JP2019056536A - Refrigeration cycle device - Google Patents

Abstract

To provide a refrigeration cycle device having excellent energy saving performance by suppressing compressor power in a defrosting operation mode while improving energy consumption efficiency during heating operation.SOLUTION: A refrigeration cycle device includes an inner heat exchanger 23 for exchanging heat between a high-pressure side refrigerant supplied from a radiator 10 to decompression means 11 and a low-pressure side refrigerant that has absorbed heat in an evaporator 12. A first high-pressure side pipe 1 and a second high-pressure side pipe 2 in which the high-pressure side refrigerant flows and a low-pressure side pipe 3 in which the low-pressure side refrigerant flows come close contact with each other. Due to this configuration, while energy consumption efficiency during heating operation is improved by improving heat exchange amount in the inner heat exchanger 23, pressure loss can be reduced by using the plurality of pipes that are the first high-pressure side pipe 1 and the second high-pressure side pipe 2, and pressure of the refrigerant discharged from a compressor 9 in a defrosting operation mode can be suppressed. Thus, energy saving performance of the refrigeration cycle device can be improved.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a refrigeration cycle apparatus.

  Conventionally, this type of refrigeration cycle apparatus is used in a heat pump hot water supply apparatus that uses the heat generated by a heat pump. Moreover, in order to improve energy consumption efficiency, the internal heat exchanger is used. (For example, refer to Patent Document 1).

  FIG. 7 is a diagram showing a conventional internal heat exchanger described in Patent Document 1. As shown in FIG. As shown in FIG. 8, the low pressure side pipe 101 through which the low pressure side refrigerant flowing out of the evaporator 12 flows and the high pressure side pipe 102 through which the high pressure side refrigerant flowing out of the radiator 10 flows are heated at the contact portions of the outer circumferences of the respective pipes. It is configured to be integrated so that it can be exchanged.

JP 2014-181870 A

  However, in the conventional configuration, the inner diameter of the high-pressure side pipe 102 is made smaller than the inner diameter of the low-pressure side pipe 101, and a groove is provided on the inner surface of the high-pressure side pipe 102 so that the heat exchange amount in the internal heat exchanger 23 is increased. Although the energy consumption efficiency of the refrigeration cycle apparatus during operation is improved, in the defrosting operation mode under environmental conditions in which frost adheres to the evaporator 12, the power of the compressor increases and energy saving performance is improved. It was damaged.

  In the defrosting operation mode, the amount of pressure reduction in the expansion valve is reduced and the evaporation temperature of the refrigerant flowing through the evaporator 12 is increased to melt and remove the frost, but in addition to the small inner diameter of the high-pressure side pipe 102 Since the inner surface has grooves, the pressure loss is large, the discharge pressure is not sufficiently suppressed, the compressor power during defrosting operation is increased, and the energy saving performance of the refrigeration cycle apparatus is reduced. It was.

  The present invention solves the above-described conventional problems, and provides a refrigeration cycle apparatus that is excellent in energy saving by suppressing the compressor power in the defrosting operation mode while improving the energy consumption efficiency during the heating operation. The purpose is to do.

  In order to solve the conventional problems, a refrigeration cycle apparatus according to the present invention includes a compressor, a radiator, a decompression unit, an evaporator, and a high-pressure refrigerant supplied from the radiator to the decompression unit. An internal heat exchanger that exchanges heat with the low-pressure side refrigerant that has absorbed heat in the evaporator, and flows the refrigerant in the order of the compressor, the radiator, the pressure reducing means, and the evaporator, A defrosting operation mode for melting frost is provided, and the internal heat exchanger is characterized in that a plurality of high-pressure side pipes through which a high-pressure side refrigerant flows and a low-pressure side pipe through which a low-pressure side refrigerant flows are in close contact with each other. Is.

  This increases the effective heat transfer area of the internal heat exchanger and increases the amount of heat exchange, improving the energy consumption efficiency during heating operation, while also suppressing the compressor power in the defrost operation mode, A refrigeration cycle apparatus capable of high operation can be provided.

  ADVANTAGE OF THE INVENTION According to this invention, the refrigeration cycle apparatus excellent in energy saving property can be provided by suppressing the compressor motive power of a defrost operation mode, improving the energy consumption efficiency at the time of heating operation.

Circuit diagram of hot water supply apparatus using refrigeration cycle apparatus in Embodiment 1 of the present invention Schematic diagram of internal heat exchanger of refrigeration cycle apparatus in Embodiment 1 of the present invention Sectional drawing in AA of the internal heat exchanger of FIG. Schematic diagram of the bending portion of the internal heat exchanger in Embodiment 1 of the present invention A diagram showing the relationship between the heat exchange amount of the internal heat exchanger and the flow rate of each high-pressure side pipe The figure which shows the relationship between the pressure loss of the low-pressure side piping of the same internal heat exchanger and the flow rate of each high-pressure side piping Cross section 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 that has absorbed heat in the evaporator. An internal heat exchanger for exchanging heat, and having a defrosting operation mode in which the refrigerant flows in the order of the compressor, the radiator, the pressure reducing unit, and the evaporator, and the frost of the evaporator is melted. The internal heat exchanger is a refrigeration cycle apparatus characterized in that a plurality of high-pressure side pipes through which a high-pressure side refrigerant flows and a low-pressure side pipe through which a low-pressure side refrigerant flows are in close contact with each other.

  Thereby, the effective heat transfer area increases, the heat exchange amount of the internal heat exchanger increases, the intake temperature to the compressor can be increased, and the refrigerant temperature supplied to the radiator increases.

  As a result, the heating efficiency of the hot water in the radiator can be improved, and the energy consumption efficiency during the heating operation can be improved. In addition, since the refrigerant branches and flows through the plurality of high-pressure side pipes, the flow rate of the high-pressure side refrigerant is reduced and the pressure loss in the high-pressure side pipes is reduced, so that the refrigerant discharge pressure from the compressor in the defrosting operation mode Since the power required for driving the compressor can be reduced, the energy saving performance of the refrigeration cycle apparatus can be improved.

  According to a second invention, in particular, in the first invention, the plurality of high-pressure side pipes are arranged so as to sandwich the low-pressure side pipe in the center, and the respective pipes have substantially the same shape. It is characterized by this.

  As a result, a plurality of high-pressure side pipes are arranged with the low-pressure side pipes sandwiched therebetween, and the temperature distribution in the cross section perpendicular to the tube axis of the low-pressure side pipes is relatively uniform. The energy consumption efficiency during the heating operation can be improved.

  In addition, since the shape of the plurality of high-pressure side pipes is the same and the flow rate of each refrigerant is uniform, the pressure loss of the high-pressure side refrigerant in the internal heat exchanger can be suppressed, and the discharge pressure of the refrigerant can be suppressed in the defrosting operation mode. Thus, the energy consumption efficiency related to the operation of the refrigeration cycle can be improved.

  In a third aspect of the invention, in particular, in the first or second aspect of the invention, the plurality of high-pressure side pipes are joined in parallel to the low-pressure side pipe, and an inner diameter of the low-pressure side pipe is equal to that of the high-pressure side pipe. It is characterized by being larger than the inner diameter.

  As a result, during heating operation, even if the specific volume of refrigerant in the low-pressure side pipe increases as the heat exchange amount of the internal heat exchanger increases, the increase in pressure loss is suppressed because the inner diameter of the low-pressure side pipe is large. be able to.

  In addition, by increasing the flow rate of the refrigerant flowing through the high-pressure side pipe, the heat transfer rate is improved, the amount of heat exchange in the internal heat exchanger is increased, and the energy consumption efficiency during the heating operation can be improved.

  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)
FIG. 1 shows a circuit configuration of a hot water supply apparatus including a refrigeration cycle apparatus according to Embodiment 1 of the present invention.

  In FIG. 1, the refrigeration cycle apparatus 7 is configured by connecting a compressor 9, a radiator 10, a decompression means 11 (expansion valve or the like), and an evaporator 12 in an annular manner through a refrigerant pipe in order. The internal heat exchanger 23 includes a first high-pressure side pipe 1, a second high-pressure side pipe 2, and a low-pressure side pipe 3, and the first high-pressure side pipe 1 and the second high-pressure side pipe 2 include a radiator 10 and a decompression unit 11. The low-pressure side pipe 3 is connected between the evaporator 12 and the compressor 9 to form a part of the refrigeration cycle apparatus 7. In the refrigeration cycle apparatus 7, carbon dioxide is enclosed as a refrigerant.

  In FIG. 2, the block diagram of the internal heat exchanger 23 is shown. In the internal heat exchanger 23, two first high-pressure side pipes 1, a second high-pressure side pipe 2, and a low-pressure side pipe 3 are arranged substantially in parallel. As shown in FIG. The second high-pressure side pipe 2 and the low-pressure side pipe 3 are joined to each other at a brazing portion 4 by brazing material or solder. At this time, it arrange | positions so that each pipe-axis center of the 1st high voltage | pressure side piping 1, the low voltage | pressure side piping 3, and the 2nd high voltage | pressure side piping 2 may be located in a line on a substantially straight line.

  Note that the number of high-pressure side pipes is not limited to two, and a plurality of higher-pressure pipes may be provided. In this case, the plurality of high-pressure side pipes are arranged at equal intervals along the outer periphery of the low-pressure side pipe 3.

  As shown in FIG. 3, the first high-pressure side pipe 1 and the second high-pressure side pipe 2 are grooved pipes provided with grooves for expanding the inner surface area on the inner surface, and the low-pressure side pipe 3 is provided with a groove on the inner surface. The inner diameter of the smooth pipe is larger than the inner diameter of the first high-pressure side pipe 1 and the second high-pressure side pipe 2.

  In FIG. 4, the block diagram of the bending part of the internal heat exchanger 23 is shown. When bending with the straight line connecting the axis centers of the first high-pressure side pipe 1, the second high-pressure side pipe 2 and the low-pressure side pipe 3 as the axes, the two high-pressure side pipes and the low-pressure side pipe have substantially the same shape, It is comprised so that the curvature of the bent part may become the same.

  In FIG. 1, a hot water storage device 8 includes a hot water storage tank 13 for storing hot water boiled by the refrigeration cycle device 7, and a hot water supply mixing valve for adjusting the temperature of hot water to a hot water supply terminal (not shown) such as a shower. 16.

  About the refrigerating-cycle apparatus comprised as mentioned above, the operation | movement and an effect | action are demonstrated below.

  First, the operation | movement at the time of the heating operation which heats warm water in the heat radiator 10 is demonstrated.

  During the heating operation, the high-temperature and high-pressure refrigerant discharged from the compressor 9 dissipates heat by exchanging heat with hot water in the radiator 10 and becomes low-temperature and high-pressure. The heated hot water is supplied to the hot water storage tank 13 and used for a shower or the like. The low-temperature and high-pressure refrigerant exiting the radiator 10 is branched and supplied to the two first high-pressure side pipes 1 and the second high-pressure side pipe 2 of the internal heat exchanger 23 and flows through the low-pressure side pipe 3. The heat is dissipated to the side refrigerant, and the temperature further decreases.

  The refrigerant that has exited the first high-pressure side pipe 1 and the second high-pressure side pipe 2 of the internal heat exchanger 23 joins each other again and is depressurized by the decompression means 11 to be in a low-temperature / low-pressure gas-liquid two-phase state.

  The refrigerant depressurized in the decompression means 11 absorbs heat from the atmosphere in the evaporator 12 and evaporates into a gas single-phase state. Further, in the low pressure side pipe 3 of the internal heat exchanger 23, the first high pressure side pipe 1, 2 It absorbs heat from the high-pressure side refrigerant flowing in the high-pressure side pipe 2 and becomes superheated, and is sucked into the compressor 9. By repeating this operation, the refrigeration cycle apparatus 7 performs a heating operation of hot water.

  Next, the operation in the defrosting operation mode for melting and removing the frost when it is attached to the evaporator 12 by the heating operation will be described.

  Since the order in which the refrigerant flows in the defrosting operation mode is the same as that in the heating operation, the description thereof is omitted. In the defrosting operation mode, the amount of decompression in the decompression means 11 is reduced, and the pressure of the refrigerant discharged from the compressor 9 is suppressed. Further, in the radiator 10, the amount of heat released from the refrigerant is suppressed as much as possible, and the medium-temperature / medium-pressure refrigerant is supplied to the evaporator 12 through the decompression means 11.

  Thus, the frost adhering to the evaporator is melted by increasing the temperature of the refrigerant flowing through the evaporator 12. The refrigerant that has dissipated heat in the evaporator 12 to melt the frost is sucked into the compressor 9. By repeating this operation, the defrosting operation mode is performed until the frost attached to the evaporator 12 melts.

  At this time, since there are two high-pressure pipes constituting the internal heat exchanger 23, the amount of heat exchange increases as compared with the case of one.

  Further, during the heating operation, since the intake temperature to the compressor 9 can be increased, the temperature of the refrigerant supplied to the radiator 10 is increased, and the radiator 10 acts to efficiently heat hot water. .

  Moreover, since there are two high-pressure side pipes constituting the internal heat exchanger 23, the pressure loss of the high-pressure side flow path is smaller than when there is one. Thereby, during the defrosting operation, the discharge pressure can be further lowered, so that the power related to the driving of the compressor 9 is suppressed.

  As described above, the energy consumption efficiency related to the operation of the refrigeration cycle apparatus can be improved in both the heating operation and the defrosting operation mode.

  Further, by making the inner diameter of the low pressure side pipe 3 larger than the inner diameter of each of the first high pressure side pipe 1 and the second high pressure side pipe 2, the specific volume in the low pressure side pipe 3 increases as the heat exchange amount increases. Even so, the pressure loss of the low-pressure side pipe 3 is suppressed. Thereby, during the heating operation, the suction pressure of the refrigerant sucked into the compressor 9 can be improved, so that the power related to the driving of the compressor 9 is suppressed.

  Further, since the inner diameters of the first high-pressure side pipe 1 and the second high-pressure side pipe 2 are made smaller than the inner diameter of the low-pressure side pipe 3, the refrigerant flowing through the first high-pressure side pipe 1 and the second high-pressure side pipe 2 is reduced. The flow rate increases. Thereby, the heat transfer rate of the refrigerant flowing through the first high-pressure side pipe 1 and the second high-pressure side pipe 2 can be improved, and the heat exchange amount in the internal heat exchanger 23 can be increased. And the temperature at the inlet of the radiator 10 rises, and the radiator 10 acts to efficiently heat the hot water.

  As described above, the increase in the suction pressure and the improvement in the heating efficiency of the radiator 10 during the heating operation can be realized at the same time, and the energy consumption efficiency related to the operation of the refrigeration cycle apparatus can be improved.

  Further, as shown in FIG. 3, two first high-pressure side pipes 1, second high-pressure side pipes 2, and low-pressure side pipes 3 are arranged so that their tube axes are in a straight line, thereby providing 2 Since the distance between the first high-pressure side pipe 1 and the second high-pressure side pipe 2 is the farthest away and the temperature distribution of the cross section perpendicular to the tube axis of the low-pressure side pipe 3 is relatively uniform, internal heat exchange The amount of heat exchange in the vessel 23 is substantially maximized.

  As a result, the intake temperature of the compressor 9 and the inlet temperature of the radiator 10 rise, and the radiator 10 acts to efficiently heat the hot water.

  Further, the effective heat transfer area 6 is doubled as compared with the conventional implementation, and the heat transfer efficiency is improved.

  As described above, the heat exchange amount in the internal heat exchanger 23 having the two first high-pressure side pipes 1 and the second high-pressure side pipe 2 is maximized, and the energy consumption efficiency related to the operation of the refrigeration cycle apparatus is improved. Can do.

  In addition, by making the three bending radii R substantially the same in the bent portion, the flow lengths of the two first high-pressure side pipes 1 and the second high-pressure side pipes 2 are made substantially the same, and the two first high-pressure side pipes 1 are made the same. The flow rate of the refrigerant flowing through the high-pressure side pipe 1 and the second high-pressure side pipe 2 is substantially the same.

  Accordingly, as shown in FIG. 5, when the flow rates of the refrigerant flowing through the two first high-pressure side pipes 1 and the second high-pressure side pipe 2 are the same, each of the first high-pressure side pipes 1 and the second high-pressure side pipes 2. The sum Q (= Q1 + Q2) of the heat exchange amounts Q1 and Q2 can be maximized, and the intake temperature to the compressor 9 can be increased during the heating operation, so that the refrigerant temperature supplied to the radiator 10 is high. Thus, the radiator 10 acts to efficiently heat the hot water.

  As shown in FIG. 6, the pressure loss ΔP is substantially minimized when the flow rates of the refrigerant flowing through the first high-pressure side pipe 1 and the second high-pressure side pipe 2 are substantially the same and there is no drift. Thereby, the pressure loss of the high-pressure side flow path in the internal heat exchanger 23 can be reduced, and the pressure of the refrigerant sucked into the compressor 9 can be improved, so that the power related to the driving of the compressor 9 is suppressed. Act on.

  As described above, the energy consumption efficiency related to heating is improved by improving the heat exchange amount in the internal heat exchanger 23 during the heating operation, and the discharge pressure is reduced by suppressing the pressure loss of the high-pressure channel in the defrosting operation mode. Suppression can be realized and the energy saving performance of the refrigeration cycle apparatus can be improved.

  As described above, since the refrigeration cycle apparatus according to the present invention can improve energy consumption efficiency, it can be applied to refrigeration cycle apparatuses such as an air conditioner, a heat pump hot water heater, and a heat pump hot water heater.

DESCRIPTION OF SYMBOLS 1 1st high pressure side piping 2 2nd high pressure side piping 3 Low pressure side piping 4 Brazing contact part 6 Effective heat-transfer area 7 Refrigeration cycle apparatus 8 Hot water storage apparatus 9 Compressor 10 Radiator 11 Decompression means 12 Evaporator 13 Hot water storage tank 16 Hot water supply mixing Valve 23 Internal heat exchanger

Claims (3)

A compressor, a radiator, a decompression means, an evaporator,
An internal heat exchanger that exchanges heat between the high-pressure refrigerant supplied from the radiator to the decompression unit and the low-pressure refrigerant absorbed by the evaporator;
A defrosting operation mode in which the refrigerant flows in the order of the compressor, the radiator, the pressure reducing unit, and the evaporator to melt the frost of the evaporator;
The internal heat exchanger has a configuration in which a plurality of high-pressure side pipes through which a high-pressure side refrigerant flows and a low-pressure side pipe through which a low-pressure side refrigerant flows are in close contact with each other. 2. The refrigeration cycle apparatus according to claim 1, wherein the plurality of high-pressure side pipes are arranged so as to sandwich the low-pressure side pipe in the center, and each pipe has substantially the same shape. . The plurality of high-pressure side pipes are joined in parallel to the low-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. Refrigeration cycle equipment.

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