JP2009092321A - Cooling/heating hot water supply system and its operating method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress a cost increase and an enlargement of the device by performing simultaneous operation of cooling and hot water supply without newly installing an indoor heat exchanger for cooling. <P>SOLUTION: This refrigerating cycle device is provided with a main refrigerant circuit formed by connecting a compressor 2, a parallel circuit in which a hot water supply heat exchanger 30 and the indoor heat exchanger 1 are juxtaposed via a refrigerant conduit 6, a first expansion valve 4, and an outdoor heat exchanger 3 sequentially connected in an annular shape, and connection piping 7 for connecting a first electromagnetic valve SV1 disposed in refrigerant piping connected to discharge piping of the compressor 2 out of refrigerant piping connected to the indoor heat exchanger 1 in the parallel circuit, a second expansion valve 23 disposed in refrigerant piping connected to outlet piping of the hot water supply heat exchanger 30 out of the refrigerant piping connected to the indoor heat exchanger 1 in the parallel circuit, and intake piping of the compressor 2 via a second electromagnetic valve SV2 branched from between the first electromagnetic valve SV1 and the indoor heat exchanger 1. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a refrigeration cycle apparatus such as a water heater and an air conditioner, and an operation method thereof.

  A conventional heat pump hot water supply / cooling device is disclosed in Patent Document 1. As shown in FIG. 9, this heat pump hot water supply / cooling apparatus includes an indoor unit A including an indoor heat exchanger 1, a compressor 2, an outdoor heat exchanger 3, a first expansion valve 4, and a liquid closing valve 5. The outdoor unit B connected by the refrigerant pipe 6, the hot water tank 14 for storing hot water to be supplied to the bathtub 13, the hot water tank heat exchanger 15 for heating the hot water stored in the hot water tank 14, and the water pipe 16 for connecting them. A hot water storage tank unit C provided with a water pump 17 for forced circulation of hot water in the hot water storage tank 14 that is provided with the operation of the hot water storage tank heat exchanger 15 that is interposed in the hot water tank water circulation circuit comprising the hot water in the bathtub 13. It is comprised from the bathtub reheating unit D provided with the bathtub heat exchanger 26 and the water pump 27 for forced circulation of the hot water of the bathtub 13 which act | operates with the action | operation of the bathtub heat exchanger 26.

The operation of the heat pump hot water supply / cooling apparatus configured as described above will be described below. The downstream side of the outdoor heat exchanger 3 of the outdoor unit B and the upstream side of the second expansion valve 23 are bypass-connected by a refrigerant pipe 25, and a normally open third electromagnetic valve SV3 is interposed in the refrigerant pipe 25, By opening the third solenoid valve SV3 and the hot water tank electromagnetic valve SVA, the refrigerant from the compressor 2 is circulated from the hot water tank heat exchanger 15 to the indoor heat exchanger 1 by bypassing the outdoor heat exchanger 3. The hot water in the hot water storage tank 14 was heated while the room was cooled.
Japanese Unexamined Patent Publication No. Sho 62-32381

  However, in the conventional configuration, in order to perform simultaneous operation of cooling and hot water supply, it is necessary to newly add an outdoor heat exchanger for cooling, and there is a problem in that the cost increases and the size of the apparatus increases. It was.

  In order to solve the above problems, in the present invention, a compressor, a parallel circuit in which a hot water supply heat exchanger and an indoor exchanger are arranged in parallel via a refrigerant pipe, a first expansion valve, A main refrigerant circuit in which the outdoor heat exchangers are sequentially connected in an annular manner, and a first electromagnetic that is disposed on the side connected to the discharge pipe of the compressor among the refrigerant pipes connected to the indoor heat exchanger in the parallel circuit. A valve, a second expansion device arranged on the refrigerant pipe connected to the indoor heat exchanger in the parallel circuit and connected to the outlet pipe of the hot water supply heat exchanger, the first electromagnetic valve, and the indoor heat A connecting pipe that branches from between the exchangers and connects to the suction pipe of the compressor via the second solenoid valve is provided.

  According to the refrigeration cycle apparatus of the present invention, since the cooling and hot water supply can be operated simultaneously without newly installing an indoor heat exchanger for cooling, an increase in cost and an increase in size of the apparatus can be suppressed.

(Embodiment 1)
Hereinafter, Embodiment 1 of the present invention will be described in detail with reference to the drawings. In addition, the same code | symbol is attached | subjected about the same structure as background art.

  In FIG. 1, the refrigeration cycle apparatus 32 according to Embodiment 1 of the present invention includes a compressor 2, a hot water supply heat exchanger 30 and an indoor exchanger 1 arranged in parallel via a refrigerant pipe 6. It was connected to the discharge pipe of the compressor 2 among the main refrigerant circuit formed by sequentially connecting the expansion valve 4 and the outdoor heat exchanger 3 in an annular manner and the refrigerant pipe connected to the indoor heat exchanger 1 in the parallel circuit. Of the first solenoid valve SV1 arranged in the direction and the refrigerant pipe connected to the indoor heat exchanger 1 in the parallel circuit, the second solenoid valve SV1 arranged in the direction connected to the outlet pipe of the hot water supply heat exchanger 30 The expansion device 23 is provided with a communication pipe 7 that branches from between the first electromagnetic valve SV1 and the indoor heat exchanger 1 and connects the suction pipe of the compressor 2 via the second electromagnetic valve SV2. .

  1 and Table 1 will be used to describe control methods in hot water single operation, heating single operation, hot water heating operation, summer hot water single operation, and hot water cooling operation in the refrigeration cycle apparatus 32 according to Embodiment 1 of the present invention. To do.

<Independent operation of hot water supply in winter>
The path through which the refrigerant flows is indicated by solid arrows. First, the refrigerant is compressed by the compressor 2 to become a high-temperature and high-pressure refrigerant, and flows into the hot water supply heat exchanger 30 to supply hot water. Here, as shown in Table 1, the first electromagnetic valve SV1 is in a closed state. Moreover, since SV2 is in a closed state as shown in Table 1, the refrigerant does not flow through the connecting pipe 7. SV3 is in an open state. The refrigerant that has flowed out of the hot water supply heat exchanger 30 flows into the first expansion valve 4. Here, the second expansion valve 23 is closed as shown in Table 1. The refrigerant flowing into the first expansion valve 4 expands to become a low temperature and low pressure, evaporates in the outdoor heat exchanger 3, and repeats a cycle of flowing into the compressor 2 in a gas state having a certain degree of superheat.
<Winter heating alone operation>
The path through which the refrigerant flows is indicated by solid arrows. First, the refrigerant is compressed by the compressor 2 to become a high-temperature and high-pressure refrigerant and flows into the indoor heat exchanger 1 for heating. Here, the first solenoid valve SV1 is open as shown in Table 1. Moreover, since SV2 is in a closed state as shown in Table 1, the refrigerant does not flow through the connecting pipe 7. SV3 is in a closed state. The refrigerant that has flowed out of the indoor heat exchanger 1 flows into the first expansion valve 4. Here, the second expansion valve 23 is open as shown in Table 1. The refrigerant flowing into the first expansion valve 4 expands to become a low temperature and low pressure, evaporates in the outdoor heat exchanger 3, and repeats a cycle of flowing into the compressor 2 in a gas state having a certain degree of superheat.
<Winter hot water heating and heating operation>
The path through which the refrigerant flows is indicated by solid arrows. First, the refrigerant is compressed by the compressor 2 to become a high-temperature and high-pressure refrigerant and flows into the hot water supply heat exchanger 30 and the indoor heat exchanger 1 to perform hot water supply and heating. Here, as shown in Table 1, the first solenoid valve SV1 and the third solenoid valve SV3 are open. Moreover, since SV2 is in a closed state as shown in Table 1, the refrigerant does not flow through the connecting pipe 7. The refrigerant flowing out of the hot water supply heat exchanger 30 and the indoor heat exchanger 1 joins and flows into the first expansion valve 4. Here, the second expansion valve 23 is open as shown in Table 1. The refrigerant flowing into the first expansion valve 4 expands to become a low temperature and low pressure, evaporates in the outdoor heat exchanger 3, and repeats a cycle of flowing into the compressor 2 in a gas state having a certain degree of superheat.
<Independent operation of hot water supply in summer>
The path through which the refrigerant flows is indicated by solid arrows. First, the refrigerant is compressed by the compressor 2 to become a high-temperature and high-pressure refrigerant, and flows into the hot water supply heat exchanger 30 to supply hot water. Here, as shown in Table 1, the first electromagnetic valve SV1 is in a closed state. Moreover, since SV2 is in a closed state as shown in Table 1, the refrigerant does not flow through the connecting pipe 7. SV3 is in an open state. The refrigerant that has flowed out of the hot water supply heat exchanger 30 flows into the first expansion valve 4. Here, the second expansion valve 23 is closed as shown in Table 1. The refrigerant flowing into the first expansion valve 4 expands to become a low temperature and low pressure, evaporates in the outdoor heat exchanger 3, and repeats a cycle of flowing into the compressor 2 in a gas state having a certain degree of superheat.
<Summer water supply and cooling operation>
A path through which the refrigerant flows is indicated by a dashed arrow. First, the refrigerant is compressed by the compressor 2 to become a high-temperature and high-pressure refrigerant, and flows into only the hot water supply heat exchanger 30 to supply hot water. Here, as shown in Table 1, the first solenoid valve SV1 is closed and the third solenoid valve SV3 is open. The refrigerant that has flowed out of the hot water supply heat exchanger 30 flows into the second expansion valve 23, expands, and becomes low temperature and low pressure. Here, the first expansion valve 4 is in a closed state as shown in Table 1. The refrigerant that has passed through the first expansion valve 4 evaporates and cools in the indoor heat exchanger 1 and repeats a cycle of flowing into the compressor 2 through the communication pipe 7. Here, SV2 is open as shown in Table 1.

  As described above, it is possible to carry out winter hot water supply single operation, heating single operation, hot water supply heating operation, summer hot water supply single operation, and hot water supply cooling operation without providing a four-way valve by installing only one indoor heat exchanger. .

  In particular, when carbon dioxide is used as the refrigerant, it is more effective not to use the four-way valve because the pressure and pressure difference become very large and the reliability of the four-way valve is impaired.

In the above description, the single cooling operation in summer is not described, but the single cooling operation cannot be performed in the configuration of FIG. That is, in the configuration of the present invention, since the heat radiator is only the hot water supply heat exchanger 30, when only cooling is performed, the hot water supply heat exchanger 30 must be used as the heat radiator, so that useless hot water is generated. Must be configured to discharge it. This configuration will be described with reference to FIG.
<Summer cooling only operation>
FIG. 2 shows a configuration in which a fourth solenoid valve, a fifth solenoid valve, and a drainage path 36 are installed in the configuration of FIG. In the case of summer cooling only operation, basically the same operation as the above-described summer hot water supply cooling operation is performed. The difference is that in the case of the hot water supply and cooling operation in summer, the generated hot water is necessary, so that all the generated hot water flows into the hot water storage tank 35 or directly into the use terminal. However, since the generated hot water is not required for the cooling only operation in summer, the fourth solenoid valve SV4 is closed and the SV5 is opened to flow into the discharge path 36 so as not to flow into the hot water storage tank 35 or the use terminal.

  By adopting the configuration as described above, a single cooling operation in summer can be performed. However, the heat in the hot water supply heat exchanger 30 is wasted and water is also wasted.

  Therefore, as shown in FIG. 3, the fourth solenoid valve SV4, the path connecting the discharge part of the compressor 2 and the outdoor heat exchanger 3 and the fifth solenoid valve SV5 are installed on the path in the configuration of FIG. Thus, it is possible to operate the cooling unit alone in summer, and the heat in the radiator is wasted, but it is possible to avoid wasting water.

  A path through which the refrigerant flows is indicated by a one-dot chain line arrow. First, the refrigerant is compressed by the compressor 2 to become a high-temperature and high-pressure refrigerant, and flows into the outdoor heat exchanger 3 to radiate heat. Here, the first electromagnetic valve SV1, the third electromagnetic valve SV3, and the fourth electromagnetic valve SV4 are closed. Further, the second solenoid valve SV2 and the fifth solenoid valve SV5 are in an open state. The refrigerant that has flowed out of the outdoor heat exchanger 3 flows into the first expansion valve 4. The refrigerant flowing into the first expansion valve 4 expands to a low temperature and low pressure, evaporates in the indoor heat exchanger 1 and cools, and flows into the compressor 2 in a gas state having a certain degree of superheat. repeat. Here, the expansion valve may be either the first expansion valve or the second expansion valve.

  Further, Table 2 shows the control of the fourth solenoid valve and the fifth solenoid valve in the hot water single operation, the heating single operation, the hot water heating operation, the hot water single operation, and the hot water cooling operation in the summer in this configuration. The control of the first expansion valve, the second expansion valve, the first electromagnetic valve, the second electromagnetic valve, and the third electromagnetic valve is the same as in Table 1.

  By adopting the configuration as described above, it is possible to perform a single cooling operation in summer, and water is not wasted.

(Embodiment 2)
Hereinafter, Embodiment 2 of the present invention will be described in detail with reference to the drawings. In addition, the same code | symbol is attached | subjected about the same structure as background art.

  Here, an operation pattern in consideration of hot water supply and cooling loads during simultaneous operation of hot water supply and cooling will be described.

  The operation method of the first embodiment is a case where both the hot water supply load and the cooling load are large. However, when the cooling load is small, the hot water supply load required by the operation method of the first embodiment cannot be provided. That is, when the cooling load is small, the amount of heat absorbed from the air is small, so that sufficient hot water cannot be supplied.

  Therefore, when the hot water supply load is large and the cooling load is small, the following control is performed. As shown in FIG. 4, the refrigerant is compressed by the compressor 2 to become a high-temperature and high-pressure refrigerant, and flows into only the hot water supply heat exchanger 30 to supply hot water. Here, as shown in Table 1, the first electromagnetic valve SV1 is in a closed state. The refrigerant that has flowed out of the hot water supply heat exchanger 30 is branched in two directions, the second expansion valve 23 and the first expansion valve 4. The refrigerant that has passed through the second expansion valve 23 evaporates and cools in the indoor heat exchanger 1, and repeats the cycle of flowing into the compressor 2 through the communication pipe 7. Here, SV2 is open as shown in Table 1. On the other hand, the refrigerant that has passed through the first expansion valve 4 sucks up the amount of heat absorbed by the indoor heat exchanger 1 in the outdoor heat exchanger 3 and flows into the compressor 2.

  As described above, even if the cooling load is reduced and the heat absorption amount from the indoor heat exchanger 1 is reduced, the necessary hot water supply load can be covered.

  Next, a refrigerant distribution control method to the indoor heat exchanger 1 and the outdoor heat exchanger 3 by flow control of the first expansion valve 4 and the second expansion valve 23 when the hot water supply load is large and the cooling load is small will be described. .

  First, when the cooling load is reduced, the refrigeration cycle behavior is as shown by the dotted line in FIG. In other words, because the evaporator cannot absorb enough heat, the difference in refrigerant enthalpy between the evaporator inlet and outlet becomes smaller, the compressor superheating degree becomes smaller, and the compressor suction density becomes smaller. It becomes difficult.

  A control method in this case will be described with reference to the flowchart of FIG.

  First, in S1, the refrigerant temperature in the outdoor heat exchanger 3 is detected in S2 by detecting the refrigerant temperature in the outdoor heat exchanger 3 in S2 by detecting the intake refrigerant temperature of the compressor 2 by the first refrigerant temperature detection means 33. Is calculated. Next, the degree of superheat SH is compared with a predetermined value a. Here, the predetermined value a is preferably 5 to 10 deg. If SH ≧ a, the operation is continued, and if SH ≦ a, the first expansion valve 4 is opened in S3. Thereafter, the process returns to S1 and the same flowchart is repeated until SH ≧ a.

  Further, if SH ≧ a is not satisfied even when the first expansion valve 4 is completely opened, the opening degree is adjusted (throttle) to close the second expansion valve 23 so that SH ≧ a is satisfied. adjust.

In addition, if the compressor suction superheat degree SH is the predetermined value a, control is performed so that the operation is continued. However, since it is necessary to read the change in the cooling load and perform the flowchart of FIG. The flowchart from S1 is performed every certain time interval (for example, every 10 minutes).

  Further, the connection position of the second expansion valve 23 may be as shown in FIG. Also in this case, the control method of the second expansion valve 23 is shown in Tables 1 and 2 in the hot water single operation, the heating single operation, the hot water heating operation and the hot water single operation in the summer, the cooling single operation, and the hot water cooling operation. This is the same as the control method of the second expansion valve shown in FIG.

  Further, the first electromagnetic valve SV1 and the second electromagnetic valve SV2 shown in FIG. 1 may be combined into a three-way valve 31 as shown in FIG.

  As shown in Table 3, the control method of the three-way valve is connected to direction a during winter hot water single operation, heating single operation, hot water supply heating operation, and b during summer hot water single operation, cooling single operation, and hot water cooling operation. Connect in the direction.

  By installing the three-way valve, the number of parts of the electromagnetic valve is reduced, the device can be downsized and the cost can be reduced.

By performing the control as described above, smooth operation can be performed even when the balance between the hot water supply load and the cooling load is lost.

  The refrigeration cycle apparatus according to the present invention can be used as a heat pump apparatus such as a water heater, a refrigeration / air-conditioning apparatus, and a drying apparatus.

Configuration diagram of a refrigeration cycle apparatus in Embodiment 1 of the present invention Configuration diagram of a refrigeration cycle apparatus in Embodiment 1 of the present invention Configuration diagram of a refrigeration cycle apparatus in Embodiment 1 of the present invention Configuration diagram of a refrigeration cycle apparatus in Embodiment 2 of the present invention Pressure-enthalpy diagram in the second embodiment of the present invention The flowchart which shows the control method in Embodiment 2 of this invention. The flowchart which shows the control method in Embodiment 2 of this invention. Configuration diagram of a refrigeration cycle apparatus in Embodiment 2 of the present invention Conventional refrigeration cycle diagram

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Indoor heat exchanger 2 Compressor 3 Outdoor heat exchanger 4 1st expansion valve 5 Liquid closing valve 6, 22, 24, 25, 29 Refrigerant piping 7, 21, 28 Communication piping 8 Indoor fan 9 Indoor fan motor 10 Outdoor Fan 11 Outdoor fan motor 12 Accumulator 13 Bathtub 14 Hot water storage tank 15 Hot water storage tank heat exchanger 16 Water piping 17, 27 Water pump 18 Hot water supply piping 19, 20 Hot water supply curan 23 Second expansion valve 26 Bath heat exchanger 30 Hot water supply heat Exchanger 31 Three-way valve 32 Refrigeration cycle device 33 First refrigerant temperature detection means 34 Second refrigerant temperature detection means 35 Hot water storage tank 36 Drainage path SVA Hot water storage tank solenoid valve SVB Bathtub solenoid valve SV1 First solenoid valve SV2 Second solenoid valve SV3 3rd solenoid valve SV4 4th solenoid valve SV5 5th solenoid valve A Indoor unit B Outdoor unit C Hot water tank unit D Bath reheating unit

Claims (4)

A main circuit formed by sequentially connecting a compressor, a hot water supply heat exchanger, and an indoor exchanger in parallel with each other in parallel through a refrigerant pipe, a first expansion valve, and an outdoor heat exchanger. A refrigerant circuit; a first solenoid valve disposed on a side connected to a discharge pipe of the compressor among refrigerant pipes connected to the indoor heat exchanger in the parallel circuit; and the room in the parallel circuit From among the refrigerant pipes connected to the heat exchanger, the second expansion device arranged on the side connected to the outlet pipe of the hot water supply heat exchanger, and between the first electromagnetic valve and the indoor heat exchanger A refrigeration cycle apparatus comprising a connecting pipe that branches and connects the suction pipe of the compressor via a second electromagnetic valve. 2. The operation of the refrigeration cycle apparatus according to claim 1, wherein when the hot water supply and the cooling are simultaneously operated, the first expansion valve is closed, the first electromagnetic valve is closed, and the second electromagnetic valve is opened. Method. In the case of simultaneously operating hot water supply and cooling, it comprises first refrigerant temperature detection means for detecting the refrigerant temperature sucked by the compressor, and second refrigerant temperature detection means for detecting the refrigerant temperature of the outdoor heat exchanger, The degree of superheat is calculated from the detection value of the first refrigerant temperature detection means and the detection value of the second refrigerant temperature detection means, and the first expansion valve is opened when the degree of superheat is smaller than a predetermined value. The operating method of the refrigeration cycle apparatus according to claim 1. In the case of simultaneously operating hot water supply and cooling, it comprises first refrigerant temperature detection means for detecting the refrigerant temperature sucked by the compressor, and second refrigerant temperature detection means for detecting the refrigerant temperature of the outdoor heat exchanger, Calculating the degree of superheat from the detection value of the first refrigerant temperature detection means and the detection value of the second refrigerant temperature detection means, and closing the second expansion valve when the degree of superheat is smaller than a predetermined value. The operating method of the refrigeration cycle apparatus according to claim 1.

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