JP2007263517A - Heat pump water heater - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heat pump water heater capable of shortening a stabilizing time of a supply hot water temperature and a hot water storage time even when hot water is used during hot water storage operation. <P>SOLUTION: The heat pump water heater is provided with a coolant circuit, a hot water storage circuit, a hot water supply circuit, and an operation control means. The hot water supply circuit has a direct hot water supply circuit carrying out supply of hot water heated by a water-coolant heat exchanger directly from a tapping fitting, and in the operation control means, if there is use of hot water during hot water storage operation, the hot water storage operation is interrupted to give priority to the use of hot water, a heat pump continues operation while maintaining maintaining a heating temperature of the hot water storage operation, and water is added to the hot water heated by the water-coolant heat exchanger to carry out hot water supply. By this, since the heat pump can continue operation while maintaining the hot water storage heating temperature, the hot water supply temperature stabilizing time at starting of hot water supply operation, and the hot water storage time after using hot water can be shortened. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a heat pump water heater, and more particularly, to an improvement in an instantaneous heat pump water heater having a direct hot water supply circuit for directly supplying hot water heated by a heat pump operation to a terminal using water.

  A conventional heat pump water heater has a large-capacity hot water storage tank similar to an electric water heater, and uses hot discount refrigerant at night to boil hot water in the heat pump refrigerant circuit and store it in the hot water storage tank. A hot water storage system that uses stored hot water during the day is common.

  On the other hand, in recent years, an instantaneous heat pump water heater has been developed in which hot water heated by a heat pump operation is directly supplied, thereby greatly reducing the size of the hot water storage tank.

  As an example of such an instantaneous heat pump water heater, a hot water storage operation is performed in advance to store hot water in a small hot water storage tank, and when the hot water is used, the heat pump heating temperature does not reach an appropriate temperature. There are some that use hot water heated by the heat pump operation and then directly supply hot water when the heating temperature by the heat pump operation reaches an appropriate temperature by mixing the water with the hot water. , See Patent Document 1).

  The operating efficiency of heat pump operation, that is, the coefficient of performance (generally referred to as COP), the higher the heating temperature, the greater the number of rotations of the compressor and the greater the mechanical loss. The lower the heating temperature, the higher the coefficient of performance and the power can be saved. .

  Here, the hot water storage temperature of the hot water storage tank is generally about 60 to 65 ° C. in summer and intermediate periods, etc., but the heat rise time of the heat pump becomes longer and the amount of hot water supplied from the hot water storage tank increases at low temperatures in winter. Is about 90 ° C.

  In addition, if hot water is used during hot water storage operation, the hot water storage operation is stopped and changed to hot water supply operation, and the heat pump lowers the heating temperature from the hot water temperature to the hot water supply temperature. The hot water supply temperature is raised to the hot water storage temperature, the hot water supply operation is changed to the hot water storage operation again, and the heat pump operation is stopped after the hot water storage operation is completed.

Japanese Patent Laid-Open No. 2005-9724

  In the conventional heat pump water heater, when hot water is used during hot water storage operation, the heat temperature of the heat pump is lowered from the hot water temperature to the hot water temperature, and after the hot water is finished, the heating temperature is raised from the hot water temperature to the hot water temperature. Since the hot water storage operation was performed, it was necessary to switch the heating temperature twice.

  Therefore, if hot water is used immediately after the start of the hot water storage operation, the hot water storage temperature and the amount of hot water are in a transient state, and it takes some time until the heat pump heating operation of the tank reaches the hot water supply temperature and stabilizes. There was a risk that the stabilization time of the hot water supply temperature would be slightly longer.

  Further, when returning from the hot water supply operation to the hot water storage operation again, the hot water storage time is somewhat longer because the hot pump cannot be stored until the heat pump operation rises from the hot water supply temperature to the hot water storage temperature.

  The two problems are that there are few problems at normal hot water storage temperature (about 60 to 65 ° C), but hot water storage temperature (about 90 ° C) at low temperatures in winter is hot water storage temperature (about 90 ° C) and hot water supply temperature. Since the temperature difference from (about 42 ° C.) is large and the surroundings are low in temperature, the heat pump reaches the hot water storage temperature (about 90 ° C.) operation from the hot water supply temperature (about 42 ° C.) operation. It takes several tens of minutes, and there is room for improvement in terms of usability when hot water is frequently used during hot water storage operation.

  The present invention is intended to solve the above-described conventional problems, and provides a heat pump water heater that aims to stabilize the hot water supply temperature and shorten the hot water storage time when hot water is used during hot water storage operation. .

  As a means for solving the problems of the conventional heat pump water heater, the present invention does not lower the heating temperature of the heat pump to the hot water supply temperature when hot water is used during the hot water storage operation, and continues the hot water storage temperature. By doing so, the hot water temperature stabilization time and hot water storage time are shortened.

  In the invention according to claim 1, a compressor, a water-refrigerant heat exchanger that performs heat exchange between water and a refrigerant, a decompression device, and an evaporator that performs heat exchange between air and a refrigerant are sequentially connected via a refrigerant pipe. It comprises a heat pump refrigerant circuit, the water refrigerant heat exchanger, a hot water storage tank for storing hot water heated by the water refrigerant heat exchanger, a hot water mixing valve, an in-machine circulation pump, and a water pipe connecting these components. A hot water storage circuit, a water refrigerant heat exchanger, a hot water storage tank, a hot water mixing valve, a hot water mixing valve, a flow rate adjusting valve, a hot metal fitting, and a water pipe connecting these components, and the compressor, decompression Operation control means for controlling the operation of an apparatus, an in-machine circulation pump, a hot water supply mixing valve, a hot water mixing valve, a flow rate adjustment valve, etc., and the hot water supply circuit directly supplies hot water heated by a water refrigerant heat exchanger from a hot metal fitting Has direct hot water supply circuit for hot water supply When the hot water is used during the hot water storage operation, the operation control means interrupts the hot water storage operation to give priority to the hot water use, and the heat pump continuously operates at the heating temperature during the hot water storage operation, A hot water storage interrupted hot water supply operation is performed in which hot water is added to hot water to supply hot water.

  That is, when hot water is used during the hot water storage operation, the heat pump operation is continuously operated at the heating temperature during the hot water storage operation, and water is added to the hot water heated by the water-refrigerant heat exchanger to supply hot water. As a result, since the heating temperature by the heat pump operation is stable, the hot water supply temperature can be immediately supplied at an appropriate temperature, and the heating temperature by the heat pump operation remains at the hot water storage temperature. You can go back. Therefore, it is possible to shorten the hot water temperature stabilization time and hot water storage time in the hot water supply operation during the hot water storage operation.

  In addition to claim 1, the invention according to claim 2 is characterized in that, when hot water is used during hot water storage operation, the operation control means restarts hot water storage operation after hot water storage interrupted hot water supply operation, The heat pump operation is stopped after completion. According to this, even if the hot water storage operation is interrupted and changed to the hot water supply operation, the heat pump is continuously operated. Therefore, the hot water storage operation can be resumed immediately after the hot water is used, and the usability can be improved.

  The invention according to claim 3 is the invention according to claim 1, in addition to claim 1, wherein when the hot water is used during the hot water storage operation, the operation control means continuously operates at the heating temperature during the hot water storage operation, During the normal temperature hot water storage operation, the hot water storage operation is performed while the hot water storage is interrupted at a heating temperature corresponding to the hot water supply temperature. In other words, the control of the heating temperature is changed between the high temperature hot water storage operation and the normal temperature hot water storage operation, and during the high temperature hot water storage operation where the temperature difference between the hot water storage temperature and the hot water supply temperature is large, the continuous operation is performed at the high temperature. It is possible to shorten the hot water temperature stabilization time and hot water storage time. On the other hand, during normal temperature hot water storage operation where the hot water supply temperature stabilization time and hot water storage time do not hinder practical use, the coefficient of performance (COP) of the heat pump operation is improved by reducing the heating temperature in accordance with the hot water supply temperature to save power. be able to.

  The invention according to claim 4 is the invention according to claim 1, in addition to claim 1, wherein when the hot water is used during hot water storage operation, the operation control means sets the heating temperature of the heat pump during high temperature hot water storage operation to the heating temperature during normal hot water storage operation. As described above, the continuous operation is performed by lowering the temperature to a predetermined temperature lower than the heating temperature during the high-temperature hot water storage operation. That is, when hot water is used during high temperature hot water storage operation, hot water is supplied by heating at a predetermined temperature between the high temperature hot water storage temperature (for example, about 90 ° C.) and the normal hot water storage temperature (for example, about 60 to 65 ° C.). The temperature stabilization time and hot water storage time can be shortened to such an extent that there is no practical problem, and the coefficient of performance (COP) of the heat pump operation can be improved. Temperature control is possible.

  In the invention according to claim 5, a compressor, a water-refrigerant heat exchanger that performs heat exchange between water and a refrigerant, a decompression device, and an evaporator that performs heat exchange between air and a refrigerant are sequentially provided via a refrigerant pipe. A connected heat pump refrigerant circuit, the water refrigerant heat exchanger, a hot water storage tank for storing hot water heated by the water refrigerant heat exchanger, a hot water supply mixing valve, an in-machine circulation pump, and a water pipe connecting these components A hot water storage circuit comprising: a water refrigerant heat exchanger, a hot water storage tank, a hot water mixing valve, a hot water mixing valve, a flow rate adjusting valve, a hot metal fitting, and a water piping connecting these components; and the compressor An operation control means for controlling the operation of a decompression device, an in-machine circulation pump, a hot water mixing valve, a hot water mixing valve, a flow rate adjusting valve, etc., and the hot water supply circuit directly discharges hot water heated by a water refrigerant heat exchanger. Direct hot water supply from the metal fittings When the hot water is used during the hot water storage operation, the operation control means continues to operate the heat pump as it is, and the hot water mixing valve closes the water refrigerant heat exchanger side and the hot water storage tank side to perform water refrigerant heat exchange. The hot water / water mixing valve side is opened, and hot water is added to hot water heated by a water / refrigerant heat exchanger to supply hot water.

  That is, if hot water is used during high-temperature hot water storage operation, the hot water storage operation is continued and the hot water mixing valve is operated to supply hot water, so there is no need to change the operation mode, and switching from hot water to hot water and from hot water to hot water storage is possible. It becomes easy, and it is possible to shorten the hot water temperature stabilization time and hot water storage time in the hot water supply operation during the hot water storage operation.

  Further, the invention according to claim 6 is the invention according to claim 5, in addition to claim 5, when the operation control means uses hot water during hot water storage operation, the hot water supply mixing valve is connected to the water refrigerant heat exchanger side after the use of hot water. The hot water / mixing valve side is closed, the water / refrigerant heat exchanger side and the hot water storage tank side are opened, the operation is continued, and the heat pump operation is stopped after the hot water storage is completed.

  Further, the invention according to claim 7 is the invention according to claim 5, in addition to claim 5, wherein when the hot water is used during the hot water storage operation, the operation control means continuously operates at the heating temperature during the high temperature hot water storage operation. In the normal temperature hot water storage operation, the operation is performed by lowering the heating temperature corresponding to the hot water supply temperature.

  Further, the invention according to claim 8 is the invention according to claim 5, in addition to claim 5, wherein when the hot water is used during hot water storage operation, the operation control means sets the heating temperature of the heat pump during high temperature hot water storage operation to the heating temperature during normal hot water storage operation. As described above, the continuous operation is performed by lowering the temperature to a predetermined temperature lower than the heating temperature during the high-temperature hot water storage operation.

  According to the inventions of claims 6 to 8, the same effects as those of the inventions of claims 2 to 4 can be obtained.

  According to the heat pump water heater of the present invention, it is possible to shorten the hot water temperature stabilization time and hot water storage time when hot water is used during hot water storage operation.

  (First Embodiment) An embodiment of the present invention will be described below with reference to FIG.

  The heat pump water heater includes a heat pump refrigerant circuit 30, a hot water supply circuit 40, and an operation control means 50.

  The heat pump refrigerant circuit 30 is a two-cycle system having two parts each, and includes refrigerant-side heat transfer tubes 2a and 2b, decompression devices 3a and 3b, and evaporators disposed in the compressors 1a and 1b and the water-refrigerant heat exchanger 2. 4a and 4b are sequentially connected via a refrigerant pipe, and a refrigerant is sealed therein.

  The compressors 1a and 1b can be controlled in capacity, and are operated with a large capacity when supplying a large amount of hot water. Here, the compressors 1a and 1b are controlled in rotation speed from a low speed (for example, 700 rpm) to a high speed (for example, 7000 rpm) by PWM control, voltage control (for example, PAM control) and a combination control thereof. It has become.

  The water refrigerant heat exchanger 2 includes refrigerant side heat transfer tubes 2a and 2b and water supply side heat transfer tubes 2c and 2d, and performs heat exchange between the refrigerant side heat transfer tubes 2a and 2b and the water supply side heat transfer tubes 2c and 2d. It is configured as follows.

  In general, an electric expansion valve or the like is used as the decompression devices 3a and 3b, and the medium temperature and high pressure refrigerant sent through the water refrigerant heat exchanger 2 is decompressed and sent to the evaporators 4a and 4b as a low-pressure refrigerant that easily evaporates. Further, the decompression devices 3a and 3b function to adjust the refrigerant circulation amount in the heat pump refrigerant circuit by changing the throttle amount of the refrigerant passage, or send the medium temperature refrigerant to the evaporators 4a and 4b in a large amount by fully opening the throttle amount. It also serves as a defroster that melts frost.

The evaporators 4a and 4b are configured as air refrigerant heat exchangers that perform heat exchange between air and refrigerant.
The hot water supply circuit 40 includes a water circulation circuit for performing hot water storage, direct hot water supply, tank hot water supply, bath hot water filling, and bath reheating.

  The hot water storage circuit is a water circuit for accumulating hot water in the hot water storage tank 8. The hot water storage tank 8, the in-machine circulation pump 9, the hydrothermal AC amount sensor 11, the water supply side heat transfer pipes 2 c and 2 d, the hot water supply mixing valve 12, and the hot water storage tank 8 are water. Sequentially connected via a pipe.

  The direct hot water supply circuit includes a water supply fitting 5, a pressure reducing valve 6, a water supply water amount sensor 7, a water supply check valve 10, a water heat AC amount sensor 11, water supply side heat transfer tubes 2c and 2d, a hot water supply mixing valve 12, a hot water mixing valve 13, and a flow rate. An adjustment valve 14 and a kitchen tapping metal fitting 15 are sequentially connected via a water pipe.

  The water supply fitting 5 is connected to a water supply source such as a water supply, and the kitchen tap fitting 15 is connected to a kitchen faucet 16 or the like.

  In the tank hot water supply circuit, a water supply fitting 5, a pressure reducing valve 6, a supply water amount sensor 7, a hot water storage tank 8, a hot water supply mixing valve 12, a hot water mixing valve 13, a flow rate adjusting valve 14, and a kitchen tapping metal fitting 15 are sequentially connected through a water pipe. It is configured.

  The bath hot water filling circuit includes a water supply fitting 5, a pressure reducing valve 6, a water supply water amount sensor 7, a water supply check valve 10, a hydrothermal AC amount sensor 11, water supply side heat transfer tubes 2 c and 2 d, a hot water supply mixing valve 12, a hot water mixing valve 13, A flow rate adjustment valve 14, a bath pouring valve 17, a flow switch 18, a bath circulation pump 19, a water level sensor 20, a bath inlet / outlet fitting 21, a bath circulation adapter 22, and a bathtub 23 are sequentially connected via a water pipe. . Moreover, it connects so that it can supply hot water to the bath faucet 27 and the shower (not shown) from the bath entry / exit metal fitting 21 with the bathtub 23.

  During bath hot water filling, hot water supply from the hot water storage tank 8 to the bathtub 23 is performed in a range where the amount of hot water in the hot water storage tank 8 does not fall below the minimum required amount as well as direct hot water supply by the bath hot water filling circuit.

  The bath memorial circuit includes a bathtub 23, a bath circulation adapter 22, a bath inlet / outlet fitting 21, a water level sensor 20, a bath circulation pump 19, a flow switch 18, a bath water heat transfer tube 25b, a bath outlet fitting 26, a bath circulation adapter 22, and a bathtub. 23 are sequentially connected via a water pipe.

  At the time of bathing, the bath water circulation is performed by the bath chasing circuit, the heat pump operation and the in-machine circulation pump 9 are operated, and hot water heated by the water refrigerant heat exchanger 2 is provided in the bath heat exchanger 25. The hot water heat transfer tube 25a is circulated, heat exchange is performed between the hot water heat transfer tube 25a and the bath water heat transfer tube 25b, and the bath is reheated.

  Next, the operation control means 50 operates / stops the heat pump refrigerant circuit 30 and controls the rotation speeds of the compressors 1a and 1b according to the operation settings of the kitchen remote controller 51 and the bath remote controller 52, and the refrigerant of the decompression devices 3a and 3b. By adjusting the throttle amount, operating / stopping the in-machine circulation pump 9 and the bath circulation pump 19, and controlling the hot water mixing valve 12, the hot water mixing valve 13, the flow rate adjusting valve 14, the bath pouring valve 17, and the hot water on / off valve 24, Operation, direct hot water supply operation, tank hot water supply operation, bath hot water operation, and bath memorial operation are performed.

  The operation control means 50 controls the rotation speed of the compressors 1a and 1b, and immediately after the start of operation, the operation control means 50 operates at a predetermined high speed rotation speed in order to shorten the heating start-up time. At the time of operation, etc., control is performed so as to operate at a low speed corresponding to the heating temperature.

  In addition, after using hot water at the water-use terminal, the hot water storage temperature and the amount of hot water are determined according to the hot water storage command of the operation control means 50, and if it is within the regulations, the hot water is stopped and the stored hot water is used and reduced below the regulation. Therefore, the instantaneous heat pump water heater is more frequently operated than the conventional hot water storage type and may be used during hot water storage operation.

  Further, the heat pump water heater includes a water supply thermistor 7a for detecting the water supply temperature, a heat exchange water inlet thermistor 2e for detecting the water temperature around the water refrigerant heat exchanger 2, a heat exchange water outlet thermistor 2f, the hot water storage temperature of the hot water storage tank 8 and Tank thermistors 8a, 8b, 8c for detecting the amount of hot water storage, the hot water mixed water thermistor 12a for detecting the temperature of the mixed water from the water / refrigerant heat exchanger 2 and the hot water storage tank 8 and adjusting the opening of the hot water mixing valve 12 , A hot water thermistor 13a for detecting the hot water temperature and adjusting the hot water mixing valve 13, a bath thermistor 18a for detecting the water temperature circulating in the bathtub 23, and a pressure sensor for detecting the discharge pressure of the compressors 1a, 1b (not shown) 1), a water level sensor 20 for detecting the water level in the bathtub 23 is provided, and each detection signal is input to the operation control means 50. The operation control means 50 controls each device based on these signals.

  In the hot water supply mixing valve 12, at the beginning of the hot water supply operation, the water refrigerant heat exchanger 2 side and the hot water mixing valve 13 side and the hot water storage tank 8 side and the hot water mixing valve 13 side are both open, so that the water refrigerant heat When hot water is supplied from both the exchanger 2 and the hot water storage tank 8 and the heating temperature in the water / refrigerant heat exchanger 2 by the heat pump becomes higher than the hot water supply temperature (about 42 ° C.), the hot water storage tank 8 side and the hot water mixing valve 13 side are closed. Thus, hot water is supplied only from the water / refrigerant heat exchanger 2.

  The hot water on / off valve 24 is provided between the water-refrigerant heat exchanger 2 and the bath heat exchanger 25. The hot water on / off valve 24 is opened when the bath is replenished to perform the bath retreat operation, and at other times the water circuit is closed. Thus, heat leakage from the water refrigerant heat exchanger 2 to the bath heat exchanger 25 is prevented.

  The water supply check valve 10 allows water to flow only in one direction to prevent backflow, and the relief valve 28 operates when the hot water pressure in the hot water storage tank 8 exceeds a predetermined level. It serves to protect the pressure of circuit components.

  Next, the operation of the heat pump water heater of this embodiment will be described based on the flowcharts of FIGS. 2 to 4 with reference to the heat pump refrigerant circuit 30 and the hot water supply circuit 40 of FIG.

  FIG. 2 is an example of a flowchart showing a hot water storage operation for boiling water in the hot water storage tank 8.

  When a hot water storage operation command is issued under the control of the operation control means 50 (step 71), the tank thermistors 8a to 8c determine the hot water temperature and the hot water storage amount (step 72). If the stored hot water is used and reduced below the specified value, the hot water storage operation is started (step 73).

  In this hot water storage operation (step 73), the operation of the compressors 1a and 1b is started, and the gaseous refrigerant in the compressors 1a and 1b is compressed and heated to become a high-temperature and high-pressure refrigerant and sent to the water refrigerant heat exchanger 2. . As a result, in the water refrigerant heat exchanger 2, the high-temperature refrigerant flowing in the refrigerant side heat transfer tubes 2a and 2b and the water flowing in the water supply side heat transfer tubes 2c and 2d exchange heat, the refrigerant dissipates heat, and the water is heated. The The radiated refrigerant is decompressed by the decompression devices 3a and 3b, and further expanded and evaporated by the evaporators 4a and 4b to become a gaseous state and return to the compressors 1a and 1b again. By continuing this heat pump operation, the water passing through the water-refrigerant heat exchanger 2 is heated.

  In the heat pump operation, when the rotation speed of the compressors 1a and 1b is increased and the refrigerant throttle amount of the decompression devices 3a and 3b is increased, the heating capacity is increased, but the mechanical loss and the heat loss are increased and the operation efficiency is decreased. Conversely, by reducing the number of rotations of the compressors 1a and 1b and reducing the refrigerant throttle amount of the decompression devices 3a and 3b, the heating capacity is reduced, but the mechanical loss and heat loss are reduced, and the operation efficiency is relatively improved. To do. That is, in the heating operation by the heat pump, it can be said that heating efficiency is improved by heating at a low temperature over time.

  Therefore, in the hot water storage operation (step 73), together with the heat pump operation, in the hot water storage circuit, the hot water supply mixing valve 12 is between the water / refrigerant heat exchanger 2 side and the hot water mixing valve 13 side, and between the hot water storage tank 8 side and the hot water mixing valve 13 side. Are opened, the water-refrigerant heat exchanger 2 and the hot water storage tank 8 side communicate with each other and are opened. (Step 73a). When the operation of the in-machine circulation pump 9 is started, the water circulation port 9, the hydrothermal AC quantity sensor 11, the water / refrigerant heat exchanger 2, the hot water supply mixing valve 12, and the hot water storage tank 8 are passed from the water inlet at the bottom of the hot water storage tank 8. Water circulates. As a result, the hot water heated by the water-refrigerant heat exchanger 2 is stored from the upper part of the hot water storage tank 8, and the hot water storage temperature and the amount of hot water are determined (step 76), and the entire hot water in the hot water storage tank 8 is boiled. When the state is reached, the operation is stopped (step 77).

  Meanwhile, the hot water temperature determination (step 74) for determining whether or not the temperature of the heated water discharged from the water-refrigerant heat exchanger 2 is appropriate is performed by the heat exchanger outlet thermistor 2f, and the hot water temperature is within the specified range. In such a case, the hot water storage operation is continued as it is (step 75), and when it is not specified, the rotation speed control of the compressors 1a and 1b, the throttle amount adjustment of the decompression devices 3a and 3b, and the flow rate adjustment by the rotation speed control of the in-machine circulation pump 9 The tapping temperature is adjusted (step 74a).

  The determination of the hot water storage temperature and the amount of hot water storage is performed by the tank thermistors 8a to 8c. If all of the tank thermistors 8a to 8c reach the specified temperature, it is determined that the hot water storage is complete, the operation is stopped, and the hot water storage is finished (step 77). .

  FIG. 3 is an example of a flowchart showing the operation during hot water supply operation when the kitchen faucet 16 is opened and hot water is used.

  When the kitchen faucet 16 is opened and the use of hot water begins (step 80), the control means 50 starts the compressors 1a and 1b and starts the operation of the heat pump refrigerant circuit 30, and the water supply fitting 5, the pressure reducing valve 6, and the amount of water supply Sensor 7, water supply check valve 10, hydrothermal AC sensor 11, water supply side heat transfer pipes 2 c and 2 d, hot water mixing valve 12, hot water mixing valve 13, flow rate adjustment valve 14, kitchen tap metal 15, kitchen faucet 16 direct hot water supply A hot water supply operation is performed directly by the circuit (step 81). At the same time, the tank hot water supply operation is performed by the tank hot water supply circuit of the water supply fitting 5, the pressure reducing valve 6, the water supply water amount sensor 7, the hot water storage tank 8, the hot water supply mixing valve 12, the hot water mixing valve 13, the flow rate adjusting valve 14, the kitchen outlet fitting 15, and the kitchen faucet 16. (Step 82).

  Here, the heat pump refrigerant circuit 30 sends the high-temperature and high-pressure refrigerant compressed by the compressors 1a and 1b to the refrigerant side heat transfer tubes 2a and 2b of the water refrigerant heat exchanger 2 and flows into the water supply side heat transfer tubes 2c and 2d. However, at the time of start-up immediately after operation, the refrigerant sent to the water-refrigerant heat exchanger 2 is not sufficiently hot and high in pressure, the temperature is low, and the entire water-refrigerant heat exchanger 2 is cooled. The heating capacity to heat the is not sufficient. As the time elapses, the refrigerant becomes high temperature and pressure, and accordingly, the amount of heat released from the generated refrigerant increases, and the ability to heat water increases.

  In addition, since it usually takes about 5 to 6 minutes for the heating capacity of the heat pump operation to reach the optimum temperature stable state, the operation control means 50 is operated at the rotational speed of the compressor until the optimum temperature stable state is reached immediately after the operation is started. Is rotated at a higher speed than usual, and a tank hot water supply operation for supplying hot water from the hot water storage tank (step 82) is performed in parallel.

  Further, the hot water supply thermistor 13a and the hot water supply amount sensor 7 determine the hot water supply temperature and the hot water supply flow rate (step 83). If not, the temperature and flow rate are adjusted (step 84a). (Step 84).

  In the determination of the direct hot water supply temperature (step 84), in the state where the heating temperature in the water refrigerant heat exchanger 2 is insufficient and the direct hot water supply temperature does not reach the specified temperature, the temperature flow rate adjustment (step 84a) of the heat pump operation is continued. Combined with the tank hot water supply operation (step 82). If the heating temperature in the water-refrigerant heat exchanger 2 rises sufficiently to the hot water supply temperature and the direct hot water supply temperature falls within the specified range, the tank hot water supply operation is stopped (step 84b), and the direct hot water supply operation (step 81) alone. The hot water supply is continued (step 85).

  Therefore, the role of the hot water storage tank 8 is an auxiliary one at the time of starting up until the heating capacity of the heat pump operation reaches a temperature sufficient for the hot water supply temperature (about 42 ° C.), and the capacity of the heat pump refrigerant circuit 30, particularly the compression. The larger the output of the machines 1a and 1b, the shorter the startup time and the smaller the hot water storage tank 8.

  Moreover, in order to cope with simultaneous use of a plurality of places by direct hot water supply such as performing hot water bathing at the same time as kitchen hot water supply, the capacity of the compressors 1a and 1b is 5 kW generally used in the conventional hot water storage system. Although it is desirable to increase it to about 20 kW, the development of a new compressor is necessary, and each part of the heat pump refrigerant circuit 30 needs to be newly studied, which is extremely difficult. Therefore, in the embodiment of the present invention, the two-cycle heat pump systems 30a and 30b using two compressors that are about twice as large as the conventional compressors are used, and the reliability of the conventional technology and the results are ensured. If the capacity of the compressor is sufficient, the application / effect of the present invention is not changed even in the one-cycle heat pump system.

Next, when the faucet is closed and the use of hot water is finished (step 86), if the tank hot water supply operation is stopped and only the direct hot water supply operation is performed, the direct hot water supply operation is stopped. When the hot water supply operation is used together, both the direct hot water supply operation and the tank hot water supply operation are stopped. (Step 87)
Furthermore, after stopping both the tank hot water supply operation and the direct hot water supply operation (step 87), the operation control means 50 starts the hot water storage operation (step 88), detects the hot water storage temperature and the hot water storage amount by the tank thermistors 8a to 8c, The hot water storage temperature and the hot water storage amount are determined with respect to the specified values (step 89). If the specified values are not reached, the hot water storage operation (step 88) is continued. If the specified values are reached, the heat pump operation is stopped and the hot water storage operation is performed. Ends (step 90).

  However, the detection of the hot water storage state by the tank thermistors 8a to 8c is always performed. If the hot water temperature and the amount of hot water remain in the hot water storage tank 8 beyond a predetermined value even after the hot water supply operation is stopped for extremely short time use, It is determined that the amount is sufficient, and the hot water storage operation (step 88) is omitted.

  As described above, the operation control means 50 is always left at a predetermined hot water storage temperature and hot water storage amount when the hot water temperature in the hot water storage tank 8 is lowered after being left for a long time and after the target operation is completed in all hot water supply operations. The hot water storage operation (step 88) is performed every time so that the hot water storage operation is ensured. Therefore, the hot water storage tank 8 always stores a predetermined amount or more of hot water at a predetermined temperature. The worry about running out of hot water can be eliminated.

  FIG. 4 is an example of a flowchart showing the operation when hot water is used during hot water storage operation. In addition, since the detailed operation | movement at the time of hot water storage operation and use of hot water is demonstrated in the said FIG. 2, FIG. 3, about each operation | movement content, it abbreviate | omits.

  When a hot water storage operation command is issued under the control of the operation control means 50 (step 91), the hot water storage temperature and the amount of hot water storage are determined (step 92). If it has decreased, the hot water storage operation is started (step 93).

  During the hot water storage operation (step 93), when a hot water storage interrupted hot water supply operation command is issued by using hot water from the kitchen faucet 16 or the like (step 94), the hot water storage operation is temporarily interrupted (step 95), and the hot water storage interrupted hot water supply operation is preferentially started. (Step 96).

  Here, the general optimum temperature when using hot water is about 42 ° C., and the hot water supply operation of the heat pump is performed by heating so as to reach 42 ° C. at the hot water use terminal. Is heated at about 90 ° C), water is mixed, and hot water is supplied at an appropriate temperature (about 42 ° C) when using hot water.

  The hot water storage interrupted hot water supply operation (step 96) at this time continues the heating temperature of the heat pump at the heating temperature in the hot water storage operation (step 93). For example, when the hot water storage temperature is operated at about 90 ° C. at low temperatures in winter, the hot water storage hot water supply operation is also operated at about 90 ° C. hot water, and the hot water supply temperature (about 42 ° C.) is set according to the amount of water supplied from the hot water mixing valve 13. After matching, hot water is supplied to the use terminal such as the kitchen faucet 16.

  Next, when the use of hot water is completed and the hot water storage interrupted hot water supply operation is stopped (step 97), the hot water storage operation is resumed (step 97). Thereafter, the hot water storage temperature and the hot water storage amount in the hot water storage tank 8 are determined (step 99). If both the hot water storage temperature and the hot water storage amount reach the specified values, the heat pump operation is stopped and the hot water storage operation is ended (step 100).

  In the flowchart of FIG. 4, the general hot water supply temperature for kitchen use, wash-use use, shower use, etc. is appropriate to be about 42 ° C. regardless of the season, but the hot water storage temperature is about 60 for normal hot water storage in the summer and intermediate periods. It is set to ~ 65 ° C, and the temperature of the hot water storage tank 8 is low and the amount of hot water used in the hot water storage tank 8 is high. In winter, the temperature is raised to about 90 ° C, thereby increasing the difference from the hot water temperature (about 42 ° C) and increasing the heat storage heat capacity. ing.

  As described above, for example, when hot water is used during a hot water storage operation at low temperatures in winter, the present invention switches to a hot water storage hot water supply operation, and the heat pump continues at a stable hot water heating temperature (about 90 ° C.). Since the hot water temperature is adjusted according to the amount of water supplied from the hot water mixing valve 13, the stabilization time of the hot water temperature (about 42 ° C.) can be shortened, and the heat pump heats the hot water even when the hot water storage operation is started after the hot water is finished. Since the operation is continued at the temperature (about 90 ° C.), the hot water storage can be started immediately by stopping the water supply from the hot water mixing valve 13 and the hot water storage time can be shortened.

  Further, in another flowchart of the present invention, in the flowchart of FIG. 4, the control for continuously operating the heat pump at the hot water storage heating temperature is applied only at the high temperature hot water storage temperature (about 90 ° C.) during the winter low temperature. The normal hot water storage temperature (about 60-65 ° C.) is used to reduce the heating temperature from the hot water storage temperature to the hot water supply temperature (about 42 ° C.), and the hot water operation is performed at low temperatures in winter. In other summer and intermediate periods, the hot water supply heating temperature is lowered to match the hot water supply temperature, thereby improving the coefficient of performance (COP) of the heat pump operation and saving power.

  Further, according to another flowchart of the present invention, in the flowchart of FIG. 4, when the hot water is used during the hot water storage operation, the heating temperature of the heat pump during the hot water storage hot water supply operation is changed. 65 ° C) or higher and a predetermined temperature lower than the high temperature hot water storage temperature (about 90 ° C). During normal hot water storage operation, hot water storage hot water supply is interrupted according to the hot water temperature (about 60 ° C to 65 ° C) to the hot water supply temperature (about 42 ° C). The operation is performed, and it is possible to obtain a balanced effect of power saving by shortening the hot water temperature stabilization time and hot water storage time and improving the coefficient of performance of the heat pump operation.

  (Second Embodiment) The second embodiment of the present invention will be described below. The component configuration, hot water storage operation, and hot water supply operation are the same as those in the first embodiment described with reference to FIGS.

  FIG. 5 is a flowchart showing the operation when hot water is used during the hot water storage operation in this embodiment, and will be described below together with the component configuration of FIG.

  When a hot water storage operation command is issued under the control of the operation control means 50 (step 101), the hot water storage temperature and the amount of hot water storage are determined (step 102). The hot water supply mixing valve 12 is configured to open water refrigerant heat exchange by opening both the water refrigerant heat exchanger 2 side and the hot water mixing valve 13 side, and the hot water storage tank 8 side and the water refrigerant heat exchanger 2 side. The hot water storage operation is started (step 103) by opening the heater 2 and the hot water storage tank 8 (step 103a). At this time, since the kitchen faucet 16 and the like are closed, no hot water flows to the hot water mixing valve 13 side.

  When a hot water use start command is issued by using hot water from the kitchen faucet 16 or the like during the hot water storage operation (step 103) (step 104), the heat pump operates at the heating temperature during the hot water storage operation higher than the hot water supply temperature (about 42 ° C.). Subsequently, since the hot water temperature on the water / refrigerant heat exchanger 2 side of the hot water supply mixing valve 12 is sufficiently higher than the hot water supply temperature, the hot water storage tank 8 side and the hot water mixing valve 13 side are closed, and the water / refrigerant heat exchanger 2 side and hot water mixing valve are closed. It operates to open the 13 side (step 104a). Therefore, the hot water discharged from the hot water refrigerant heat exchanger 2 by the heat pump operation is switched from the hot water storage tank 8 side to the hot water mixing valve 13 side. At the same time, the hot-water mixing valve 12 is heated by the water-refrigerant heat exchanger 2 so that the hot-water supply temperature reaches an appropriate temperature (about 42 ° C.) by detecting the hot-water supply temperature by the hot-water supply thermistor 13a. Mix and adjust (step 104b).

  Next, when the use of hot water in the kitchen faucet 16 or the like is finished and a hot water use end command is issued (step 105), the hot water mixing valve 12 opens the hot water tank 8 and the hot water mixing valve 13 to open the water refrigerant heat exchanger 2. The hot water storage operation is continued (step 103).

  Thereafter, the hot water storage temperature and the amount of hot water stored in the hot water storage tank 8 are determined (step 106). If both the hot water storage temperature and the amount of hot water reach the specified values, the heat pump operation is stopped and the hot water storage operation is terminated (step 107).

As described above, when hot water is used during hot water storage operation, the present invention performs the switching operation of the hot water mixing valve 12 and the water supply adjustment of the hot water mixing valve 13 while continuing the hot water storage operation without changing the operation mode. In response to the use of hot water, the hot water storage operation can be continued as it is after the use of hot water, so that the hot water storage time can be shortened. By changing the heating temperature, the same effect as in the first embodiment can be obtained.

  In the present invention, the hot water storage temperature and the hot water supply temperature have been described as predetermined values. For example, when the hot water supply temperature from the kitchen faucet 16 is set to 42 ° C., the water refrigerant heat exchanger 2 outlet temperature represents the heat loss of the water pipe. The temperature setting of each part in consideration of heat loss in the refrigerant circuit component, the water supply circuit component and each pipe, such as 45 ° C., does not impair the effect of the present invention, and the present invention includes these temperature adjustments. Is.

  The hot water supply on / off valve 12 switches hot water from the water / refrigerant heat exchanger 2 and the hot water storage tank 8 with a single valve. However, the present invention is not limited to this, and any hot water can be used. Even if another switching system is used or two valves are used, the effect of the present invention is not affected.

It is a schematic diagram which shows one Example of schematic structure of the heat pump refrigerant circuit, the hot water supply circuit, the operation control means, and components in the heat pump water heater of this invention. It is a flowchart which shows the operation | movement at the time of the hot water storage driving | operation in the heat pump water heater of this invention. It is a flowchart which shows the operation | movement at the time of the hot water supply driving | operation in the heat pump water heater of this invention. It is a flowchart which shows temperature control at the time of hot water use being performed at the time of the hot water storage driving | operation of the heat pump water heater in 1st Example of this invention. It is a flowchart which shows temperature control at the time of hot water use being performed at the time of the hot water storage operation of the heat pump water heater in the 2nd Example of this invention.

Explanation of symbols

1a, 1b Compressor 2 Water refrigerant heat exchanger 2a, 2b Refrigerant side heat transfer pipe 2c, 2d Water supply side heat transfer pipe 2e Heat exchange water inlet thermistor 2f Heat exchange water outlet thermistor 3a, 3b Decompression device 4a, 4b Evaporator 5 Water supply fitting 6 Pressure reducing valve 7 Water supply amount sensor 7a Water supply thermistor 8 Hot water storage tank 8a-8c Tank thermistor 9 Circulation pump 10 Water supply check valve 11 Hydrothermal AC sensor 12 Hot water mixing valve 12a Hot water mixing water thermistor 13 Hot water mixing thermistor 14 Flow adjustment valve 15 Kitchen outlet metal fittings 16 Kitchen faucet 19 Bath circulation pump 23 Bath 25 Bath heat exchanger 27 Bath faucet 30 Heat pump refrigerant circuit 40 Hot water supply circuit 50 Operation control means 51 Kitchen remote control 52 Bath remote control

Claims (8)

A heat pump refrigerant circuit in which a compressor, a water refrigerant heat exchanger that performs heat exchange between water and refrigerant, a decompression device, and an evaporator that performs heat exchange between air and refrigerant are sequentially connected via a refrigerant pipe;
A hot water storage circuit comprising the water refrigerant heat exchanger, a hot water storage tank for storing hot water heated by the water refrigerant heat exchanger, a hot water supply mixing valve, an in-machine circulation pump, and water piping connecting these components;
A hot water supply circuit comprising a water refrigerant heat exchanger, a hot water storage tank, a hot water mixing valve, a hot and cold water mixing valve, a flow rate adjusting valve, a hot metal fitting, and a water pipe connecting these components;
Operation control means for controlling the operation of the compressor, the pressure reducing device, the in-machine circulation pump, the hot water supply mixing valve, the hot water mixing valve, the flow rate adjustment valve, and the like,
The hot water supply circuit has a direct hot water supply circuit for supplying hot water heated by a water-refrigerant heat exchanger directly from a hot water outlet fitting,
When the hot water is used during hot water storage operation, the operation control means interrupts the hot water storage operation to give priority to hot water use, and the heat pump is continuously operated at the heating temperature during the hot water storage operation and heated by the water refrigerant heat exchanger. Heat pump water heater that performs hot water storage interrupted hot water operation that adds hot water to hot water. 2. The heat pump hot water supply according to claim 1, wherein, when hot water is used during the hot water storage operation, the operation control means restarts the hot water storage operation after performing the hot water storage interrupted hot water supply operation, and stops the heat pump operation after the hot water storage operation is completed. Machine. When hot water is used during hot water storage operation, the operation control means continuously operates at the heating temperature during the hot water storage operation and lowers the heating temperature to match the hot water temperature during normal temperature hot water storage operation. The heat pump water heater according to claim 1, wherein the hot water storage is interrupted. When hot water is used during hot water storage operation, the operation control means lowers the heating temperature of the heat pump to a predetermined temperature that is higher than the heating temperature during normal hot water storage operation and lower than the heating temperature during high temperature hot water storage operation. The heat pump water heater according to claim 1, which is continuously operated. A heat pump refrigerant circuit in which a compressor, a water refrigerant heat exchanger that performs heat exchange between water and refrigerant, a decompression device, and an evaporator that performs heat exchange between air and refrigerant are sequentially connected via a refrigerant pipe;
A hot water storage circuit comprising the water refrigerant heat exchanger, a hot water storage tank for storing hot water heated by the water refrigerant heat exchanger, a hot water supply mixing valve, an in-machine circulation pump, and water piping connecting these components;
A hot water supply circuit comprising a water refrigerant heat exchanger, a hot water storage tank, a hot water mixing valve, a hot and cold water mixing valve, a flow rate adjusting valve, a hot metal fitting, and a water pipe connecting these components;
Operation control means for controlling the operation of the compressor, the pressure reducing device, the in-machine circulation pump, the hot water supply mixing valve, the hot water mixing valve, the flow rate adjustment valve, and the like,
The hot water supply circuit has a direct hot water supply circuit for supplying hot water heated by a water-refrigerant heat exchanger directly from a hot water outlet fitting,
When the hot water is used during the hot water storage operation, the operation control means continuously operates the heat pump, and the hot water mixing valve closes the water refrigerant heat exchanger side and the hot water storage tank side, the water refrigerant heat exchanger side and the hot water water. Heat pump water heater that opens the mixing valve and adds hot water to hot water heated by a water-refrigerant heat exchanger to supply hot water The hot water mixing valve closes the water refrigerant heat exchanger side and the hot water mixing valve side when the hot water is used during hot water storage operation, and the hot water mixing valve closes the water refrigerant heat exchanger side and the hot water mixing valve side. 6. The heat pump water heater according to claim 5, wherein the operation is continued by opening the side, and the heat pump operation is stopped after the hot water storage is completed. When hot water is used during the hot water storage operation, the operation control means continuously operates at the heating temperature during the high temperature hot water storage operation and decreases to a heating temperature corresponding to the hot water temperature during the normal temperature hot water storage operation. The heat pump water heater according to claim 5, wherein the operation is performed. When hot water is used during hot water storage operation, the operation control means lowers the heating temperature of the heat pump to a predetermined temperature that is higher than the heating temperature during normal hot water storage operation and lower than the heating temperature during high temperature hot water storage operation. The heat pump water heater according to claim 5, which is continuously operated.

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