JP4215735B2 - Heat pump water heater - Google Patents

Description

  The present invention relates to an improvement in usability in a low-temperature frosting condition of a heat pump water heater.

  The conventional heat pump water heater has a large hot water storage tank with a capacity of 300L to 500L, similar to an electric water heater, operates a heat pump in the middle of the night using cheap nighttime discounted electricity, boils hot water, and hot water storage tank A hot water storage system in which the stored hot water is used during the day is generally used.

  In recent years, by providing a tank hot water supply circuit that supplies hot water from a hot water storage tank at the start of operation and a direct hot water supply circuit that directly supplies hot water heated by the heat pump operation, when using hot water at a water-using terminal such as a faucet, heat pump operation is performed as needed. An instantaneous heat pump water heater that directly supplies hot water to a terminal using water has been proposed.

  There exists what was disclosed by Unexamined-Japanese-Patent No. 2003-240339 (patent document 1) as such an instantaneous heat pump water heater.

  Also, the hot water in the storage tank is used at the start of operation, and if the hot water temperature in the tank is lowered after the hot water supply is finished, the heat pump cycle is operated, and the operation is stopped when the hot water in the storage tank reaches a predetermined temperature. .

JP 2003-240339 A

  In the heat pump water heater disclosed in Patent Document 1, when long-time heat pump operation such as bath hot water (pouring) is performed at low temperatures in winter, frost forms on the entire surface of the air heat exchanger, depending on the outside temperature. There was a case. In such a case, if a tank hot water storage operation is performed in which the tank hot water is replenished after the hot water supply is completed, the heating capacity is reduced due to frost formation of the air heat exchanger, so that a long time is required for the tank hot water storage operation. . If the next hot water supply was started because the tank hot water could not be replenished sufficiently, there was a risk of disturbing the hot water.

  That is, when the tank hot water storage operation is performed in a state where frost is formed on the air heat exchanger that collects heat from the outside air, the frost formation further proceeds and a frozen state is obtained. As a result, the performance of the air heat exchanger is further deteriorated, and even if the heat pump is continuously operated from the bath hot water supply to the tank reheating, the heating capacity is remarkably reduced.

  For example, if a shower is used within a short period of time after the end of hot water supply when the outside air temperature is low in winter, the air heat exchanger becomes frosted and the amount of hot water or low temperature hot water is likely to occur.

  An object of the present invention is to provide a heat pump water heater that minimizes the influence of heating capacity reduction due to frost formation and improves usability.

  In order to solve the above-described problems, the heat pump water heater of the present invention detects the temperature of the air heat exchanger, and the defrost start temperature indicating the state where frost is attached and the defrost operation is required, and the defrost start temperature thereof. A lower defrosting temperature is set in advance. The defrosting-required temperature is a temperature in a state where the frost is considerably accumulated and the heating capacity is remarkably lowered unless priority is given to the defrosting operation.

  The heat pump water heater of the present invention is a heat pump water heater having a hot water storage tank provided with a defrosting start temperature and a defrosting necessary temperature, and determines the frosting state of the air heat exchanger at a low temperature in winter by temperature. The above-described object is achieved by performing operation control suitable for the frosting state.

The invention according to claim 1 includes a compressor, a water-refrigerant heat exchanger for exchanging heat between supplied water and refrigerant, a decompression device, an air heat exchanger for exchanging heat between air and refrigerant, and a refrigerant pipe. The heat pump refrigerant circuit sequentially connected via the water refrigerant heat exchanger, the hot water storage tank for storing hot water heated by the water refrigerant heat exchanger, the hot water mixing valve, and the flow control valve are connected via the water pipe. A defrosting start temperature and a defrosting required temperature lower than the defrosting start temperature are preset, and the temperature of the air heat exchanger is set to the defrosting start temperature and the defrosting temperature. If the temperature is within the required frost temperature range, after the hot water supply operation at the water-use terminal is completed, the tank hot-water storage operation is executed, and then the refrigerant that is hotter than the water-use terminal hot-water operation and the tank hot-water operation To melt the frost of the air heat exchanger Run the defrosting operation, if the temperature of the air heat exchanger is lower than the defrosting requiring temperature temperature after the hot water supplying operation is finished, perform a tank hot-water stocking operation after performing the defrosting operation of the air heat exchanger Control means.

As a result, the frosting state of the air heat exchanger is determined by temperature, and the defrosting required temperature that requires immediate defrosting operation is set in addition to the defrosting start temperature that is the normal frosting state. By providing a control means that changes the defrosting control according to the temperature of the exchanger, specifically, the start timing of the defrosting operation, there is no need for the user to consider the response, and the operation control conforms to the frosting state. It is possible to improve usability at low temperatures in winter.
Next, the invention according to claim 2 is the invention according to claim 1, wherein the defrosting operation is performed by opening the throttle amount of a decompression device having a variable throttle amount and sending the refrigerant to the air heat exchanger. Is.

Next, in addition to claim 1, the invention relating to claim 3 is that in addition to claim 1, the hot water supply circuit includes a direct hot water supply circuit for directly supplying hot water heated by the water-refrigerant heat exchanger to the water use terminal, and a water use terminal from the hot water storage tank. It is possible to compensate for the heating delay at the start of heat pump operation with tank hot water, and to integrate the hot water storage unit and heat pump unit by drastically downsizing the hot water storage tank. The effect in the instantaneous heat pump water heater of Claim 1 can be made more remarkable.

The invention according to claim 4 is the invention according to claim 4 , in addition to claim 1, since the defrosting required temperature is a plurality of temperatures set corresponding to the outside air temperature. Generally, the lower the outside air temperature is, the lower the absolute humidity is. Since the amount of frost on the heat exchanger is also reduced, the defrosting required temperature can be set to a low value corresponding to the outside air temperature, so that the operation control according to the frost amount can be performed, and the emergency defrosting operation is performed. Therefore, it is possible to provide a defrosting required control means that is more convenient to use.

Next, in addition to claim 1, the invention according to claim 5 has a defrosting necessary control means for displaying an alarm by displaying characters or blinking characters when the defrosting required temperature is reached. The amount of frost formation is large and it is necessary to prioritize the defrosting operation, and it is not necessary to feel anxiety even if the amount of hot water is reduced. It is possible to take measures such as extending the length.

Next, in addition to claim 1, the invention according to claim 6 has a defrosting necessary control means for performing alarm display by voice when the defrosting required temperature is reached. You can know by voice that it is necessary to prioritize a lot of defrosting operation, and it is convenient to understand without looking at the display on the kitchen remote control, etc. It is possible to take measures such as prolonging use.

  ADVANTAGE OF THE INVENTION According to this invention, a user's anxiety can be eliminated and the usability at the time of winter low temperature can be improved.

  Embodiments of the present invention will be described below with reference to the drawings.

  The heat pump water heater according to one embodiment of the present invention shown in FIG. 1 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 air heat disposed in the compressors 1a and 1b and the water-refrigerant heat exchanger 2. The exchangers 4a and 4b are sequentially connected through refrigerant pipes, and the refrigerant is sealed in the refrigerant circuit 30.

  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 (eg, 700 rpm) to a high speed (eg, 7000 rpm) by PWM control, voltage control (eg, 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. .

  In general, an electric expansion valve 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 air heat exchangers 4a and 4b as a low pressure refrigerant that easily evaporates. Further, the pressure reducing devices 3a and 3b change the throttle amount of the refrigerant passage to adjust the refrigerant circulation amount in the heat pump circuit, or send the medium temperature refrigerant to the air heat exchangers 4a and 4b in a large amount with the throttle amount fully opened. It also serves as a defroster that melts frost.

  The air heat exchangers 4a and 4b are installed on the outer surface of the main body and function as an air refrigerant heat exchanger that exchanges heat between the outside air and the refrigerant by ventilation of a fan (not shown).

  The hot water supply circuit 40 includes a water circulation circuit for performing direct hot water supply, tank hot water storage, tank hot water supply, bath hot water filling, and bath renewal.

  The direct hot water supply circuit has a water supply pipe and a hot water supply pipe. The water supply pipe is connected to a water supply fitting 5 connected to a water supply pipe which is a water supply source outside the apparatus such as water supply, and water supply side heat transfer pipes 2c and 2d of the water refrigerant heat exchanger 2. The hot water supply pipe is connected to the water supply side heat transfer pipes 2c and 2d of the water refrigerant heat exchanger 2 and the kitchen tap metal fitting 15 connected through a pipe to the kitchen faucet 16 which is one of the hot water outlet terminals outside the apparatus.

  In the middle of the water supply pipe, a pressure reducing valve 6, a water supply water amount sensor 7 for measuring the amount of water supplied, a water supply check valve 10, and a hydrothermal water exchange amount sensor 11 are sequentially provided.

  A hot water mixing valve 12 for mixing hot water from the hot water storage tank 8, a hot water mixing valve 13 connected to a water pipe branched from the water supply pipe, and a flow rate adjusting valve 14 for adjusting the flow rate of hot water to be discharged are provided in the middle of the hot water supply pipe. It is provided sequentially.

  The pressure reducing valve 6 controls, for example, a high water pressure with a variation of 200 to 500 kPa supplied from a water supply source to a constant water pressure suitable for use of about 170 kPa. The water supply check valve 10 allows water to flow only in one direction and prevents backflow.

  In addition to the kitchen faucet 16, the kitchen tapping metal fitting 15 is connected to the bath faucet 26 and the shower 27 so as to supply hot water.

  The tank hot water storage circuit is configured by sequentially connecting a hot water storage tank 8, an in-machine circulation pump 9, a hydrothermal water exchange amount sensor 11, a water supply side heat transfer pipe 2c, 2d, a hot water supply mixing valve 12, and a hot water storage tank 8 through a water pipe. .

  The tank hot water supply circuit is provided by branching from the middle of each of the above-mentioned water supply pipe and hot water supply pipe, and the hot water storage tank 8 is connected to the water supply pipe before and after the check valve 10 via the water pipe, The hot water supply pipe is connected to the hot water supply mixing valve 12 through a water pipe. This circuit mainly supplies hot water stored in the hot water storage tank 8 to the hot water supply pipe with the water pressure of the supplied water.

  In the bath hot water filling circuit, the above-described water supply pipe and the pipes to the water supply side heat transfer pipes 2c and 2d are common to the direct hot water supply circuit. Then, the hot water supply pipe is preceded by the flow rate adjustment valve 14 and is connected to the hot water inlet / outlet fitting 20 as a bath hot water pipe. The bath hot water piping includes a bath pouring valve 17 that opens when pouring into the bathtub 22, a flow switch 18 that detects the direction of water flow, a bath circulation pump 19, and a hot and cold water fitting 20 through the water piping. Connected sequentially. Moreover, the incoming / outgoing hot water fitting 20 and the bath hot / cold water fitting 24 are connected to the bathtub 22 via the bath circulation adapter 21.

  In addition, during bath hot water filling, hot water supply from the hot water storage tank 8 to the bathtub 22 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. Here, the minimum required amount is the amount of hot water remaining in the tank for the shower immediately after completion of the bath hot water filling.

  The bath memorial circuit is composed of a bathtub 22, a bath circulation adapter 21, an inlet / outlet fitting 20, a bath circulation pump 19, a flow switch 18, a bath water heat transfer pipe 23b, a bath outlet fitting 24, a bath circulation adapter 21, and a bathtub 22 with water piping. Are connected in sequence.

  In addition, when bathing, the heat pump operation and the in-machine circulation pump 9 are operated along with the water circulation of the bath water by the bath chasing circuit, and the hot water heated by the water refrigerant heat exchanger 2 is used for the bath through the hot water on / off valve 25. It is made to circulate to the hot water heat exchanger tube 23a provided in the heat exchanger 23, heat is exchanged between the hot water heat exchanger tube 23a and the bath water heat exchanger tube 23b, 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 opening / closing valve 25, Hot water storage operation, direct hot water supply operation, tank hot water supply operation, bath hot water operation, bath memorial operation and defrosting operation are performed.

  Further, the operation control means 50 controls the rotation speed of the compressors 1a and 1b, and immediately after starting operation, operates at a high speed rotation speed in order to shorten the heating start-up time, and at a stable rotation speed corresponding to the hot water supply temperature and flow rate. Control to drive.

  Further, the operation control means 50 performs control so that hot water of a predetermined temperature is always stored in the hot water storage tank by stopping the operation after performing the hot water storage operation of the tank after the hot water supply at the water use terminal is completed. Each time it has a tank hot water storage operation means.

  It should be noted that the tank hot water storage operation after the end of hot water supply is not performed every time, and the necessity of the tank hot water storage operation may be determined based on the temperature of the tank thermistors 8a to 8d.

  Moreover, the operation control means 50 always detects the outside air temperature and the temperature of the air heat exchangers 4a and 4b, and requires a defrosting start temperature indicating that it is in a frosting state, and an immediate defrosting operation. The defrosting required control means for setting the defrosting necessary temperature indicating the temperature and operating when the temperature is equal to or lower than the defrosting necessary temperature, and performing the defrost priority operation control and the character display on the remote control screen, the flashing display or the voice alarm display. have.

  That is, at the end of the hot water supply operation, if the temperature of the air heat exchanger is higher than the defrosting start temperature, after the hot water supply ends, the tank hot water storage operation is performed without performing the defrosting operation, and then the operation is stopped. If it is within the frost required temperature range, after the hot water supply is completed, perform the tank hot water storage operation, then perform the defrost operation, stop the operation, and if the temperature of the air heat exchanger is lower than the defrost required temperature, Character display, blinking display, or alarm display by voice is performed, and after the hot water supply is completed, the defrosting operation is performed first, and then the tank hot water storage operation is performed to stop the operation.

  If the temperature is within the range of the defrosting start temperature and the defrosting required temperature, after the hot water supply is completed, a predetermined amount of hot water is stored in the hot water storage tank, and then defrosting is performed. After the defrosting, the remaining amount of the hot water storage tank is further stored. You may make it let it. Thereby, in consideration of the case where the hot water is supplied again after the hot water supply is finished, the predetermined amount of tank hot water storage and defrosting can be completed in a shorter time.

  Further, the heat pump water heater includes a feed water thermistor 7a for detecting the feed water temperature, a hydrothermal thermistor 2e for detecting the tapping temperature of the water refrigerant heat exchanger 2, and a tank thermistor 8a for detecting the hot water storage temperature and the amount of hot water stored in the hot water storage tank 8. 8b, 8c, 8d, a mixed temperature thermistor 12a for detecting the mixing temperature of the direct hot water supply by the heat pump and the tank hot water from the hot water storage tank, a hot water thermistor 14a for detecting the hot water temperature, a bath thermistor 18a for detecting the temperature of the bath water, And air heat exchanger thermistors 4c and 4d for detecting the temperature of the air heat exchangers 4a and 4b, an air thermistor (not shown) for detecting the outside air temperature, and a pressure sensor 1c for detecting the discharge pressure of the compressors 1a and 1b, 1d and a water level sensor 22a for detecting the water level in the bathtub 22 are provided, and each detection signal is input to the operation control means 50. And it is configured to be. The operation control means 50 controls each device based on these signals.

  The hot / cold water open / close valve 25 is provided between the water / refrigerant heat exchanger 2 and the bath heat exchanger 23, and the water circuit is closed and the bath / heat exchanger 23 is closed from the water / refrigerant heat exchanger 2 except during bath replenishment. This is to prevent the leakage of heat to.

  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 will be described based on the flowcharts of FIGS. 2 to 7 with reference to the heat pump circuit 30 and the hot water supply circuit 40 of FIG.
FIG. 2 is an example of a flowchart showing the necessary operations during installation.
The heat pump water heater is transported from the manufacturing site and installed at the installation location desired by the user. The water supply fitting 5 is used as a water supply source such as water supply, and the kitchen outlet fitting 15 is provided as a kitchen faucet 16, a bath faucet 26, and a shower 27. The hot water fitting 20 is connected to the bath circulation adapter 21, the bath faucet 26 and the shower 27, and the bath hot water fitting 24 is connected to the bath circulation adapter 21 (step 60), and then the kitchen faucet 16 or the relief valve 28 for venting air. Is opened (step 61), and the main plug of the water supply source is opened (step 62), the in-machine water supply is started from the water supply source, and after the water is depressurized to a constant pressure by the pressure reducing valve 6, the hot water storage tank 8 and water It flows into the refrigerant heat exchanger 2 and each water pipe (step 63). After confirming that the interior of the machine is full due to overflow of water from the faucets 16 and 26 or the relief valve 28 (step 64), the faucets 16 and 26 or the relief valve 28 are closed and the in-flight water supply is finished (step). 65).

  In addition, each apparatus at the time of installation of a heat pump water heater is set to the following initial states. That is, the hot water supply mixing valve 12 and the hot water mixing valve 13 are open in both directions, the flow rate adjustment valve 14 and the water on / off valve 25 are open, and the bath pouring valve 17 is closed.

Next, the power switch is turned on (step 66), and the bath water filling operation is performed (step 67).
In the bathtub water filling operation, the bath pouring valve 17 is opened and water is poured into the bathtub until the water overflows (step 68). The capacity of the bathtub is automatically calculated by the water level sensor 22a and the water supply amount sensor 7 (step 69), and the bathtub capacity is set. (Step 70) is performed, which is utilized for bath hot water filling in bath automatic operation after setting, hot water control at the time of bathing, and the like. Therefore, the bathtub water filling operation is required only once when the heat pump water heater is installed.

  Next, FIG. 3 is an example of a flowchart showing a tank hot water storage operation for boiling water in the hot water storage tank.

  When a tank hot water storage operation instruction is issued under the control of the operation control means 50 (step 71), the hot water storage temperature and the hot water storage amount are determined by the tank thermistors 8a to 8d (step 72). If the stored hot water is used and reduced below the specified level, the tank hot water storage operation is started (step 73).

  In this tank 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. It is. 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 depressurized by the decompression devices 3a and 3b, and further expanded and evaporated by the air heat exchangers 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, heating at a low temperature over time improves heating efficiency.

  For example, it can be said that the direct hot water supply operation in which the hot water is heated up to a use temperature of 42 ° C. and the hot water supply operation is higher in efficiency than the tank hot water storage operation in which the water is heated to a high temperature of 60 ° C. or higher.

  In the tank hot water storage operation (step 73), along with the heat pump operation, in the tank hot water circuit, the hot water mixing valve 12 opens the hot water storage tank 8 side and closes the hot water mixing valve 13 side from the water / refrigerant heat exchanger 2 side (step). 73a), the hot water on / off valve 25 is closed (step 73b). Furthermore, the operation of the in-machine circulation pump 9 is started, and the in-machine circulation pump 9, the hydrothermal water exchange amount 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 lower part 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 when the entire hot water storage tank 8 reaches the boiling state, it is determined that the hot water storage is complete (step 76), and the operation is stopped. (Step 77).

  Note that the hot water temperature determination (step 74) for determining whether or not the temperature of the heated water discharged from the water heat exchanger 2 is appropriate is performed by the hydrothermal thermistor 2e, and the hot water temperature is within a specified value. Continues the tank hot water storage operation as it is (step 75). If it is outside the specified value, the temperature of the hot water is controlled by controlling the rotational speed of the compressors 1a and 1b, adjusting the throttle amount of the decompression devices 3a and 3b, and controlling the rotational speed of the in-machine circulation pump 9. Is adjusted (step 74a).

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

FIG. 4 is an example of a flowchart showing the 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 is started (step 80), the operation control means 50 starts the compressors 1a and 1b and starts the operation of the heat pump circuit 30, and the water supply fitting 5, the pressure reducing valve 6, and the amount of water supply By means of a hot water supply circuit of a sensor 7, a water supply check valve 10, a hydrothermal water exchange amount sensor 11, a water refrigerant heat exchanger 2, a hot water mixing valve 12, a hot water mixing valve 13, a flow rate adjusting valve 14, a kitchen outlet 15, and a kitchen faucet 16. Direct hot water supply operation (step 81) is performed. At the same time, a tank hot water supply operation is performed by a hot water supply circuit of a water supply fitting 5, a pressure reducing valve 6, a water supply 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, a kitchen outlet fitting 15, Step 82) is performed.

  Here, the heat pump refrigerant circuit 30 sends the high-temperature 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 the water flowing in from the water supply-side heat transfer tubes 2c and 2d. Although it heats and flows out to the hot water supply mixing valve 12 side, when the operation starts, the refrigerant sent to the water refrigerant heat exchanger 2 is not sufficiently high-temperature and high-pressure, the temperature is low, and the entire water-refrigerant heat exchanger 2 is Since it is cold, the heating ability to heat water 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 takes several minutes for the heating capacity of the heat pump operation to reach the high temperature stable state, the operation control means 50 sets the rotation speed of the compressor from the normal time for a predetermined time immediately after reaching the high temperature stable state immediately after the start of operation. Operation control is performed at high speed rotation, and the rise time of the water heating and hot water supply operation can be shortened. However, the operation control means 50 is used after a tank hot water supply operation (step 82) for supplying hot water from a hot water storage tank for a predetermined time immediately after the start of operation. Is operated to stop the tank hot water supply operation (step 84b), and switch to the direct hot water supply operation only and continue the hot water supply operation (step 85).

  Specifically, the opening degree of the mixing valve 12 is adjusted so that the mixing temperature thermistor 12a becomes the target temperature. That is, if the temperature of the direct hot water supply does not reach the target value, the tank hot water is added, and if the temperature of the direct hot water supply reaches the target value, the hot water is not supplied from the tank and only the direct hot water is supplied.

  During this time, the hot water supply thermistor 14a and the feed water amount sensor 7 determine the hot water supply temperature and flow rate (step 83). If the temperature is not specified, 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 start-up until the heating capacity of the heat pump operation reaches a temperature sufficient for the hot water supply temperature (usually 40 to 42 ° C.). In particular, the larger the compressor output, the shorter the startup time and the smaller the hot water storage tank 8.

  In addition, in order to support simultaneous use of a plurality of locations such as hot water supply in the kitchen at the same time as bath hot water filling, even if tank hot water is used at the start of operation, the capacity of the compressor 8 can be used as hot water supply capacity after stable heating. It is desirable to increase the power to about 20 kW, which is four times or more than the conventional 5 kW, but it is necessary not only to develop a new compressor but also to newly develop each component of the heat pump refrigerant circuit 30. It is extremely difficult. Therefore, in the embodiment of the present invention, the two-cycle heat pump system 30a, 30b using two compressors about twice as large as the conventional compressor is used, and the reliability of the conventional technology and the results are ensured, If even one compressor capacity is sufficient, the application and effect of the present invention will not change even in the one-cycle heat pump system.

Next, when the faucet is closed and the use of hot water is completed (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 both are used, both the direct hot water supply operation and the tank hot water supply operation are stopped. (Step 87)
Furthermore, the operation control means 50 detects and determines the temperature of the air heat exchangers 4a and 4b with the air heat exchanger thermistors 4c and 4d, and stops the heat pump operation after performing the following operation.

  First, when the hot water supply operation is stopped (step 87), if the temperature of the air heat exchangers 4a and 4b is equal to or higher than the defrosting start temperature, after the hot water supply operation is stopped, the defrost operation is not performed and the tank hot water storage operation is performed (step). 89a), the operation is stopped (step 90).

Next, when the temperature of the air heat exchangers 4a and 4b is between the defrosting start temperature and the defrosting required temperature, after the hot water supply operation is stopped, the tank hot water storage operation is performed (step 89b) and the defrosting operation is further performed. After (step 89c). (Step 90)
Further, when the temperature of the air heat exchangers 4a and 4b is equal to or lower than the defrosting required temperature, it is necessary to defrost by means such as character display or blinking display or sound on the remote control operation surface by the defrosting necessary control means. An alarm is displayed (step 89d), the hot water supply operation is stopped, the defrosting operation is performed (step 89e), the tank hot water storage operation is further performed (step 89f), and the operation is stopped. (Step 90)
In the tank hot water storage operation, the hot water storage temperature and the amount of hot water are detected by the tank thermistors 8a to 8d.

  However, detection of the tank hot water storage state by the tank thermistors 8a to 8d is always performed, and the hot water temperature and the amount of hot water remain in the hot water storage tank 8 at a predetermined value or more even after the water heating hot water supply operation is stopped for extremely short time use. Is determined to be hot water storage completion, and the tank hot water storage operation (step 88) is not performed.

  As described above, the operation control means 50 has a tank hot water storage operation function every time the tank hot water storage operation (step 88) is performed until the hot water storage is completed after completing the target operation in every operation. The hot water storage tank 8 always stores a predetermined amount of hot water at a predetermined temperature or more, so that it is possible to eliminate the fear of a drop in hot water at the start of operation and hot water during use.

  FIG. 5 is a temperature diagram for explaining the defrosting start temperature, the defrosting required temperature, and the defrosting end temperature based on the outside air temperature and the air heat exchanger temperature. The vertical axis shows the air heat exchanger temperature, the horizontal axis shows the outside air temperature, the diagram A shows the defrosting end temperature, the diagram B shows the defrosting start temperature, and the diagram C shows an example of the defrosting required temperature in descending order of temperature. Show.

  For example, when washing dishes in the kitchen at an outdoor temperature of 5 ° C. in winter, the hot water use time is about 5 minutes to 10 minutes at the longest, and the amount of frost formation is relatively small, resulting in point E between the diagrams BC. When the dishwashing is completed, after the hot water supply operation is stopped, the tank hot water storage operation is performed, and then the defrosting operation is performed and the operation is stopped.

  However, if the hot water bathing operation is performed under the same conditions as described above, the hot water supply operation time takes about 30 minutes, the amount of frost formation increases, the ventilation of the air heat exchanger is hindered, and the heating capacity is reduced. Further, when ventilation is hindered, the amount of heat exchange between the air and the refrigerant is reduced, and the temperature of the air heat exchanger is further lowered, resulting in a point F lower than that in the diagram C.

  If the tank hot water storage operation is performed first as in the case where the temperature of the air heat exchanger is point E, the tank hot water storage operation takes a long time due to insufficient heating capacity. If a shower or faucet is used in a state where the amount of hot water stored in the tank is insufficient, problems such as insufficient amount of hot water or a decrease in hot water temperature are likely to occur.

  Therefore, when the defrosting necessity control means is provided and becomes below the diagram C, the defrosting operation is preferentially displayed to notify the user, and after the hot water filling operation is completed, the defrosting operation is first performed. A tank hot water storage operation is performed after the operation is completed, and the operation is stopped.

  In the defrosting operation, the refrigerant throttle amounts of the decompression devices 3a and 3b are fully opened in FIG. 1, and the high-temperature refrigerant is sent to the air heat exchangers 4a and 4b to melt the frost by the heat of the refrigerant. Since the defrosting end temperature of A is reached and the subsequent tank hot water storage operation is performed promptly, the tank hot water storage can be ended early.

  Moreover, since the absolute humidity of outside air will fall extremely and it will reduce the amount of frost formation when it will be 0 degrees C or less, the defrost start temperature of the diagram B and the defrost required temperature of the diagram C are set low. On the contrary, the defrosting end temperature shown in the diagram A is set to be slightly higher when the outside air temperature is 0 ° C. or lower because the lower the outside air temperature, the longer the heating defrosting takes.

  Further, when the air heat exchanger temperature is higher than the defrosting start temperature in the diagram B, the defrosting operation is not necessary in a state where almost no frost is formed.

  Note that the diagrams A, B, and C in FIG. 5 are merely examples, and differ depending on the component configuration and capacity of the heat pump circuit, and the present invention is effective even if the temperature, curve, and the like of the diagram are variously different. It is obtained.

  FIG. 6 is an example of a flowchart showing a hot water filling operation by bath automatic operation. The bath automatic button is pressed and turned on (step 91), and when the set time comes, bath hot water filling operation starts (step 92), the bath pouring valve 17 is opened, and bath hot water supply is performed (step 93).

  In the bath hot water supply (step 93), the direct hot water supply operation and the tank hot water supply operation are used in combination as in the hot water use described with reference to FIG. That is, the direct hot water supply operation and the tank hot water supply operation are performed simultaneously for several minutes immediately after the start of the heat pump operation. When the direct hot water supply temperature reaches a stable state, the tank hot water supply operation is stopped and only the direct hot water supply operation is performed.

  Further, during the bath water supply operation, the bath thermistor 18a detects the bath hot water temperature to determine the hot water supply temperature (step 94). If the temperature is not specified, the temperature is adjusted (step 94a). (Step 95).

  Furthermore, the water level in the bathtub is detected by the water level sensor 22a, and the amount of bathing water is determined (step 96).

In the bath hot water amount determination (step 96), the bath hot water supply is continued (step 95) if it is not specified, and the bath hot water supply and the heat pump operation are stopped when the specified value is reached. (Step 97)
When the hot water bathing operation is stopped (step 97), the temperature of the air heat exchanger is determined in the same manner as in FIG. 4 (step 98), and based on whether the defrosting start temperature and the defrosting required temperature are appropriate or not. The defrosting indication, the tank hot water storage operation, and the defrosting operation are performed (steps 99a to 99f), and the operation is stopped. (Step 100)
FIG. 7 is an example of a flowchart showing bath remedy by automatic bath operation. The bath automatic button is pressed and turned on (step 101). When the set time comes, the bath filling operation described in FIG. 6 is started (step 102), and then the bath filling operation is terminated (step 103). Then, the bath heat insulation operation is started (step 104).

  After completion of the bath hot water operation (step 103), the bath temperature is detected by the bath thermistor 18a. If the bath temperature is within the specified value in the bath temperature determination (step 105), the bath is kept warm. A memorial operation is performed (step 106). In addition, when the water level sensor 22a detects the amount of hot water in the bathtub every predetermined time (for example, 10 minutes) and the bath hot water filling amount determination (step 107) is within the specified value, the bath is kept warm. Performs bath addition hot water (step 108).

  Further, when the set time for automatic bath operation has elapsed, the bath heat retention operation is terminated (step 109), and the bath automatic operation is terminated (step 110).

  As described above in detail, the present invention has a great effect in the instantaneous heat pump having a hot water storage tank, which eliminates problems caused by frost formation at low temperatures in winter and improves tank hot water storage operation, energy saving, and usability. .

  In addition, the user can know that the amount of frost formation is large and that it is necessary to prioritize the defrosting operation by displaying on the remote control or by voice, and will not feel uneasy even if the amount of hot water supply decreases. In addition, if frosting occurs that hinders tank hot water storage operation, tank hot water storage operation is performed after the hot water supply is completed, and after defrosting operation, defrosting and tank hot water storage can be performed efficiently, greatly improving the ease of use at low temperatures in winter Can be improved.

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 one Example of the check operation at the time of installation and piping connection in the heat pump water heater of this invention. It is a flowchart which shows one Example of the operation | movement at the time of the tank hot water storage driving | operation in the heat pump water heater of this invention. It is a flowchart which shows one Example of the operation | movement at the time of hot water use in the heat pump water heater of this invention. In the heat pump water heater of this invention, it is a temperature diagram which shows one Example of the setting value of the external temperature and the temperature of an air heat exchanger, and the defrost start temperature and defrost required temperature. It is a flowchart which shows one Example of the operation | movement at the time of bath hot water filling in bath automatic operation. It is a flowchart which shows one Example of the operation | movement at the time of the bath heat retention in bath automatic operation.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1a, 1b ... Compressor 1c, 1d ... Pressure sensor 2 ... Water refrigerant | coolant heat exchanger 2a, 2b ... Refrigerant side heat exchanger tube 2c, 2d ... Feed water side heat exchanger tube 2e ... Hydrothermal exchange thermistor 3a, 3b ... Pressure reducing device 4a, 4b ... Air heat exchangers 2c, 2d ... Air heat exchanger thermistor 5 ... Water supply fitting 6 ... Pressure reducing valve 7 ... Water supply water amount sensor 8 ... Hot water storage tank 8a-8d ... Tank thermistor 9 ... In-machine circulation pump 10 ... Water supply check valve 11 ... Water Heat exchange water quantity sensor 12 ... Hot water supply mixing valve 12a ... Mixing temperature thermistor 13 ... Hot water / water mixing valve 14 ... Flow rate adjusting valve 15 ... Kitchen outlet metal 16 ... Kitchen faucet 17 ... Bath pouring valve 18 ... Flow switch 19 ... Bath circulation pump 20 ... Bathtub adapter 21 ... Bath circulation adapter 22 ... Bathtub 22a ... Water level sensor 23 ... Bath heat exchanger 23a ... Hot water heat transfer pipe 23b ... Bath water heat transfer pipe 24 ... Bath hot spring fitting 2 ... hot water off valve 26 ... bath cock 27 ... Shower 28 ... relief valve 30 ... heat pump refrigerant circuit 40 ... hot water supply circuit 50 ... operation control means 51 ... Kitchen remote control 52 ... bath remote controller.

Claims (6)

A heat pump refrigerant circuit in which a compressor, a water-refrigerant heat exchanger that exchanges heat between supplied water and refrigerant, a decompression device, and an air heat exchanger that exchanges heat between air and refrigerant are sequentially connected via a refrigerant pipe When,
A hot water supply circuit in which 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, and a flow rate adjustment valve are connected via a water pipe ;
The temperature of the air heat exchanger is set in advance to the defrosting start temperature and the defrosting required temperature lower than the defrosting starting temperature, and the temperature of the air heat exchanger is within the range of the defrosting starting temperature and the defrosting required temperature. In the water use terminal, after completion of the hot water supply operation at the water use terminal, after executing the tank hot water storage operation , a refrigerant having a temperature higher than that in the water use terminal hot water supply operation and the tank hot water storage operation is sent to the air heat exchanger. Execute a defrosting operation to melt the frost of the air heat exchanger. If the temperature of the air heat exchanger is lower than the defrosting required temperature, execute the defrosting operation of the air heat exchanger after the hot water supply operation is completed. And a heat pump water heater provided with a control means for executing a tank hot water storage operation . 2. The heat pump water heater according to claim 1, wherein the defrosting operation is performed by opening a throttle amount of a decompression device having a variable throttle amount and sending a refrigerant to an air heat exchanger. The hot water supply circuit includes a direct hot water supply circuit for directly supplying hot water heated by a water refrigerant heat exchanger to a water using terminal, and a tank hot water supply circuit for supplying hot water from a hot water storage tank to the water using terminal. The heat pump water heater according to 1. The heat pump water heater according to claim 1, wherein the defrosting required temperature is a plurality of temperatures set corresponding to an outside air temperature. 2. The heat pump water heater according to claim 1, further comprising a defrosting necessary control means for performing an alarm display by displaying characters or flashing characters when the defrosting required temperature is reached. The heat pump water heater according to claim 1, further comprising a defrosting necessity control means for performing an alarm display by voice when the defrosting temperature is reached.

Images