration cycle apparatus according to the embodiment of the present invention with the heat exchange amount in the subcooling circuit of the comparative example.
Fig. 4 is a cross-sectional view showing another example of the branch portion of the refrigeration cycle apparatus according to the embodiment of the present invention.
Fig. 5 is a cross-sectional view showing another example of the branching portion of the refrigeration cycle apparatus according to the embodiment of the present invention.
Detailed Description
An embodiment of a refrigeration cycle apparatus according to the present invention will be described with reference to fig. 1 to 5. In the drawings, the same or corresponding components are denoted by the same reference numerals.
Fig. 1 is a schematic diagram of a refrigeration cycle apparatus according to an embodiment of the present invention.
As shown in fig. 1, the refrigeration cycle apparatus 1 according to the present embodiment is, for example, an air conditioner. The refrigeration cycle device 1 includes: the refrigerant system includes a compressor 2, an outdoor heat exchanger 3, an outdoor expansion valve 9, a supercooling circuit 5, an indoor expansion valve 6, an indoor heat exchanger 7, and a refrigerant pipe 8 that connects the compressor 2, the outdoor heat exchanger 3, the supercooling circuit 5, the indoor expansion valve 6, and the indoor heat exchanger 7 and allows refrigerant to flow therethrough.
The refrigeration cycle apparatus 1 includes a four-way valve 11 and an accumulator 12 provided in a refrigerant pipe 8 between the four-way valve 11 and the compressor 2, and the four-way valve 11 sends the refrigerant discharged from the compressor 2 to either one of the outdoor heat exchanger 3 and the indoor heat exchanger 7 and causes the compressor 2 to suck the refrigerant again that has passed through either one of the outdoor heat exchanger 3 and the indoor heat exchanger 7.
The refrigeration cycle apparatus 1 includes an outdoor unit 15 provided outside a building such as a house or a building, and an indoor unit 16 provided inside the building. The refrigeration cycle apparatus 1 according to the present embodiment includes, for example, one outdoor unit 15 and a plurality of indoor units 16 connected in parallel to the outdoor unit 15.
The outdoor unit 15 houses the compressor 2, the outdoor heat exchanger 3, the outdoor expansion valve 9, the subcooling circuit 5, the four-way valve 11, and the memory 12. The outdoor unit 15 is provided with an outdoor fan 21, and the outdoor fan 21 sucks air from the outside of the outdoor unit 15 and blows air that has exchanged heat with the outdoor heat exchanger 3 to the outside of the outdoor unit 15. The outdoor blower 21 includes a propeller fan 22 opposed to the outdoor heat exchanger 3 and a motor 23 for rotationally driving the propeller fan 22.
The indoor unit 16 houses an indoor expansion valve 6 and an indoor heat exchanger 7. The indoor unit 16 is provided with an indoor blower 25, and the indoor blower 25 sucks air from outside the indoor unit 16 and blows air that has exchanged heat with the indoor heat exchanger 7 to outside the indoor unit 16. The indoor blower 25 includes a propeller fan 26 opposed to the indoor heat exchanger 7 and a motor 27 for rotationally driving the propeller fan 26.
The outdoor heat exchanger 3 and the indoor heat exchanger 7 are, for example, fin-tube type.
The outdoor heat exchanger 3 functions as a condenser when the refrigeration cycle apparatus 1 is operated to perform cooling operation, and functions as an evaporator when the refrigeration cycle apparatus 1 is operated to perform heating operation.
The indoor heat exchanger 7 functions as an evaporator when the refrigeration cycle apparatus 1 is operated to perform cooling operation, and functions as a condenser when the refrigeration cycle apparatus 1 is operated to perform heating operation.
The compressor 2 compresses, boosts, and discharges a refrigerant. The compressor 2 may be a device that changes the operating frequency by known inverter control, for example, or may be a device that cannot change the operating frequency.
The indoor expansion Valve 6 and the outdoor expansion Valve 9 are, for example, PMV (Pulse Motor Valve). The indoor expansion valve 6 and the outdoor expansion valve 9 are capable of adjusting the valve opening degree. The indoor expansion valve 6 functions mainly as an expansion valve during cooling operation and functions mainly as a control valve for adjusting the degree of supercooling of the indoor heat exchanger 7 during heating operation. On the other hand, the outdoor expansion valve 9 functions mainly as an expansion valve during the heating operation and functions mainly as a control valve for adjusting the degree of supercooling of the outdoor heat exchanger 3 during the cooling operation. Although not shown, the indoor expansion valve 6 and the outdoor expansion valve 9 include, for example, a valve main body having a through hole, a needle that can advance and retreat with respect to the through hole, and a power source that advances and retreats the needle. When the through hole is closed with the needle, the indoor expansion valve 6 and the outdoor expansion valve 9 stop (shut off) the flow of the refrigerant in the refrigeration cycle apparatus 1. At this time, the indoor expansion valve 6 and the outdoor expansion valve 9 are in a closed state, and the opening degrees of the indoor expansion valve 6 and the outdoor expansion valve 9 are the smallest. When the pin is farthest from the through hole, the circulation amount of the refrigerant of the refrigeration cycle device 1 will be maximized. At this time, the opening degrees of the indoor expansion valve 6 and the outdoor expansion valve 9 are maximized.
The power source is, for example, a stepping motor. When the pulse number inputted to the stepping motor is 0 pulse, the indoor expansion valve 6 and the outdoor expansion valve 9 are closed. When the pulse number inputted to the stepping motor is the maximum pulse, the indoor expansion valve 6 and the outdoor expansion valve 9 reach the maximum opening degree. The maximum number of pulses is, for example, several hundred pulses, for example, 500 pulses.
The refrigerant pipe 8 connects the compressor 2, the accumulator 12, the four-way valve 11, the outdoor heat exchanger 3, the outdoor expansion valve 9, the subcooling circuit 5, the indoor expansion valve 6, and the indoor heat exchanger 7. The refrigerant pipe 8 includes a main circuit pipe 31, a bypass circuit pipe 32 branching from the middle of the main circuit pipe 31 connecting the supercooling circuit 5 and the indoor expansion valve 6 and bypassing the refrigerant to the compressor 2, and a branching portion 33 branching the bypass circuit pipe 32 from the main circuit pipe 31, wherein the main circuit pipe 31 circulates the refrigerant through the compressor 2, the accumulator 12, the four-way valve 11, the outdoor heat exchanger 3, the outdoor expansion valve 9, the supercooling circuit 5, the indoor expansion valve 6, and the indoor heat exchanger 7.
The main circuit pipe 31 includes a first main refrigerant pipe 31a connecting the discharge side of the compressor 2 and the four-way valve 11, a second main refrigerant pipe 31b connecting the suction side of the compressor 2 and the four-way valve 11, a third main refrigerant pipe 31c connecting the four-way valve 11 and the outdoor heat exchanger 3, a fourth main refrigerant pipe 31d connecting the outdoor heat exchanger 3 and the indoor heat exchanger 7, and a fifth main refrigerant pipe 31e connecting the indoor heat exchanger 7 and the four-way valve 11.
The fourth main refrigerant pipe 31d connects the outdoor heat exchanger 3 and the indoor heat exchanger 7 via the first pipe connection 31f of the outdoor unit 15 and the second pipe connection 31g of the indoor unit 16.
The fifth main refrigerant pipe 31e connects the indoor heat exchanger 7 and the four-way valve 11 via the third pipe connection 31h of the indoor unit 16 and the fourth pipe connection 31i of the outdoor unit 15.
The branch portion 33 is disposed in the middle of the fourth main refrigerant pipe 31d that connects the outdoor heat exchanger 3 and the first pipe connection portion 31f of the outdoor unit 15.
The accumulator 12 is provided midway in the second main refrigerant pipe 31 b.
The outdoor expansion valve 9, the subcooling circuit 5, and the indoor expansion valve 6 are provided midway in the fourth main refrigerant pipe 31 d. The subcooling circuit 5 is closer to the outdoor heat exchanger 3 than the indoor expansion valve 6. The outdoor expansion valve 9 is closer to the outdoor heat exchanger 3 than the subcooling circuit 5. The indoor expansion valve 6 is closer to the indoor heat exchanger 7 than the subcooling circuit 5. In other words, the outdoor expansion valve 9 is disposed between the outdoor heat exchanger 3 and the subcooling circuit 5. The subcooling circuit 5 is disposed between the outdoor heat exchanger 3 and the indoor expansion valve 6. The subcooling circuit 5 is disposed between the outdoor expansion valve 9 and the indoor expansion valve 6. The outdoor expansion valve 9 is disposed in the middle of the fourth main refrigerant pipe 31d connecting the outdoor heat exchanger 3 and the first pipe connection portion 31f of the outdoor unit 15. The subcooling circuit 5 is disposed in the middle of the fourth main refrigerant pipe 31d that connects the outdoor heat exchanger 3 and the first pipe connection portion 31f of the outdoor unit 15. The indoor expansion valve 6 is disposed in the middle of the fourth main refrigerant pipe 31d that connects the second pipe connection portion 31g of the indoor unit 16 and the indoor heat exchanger 7.
The four-way valve 11 switches the flow direction of the refrigerant in the refrigerant pipe 8. When the refrigeration cycle apparatus 1 is caused to perform a cooling operation (flow of refrigerant indicated by a solid line in fig. 1) to lower the room temperature in the building, the four-way valve 11 causes the refrigerant to flow from the first main refrigerant pipe 31a to the third main refrigerant pipe 31c, and causes the refrigerant to flow from the fifth main refrigerant pipe 31e to the second main refrigerant pipe 31 b. When the refrigeration cycle apparatus 1 is caused to perform a heating operation (a flow of refrigerant indicated by a broken line in fig. 1) to increase the room temperature in the building, the four-way valve 11 causes the refrigerant to flow from the first main refrigerant pipe 31a to the fifth main refrigerant pipe 31e, and causes the refrigerant to flow from the third main refrigerant pipe 31c to the second main refrigerant pipe 31 b.
Fig. 2 is a schematic diagram of a subcooling circuit of a refrigeration cycle apparatus according to an embodiment of the present invention.
As shown in fig. 1 and 2, the subcooling circuit 5 of the refrigeration cycle apparatus 1 according to the present embodiment includes a bypass pipe 32, a subcooling expansion valve 41, and a subcooling heat exchanger 42.
The bypass circuit pipe 32 branches the refrigerant flowing from the outdoor heat exchanger 3 to the main circuit pipe 31 of the indoor heat exchanger 7 during the cooling operation, so that the refrigerant in the main circuit pipe 31 bypasses the indoor expansion valve 6 and the indoor heat exchanger 7 to the accumulator 12. The bypass circuit pipe 32 branches from a branching portion 33, that is, a middle portion of the fourth main refrigerant pipe 31d connecting the outdoor heat exchanger 3 and the first pipe connecting portion 31f of the outdoor unit 15. The bypass circuit pipe 32 joins the second main refrigerant pipe 31b of the main circuit pipe 31 in the middle of the second main refrigerant pipe 31b connecting the accumulator 12 and the four-way valve 11.
The subcooling expansion valve 41 decompresses the refrigerant flowing from the branch portion 33 into the bypass pipe 32.
The supercooling heat exchanger 42 exchanges heat between the refrigerant decompressed by the cooling expansion valve 41 and the refrigerant flowing through the main circuit pipe 31 (specifically, a portion upstream of the branch portion 33 in the fourth main refrigerant pipe 31d), and supercools the refrigerant flowing through the main circuit pipe 31.
The bypass pipe 32 includes a first bypass refrigerant pipe 32a connecting the branching portion 33 and the subcooling expansion valve 41, a second bypass refrigerant pipe 32b connecting the subcooling expansion valve 41 and the subcooling heat exchanger 42, and a third bypass refrigerant pipe 32 connecting the subcooling heat exchanger 42 and the second main refrigerant pipe 31b of the main pipe 31.
The refrigeration cycle apparatus 1 includes a control unit 45, and the control unit 45 is electrically connected to the four-way valve 11 via a signal line (not shown). The controller 45 may be connected to the compressor 2 capable of changing the operating frequency.
The control unit 45 includes a central processing unit (not shown) and a storage unit (not shown) for storing various calculation programs and parameters executed by the central processing unit. The control unit 45 reads various control programs from the auxiliary storage device into the main storage device, and the central processing unit executes the various control programs read from the main storage device.
The control unit 45 switches the state of the four-way valve 11 based on a request input to an input device such as a remote controller, for example, and switches the cooling operation and the heating operation of the refrigeration cycle apparatus 1.
The controller 45 controls the opening degree of the subcooling expansion valve 41 based on a first temperature sensor 46 that measures the temperature of the refrigerant flowing through the fourth main refrigerant tube 31d between the outdoor heat exchanger 3 and the subcooling circuit 5, a second temperature sensor 47 that measures the temperature of the refrigerant flowing through the fourth main refrigerant tube 31d between the subcooling circuit 5 and the first pipe connecting portion 31f, a third temperature sensor 48 that measures the temperature of the refrigerant flowing through the third bypass refrigerant tube 32c, and the suction saturation temperature.
The suction saturation temperature is obtained by converting the value of the suction pressure sensor 49, and the pressure sensor 49 measures the pressure of the refrigerant flowing through the fourth main refrigerant pipe 31 d.
During the cooling operation, the refrigeration cycle apparatus 1 discharges a compressed high-temperature and high-pressure refrigerant from the compressor 2, and sends the refrigerant to the outdoor heat exchanger 3 via the four-way valve 11. The outdoor heat exchanger 3 exchanges heat between air outside the building and the refrigerant passing through the tubes, and cools the refrigerant to be in a high-pressure liquid state. That is, during the cooling operation, the outdoor heat exchanger 3 functions as a condenser. The refrigerant having passed through the outdoor heat exchanger 3 becomes a low-pressure gas-liquid two-phase refrigerant decompressed by the indoor expansion valve 6, and reaches the indoor heat exchanger 7. The indoor heat exchanger 7 exchanges heat between air in the building and refrigerant passing through the tubes to cool the air in the building. At this time, the indoor heat exchanger 7 functions as an evaporator that evaporates the refrigerant and turns it into a gas state. The refrigerant having passed through the indoor heat exchanger 7 is sucked and returned to the compressor 2.
On the other hand, during the heating operation, the refrigeration cycle apparatus 1 reverses the four-way valve 11 to generate a flow of refrigerant in the refrigeration cycle that is opposite to the flow of refrigerant during cooling, and causes the indoor heat exchanger 7 to function as a condenser and the outdoor heat exchanger 3 to function as an evaporator.
The refrigeration cycle apparatus 1 may be a device dedicated for cooling that does not include the four-way valve 11. In this case, the discharge side of the compressor 2 is connected to the outdoor heat exchanger 3 through the refrigerant pipe 8, and the suction side of the compressor 2 is connected to the indoor heat exchanger 7 through the refrigerant pipe 8.
The subcooling circuit 5 is configured to reduce the dryness of the refrigerant flowing from the outdoor heat exchanger 3 to the indoor expansion valve 6, and to reduce the amount of refrigerant circulating through the indoor unit 16.
The subcooling circuit 5 is generally used for a refrigeration operation. The subcooling circuit 5 branches a part of the liquid refrigerant condensed in the outdoor heat exchanger 3 at the branch portion 33, and causes the part to expand at a low pressure in the subcooling expansion valve 41. The supercooling heat exchanger 42 exchanges heat between the two-phase refrigerant decompressed and expanded by the supercooling expansion valve 41 and the refrigerant flowing through the main circuit pipe 31 (more specifically, a portion upstream of the branch portion 33 in the fourth main refrigerant pipe 31d) to cool the refrigerant flowing through the main circuit pipe 31.
In addition, when a part of the refrigerant is not condensed in the outdoor heat exchanger 3 and flows out to the fourth main refrigerant pipe 31d while maintaining the gas refrigerant, there is a possibility that the two-phase refrigerant flows into the subcooling circuit 5. Generally, the subcooling expansion valve 41 does not have a sufficient pipe diameter for the two-phase refrigerant to flow through. Therefore, the subcooling circuit 5 cannot sufficiently ensure the flow rate of the refrigerant. Also, the heat exchange amount of the subcooling circuit 5 is reduced. When the amount of heat exchange in the subcooling circuit 5 is reduced, the gas refrigerant is mixed into the fourth main refrigerant pipe 31d of the main circuit pipe 31, and the gas refrigerant is sent to the indoor unit 16.
Therefore, the branch portion 33 of the refrigeration cycle apparatus 1 according to the present embodiment includes the upstream pipe portion 51, the main circuit branch pipe portion 52 that branches upward (solid arrow U in fig. 2) from the upstream pipe portion 51 and that leads to the indoor expansion valve 6, and the bypass circuit branch pipe portion 53 that branches downward (solid arrow D in fig. 2) from the upstream pipe portion 51 and that leads to the subcooling circuit 5. The upstream tube portion 51 and the main circuit branch tube portion 52 correspond to a part of the fourth main refrigerant tube 31d of the main circuit tube 31, and the bypass circuit branch tube portion 53 corresponds to a part of the first bypass refrigerant tube 32a of the bypass circuit tube 32.
The main circuit branch pipe portion 52 and the bypass circuit branch pipe portion 53 are continuous straight pipes 55. In other words, the main circuit branch pipe portion 52, which is a part of the straight pipe 55, corresponds to a part of the fourth main refrigerant pipe 31d of the main circuit pipe 31, and the bypass circuit branch pipe portion 53, which is the remaining part of the straight pipe 55, corresponds to a part of the first bypass refrigerant pipe 32a of the bypass circuit pipe 32. The straight pipe 55 has substantially the same flow path cross-sectional area from a portion corresponding to the main circuit branch pipe portion 52 to a portion corresponding to the bypass circuit branch pipe portion 53. The boundary between the fourth main refrigerant pipe 31d of the main loop pipe 31 and the first detour refrigerant pipe 32a of the bypass loop pipe 32 is a merging portion of the straight pipe 55 and the upstream pipe 51.
The fourth main refrigerant pipe 31d may be bent except for a portion corresponding to the straight pipe 55. The first bypass refrigerant pipe 32a may be bent except for a portion corresponding to the remaining portion of the straight pipe 55.
The main circuit branch pipe portion 52 and the bypass circuit branch pipe portion 53 extend substantially in the vertical direction. The main circuit branch pipe portion 52 and the bypass circuit branch pipe portion 53 may be inclined within a range of 30 degrees (± 30 degrees) with respect to the vertical line VL.
The upstream pipe portion 51 stands on the straight pipe 55. In other words, the upstream pipe portion 51 abuts on the straight pipe 55 from the radial direction of the straight pipe 55. The upstream pipe portion 51 extends substantially horizontally. The upstream pipe portion 51 may be inclined within a range of 45 degrees (± 45 degrees) with respect to the water surface HP. The angle θ formed by the upstream pipe portion 51 and the straight pipe 55 is preferably 45 degrees or more.
For example, when the upstream pipe portion 51 abuts on the straight pipe 55 from the radial direction of the straight pipe 55, the angle θ formed by the upstream pipe portion 51 and the straight pipe 55 is 90 degrees. In this case, the upstream pipe portion 51 and the straight pipe 55 are shaped such that the T-shape is inverted by 90 degrees.
The flow path cross-sectional area PA1 of the straight pipe 55 is 2 times or more the flow path cross-sectional area PA2 of the upstream pipe portion 51.
The branching portion 33 of the refrigeration cycle apparatus 1 according to the present embodiment generates a main flow (a flow of the refrigerant flowing through the main circuit pipe 31) in the direction of the solid arrow a in fig. 2, and generates a bypass flow (a flow of the refrigerant flowing through the subcooling circuit 5) in the direction of the solid arrow B in fig. 2. The amount of refrigerant that bypasses the subcooling circuit 5 is determined by the inner diameter of the bypass pipe 32 and the valve opening degree of the subcooling expansion valve 41. The amount of refrigerant that bypasses the subcooling circuit 5 is, for example, 0% (when the subcooling expansion valve 41 is fully closed) to 20% (when the subcooling expansion valve 41 is fully opened) of the main flow. Therefore, in the first bypass refrigerant pipe 32a, the gas refrigerant is separated upward and the liquid refrigerant is separated downward due to the influence of buoyancy and gravity. Then, the proportion of the liquid refrigerant flowing into the subcooling circuit 5 increases, and the proportion of the gas refrigerant flowing into the subcooling circuit 5 decreases.
Once the flow rate of the liquid refrigerant flowing into the supercooling circuit 5 is secured, the gas-liquid two-phase refrigerant can be condensed into the liquid refrigerant in the supercooling circuit 5 even if the gas-liquid two-phase refrigerant flows out of the outdoor heat exchanger 3. That is, outflow of the gas refrigerant to the indoor unit 16 side is suppressed.
When the flow path cross-sectional area of the straight pipe 55 is 2 times or more the flow path cross-sectional area of the upstream pipe portion 51, the flow velocity of the refrigerant in the straight pipe 55 is suppressed. This suppression effect suppresses the flow velocity of the refrigerant in the first bypass refrigerant tube 32a (i.e., the flow velocity of the bypass flow) to about 1, for example, of the flow velocity of the refrigerant in the fourth main refrigerant tube 31d (i.e., the flow velocity of the main flow). The suppression of the flow velocity of the refrigerant makes the buoyancy of the gas refrigerant larger than the force received from the flow of the liquid refrigerant. Therefore, the effect of gas-liquid separation is more remarkable.
Fig. 3 is a diagram obtained by comparing the heat exchange amount in the subcooling circuit of the refrigeration cycle apparatus according to the embodiment of the present invention with the heat exchange amount in the subcooling circuit of the comparative example.
A solid line α in fig. 3 shows a relationship between dryness and a heat exchange amount in the subcooling circuit 5 of the refrigeration cycle apparatus 1 according to the present embodiment. A broken line β in fig. 3 shows a relationship between the dryness fraction and the heat exchange amount in the subcooling circuit of the refrigeration cycle apparatus of the comparative example.
Here, first, the branching portion of the refrigeration cycle apparatus of the comparative example includes a main circuit pipe (corresponding to the fourth main refrigerant pipe 31d) extending in the horizontal direction and connecting the outdoor heat exchanger 3 and the indoor heat exchanger 7, and a bypass circuit pipe (corresponding to the first bypass refrigerant pipe 32a) branching downward from the lower surface of the main circuit pipe and connecting to the subcooling expansion valve 41. In other words, the refrigeration cycle apparatus of the comparative example includes a T-shaped branch portion drawn by the main circuit pipe and the bypass circuit pipe depending from the straight pipe portion of the main circuit pipe.
As shown in fig. 3, in the refrigeration cycle apparatus of the comparative example, when the dryness is not equal to or less than the zero value, the flow rate in the subcooling expansion valve cannot be secured. Therefore, if the dryness of the subcooling circuit of the comparative example exceeds a zero value, the heat exchange amount is insufficient.
In the refrigeration cycle apparatus 1 according to the present embodiment, the liquid refrigerant can be caused to flow through the subcooling expansion valve 41 even in the gas-liquid two-phase region where the dryness is greater than zero due to the gas-liquid separation effect of the branch portion 33. Therefore, the subcooling circuit 5 according to the present embodiment can increase the amount of heat exchange even when the dryness is greater than zero.
Fig. 4 and 5 are cross-sectional views showing other examples of the branch portion of the refrigeration cycle apparatus according to the embodiment of the present invention. Fig. 4 is a cross-sectional view passing through the center of the upstream pipe portion 51 of the branch portion 33 and orthogonal to the centers of the main circuit branch pipe portion 52 and the bypass circuit branch pipe portion 53. Fig. 5 is a cross-sectional view through the centers of the main circuit branch pipe portion 52 and the bypass circuit branch pipe portion 53.
As shown in fig. 4 and 5, the refrigeration cycle device 1 according to the present embodiment includes a branch portion 33A. An extension line of the center line Ca of the upstream pipe portion 51 of the branch portion 33A does not intersect the center line Cb of the main circuit branch pipe portion 52 and the center line Cc of the bypass circuit branch pipe portion 53. In other words, the extension of the center line Ca of the upstream pipe portion 51 is offset radially outward of the main circuit branch pipe portion 52 and the bypass circuit branch pipe portion 53 with respect to the center line Cb of the main circuit branch pipe portion 52 and the center line Cc of the bypass circuit branch pipe portion 53.
In the cross section of fig. 4, the upstream pipe portion 51 is preferably connected along a tangent line TL of the main-circuit branch pipe portion 52 and the bypass-circuit branch pipe portion 53.
The pipe diameter of the upstream pipe portion 51 is preferably equal to or less than one-half of the pipe diameters of the main circuit branch pipe portion 52 and the bypass circuit branch pipe portion 53.
In the branch portion 33A, the refrigerant flowing from the upstream pipe portion 51 into the straight pipe 55 (the main circuit branch pipe portion 52 and the bypass circuit branch pipe portion 53) flows in the circumferential direction (solid arrow R) in the straight pipe 55. The swirling flow R produces a separation effect of the gas refrigerant g and the liquid refrigerant l by a centrifugal force at a branching portion between the upstream pipe portion 51 and the straight pipe 55. The swirling flow R reduces the flow velocity of the refrigerant in the longitudinal direction in the straight pipe 55. Such a decrease in the flow velocity tends to cause the gas refrigerant to float upward and the liquid refrigerant to drop (descend) downward. That is, the ratio of the liquid refrigerant supplied to the subcooling circuit 5 is increased.
The refrigeration cycle device 1 according to the present embodiment includes the branching portions 33, 33A, and the branching portions 33, 33A include the main circuit branching pipe portion 52 that branches upward from the upstream pipe portion 51 and that leads to the indoor expansion valve 6, and the bypass circuit branching pipe portion 53 that branches downward from the upstream pipe portion 51 and that leads to the subcooling circuit 5. Therefore, even when the refrigerant in the gas-liquid two-phase state flows out of the outdoor heat exchanger 3, the refrigeration cycle apparatus 1 can increase the proportion of the liquid refrigerant flowing into the subcooling circuit 5 and decrease the proportion of the gas refrigerant flowing into the subcooling circuit 5. When the flow rate of the liquid refrigerant flowing into the supercooling circuit 5 is secured, the refrigerant in the gas-liquid two-phase state can be condensed into the liquid refrigerant in the supercooling circuit 5 even if the refrigerant in the gas-liquid two-phase state flows out of the outdoor heat exchanger 3. That is, the refrigeration cycle device 1 can suppress the outflow of the gas refrigerant to the indoor unit 16 side by the branches 33 and 33A having a simple structure.
The refrigeration cycle apparatus 1 according to the present embodiment includes a continuous straight pipe 55 serving as the main circuit branch pipe portion 52 and the bypass circuit branch pipe portion 53, and the upstream pipe portion 51 standing on the straight pipe 55. Therefore, the refrigeration cycle device 1 can suppress the outflow of the gas refrigerant to the indoor unit 16 side by the branches 33 and 33A having extremely simple structures.
The refrigeration cycle apparatus 1 according to the present embodiment includes a straight pipe 55, and the straight pipe 55 has a flow passage cross-sectional area that is 2 times or more the flow passage cross-sectional area of the upstream pipe portion 51. Therefore, the refrigeration cycle apparatus 1 can suppress the flow velocity of the refrigerant in the straight pipe 55. This suppressing effect greatly reduces the flow velocity of the refrigerant in the first bypass refrigerant pipe 32a compared to the flow velocity of the refrigerant in the fourth main refrigerant pipe 31 d. This reduction in the flow rate of the refrigerant causes the buoyancy of the gaseous refrigerant to be greater than the force received from the flow of the liquid refrigerant. That is, the refrigeration cycle apparatus 1 can more significantly exhibit the effect of gas-liquid separation.
The refrigeration cycle device 1 according to the present embodiment includes an upstream pipe portion 51 extending substantially in the horizontal direction, a main circuit branch pipe portion 52 extending substantially in the vertical direction, and a bypass circuit branch pipe portion 53. Therefore, the refrigeration cycle apparatus 1 can more reliably separate the refrigerant in the gas-liquid two-phase state flowing into the branching portions 33, 33A into the gas refrigerant and the liquid refrigerant, and can introduce the separated liquid refrigerant into the subcooling circuit 5.
The refrigeration cycle device 1 according to the present embodiment has an extension line of the center line of the upstream pipe portion 51, which does not intersect the center line of the main circuit branch pipe portion 52 and the center line of the bypass circuit branch pipe portion 53. Therefore, the refrigeration cycle apparatus 1 generates a swirling flow in the branch portion 33A, and can supplement the separation effect of the gas refrigerant and the liquid refrigerant by the centrifugal force, in addition to the separation effect of the gas refrigerant and the liquid refrigerant by the gravity.
Therefore, according to the refrigeration cycle apparatus 1 designed in the present embodiment, the performance of the subcooling circuit 5 can be fully exhibited by the branch portions 33 and 33A having a simple structure.
Several embodiments of the present invention have been described, but these embodiments are presented by way of example only and are not intended to limit the scope of the invention. These new embodiments may be implemented in other various ways, and various omissions, substitutions, and changes may be made without departing from the scope of the invention. These embodiments and modifications are included in the scope and gist of the invention, and are also included in the invention described in the scope of the claims and the equivalent scope thereof.
Description of the reference symbols
1 refrigeration cycle device
2 compressor
3 outdoor heat exchanger
5 subcooling circuit
6 indoor expansion valve
7 indoor heat exchanger
8 refrigerant pipe
9 outdoor expansion valve
11 four-way valve
12 memory
15 outdoor unit
16 indoor unit
21 outdoor blower
Propeller fan of 22 outdoor blower
23 outdoor blower motor
25 indoor blower
Propeller fan for 26 indoor blower
27 motor of indoor blower
31 main loop pipe
31a first main refrigerant pipe
31b second main refrigerant pipe
31c third main refrigerant pipe
31d fourth main refrigerant pipe
31e fifth main refrigerant pipe
31f first pipe connection part
31g second pipe connection part
31h third pipe connection part
31i fourth pipe connection part
32 bypass loop pipe
32a first bypass refrigerant pipe
32b second bypass refrigerant pipe
32c third bypass refrigerant pipe
33. 33A branch part
41 supercooling expansion valve
42 supercooling heat exchanger
45 control part
46 first temperature sensor
47 second temperature sensor
48 third temperature sensor
51 upstream pipe part
52 main circuit branch pipe part
53 bypass circuit branch pipe part
And (5) a straight pipe 55.
Claims (5)
1. A refrigeration cycle apparatus, comprising:
a compressor;
a condenser;
an indoor expansion valve;
a supercooling circuit disposed between the condenser and the indoor expansion valve;
an evaporator; and
a refrigerant pipe connecting the compressor, the condenser, the supercooling circuit, the indoor expansion valve, and the evaporator to circulate a refrigerant,
the refrigerant pipe has: a main circuit pipe circulating the refrigerant in the compressor, the condenser, the subcooling circuit, the indoor expansion valve, and the evaporator; a bypass pipe that branches from a middle of the main pipe connecting the subcooling circuit and the indoor expansion valve and bypasses the refrigerant to the compressor; and a branch portion between the main loop pipe and the bypass loop pipe,
the branch portion includes: an upstream pipe portion; a main circuit branch pipe portion that branches upward from the upstream pipe portion and that branches toward the indoor expansion valve; and a bypass circuit branch pipe portion branching downward from the upstream pipe portion and extending toward the subcooling circuit.
2. The refrigeration cycle apparatus according to claim 1,
the main circuit branch pipe portion and the bypass circuit branch pipe portion are continuous straight pipes,
the upstream pipe portion is erected on the straight pipe.
3. The refrigeration cycle apparatus according to claim 1 or 2,
the flow path cross-sectional area of the straight pipe is 2 times or more the flow path cross-sectional area of the upstream pipe portion.
4. The refrigeration cycle apparatus according to any one of claims 1 to 3,
the upstream pipe portion extends substantially in a horizontal direction,
the main circuit branch pipe portion and the bypass circuit branch pipe portion extend substantially in a vertical direction.
5. The refrigeration cycle apparatus according to any one of claims 1 to 4,
an extension line of the center line of the upstream pipe portion does not intersect with the center line of the main circuit branch pipe portion and the center line of the bypass circuit branch pipe portion.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| PCT/JP2018/035376 WO2020065712A1 (en) | 2018-09-25 | 2018-09-25 | Refrigeration cycle device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN112771319A true CN112771319A (en) | 2021-05-07 |
Family
ID=69950436
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201880097837.9A Pending CN112771319A (en) | 2018-09-25 | 2018-09-25 | Refrigeration cycle device |
Country Status (4)
| Country | Link |
|---|---|
| EP (1) | EP3859230A4 (en) |
| JP (1) | JP7054419B2 (en) |
| CN (1) | CN112771319A (en) |
| WO (1) | WO2020065712A1 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114992899B (en) * | 2022-06-10 | 2023-06-16 | 海信空调有限公司 | Air conditioner and oil blocking prevention control method thereof |
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| JPH09310925A (en) * | 1996-05-21 | 1997-12-02 | Hitachi Ltd | Air conditioner |
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| JP2002200402A (en) * | 2000-12-28 | 2002-07-16 | Ryosaku Fujisato | Gas-liquid separator and gas-liquid separating apparatus provided therewith |
| US6938438B2 (en) * | 2003-04-21 | 2005-09-06 | Carrier Corporation | Vapor compression system with bypass/economizer circuits |
| JP2005233551A (en) | 2004-02-20 | 2005-09-02 | Mitsubishi Electric Corp | Refrigeration cycle device |
| JP5197444B2 (en) * | 2009-03-10 | 2013-05-15 | 三菱電機株式会社 | Gas-liquid separator and refrigeration cycle equipment equipped with it |
| WO2015056704A1 (en) * | 2013-10-17 | 2015-04-23 | 東芝キヤリア株式会社 | Refrigeration cycle device |
| US10260780B2 (en) * | 2015-10-27 | 2019-04-16 | Gd Midea Heating & Ventilating Equipment Co., Ltd. | Enhanced vapor injection air conditioning system |
| WO2018047511A1 (en) * | 2016-09-12 | 2018-03-15 | 三菱電機株式会社 | Heat exchanger and air-conditioner |
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2018
- 2018-09-25 JP JP2020547626A patent/JP7054419B2/en active Active
- 2018-09-25 CN CN201880097837.9A patent/CN112771319A/en active Pending
- 2018-09-25 EP EP18935610.8A patent/EP3859230A4/en active Pending
- 2018-09-25 WO PCT/JP2018/035376 patent/WO2020065712A1/en unknown
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH05322383A (en) * | 1992-05-15 | 1993-12-07 | Daikin Ind Ltd | Gas/liquid separator |
| CN102032699A (en) * | 2009-10-05 | 2011-04-27 | 松下电器产业株式会社 | Refrigeration cycle apparatus and hot water heater |
| CN103225935A (en) * | 2013-04-22 | 2013-07-31 | 重庆美的通用制冷设备有限公司 | Gas-liquid separator, air source heat recovery system, water chiller and heat pump |
| JP2015143614A (en) * | 2015-03-17 | 2015-08-06 | 株式会社サムスン日本研究所 | Refrigerant amount detector |
| CN205784060U (en) * | 2016-05-18 | 2016-12-07 | 天津大学 | A kind of impacting type T-shaped pipe composition regulation device for non-azeotropic working medium composition regulation |
Also Published As
| Publication number | Publication date |
|---|---|
| JPWO2020065712A1 (en) | 2021-08-30 |
| JP7054419B2 (en) | 2022-04-13 |
| WO2020065712A1 (en) | 2020-04-02 |
| EP3859230A1 (en) | 2021-08-04 |
| EP3859230A4 (en) | 2022-05-04 |
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