JP2014196849A - Heat pump water heater - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat pump water heater capable of improving a performance for preventing freezing of water in pipes in the heat pump water heater by including a circulation pump in a heat pump unit.SOLUTION: A heat pump water heater comprises: a heat pump unit 30 that includes therein a heat pump cycle 2 formed by connecting a compressor 6, water-refrigerant heat exchanger 7, decompression means 4, and an evaporator 5, and a circulation pump 14; a hot water storage unit 20 including therein a hot water storage tank 1 storing hot water heated by the water-refrigerant heat exchanger 7; and a control device 50. A lower portion of the hot water storage tank 1 is connected only to a water intake side of the water-refrigerant heat exchanger 7 via the circulation pump 14, and a hot water outlet side of the water-refrigerant heat exchanger 7 is connected only to an upper portion of the hot water storage tank 1. The control device 50 has a frosting prevention operation mode for driving at least the circulation pump 14 to transport the water in the lower portion of the hot water storage tank 1 to the upper portion thereof via the water-refrigerant heat exchanger 7.

Description

  The present invention relates to a heat pump water heater.

  Conventionally, this type of heat pump hot water supply apparatus is used to prevent freezing of water in a pipe connecting a heat pump unit having a built-in heat pump cycle and a hot water storage unit having a built-in hot water tank when the outside air temperature decreases. The amount of heat was replenished by circulating the hot water in the pipe or by heating the circulating water with heat generated by operating a heat pump cycle (see, for example, Japanese Patent Application Laid-Open Publication No. HEI 10-110826). ).

  FIG. 3 shows a conventional heat pump hot-water supply device described in Patent Document 1.

  The heat pump unit 130 includes a heat pump cycle 102, and the hot water storage unit 120 includes a hot water storage tank 101 that stores hot water heated by the heat pump cycle 102.

  The heat pump cycle 102 is formed by connecting a compressor 106, a water refrigerant heat exchanger 107, a decompression means 104, and an air heat exchanger (evaporator) 105 in a ring shape with a refrigerant pipe 103.

  The refrigerant sealed in the heat pump cycle 102 is sucked into the compressor 106 in a low-pressure gas state, compressed into a high-temperature and high-pressure state, and then transferred to the water-refrigerant heat exchanger 107 and transferred from the hot water storage tank 101. It exchanges heat with water and becomes itself in a low temperature and high pressure state.

  Thereafter, the refrigerant becomes a gas-liquid two-phase refrigerant expanded to a low-temperature and low-pressure state by the decompression means 104 such as an expansion valve, and the air heat exchanger 105 absorbs heat from the outside air blown by the blowing means 108 to become a low-pressure gas refrigerant. The cycle of being inhaled by the machine 106 is repeated.

  Further, the bottom of the hot water storage tank 101, the circulation pump 114, and the water refrigerant heat exchanger 107 are sequentially connected by the water inlet pipe 109, and the hot water outlet pipe 110 connected to the outlet of the water refrigerant heat exchanger 107 is connected to the three-way valve 113. The three-way valve 113 is connected to a hot water storage pipe 111 connected to the upper part of the hot water storage tank 101 and a bypass pipe 112 connected to the lower part of the hot water storage tank 101.

  The controller 150 controls the temperature of the hot water at this time, the number of revolutions of the circulation pump 114, and the operation of each component of the heat pump cycle 102.

  When the outside temperature detecting means 115 detects a predetermined temperature (set temperature 1) or less, the freeze prevention operation mode 1 is activated.

  When the anti-freezing operation mode 1 is activated, the control unit 150 drives the three-way valve 113 to the bypass pipe 112 side to supply the water below the hot water storage tank 101 to the inlet pipe 109, the water / refrigerant heat exchanger 107, the outlet pipe 110, Circulation with the bypass piping 112 and the lower part of the hot water storage tank 101 is performed to prevent the water in each piping from being frozen.

When the outside air temperature detecting means 115 detects a predetermined temperature (set temperature 2) lower than the set temperature 1, only the amount of heat in the water in the lower part of the hot water storage tank 101 used in the freeze prevention operation mode 1 is used in each pipe. Since it is insufficient to prevent the water from being frozen, the control means 150 operates the circulation pump 114 and also operates the heat pump cycle 102 to heat the circulating water in the water / refrigerant heat exchanger 107. Then, the anti-freezing operation mode 2 for replenishing heat is started.

JP 2004-257583 A

  However, in the conventional anti-freezing operation, the circulation pump 114 is operated, and while the water in the lower part of the hot water storage tank 101 is conveyed to the water / refrigerant heat exchanger 107 through the water inlet pipe 109, the circulation pump 114 is operated in the hot water storage unit. Since the heat pump unit 130 and the hot water storage unit 120 are connected to each other, the heat generated when the circulation pump 114 is driven is dissipated in the water inlet pipe 109 connecting the heat pump unit 130 and the hot water storage unit 120. It was not utilized and had a problem that heat dissipation loss occurred.

  The present invention solves the above-mentioned conventional problems, and provides a heat pump hot water supply apparatus that improves the prevention of water freezing in piping in the apparatus by incorporating a circulation pump in the heat pump unit. Objective.

  In order to solve the conventional problems, a heat pump water heater of the present invention includes a heat pump unit formed by connecting a compressor, a water-refrigerant heat exchanger, a decompression unit, and an evaporator, and a heat pump unit including a circulation pump. A hot water storage unit containing a hot water storage tank for storing hot water heated by the water refrigerant heat exchanger, and a control device, and a lower portion of the hot water storage tank is connected to an inlet side of the water refrigerant heat exchanger via the circulation pump And the hot water side of the water refrigerant heat exchanger is connected only to the upper part of the hot water storage tank, and the control device drives at least the circulation pump so that the water in the lower part of the hot water storage tank is supplied to the water refrigerant. It has a freezing prevention operation mode in which it is conveyed to the upper part of the hot water storage tank via a heat exchanger.

  As a result, in the freeze prevention operation mode, the circulation pump is driven and the water in the lower part of the hot water storage tank in the hot water storage unit is conveyed to the water / refrigerant heat exchanger in the heat pump unit, but the circulation pump is built in the heat pump unit. Therefore, while the water in the lower part of the hot water storage tank is transported from the hot water storage unit to the heat pump unit, the heat generated by driving the circulation pump does not radiate heat. Can be effectively utilized as the amount of heat transferred to the water-refrigerant heat exchanger, so that it is possible to provide a heat pump hot water supply apparatus that has improved the performance of preventing the water in the piping in the apparatus from freezing.

  ADVANTAGE OF THE INVENTION According to this invention, the heat pump hot water supply apparatus which improved the prevention performance of the water freezing in the piping in an apparatus can be provided by incorporating a circulation pump in a heat pump unit.

The block diagram of the heat pump hot-water supply apparatus in Embodiment 1 of this invention Control flow chart of anti-freezing operation of the heat pump water heater Configuration diagram of conventional heat pump water heater

  A first invention is a heat pump unit including a heat pump cycle and a circulation pump formed by connecting a compressor, a water refrigerant heat exchanger, a decompression means, and an evaporator, and hot water heated by the water refrigerant heat exchanger. A hot water storage unit including a hot water storage tank for storing hot water, and a control device; a lower part of the hot water storage tank is connected to a water inlet side of the water refrigerant heat exchanger and a hot water side of the water refrigerant heat exchanger via the circulation pump; The hot water tank is connected only to the upper part of the hot water storage tank, and the control device drives at least the circulation pump, and the water in the lower part of the hot water storage tank is passed through the water refrigerant heat exchanger to the upper part of the hot water storage tank. A heat pump hot water supply apparatus having an anti-freezing operation mode for transporting to a heat pump.

  As a result, in the freeze prevention operation mode, the circulation pump is driven and the water in the lower part of the hot water storage tank in the hot water storage unit is conveyed to the water / refrigerant heat exchanger in the heat pump unit, but the circulation pump is built in the heat pump unit. Therefore, while the water in the lower part of the hot water storage tank is transported from the hot water storage unit to the heat pump unit, the heat generated by driving the circulation pump does not radiate heat. Can be effectively utilized as the amount of heat transferred to the water-refrigerant heat exchanger, so that it is possible to provide a heat pump hot water supply apparatus with improved performance of preventing freezing of water in the piping in the apparatus.

  The second invention is characterized in that, in the first invention, in particular, the control device executes the operation of the heat pump cycle, and heats the circulating water by the circulation pump in the water refrigerant heat exchanger. The heat pump water heater that improves the water freezing prevention performance in the pipes in the equipment by operating the heat pump cycle and replenishing the amount of heat generated by the operation of the heat pump cycle in the water refrigerant heat exchanger Can provide.

  According to a third aspect of the present invention, particularly in the first or second aspect of the present invention, the water refrigerant heat exchanger further includes an incoming water temperature detecting means disposed on the incoming side of the water refrigerant heat exchanger, and the control device detects the detected temperature of the incoming water temperature detecting means. The anti-freezing operation is performed when is lower than a predetermined value.

  Thus, when the detected temperature of the incoming water temperature detecting means determines that the water in the piping of the apparatus may be frozen, the circulating pump is driven, and the water below the hot water storage tank in the hot water storage unit is It is transported to the water-refrigerant heat exchanger in the heat pump unit, but the circulation pump is built in the heat pump unit, so that the circulation pump is driven while water is transferred from the hot water storage unit to the heat pump unit. Since the heat generated by the heat does not radiate, the heat generated by the circulation pump being driven can be effectively transferred and utilized as the amount of heat transferred to the water-refrigerant heat exchanger. It is possible to provide a heat pump hot-water supply device with improved water freezing prevention performance.

  According to a fourth aspect of the invention, in particular, in the second aspect of the invention, the control device includes an outside air temperature detection unit, and the control device executes the operation of the heat pump cycle when the detected temperature of the outside air degree detection unit is lower than a predetermined value. It is characterized by.

  As a result, the amount of water in the lower part of the hot water storage tank and the amount of heat generated when the circulation pump is driven are used to freeze the water in the piping communicating with the upper and lower parts of the hot water tank through the water / refrigerant heat exchanger. If the heat pump cycle is operated and the amount of heat generated by the operation of the heat pump cycle is replenished by the water / refrigerant heat exchanger, the performance of preventing water freezing in the piping in the apparatus can be improved. An improved heat pump water heater can be provided.

  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 is a diagram showing a configuration of a heat pump hot water supply apparatus according to the first embodiment of the present invention.

  In FIG. 1, the heat pump unit 30 includes a heat pump cycle 2 and a circulation pump 14, and the hot water storage unit 20 includes a hot water storage tank 1 that stores hot water heated in the heat pump cycle 2.

  The heat pump cycle 2 is formed by connecting a compressor 6, a water / refrigerant heat exchanger 7, a decompression means 4 such as an expansion valve, and an air heat exchanger (evaporator) 5 sequentially in an annular manner by a refrigerant pipe 3. ing.

  The lower part (bottom part) of the hot water storage tank 1, the circulation pump 14, and the water inlet side of the water refrigerant heat exchanger 7 are sequentially connected by the water inlet pipe 9 and also connected to the outlet side of the water refrigerant heat exchanger 7. The hot water supply pipe 10 is connected to only the upper part (top surface) of the hot water storage tank 1 without being branched.

  In addition, operation control of each component of the heat pump unit 30 and the hot water storage unit 20 is performed by the control device 50.

  The heat pump unit 30 has an outside air temperature detection means 15 for detecting the outside air temperature, and a tapping pipe 10 on the tapping side of the water refrigerant heat exchanger 7 detects a tapping temperature from the water refrigerant heat exchanger 7. The incoming water temperature detection means 16 for detecting the incoming water temperature to the water refrigerant heat exchanger 7 is disposed in the incoming water pipe 9 where the hot water temperature detection means 17 is on the incoming side of the water refrigerant heat exchanger 7.

  Here, in the heat pump hot water supply apparatus having the above-described configuration, the operation of the hot water storage operation for storing hot water in the hot water storage tank 1 will be described.

  In the heat pump cycle 2, when driving of the compressor 6 is started, a refrigerant, for example, carbon dioxide is compressed to a high temperature and a high pressure, dissipated in the water refrigerant heat exchanger 7, and low temperature and low pressure are reduced by the pressure reducing means 4 such as an expansion valve. And then flows into the air heat exchanger 7 (evaporator).

  The refrigerant absorbs heat in the air heat exchanger 7 (evaporator) by the air generated by the rotation of the air blowing means 8 such as a fan, and returns to the compressor 6 again. At this time, the high pressure and discharge temperature of the compressor 6 of the heat pump cycle 2 are increased stepwise.

  On the other hand, the circulation pump 14 that conveys the water in the lower part of the hot water storage tank 1 to the water-refrigerant heat exchanger 7 is stopped until the temperature of the refrigerant rises or is driven at a low speed.

  Thereafter, as the refrigerant temperature rises stepwise, the driving speed of the circulation pump 14 also rises, and the hot water temperature detection means 17 for detecting the hot water temperature from the water / refrigerant heat exchanger 7 has a predetermined temperature. The number of rotations of the circulation pump 14 is controlled by the control device 50. In the water / refrigerant heat exchanger 7, the refrigerant of the heat pump cycle 2 exchanges heat with the circulating water by the circulation pump 14, and the circulating water reaches a predetermined temperature. Heated to produce temperature.

  And the produced | generated temperature flows in the hot-water supply piping 10, flows in into the upper part of the hot water storage tank 1, and hot water is stored.

  As a result, hot water is not mixed in the hot water storage tank 1 and hot water is stored in the upper part and low temperature water is stored in the lower part. That is, a temperature stratification is formed in the hot water storage tank 1 to improve efficiency during hot water storage operation. Also effective for hot water supply at high temperatures.

Here, when the temperature of the relatively high temperature water in the outlet pipe 10 connected only to the upper part of the hot water storage tank 1 is lowered due to heat dissipation, the density increases. Therefore, the configuration of the first embodiment is The lower part of the hot water storage tank 1 is connected to the water inlet side of the water refrigerant heat exchanger 7 by the inlet water pipe 9, the outlet side of the water refrigerant heat exchanger 7 is connected to the upper part of the hot water tank 1 by the outlet water pipe 10, and the lower part of the hot water tank 1. The water refrigerant heat exchanger 7 and the upper part of the hot water storage tank 1 are connected so as to be always in direct communication, thereby connecting the lower part of the hot water storage tank 1, the water refrigerant heat exchanger 7 and the upper part of the hot water storage tank 1. Due to the head difference between the hot water supply pipe 10 and the incoming water pipe 9, the water whose temperature has decreased is moved to the water / refrigerant heat exchanger 7 side, and the hot water in the upper part of the hot water storage tank 1 also flows out of the hot water storage tank 1. The hot water stored in the upper part of the tank 1 Through the refrigerant heat exchanger 7, natural convection flows into the lower part of the hot water storage tank 1 low-temperature water is stored is generated.

  That is, since hot water is stored in the upper part of the hot water storage tank 1 and low temperature water is stored in the lower part, the hot water passes through the hot water piping 10, the air heat exchanger 7, and the incoming water pipe 9 to store hot water. It flows to the lower part of the tank 1.

  Further, when the outside air temperature is low, when the wall surface of the hot water supply pipe 10 is cooled by the outside air, the flow of this natural convection becomes larger, so that the water in the apparatus can be prevented from freezing without driving the circulation pump 14. Therefore, the driving time of the circulation pump 14 can be shortened, and the power consumption can be reduced.

  Next, the freeze prevention operation | movement operation | movement of the heat pump hot-water supply apparatus in the 1st Embodiment of this invention is demonstrated based on the control flowchart shown in FIG.

  First, at Step 1, the detected temperature of the incoming water temperature detection means 16 is lower than a predetermined temperature 1 (for example, 5 ° C.) at which it is determined that the water in the piping of the apparatus may be frozen only by the natural convection. In Step 2, it is determined whether or not the detected temperature of the outside air temperature detecting means 15 is lower than a predetermined temperature 2 (for example, 2 ° C.).

  In Step 1, when the detected temperature of the incoming water temperature detection means 16 is equal to or higher than a predetermined temperature 1 (for example, 5 ° C.), the process returns to the initial state of the freezing operation flowchart, and Step 1 is determined every predetermined time interval.

  If the detected temperature of the incoming water temperature detecting means 16 is lower than the predetermined temperature 1 (for example, 5 ° C.) in Step 1, the process proceeds to Step 2, and the detected temperature of the outside air temperature detecting means 15 is the predetermined temperature 2 (for example, 2). If it is above, the circulation pump 14 is driven and the water in the lower part of the hot water storage tank 1 is transported only to the upper part of the hot water storage tank 1 through the water / refrigerant heat exchanger 7 to prevent freezing. (Step 3).

  In the freeze prevention operation 1, the circulation pump 14 is driven without operating the heat pump cycle 2, and the water below the hot water storage tank 1 in the hot water storage unit 20 is conveyed to the water refrigerant heat exchanger 7 in the heat pump unit 30. However, since the circulation pump 14 is built in the heat pump unit 30, the heat generated by driving the circulation pump 14 while the water in the lower part of the hot water storage tank 1 is conveyed from the hot water storage unit 20 to the heat pump unit 30 is generated. Since heat is not dissipated, the heat generated by driving the circulation pump 14 can be effectively transferred and utilized as the amount of heat transferred to the water / refrigerant heat exchanger 7 and the hot water piping 10. It is possible to provide a heat pump hot-water supply device with improved freezing prevention performance.

  Further, since the heat of the water in the lower part of the hot water storage tank 1 is conveyed to the water inlet pipe 9, heat is simultaneously applied to the two pipes of the water inlet pipe 9 and the hot water outlet pipe 10 between the hot water storage unit 20 and the heat pump unit 30. The anti-freezing effect can be obtained quickly.

  Next, the incoming water temperature is gradually increased by the freeze prevention operation 1 in Step 3, and it is determined in Step 4 whether or not the detected temperature of the incoming water temperature detecting means 16 is equal to or higher than a predetermined temperature 3 (for example, 10 ° C.). If it is 3 (for example, 10 ° C.) or higher, the freeze prevention operation is stopped (Step 7).

  Next, returning to Step 2 outside air temperature determination for determining whether or not the detected temperature of the outside air temperature detecting means 15 is lower than a predetermined temperature 2 (for example, 2 ° C.), the detected temperature of the outside air temperature detecting means 15 is When the temperature is equal to or lower than a predetermined temperature 2 (for example, 2 ° C.), the freeze prevention operation 2 in Step 5 is performed.

  The freeze prevention operation 2 is an operation mode in which the heat pump cycle 2 is operated in the operation mode of the freeze prevention operation 1 and a function of exchanging heat with circulating water by the circulation pump 14 in the water / refrigerant heat exchanger 7 is added. In this operation, the cycle 2 is operated and the water refrigerant heat exchanger 7 replenishes the amount of heat generated by the operation of the heat pump cycle 2.

  At this time, the hot water temperature detection means 17 for detecting the temperature of the hot water from the water-refrigerant heat exchanger 7 is set to a relatively low temperature, for example, 65 ° C. so as not to lower the operation efficiency of the heat pump cycle 2.

  Next, in Step 6, it is determined whether or not the detected temperature of the incoming water temperature detection means 16 is equal to or higher than a predetermined temperature 3 (for example, 10 ° C.). Is stopped (Step 7).

  At this time, the target hot water temperature from the water refrigerant heat exchanger 7 when the heat pump cycle 2 is operated is 65 ° C., but the target hot water temperature from the water refrigerant heat exchanger 7 when the heat pump cycle 2 is operated is Is considered to be a temperature higher than the detected temperature of the hot water storage temperature detection means 18 disposed in the upper part of the hot water storage tank 1 during operation.

  Since the temperature stratification is formed in the hot water storage tank 1, since the temperature higher than that of the hot water storage tank 1 flows into the upper part of the hot water storage tank 1 and is stored in the hot water, the temperature stratification is not destroyed. A heat pump water heater can be used.

  Further, in the heat pump cycle 2, since the heat pump cycle is used, sound and vibration are generated, and sound is also generated when the circulation pump 14 is driven.

  By incorporating the circulation pump 14 in the heat pump unit 30, sound and vibration sources are gathered in one place, and discomfort due to noise can be reduced for the user.

  In addition, since noise from the hot water storage unit 20 is eliminated, it is possible to improve efficiency when the heat pump hot water supply device is used by arranging the hot water storage unit 20 in a room and suppressing heat radiation to the outside air.

  As described above, the heat pump hot water supply apparatus according to the present invention can provide a heat pump hot water supply apparatus that improves the prevention of water freezing in the piping in the apparatus by incorporating a circulation pump in the heat pump unit. It can be applied not only to home use but also to large heat pump water heaters for business use.

DESCRIPTION OF SYMBOLS 1 Hot water storage tank 2 Heat pump cycle 3 Refrigerant piping 4 Pressure reduction means 5 Air heat exchanger (evaporator)
DESCRIPTION OF SYMBOLS 6 Compressor 7 Water refrigerant | coolant heat exchanger 8 Blowing means 9 Inlet piping 10 Outlet piping 14 Pump 15 Outside air temperature detection means 16 Incoming water temperature detection means 18 Hot water storage temperature detection means 20 Hot water storage unit 30 Heat pump unit 50 Control apparatus

Claims (4)

Built-in heat pump unit with built-in heat pump cycle and circulation pump formed by connecting compressor, water refrigerant heat exchanger, pressure reducing means, evaporator, and hot water storage tank for storing hot water heated by the water refrigerant heat exchanger The hot water storage unit and a control device are provided, the lower part of the hot water storage tank is connected to the inlet side of the water refrigerant heat exchanger via the circulation pump, and the outlet side of the water refrigerant heat exchanger is only the upper part of the hot water storage tank. Anti-freezing operation in which the control device drives at least the circulation pump and conveys water in the lower part of the hot water storage tank to the upper part of the hot water storage tank via the water refrigerant heat exchanger. A heat pump water heater having a mode. The said control apparatus performs the driving | operation of the said heat pump cycle, and heats the circulating water by the said circulation pump in the said water refrigerant | coolant heat exchanger, The heat pump hot-water supply apparatus of Claim 1 characterized by the above-mentioned. Incoming water temperature detecting means disposed on the incoming side of the water refrigerant heat exchanger is provided, and the control device performs the freeze prevention operation when the detected temperature of the incoming water temperature detecting means is lower than a predetermined value. The heat pump hot-water supply apparatus according to claim 1 or 2. The heat pump hot water supply apparatus according to claim 2, further comprising an outside air temperature detecting unit, wherein the control device executes the operation of the heat pump cycle when a temperature detected by the outside air degree detecting unit is lower than a predetermined value. .

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