JP5530904B2 - Heat pump type hot water generator - Google Patents

Description

  The present invention relates to a binary refrigeration cycle apparatus.

  In a heat pump type hot water generator, a binary refrigeration cycle having a high temperature side refrigeration cycle and a low temperature side refrigeration cycle may be used to generate high temperature hot water.

  Here, in the heat pump type hot water generator of the air heat source, frost is formed on the air-side heat exchanger depending on the operation state such as when the outside air temperature is low. For this reason, in order to maintain a proper heating operation, it is indispensable to remove frost (defrosting).

  A general defrosting method in the heat pump type device of this air heat source is “reverse cycle defrost”. In the case of a dual refrigeration cycle apparatus, a device configuration using a four-way switching valve is known for both the high temperature side refrigeration cycle and the low temperature side refrigeration cycle (see, for example, Patent Document 1).

JP 59-38568

  However, when the defrosting operation is performed with the configuration of the dual refrigeration cycle disclosed in Japanese Patent Laid-Open No. 59-38568, performing the defrosting performs the reverse cycle operation, that is, performs the cooling operation. It will be. That is, although the heating operation is normally performed and heat is supplied to the load, the defrosting operation corresponding to the cooling operation is performed although it is temporary.

  Then, this invention aims at providing the dual refrigeration cycle apparatus which can defrost at high speed, without cooling the heating target object heated with the thermal radiation heat exchanger at the time of a heating operation. .

The heat pump type hot water generator of the present invention comprises a high temperature side refrigeration cycle, a low temperature side refrigeration cycle, and an intermediate heat exchanger that performs heat exchange between the high temperature side refrigeration cycle and the low temperature side refrigeration cycle, The high temperature side refrigeration cycle is configured by sequentially connecting a high temperature side compressor, a heat radiation heat exchanger, a high temperature side decompression device, and the intermediate heat exchanger, and the low temperature side refrigeration cycle includes a low temperature side compressor, The intermediate heat exchanger, the low-temperature side pressure reducing device, and the air heat exchanger are sequentially connected, and the high-temperature side refrigeration cycle is configured to pass the refrigerant discharged from the high-temperature side compressor to the radiating heat exchanger. a hot gas bypass circuit to be introduced into the intermediate heat exchanger bypassing the state where the discharged refrigerant is not introduced into the hot gas bypass circuit to a state in which it is introduced into the hot gas bypass circuit from the high-temperature side compressor The low temperature side refrigeration cycle includes a state where refrigerant discharged from the low temperature side compressor is introduced into the intermediate heat exchanger and the air heat exchanger. comprising switching Ru low temperature side flow passage switching mechanism and a state, the heat radiation from the radiator heat exchanger when generating the hot water is introduced into the refrigerant discharged from the high-temperature side compressor to the hot gas bypass circuit Without controlling the high temperature side flow path switching mechanism to be introduced into the heat dissipation heat exchanger, and the low temperature side flow into the state where refrigerant discharged from the low temperature side compressor is introduced into the intermediate heat exchanger. controls road switching mechanism, when defrosting the air heat exchanger of the low temperature side refrigerating cycle, said radiator heat exchanger to introduce refrigerant discharged from the high-temperature side compressor to the hot gas bypass circuit And to the intermediate heat exchanger Controlling the hot-side flow path switching mechanism in a state of, and, and controls said low-temperature side flow path switching mechanism in a state of introducing the refrigerant discharged from the low temperature side compressor to the air heat exchanger To do.

  ADVANTAGE OF THE INVENTION According to this invention, it can defrost at high speed, without cooling the heating target object heated with the thermal radiation heat exchanger at the time of a heating operation.

It is a refrigeration cycle system diagram of Embodiment 1 of the present invention.

  FIG. 1 shows a dual refrigeration cycle apparatus according to an embodiment of the present invention.

  This dual refrigeration cycle apparatus includes a high temperature side refrigeration cycle A, a low temperature side refrigeration cycle B, and an intermediate heat exchanger 5 that performs heat exchange between the high temperature side refrigeration cycle A and the low temperature side refrigeration cycle B.

  Specifically, this dual refrigeration cycle apparatus is an apparatus that generates high-temperature hot water, and is also referred to as a heat pump type high-temperature water generator. Moreover, the heat radiation heat exchanger 7 can also be called a water side heat exchanger.

  The high temperature side refrigeration cycle A is configured by sequentially connecting a high temperature side compressor 6, a heat radiation heat exchanger 7, a high temperature side pressure reducing device 8, and an intermediate heat exchanger 5. On the other hand, the low temperature side refrigeration cycle B is configured by sequentially connecting a low temperature side compressor 1, an intermediate heat exchanger 5, a low temperature side pressure reducing device 3, and an air heat exchanger 2.

  The high temperature side refrigeration cycle A includes a hot gas bypass circuit 10 that introduces refrigerant discharged from the high temperature side compressor 6 into the intermediate heat exchanger 5 by bypassing the heat dissipation heat exchanger 7, and refrigerant discharged from the high temperature side compressor 6. Is provided with a high-temperature side channel switching mechanism 9 for switching between a state where the gas is introduced into the hot gas bypass circuit 10 and a state where the gas is not introduced into the hot gas bypass circuit 10.

  The high temperature side flow path switching mechanism 9 switches between a state in which the refrigerant discharged from the high temperature side compressor 6 is introduced into the radiant heat exchanger 7 and a state where the refrigerant is introduced into the radiant heat exchanger 7 and the intermediate heat exchanger. It is. Specifically, the high temperature side flow path switching mechanism 9 is configured by an electromagnetic valve (two-way valve) disposed in the hot gas bypass circuit 10.

  The low temperature side refrigeration cycle B includes a low temperature side flow path switching mechanism 4 that switches between a state where refrigerant discharged from the low temperature side compressor 1 is introduced into the intermediate heat exchanger 5 and a state where refrigerant is introduced into the air heat exchanger 2. Prepare. The low temperature side channel switching mechanism 4 is constituted by a four-way switching valve.

  During the heating operation, in the low temperature side refrigeration cycle B, the refrigerant flows in the direction of the arrow indicated by the solid line.

  First, the high-temperature and high-pressure gas refrigerant compressed by the low-temperature side compressor 1 is cooled and condensed and liquefied by an intermediate heat exchanger 5 corresponding to a condenser that flows in via the low-temperature side flow path switching mechanism 4. This high-pressure liquid refrigerant is a cycle that is decompressed by the low-temperature side decompression device 3 and then evaporated by the air heat exchanger 2 corresponding to the evaporator to become a low-temperature and low-pressure gas refrigerant and return to the low-temperature side refrigeration cycle low-temperature side compressor 1. .

  Similarly, in the high temperature side refrigeration cycle A, each of the high temperature side compressor 6, the radiant heat exchanger 7 corresponding to a condenser, the high temperature side pressure reducing device 8, and the intermediate heat exchanger 5 corresponding to an evaporator has refrigerant. It is a configuration that circulates.

  Next, the control at the time of the defrost operation for removing the frost which has arrived at the air heat exchanger 2 of the low temperature side refrigerating cycle B is demonstrated.

  When defrosting the air heat exchanger 2 of the low temperature side refrigeration cycle B, the high temperature side flow path switching mechanism 9 is controlled so that the refrigerant discharged from the high temperature side compressor 6 is introduced into the hot gas bypass circuit 10; In addition, the low temperature side flow path switching mechanism 4 is controlled so that the refrigerant discharged from the low temperature side compressor 1 is introduced into the air heat exchanger 2. Specifically, when the air heat exchanger 2 of the low temperature side refrigeration cycle B is defrosted, the refrigerant discharged from the high temperature side compressor 6 is introduced into the heat radiation heat exchanger 7 and the intermediate heat exchanger 5. The high temperature side flow path switching mechanism 9 is controlled.

  Specifically, during the defrosting operation, in the low temperature side refrigeration cycle B, the refrigerant flows in the direction of the arrow indicated by a broken line.

  First, the high-temperature and high-pressure gas refrigerant compressed by the low-temperature side compressor 1 flows into the air heat exchanger 2 that has become frosted through the low-temperature side flow path switching mechanism 4. Here, the high-temperature and high-pressure gas refrigerant is cooled and condensed and liquefied by melting frost attached to the air heat exchanger 2. The high-pressure liquid refrigerant is depressurized by the low-temperature side decompression device 3 and then evaporated in the evaporator by the intermediate heat exchanger 5 to become a low-temperature and low-pressure gas refrigerant and return to the low-temperature side refrigeration cycle low-temperature side compressor 1.

  On the other hand, in the high temperature side refrigeration cycle A, the low temperature side refrigeration cycle B performs the defrosting operation by the reverse cycle operation, but, similarly to the heating operation, the high temperature side compressor 6, the heat radiation heat exchanger 7 corresponding to the condenser, The refrigerant still circulates in the high-temperature decompression device 8 and the intermediate heat exchanger 5 corresponding to the evaporator.

  In the intermediate heat exchanger 5, the low temperature side refrigeration cycle B performs a defrosting operation to cause a temperature drop in the intermediate heat exchanger 5, but the high temperature side in the hot gas bypass circuit 10 of the high temperature side refrigeration cycle A. The flow path switching mechanism 9 is opened, and high-temperature and high-pressure gas refrigerant is appropriately supplied to the intermediate heat exchanger 5 in accordance with the defrosting operation. Therefore, it is possible to suppress the temperature drop of the supply water temperature during defrosting and maintain an appropriate defrosting operation.

  By doing so, the temperature fall of the intermediate heat exchanger 5 is suppressed, and the air heat exchanger 2 which is indispensable as a heat pump apparatus can be defrosted.

  In addition, since the heating operation is continued without performing the reverse cycle operation in the high temperature side refrigeration cycle A, it is also possible to suppress the temperature decrease of the heat radiation heat exchanger 7 connected to the load side equipment. And hot water can be continuously supplied by suppressing the fall of the heating capability at the time of a defrost operation to the minimum.

  As described above, according to the dual refrigeration cycle apparatus according to the present embodiment, when the air heat exchanger 2 of the low temperature side refrigeration cycle B is frosted, the low temperature side refrigeration cycle AB has the low temperature side flow path switching mechanism 4. Since the so-called reverse cycle operation in which the refrigerant discharged from the low-temperature side compressor 1 is introduced into the air heat exchanger 2 is switched, defrosting can be performed at high speed. On the other hand, in the high temperature side refrigeration cycle A, the so-called hot gas bypass operation in which the refrigerant discharged from the high temperature side compressor 6 is introduced into the hot gas bypass circuit 10 is performed, so that heat can be supplied to the intermediate heat exchanger 5. And heat is not taken from the heat-dissipating heat exchanger 7.

  Therefore, defrosting can be performed at high speed without cooling the object to be heated heated by the heat radiation heat exchanger 7 during the heating operation.

  Further, according to the above-described dual refrigeration cycle apparatus, the high temperature side refrigeration cycle provided with the heat radiation heat exchanger 7 connected to the load facility during the defrosting operation in the low temperature side refrigeration cycle that is indispensable in the heat pump type apparatus of the air heat source. Then, the operation corresponding to the defrosting operation of the low temperature side refrigeration cycle and the heating operation for the heat radiation heat exchanger 7 can be performed. Thereby, with respect to the configuration in which the reverse cycle defrosting operation using the four-way switching valve is performed in the high temperature side refrigeration cycle, the low temperature side refrigeration cycle B is temporarily reduced in supply water temperature during defrosting, It becomes possible to suppress the water temperature drop in the installed water tank.

  In addition, conventionally, due to the product protection control operation that occurs due to the combination with the load side equipment configuration, such as when the capacity of the water tank installed on the load side is extremely small, the water temperature significantly decreases with defrosting operation, etc. Although there is a risk of stopping the apparatus or stopping the load side equipment, the above two-way refrigeration cycle apparatus can also suppress such inconvenience.

  Furthermore, since the configuration of the high temperature side refrigeration cycle A is not a device configuration using a four-way switching valve, the circuit configuration is simple with a small number of parts. Here, in terms of simplification of the circuit configuration, it is also a suggestion that not only the high-temperature side refrigeration cycle A but also the low-temperature side refrigeration cycle B has a configuration having a hot gas bypass circuit by eliminating the four-way switching valve. However, from the viewpoint of performing defrosting of the air heat exchanger 2, the reverse cycle defrosting operation is desirable because a larger defrosting capability can be obtained. For this reason, there is an effect that it can be as simple as possible and has a high defrosting capability.

  Moreover, if it is the said structure, it is also possible to use an inexpensive package air conditioner as an air-conditioning harmony apparatus for the low temperature side refrigerating cycle B, and it becomes possible to aim at cost reduction with simplification of a circuit structure.

  The dual refrigeration cycle apparatus according to this embodiment is not limited to the configuration of the above embodiment, and various modifications can be made without departing from the spirit of the invention.

  For example, in the above embodiment, the high temperature side flow path switching mechanism 9 has been described as being configured by an electromagnetic valve (two-way valve) disposed in the hot gas bypass circuit 10, but the discharge from the high temperature side compressor 6 is performed. The present invention is not limited to this as long as the refrigerant can be switched between a state where the refrigerant is introduced into the hot gas bypass circuit 10 and a state where the refrigerant is not introduced into the hot gas bypass circuit 10. For example, a junction between the hot gas bypass circuit 10 and a path from the high temperature side compressor to the heat radiation heat exchanger 7, or a merge between the hot gas bypass circuit 10 and the path from the high temperature side decompression device 8 to the intermediate heat exchanger 5. A three-way valve may be arranged in the part.

  When a three-way switching valve is used as the three-way valve, there is a configuration for switching between a state in which the refrigerant discharged from the high-temperature side compressor 6 is supplied only to the radiant heat exchanger 7 and a state in which only the radiant heat exchanger 7 is introduced. Conceivable. Further, when a flow rate ratio adjusting valve is used as the three-way valve, the refrigerant discharged from the high temperature side compressor 6 is supplied only to the radiant heat exchanger 7 and introduced into the radiant heat exchanger 7 and the hot gas bypass circuit 10. A configuration for switching the state to be performed can be considered.

  Moreover, in the said embodiment, although the low temperature side flow-path switching mechanism 4 demonstrated as what is comprised with a four-way switching valve, if it is a structure which can perform what is called a reverse cycle operation which reverses the flow direction of a refrigerant | coolant, It is not limited to a four-way switching valve.

  Moreover, in the said embodiment, although the thermal radiation heat exchanger 7 of the high temperature side refrigerating cycle A demonstrated as what heats water, the heating object is not restricted to water, Liquid such as brine may be sufficient, and air It may be.

DESCRIPTION OF SYMBOLS 1 Low temperature side compressor 2 Air heat exchanger 3 Low temperature side decompression device 4 Low temperature side flow path switching mechanism 5 Intermediate heat exchanger 6 High temperature side compressor 7 Radiation heat exchanger 8 High temperature side decompression device 9 High temperature side flow path switching mechanism 10 Hot gas bypass circuit

Claims (1)

A high temperature side refrigeration cycle, a low temperature side refrigeration cycle, and an intermediate heat exchanger that performs heat exchange between the high temperature side refrigeration cycle and the low temperature side refrigeration cycle,
The high temperature side refrigeration cycle is configured by sequentially connecting a high temperature side compressor, a heat dissipation heat exchanger, a high temperature side pressure reducing device, and the intermediate heat exchanger,
The low temperature side refrigeration cycle is configured by sequentially connecting a low temperature side compressor, the intermediate heat exchanger, a low temperature side pressure reducing device, and an air heat exchanger,
The high temperature side refrigeration cycle includes a hot gas bypass circuit that introduces refrigerant discharged from the high temperature side compressor into the intermediate heat exchanger by bypassing the heat dissipation heat exchanger, and refrigerant discharged from the high temperature side compressor. wherein a hot-side flow path switching mechanism for switching between a state that is not introduced to a state in which it is introduced into the hot gas bypass circuit to the hot gas bypass circuit,
Said cold side refrigeration cycle, a state in which refrigerant discharged from the low-temperature side compressor is introduced into the intermediate heat exchanger, said air heat Ru switched between a state that is introduced into exchanger low temperature side flow passage switching mechanism With
When generating high-temperature water by heat radiation from the heat-dissipating heat exchanger, the high-temperature water is introduced into the heat-dissipating heat exchanger without introducing the refrigerant discharged from the high-temperature side compressor into the hot gas bypass circuit. Controlling the low-temperature side flow path switching mechanism to control the side flow path switching mechanism and introducing the refrigerant discharged from the low-temperature side compressor into the intermediate heat exchanger;
When defrosting the air heat exchanger of the low temperature side refrigerating cycle, the refrigerant discharged from the high-temperature side compressor to the radiator heat exchanger and the intermediate heat exchanger is introduced into the hot gas bypass circuit The high temperature side flow path switching mechanism is controlled in a state of introduction , and the low temperature side flow path switching mechanism is controlled in a state of introducing refrigerant discharged from the low temperature side compressor into the air heat exchanger. Heat pump type high temperature water generator .

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