JP2014181870A - Refrigeration cycle device - Google Patents

Abstract

A refrigeration cycle apparatus including an internal heat exchanger having excellent heat exchange performance by increasing a heat transfer area between a high-pressure side pipe of an internal heat exchanger and a high-pressure side refrigerant.
Internal heat exchanged between a compressor, a radiator, a decompressor, an evaporator, and a high-pressure refrigerant supplied from the radiator to the decompressor and a low-pressure refrigerant decompressed by the decompressor. The high-pressure side pipe 131 that includes the exchanger and in which the high-pressure side refrigerant flows in the internal heat exchanger is a refrigeration cycle device having an uneven portion 134 on the inner surface, and the high-pressure side that flows through the high-pressure side pipe 131 and the high-pressure side pipe 131. As the heat transfer area with the refrigerant increases and the turbulent flow promoting effect is produced by the uneven portion 134, the heat transfer coefficient between the high pressure side pipe 131 and the high pressure side refrigerant flowing inside the high pressure side pipe 131 is improved. The amount of heat exchange between the high-pressure side refrigerant and the low-pressure side refrigerant can be increased.
[Selection] Figure 2

Description

  The present invention relates to a refrigeration cycle apparatus.

  Conventionally, a refrigerant that has flowed out of the radiator and a refrigerant that has flowed out of the evaporator are connected to a refrigeration cycle apparatus formed by connecting a compressor, a radiator, a decompression unit, and an evaporator in a ring shape with a refrigerant pipe. An internal heat exchanger for heat exchange may be provided, and a schematic diagram of this internal heat exchanger is shown in FIG.

  In FIG. 4, in the refrigeration cycle apparatus formed by connecting a compressor, a radiator, a decompression unit, and an evaporator in a ring shape with refrigerant piping, the internal heat exchanger has a low-pressure side through which the low-pressure refrigerant flowing out of the evaporator flows. A pipe 132 and a high-pressure pipe 131 through which the high-pressure refrigerant that has flowed out of the radiator flows, and is integrally formed so that the low-pressure refrigerant and the high-pressure refrigerant can exchange heat; A configuration surrounded by 135 is disclosed (for example, see Patent Document 1).

JP 2004-85183 A

  However, the conventional prior art document discloses that the amount of heat exchange in the internal heat exchanger is determined by appropriately setting the contact area between the high-pressure side pipe and the low-pressure side pipe. No technical matter is disclosed that the pipe and the refrigerant flowing in the pipe and the heat transfer area affect the heat exchange amount.

  The present invention solves the above-described conventional problems, and includes an internal heat exchanger with excellent heat exchange performance by increasing the heat transfer area between the high-pressure side piping and the high-pressure side refrigerant of the internal heat exchanger. A refrigeration cycle apparatus is provided.

  In order to achieve the above object, a refrigeration cycle apparatus according to the present invention includes a compressor, a radiator, a decompression unit, an evaporator, a high-pressure side refrigerant supplied from the radiator to the decompression unit, and the decompression unit. An internal heat exchanger that exchanges heat with the low-pressure side refrigerant decompressed by the means, and the high-pressure side pipe through which the high-pressure side refrigerant flows in the internal heat exchanger has an uneven portion on the inner surface. It is.

  As a result, the heat transfer area between the high-pressure side pipe and the high-pressure side refrigerant flowing inside the high-pressure side pipe is increased, and a turbulent flow promoting effect is produced by the uneven portion, so that the high-pressure flowing inside the high-pressure side pipe and the high-pressure side pipe By improving the heat transfer coefficient with the side refrigerant, the amount of heat exchange between the high-pressure side refrigerant and the low-pressure side refrigerant can be increased.

  ADVANTAGE OF THE INVENTION According to this invention, the refrigeration cycle apparatus provided with the internal heat exchanger excellent in heat exchange performance can be provided by increasing the heat transfer area of the high voltage | pressure side piping and high pressure side refrigerant | coolant of an internal heat exchanger.

Schematic diagram of internal heat exchanger according to Embodiment 1 of the present invention XX sectional view of FIG. 1 is a circuit configuration diagram of a refrigeration cycle apparatus according to Embodiment 1 of the present invention. Overview of conventional internal heat exchanger

  The first invention includes a compressor, a radiator, a decompression unit, an evaporator, a high-pressure side refrigerant supplied from the radiator to the decompression unit, and a low-pressure side refrigerant decompressed by the decompression unit. An internal heat exchanger for exchanging heat, and the high-pressure side pipe through which the high-pressure side refrigerant flows in the internal heat exchanger has a concavo-convex portion on the inner surface.

  As a result, the heat transfer area between the high-pressure side pipe and the high-pressure side refrigerant flowing inside the high-pressure side pipe is increased, and a turbulent flow promoting effect is produced by the uneven portion, so that the high-pressure flowing inside the high-pressure side pipe and the high-pressure side pipe By improving the heat transfer coefficient with the side refrigerant, the amount of heat exchange between the high-pressure side refrigerant and the low-pressure side refrigerant can be increased.

  In addition, by providing an uneven portion on the inner surface of the high-pressure side pipe, that is, an inner grooved pipe, a vortex is generated when refrigerant flows through the high-pressure side pipe, resulting in energy loss (pressure loss). Since the high-pressure side refrigerant flows between the radiator and the decompression means, even if a pressure loss occurs in the high-pressure side refrigerant in the internal heat exchanger, if the amount of decompression in the decompression means is varied and adjusted, Since the pressure difference does not fluctuate, the operating efficiency of the equipment is not reduced.

  Thereby, the amount of heat exchange in the internal heat exchanger can be increased while improving the energy efficiency of the refrigeration cycle apparatus.

  2nd invention is equipped with the defrost operation mode which melt | dissolves the frost adhering to the said evaporator, In the said defrost operation mode, a refrigerant | coolant is the said high pressure side piping of the said compressor, the said heat radiator, and the said internal heat exchanger, The pressure reducing means, the evaporator, the low-pressure side pipe of the internal heat exchanger, and the compressor are circulated in this order.

  Thereby, in the hot water storage operation mode in which water or the like is heated with a radiator, the heat exchange amount of the internal heat exchanger can be increased, the energy efficiency of the refrigeration cycle apparatus can be improved, and in the defrost operation mode, The refrigerant is wet-compressed by the compressor and discharged from the compressor together with the lubricating oil of the compressor, and this lubricating oil adheres to the uneven part (groove part) of the high-pressure side pipe of the internal heat exchanger, so that the defrosting operation is performed. The heat exchange efficiency of the high-pressure side refrigerant and the low-pressure side refrigerant in the internal heat exchanger can be reduced, and as a result, the heat release amount of the high-pressure side refrigerant in the internal heat exchanger is reduced, and the high-pressure side refrigerant The defrosting operation time can be shortened because the heat it has can be efficiently transmitted to the evaporator and used for defrosting.

  The third invention is characterized in that the pressure reducing means is arranged vertically above the radiator.

Thereby, in the hot water storage operation mode in which water or the like is heated by the radiator, the heat exchange amount of the internal heat exchanger can be increased, and the energy efficiency of the refrigeration cycle apparatus can be improved and the refrigerant in the defrost operation mode. Is wet-compressed by the compressor and discharged from the compressor together with the lubricating oil of the compressor, but the refrigerant flows from the radiator to the high-pressure side piping of the internal heat exchanger and the decompression means, and the decompression means dissipates heat. The lubricating oil adheres to the uneven part (groove part) of the high-pressure side pipe of the internal heat exchanger and is lubricated to the uneven part (groove part) by the action of gravity. Due to the oil remaining easily, the heat exchange efficiency of the high-pressure side refrigerant and the low-pressure side refrigerant in the internal heat exchanger can be reduced during the defrosting operation. As a result, the high-pressure side refrigerant in the internal heat exchanger can be reduced. The heat dissipation is reduced The heat of the high-pressure side refrigerant can efficiently transmitted to the evaporator, that can be utilized in defrosting, it is possible to shorten the defrosting operation time.

  The fourth invention is characterized in that the low-pressure side refrigerant of the internal heat exchanger is a refrigerant supplied from the evaporator to the compressor.

  As a result, the refrigerant can be operated in a wet state over substantially the entire area of the evaporator, so that the heat exchange efficiency of the evaporator can be increased and the degree of superheat of the refrigerant sucked into the compressor can be sufficiently increased. It is possible to improve the energy efficiency of the refrigeration cycle apparatus.

  The fifth invention is characterized in that the inner surface of the low-pressure side pipe through which the low-pressure side refrigerant flows in the internal heat exchanger is smooth.

  As a result, the contact area between the low-pressure side refrigerant and the low-pressure side pipe is reduced and the pressure loss of the low-pressure side refrigerant is reduced as compared with the case where the uneven portion (groove) is provided in the low-pressure side pipe. As a result, the energy efficiency of the refrigeration cycle apparatus can be improved.

  In a sixth aspect of the present invention, the low pressure side pipe through which the low pressure side refrigerant flows in the internal heat exchanger is joined in parallel with the high pressure side pipe, and the inner diameter of the low pressure side pipe is larger than the inner diameter of the high pressure side pipe. It is characterized by.

  As a result, the internal surface area of the low-pressure side pipe can be made relatively large, so that the thermal resistance between the low-pressure side refrigerant and the low-pressure side pipe and the thermal resistance between the high-pressure side refrigerant and the high-pressure side pipe are made relatively uniform. The heat exchange efficiency in the internal heat exchanger can be improved, and the energy efficiency of the refrigeration cycle apparatus can be improved.

  The seventh invention is characterized in that the refrigerant is carbon dioxide, and since it is a non-flammable refrigerant, there is an effect that the risk of ignition or explosion can be eliminated.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments.

(Embodiment 1)
The configuration of the internal heat exchanger and the heat pump water heater in the first embodiment of the present invention will be described below with reference to the drawings.

  FIG. 1 is a schematic diagram of an internal heat exchanger according to a first embodiment of the present invention. FIG. 2 is a sectional view taken along line XX in FIG.

  1 and 2, the high-pressure side pipe 131 and the low-pressure side pipe 132 of the internal heat exchanger 13 are in contact with each other at the joint 133 so that the high-pressure refrigerant and the low-pressure refrigerant flowing inside can exchange heat. Are arranged in parallel.

  Here, the inner surface of the high-pressure side pipe 131 is processed to provide an uneven portion 134 that is a groove for promoting heat transfer, and the inner surface of the low-pressure side pipe 132 is smoothed to reduce pressure loss. It is said.

  The joint 133 between the high-pressure side pipe 131 and the low-pressure side pipe 132 is metal-bonded by solder to promote heat transfer, and the inner diameter of the low-pressure side pipe is larger than the inner diameter of the high-pressure side pipe.

  The end of the high-pressure side pipe 131 of the internal heat exchanger 13 is connected to the refrigerant pipe on the outlet side of the radiator 12 and the refrigerant pipe on the inlet side of the decompression means 14, and the end of the low-pressure side pipe 132 is The refrigerant pipe on the outlet side of the evaporator 15 and the refrigerant pipe on the suction side of the compressor 11 are connected to each other.

  FIG. 3 is a circuit configuration diagram of a heat pump hot water supply apparatus including the refrigeration cycle apparatus of the first embodiment. In FIG. 3, the heat pump hot water supply apparatus includes a refrigeration cycle apparatus 10 and a hot water storage apparatus 20.

  The refrigeration cycle apparatus 10 is configured by connecting a compressor 11, a radiator 12, a decompression unit 14, and an evaporator 15 in an annular manner with a refrigerant pipe in order. Here, the decompression means 14 is disposed vertically above the radiator 12. In the refrigeration cycle apparatus 10, carbon dioxide is enclosed as a refrigerant.

  The internal heat exchanger 13 includes a high-pressure side refrigerant that flows through a high-pressure side pipe 131 that is disposed between the radiator 12 and the decompression unit 14, and a low-pressure side that is disposed between the evaporator 15 and the compressor 11. Heat exchange is performed with the low-pressure refrigerant flowing through the pipe 132.

  The radiator 12 exchanges heat between the high-pressure refrigerant discharged from the compressor 11 and the hot water supplied from the hot water storage tank 21 via the water pipe 18 to generate hot water. The evaporation fan 17 is a blower for blowing air to the evaporator 15.

  The hot water storage device 20 includes a hot water storage tank 21, and a water supply pipe 22 at the bottom of the hot water storage tank 21 is connected to a pipe such as a water pipe.

  Further, the hot water storage device 20 has a boiling circuit that returns from the boiling forward piping 23 to the hot water storage tank 21 via the water supply pump 24, the water piping 18, the radiator 12, the boiling return piping 19, and the three-way switching valve 25. ing.

  The hot water mixing valve 28 is provided in the mixing portion of the water supply pipe 22 and the hot water outlet pipe 29 coming out of the hot water storage tank 21, and the hot water adjusted to the set temperature by the hot water mixing valve 28 flows through the hot water supply pipe 40. ing. In addition, an operation instruction to each operation component is performed by a control device (not shown).

  About the heat pump hot-water supply apparatus comprised as mentioned above, the hot water storage driving | operation operation | movement is demonstrated below.

  During the hot water storage operation, the refrigerant sealed in the refrigeration cycle apparatus 10 is sucked into the compressor 11 in a low-pressure gas state and compressed to a high-temperature and high-pressure supercritical state. The compressed refrigerant is transferred to the radiator 12 and exchanges heat with the water transferred from the hot water storage tank 21, and then radiates heat to the low-pressure side refrigerant in the internal heat exchanger 13. Become.

  Thereafter, the refrigerant becomes a gas-liquid two-phase refrigerant expanded to a low-temperature and low-pressure state by the decompression means 14 such as an expansion valve, and after absorbing heat from the outside air blown by the evaporation fan 17 by the evaporator 15, the internal heat exchanger 13. Then, the operation of absorbing heat from the high-pressure side refrigerant to become a low-pressure gas refrigerant and being sucked into the compressor 11 is repeated.

  On the other hand, the water at the bottom of the hot water storage tank 21 is conveyed to the radiator 12 through the water supply pump 24 through the boiling forward pipe 23 and the water pipe 18, and exchanges heat with the refrigerant of the refrigeration cycle apparatus 10 to heat itself. It becomes warm water.

  Thereafter, the heated hot water is returned to the top or bottom of the hot water storage tank 21 via the boiling return pipe 19 and the three-way switching valve 25.

  The temperature of the outlet hot water of the radiator 12 does not reach the target boiling temperature immediately after the start of the refrigeration cycle apparatus 10, but requires a predetermined time.

  While the temperature detected by the tapping temperature detection means 191 (hereinafter referred to as the detected temperature) is lower than the target boiling temperature (for example, when the temperature difference between the target boiling temperature and the detected temperature is a predetermined value or more), The hot water in the boiling return pipe 19 is returned to the bottom of the hot water storage tank 21 through the boiling bypass pipe 26 by the three-way switching valve 25.

  Thereafter, when the detected temperature approaches the target boiling temperature (for example, when the temperature difference between the target boiling temperature and the detected temperature becomes less than a predetermined value), the three-way switching valve 25 is switched and the boiling return pipe 19 is switched. The hot water is boiled up and returned to the upper part of the hot water storage tank 21 through the piping 27.

  Through the above operation, the hot temperature heated by the refrigeration cycle apparatus 10 is stored in the hot water storage tank 21.

  Next, the defrosting operation operation of the heat pump water heater will be described.

  When the hot water storage operation is performed in a state where the outside air temperature is low, frost is formed on the evaporator 15, and the heat absorption capability of the evaporator 15 is significantly reduced.

  Here, a defrosting operation for defrosting the frost attached to the evaporator 15 is performed. The defrosting operation starts when the controller (not shown) determines that frost has adhered to the evaporator 15 based on information from a temperature sensor (not shown) disposed in the vicinity of the evaporator 15. Is done.

  First, the water pump 24 and the evaporation fan 17 are stopped, and the opening of the valve of the decompression means 14 is opened. The high-temperature refrigerant compressed by the compressor 11 flows through the radiator 12, the high-pressure side pipe 131 of the internal heat exchanger 13, and the decompression means 14, flows into the evaporator 15, and defrosts with the heat of the refrigerant. After flowing through the low-pressure side pipe 132 of the internal heat exchanger 13, it is sucked into the compressor 11.

  In addition, when the control device (not shown) judges that the frost adhering to the evaporator 15 has melted based on information from a temperature sensor (not shown) disposed in the vicinity of the evaporator 15, The defrosting operation is terminated, and then a hot water storage operation is performed.

  Here, according to the first embodiment, with the above-described configuration, the process of providing the concave and convex portion 134 that forms a groove on the inner surface of the high-pressure side pipe 131, the interior of the high-pressure side pipe 131 and the high-pressure side pipe 131 is formed. The heat transfer area with the flowing high-pressure side refrigerant is increased, and the heat transfer coefficient between the high-pressure side refrigerant and the high-pressure side pipe 131 is improved by the effect of promoting turbulence by the uneven portion 134 (groove). There is an effect that the amount of heat exchange with the refrigerant increases.

  On the other hand, the use of an internally grooved tube provided with an uneven portion 134 (groove) on the inner surface of the high-pressure side pipe 131 causes vortices inside the high-pressure side pipe 131, resulting in energy loss (pressure loss). Since the high-pressure side refrigerant flows between the radiator 12 and the decompression means 14, even if a pressure loss occurs in the high-pressure side refrigerant in the internal heat exchanger 13, if the amount of decompression in the decompression means 14 is varied and adjusted, Since the high-low pressure difference in the refrigeration cycle does not fluctuate, the operating efficiency of the equipment is not reduced.

  Thereby, the amount of heat exchange in the internal heat exchanger 13 can be increased while improving the energy efficiency of the refrigeration cycle apparatus.

  Further, in the defrosting operation mode in which the frost adhering to the evaporator 15 is melted, the refrigerant is the compressor 11, the radiator 12, the high-pressure side pipe 131 of the internal heat exchanger 13, the decompression means 14, the evaporator 15, and the internal heat exchange. In the hot water storage operation mode, the heat exchange amount of the internal heat exchanger 13 can be increased and the energy efficiency of the refrigeration cycle apparatus is improved by circulating the low pressure side pipe 132 of the compressor 13 and the compressor 11 in this order. In addition, in the defrosting operation, the refrigerant is wet-compressed by the compressor 11 and discharged from the compressor 11 together with the lubricating oil of the compressor 11. This lubricating oil is discharged from the high-pressure side pipe 131 of the internal heat exchanger 13. By adhering to the concavo-convex portion 134 (groove portion), the heat exchange efficiency of the high-pressure side refrigerant and the low-pressure side refrigerant in the internal heat exchanger 13 can be reduced during the defrosting operation, and as a result, the internal heat exchange Heat radiation amount of the high-pressure side refrigerant in 13 is reduced, can transmit the heat of the high-pressure side refrigerant to efficiently evaporator 15, that can be utilized in defrosting, it is possible to shorten the defrosting operation time.

  Further, in the defrosting operation, the refrigerant flows from the radiator 12 to the high-pressure side pipe 131 of the internal heat exchanger 13 and the decompression means 14, and the decompression means 14 is located above the radiator 12 in the vertical direction. The lubricating oil adhering to the uneven portion 134 (groove portion) of the high-pressure side pipe 131 of the internal heat exchanger 13 is likely to remain in the uneven portion 134 (groove portion) due to the gravity action. Thus, during the defrosting operation, the heat exchange efficiency between the high-pressure side refrigerant and the low-pressure side refrigerant in the internal heat exchanger 13 can be reduced, and as a result, the heat release amount of the high-pressure side refrigerant in the internal heat exchanger 13 can be reduced. The defrosting operation time can be shortened by being reduced and being able to efficiently transmit the heat of the high-pressure side refrigerant to the evaporator 15 and utilizing it for defrosting.

  In addition, since the inner surface of the low-pressure side pipe 132 through which the low-pressure side refrigerant flows in the internal heat exchanger 13 is smooth, the low-pressure side refrigerant and the low-pressure side are compared with the case where the concave-convex part (groove part) is provided in the low-pressure side pipe. Since the contact area of the piping is reduced and the pressure loss of the low-pressure side refrigerant is reduced, the suction pressure of the compressor 11 is increased, and the energy efficiency of the refrigeration cycle apparatus can be improved.

  In addition, the low-pressure side pipe 132 through which the low-pressure side refrigerant flows in the internal heat exchanger 13 is joined in parallel with the high-pressure side pipe 131, and the inner diameter of the low-pressure side pipe 132 is larger than the inner diameter of the high-pressure side pipe 131. The inner surface area of the side pipe 132 can be made relatively large, the thermal resistance between the low pressure side refrigerant and the low pressure side pipe, and the thermal resistance between the high pressure side refrigerant and the high pressure side pipe 131 can be made relatively uniform, The heat exchange efficiency in the internal heat exchanger 13 can be improved, and the energy efficiency of the refrigeration cycle apparatus can be improved.

  As described above, the refrigeration cycle apparatus according to the present invention includes the internal heat exchanger having excellent heat exchange performance by increasing the heat transfer area between the high-pressure side pipe and the high-pressure side refrigerant of the internal heat exchanger. Since a refrigeration cycle apparatus can be provided, it can be applied to a refrigeration cycle apparatus equipped with an internal heat exchanger.

DESCRIPTION OF SYMBOLS 10 Refrigeration cycle apparatus 11 Compressor 12 Radiator 13 Internal heat exchanger 14 Depressurization means 15 Evaporator 131 High pressure side piping 132 Low pressure side piping 133 Joint part 134 Uneven part (groove part)

Claims (7)

Internal heat exchange in which heat is exchanged between the compressor, the radiator, the decompression means, the evaporator, the high-pressure side refrigerant supplied from the radiator to the decompression means, and the low-pressure side refrigerant decompressed by the decompression means The high-pressure side pipe through which the high-pressure side refrigerant flows in the internal heat exchanger has an uneven portion on the inner surface. A defrosting operation mode for melting frost adhering to the evaporator, and in the defrosting operation mode, the refrigerant is the compressor, the radiator, the high-pressure side piping of the internal heat exchanger, the decompression means, the evaporation The refrigeration cycle apparatus according to claim 1, wherein the refrigeration cycle apparatus is circulated in the order of a compressor, a low-pressure side pipe of the internal heat exchanger, and the compressor. The refrigeration cycle apparatus according to claim 2, wherein the decompression means is disposed vertically above the radiator. The refrigeration cycle apparatus according to any one of claims 1 to 3, wherein the low-pressure side refrigerant of the internal heat exchanger is a refrigerant supplied from the evaporator to the compressor. 5. The refrigeration cycle apparatus according to claim 1, wherein an inner surface of the low-pressure side pipe through which the low-pressure side refrigerant flows in the internal heat exchanger is smooth. The low-pressure side pipe through which the low-pressure side refrigerant flows in the internal heat exchanger is joined in parallel to the high-pressure side pipe, and an inner diameter of the low-pressure side pipe is larger than an inner diameter of the high-pressure side pipe. The refrigeration cycle apparatus according to any one of 1 to 5. The refrigeration cycle apparatus according to any one of claims 1 to 6, wherein the refrigerant is carbon dioxide.