Heat pump water heater

Description: TECHNICAL FIELD [Detailed description of the invention]

【0001】

[Technical field to which the invention belongs]

The present invention relates to a heat pump water heater capable of supplying hot water by heating water in a hot water storage tank by a heat pump type refrigeration cycle, and more particularly to a heat pump water heater for which a control method is optimized.

【0002】

[Conventional technology]

Conventionally, as an example of this type of heat pump water heater, for example, as shown in FIG. 9, a heat pump type refrigerating cycle 1 that circulates a refrigerant and water that supplies water heated by the refrigerant of the refrigerating cycle 1 to a hot water storage tank 11 Some are equipped with a circuit 10.

【0003】

In the refrigeration cycle 1, the compressor 2, the four-way valve 3, the primary side heat exchange pipe 4a of the water heat exchanger 4, the expansion valve 5, and the outdoor air heat exchanger 6 are sequentially connected by the refrigerant pipe 7 in this order to circulate the refrigerant. Make up a closed loop. Reference numeral 4c in FIG. 9 is a condensation temperature sensor installed in the middle portion of the water heat exchanger 4 to detect the condensation temperature of the refrigerant.

【0004】

On the other hand, in the water circuit 10, the primary side heat exchange pipe 4a of the water heat exchanger 3 and the heat exchangeable secondary side heat exchange pipe 4b, the hot water storage tank 11, and the pump 12 are connected in this order by the water pipe 13. , Consists of a closed loop that circulates water (or hot water).

【0005】

The hot water storage tank 11 is provided with a hot water inlet / outlet 11a that doubles as a hot water inlet and a hot water supply port for supplying hot water from the water heat exchanger 4, and water is provided at one end of a bifurcated branch pipe connected to the hot water inlet / outlet 11a. While connecting to the water channel on the water outlet side of the heat exchanger 4, the other end of the branch pipe is connected to the hot water supply line 16. On the other hand, at the bottom of the hot water supply tank 11, a water inlet 11b and a water outlet 11c for receiving water are provided, and a water supply line 17 is connected to the water inlet 11b. The hot water storage tank 11 is housed in a hot water storage casing 15 while a water temperature sensor 14 for detecting the water temperature of the stored water is arranged at the inner bottom thereof. On the other hand, the compressor 2 including the water heat exchanger 4, the four-way valve 3, the components of the refrigeration cycle 1 such as the outdoor air heat exchanger 6, and the pump 12 are housed in the heat source machine casing 8.

【0006】

During the hot water storage operation of this heat pump water heater, the refrigerant circulates in the refrigeration cycle 1 in the direction indicated by the arrow in FIG. 9, and the water heat exchanger 4 acts as a condenser, while the air heat exchanger 6 acts as an evaporator. It works. For this reason, the water pumped by the pump 12 from the water outlet 11c at the bottom of the hot water storage tank 11 passes through the secondary heat exchange pipe 4b of the water heat exchanger 4 and is passed through the primary heat exchange pipe 4b. It is heated by the heat of condensation of a high-temperature and high-pressure gaseous refrigerant that passes through the hot water to become hot water, and this hot water is supplied into the hot water storage tank 11 via the water pipe 13 by the water supply of the pump 12 from the hot water inlet / outlet 11 above the hot water storage tank 11.

【0007】

By repeatedly heating the hot water stored in the hot water storage tank 11 by the water heat exchanger 4, the hot water storage temperature in the hot water storage tank 11 is gradually raised from the top, corresponding to the inlet water temperature set value of the water heat exchanger 4. When the temperature rises to a predetermined hot water storage temperature, the hot water storage operation is stopped, and thereafter, the hot water supply operation for supplying the hot water storage at the predetermined temperature is waited for.

【0008】

[Problems to be Solved by the Invention]

However, in such a conventional heat pump water dispenser, the capacities of the compressor 2 and the pump 12 are fixed and not variable, and the expansion valve 5 also has a fixed throttle. Therefore, as shown in FIG. 10, the hot water storage tank. As the water temperature A in 11 rises, the condensation temperature B of the water heat exchanger 4 rises, so the compressor 2 with a fixed capacity is used at the condensation temperature (heat exchange intermediate temperature), which is the limit of its use, for example, about 65 ° C. Since it can be used only to a certain degree, there is a problem that the temperature of the hot water stored in the hot water storage tank 11 can be raised only to about 60 ° C, for example.

【0009】

Further, since the capacity of the compressor 2 and the pump 12 is fixed, it is difficult to operate the hot water storage in response to load fluctuations such as a decrease in the outside air temperature, and it takes a long time to operate the hot water storage to raise the temperature of the hot water to a predetermined temperature.

【0010】

Further, the defrosting operation for defrosting the frost formation of the outdoor air heat exchanger 6 is a so-called reverse defrosting operation in which the four-way valve 3 is switched in the opposite direction to the hot water storage operation, in which case water heat exchange is performed. Despite the fact that the vessel 4 acts as an evaporator (cooler), the pump continues to operate, so that the water cooled by the water heat exchanger 4 is supplied into the hot water storage tank 11 and the hot water storage temperature is adjusted. There is a problem of lowering it.

【0011】

Furthermore, since the heat exchange capacity of the outdoor air heat exchanger 6 is fixed, the refrigerating capacity changes greatly with respect to changes in the outside air temperature, so that the amount of hot water stored at a predetermined temperature is stable regardless of the outside air temperature. There is a problem that it is difficult to secure.

【0012】

The present invention has been made in consideration of such circumstances, and an object of the present invention is that the hot water storage temperature can be efficiently raised to a high temperature by optimizing the control method, and energy saving and controllability can be achieved. It is to provide an excellent heat pump water heater.

【0013】

[Means for solving problems]

The invention of claim 1 sequentially connects an outdoor air heat exchanger provided with a compressor having a variable capacity, a first heat exchange pipe of a water heat exchanger, a flow control valve, and an outdoor fan having a variable rotation speed, while the above. A refrigeration cycle in which the discharge side of the compressor and the refrigerant inlet side of the outdoor air heat exchanger are communicated with each other by a bypass path, and the refrigerant is circulated by interposing an on-off valve in the bypass path, and the first of the water heat exchanger. The water outlet of the heat exchange tube and the second heat exchange tube that can exchange heat are connected to the upper part of the hot water storage tank by a water pipe, while the variable flow rate pump and the above second heat exchange tube are connected to the lower part of this hot water storage tank. A water circuit that circulates water by sequentially connecting water inlets with water pipes, a water temperature sensor installed in the lower part of the hot water storage tank to detect the water temperature in the hot water storage tank, and a hot water storage tank control provided in the hot water storage tank. While the hot water storage operation is started when the hot water storage operation start command signal is received from the device or the remote controller, the controller that sets the boiling temperature of the hot water storage in this hot water storage tank based on the water temperature detected by the water temperature sensor. It is a heat pump water exchanger characterized by having.

【0014】

According to the present invention, the remote controller can perform the necessary operations to start the hot water storage operation, or the hot water storage tank controller can time the start time of the midnight time zone when the electricity charge set in advance is cheap. When a hot water storage operation start command signal is given to the controller from these remote controllers or the hot water storage tank controller, the hot water storage operation for raising the temperature of the hot water stored in the hot water storage tank to a predetermined boiling temperature can be started.

【0015】

According to the invention of claim 2, the controller determines the initial operating frequency of the compressor at the start of hot water storage operation based on the water temperature detection value of the water temperature sensor, and controls the number of revolutions of the compressor. The pump control means for controlling the pump so as to gradually increase the flow rate of the pump from the start of the hot water storage operation, and the initial opening degree of the flow rate control valve at the start of the hot water storage operation for a predetermined time, and then the above. A flow control valve opening control means that controls the opening of the flow control valve so that the difference between the suction side temperature of the compressor and the evaporation temperature of the outdoor air heat exchanger becomes constant at a predetermined value, and the outdoor air heat. A heat pump water heater characterized in that it is provided with an outdoor fan control means for controlling the operating rotation rate of the outdoor fan of the exchanger per unit time based on the operating frequency and the outdoor temperature of the compressor. is there.

【0016】

According to the third aspect of the present invention, in the compressor control means, after the start of the hot water storage operation, the deviation between the water outlet temperature on the water outlet side of the water heat exchanger and the boiling temperature set value of the hot water storage is set every predetermined control time. And, it has a compressor operating frequency correction function that calculates the amount of change in this deviation, obtains the correction amount of the operating frequency of the compressor from these deviations and the amount of change, and corrects the current operating frequency by this correction amount. However, the pump control means has a function of controlling the pump flow rate to be maintained at a predetermined flow rate after the start of the hot water storage operation, and the flow rate control valve opening control means compresses the refrigeration cycle after the start of the hot water storage operation. The outdoor fan control means has a function of controlling the opening degree of the flow control valve so that the amount of super heat, which is the difference between the suction side temperature of the machine and the evaporation temperature of the outdoor air heat exchanger, becomes constant at a predetermined value. The heat pump water dispenser according to claim 2, further comprising a function of controlling the rotation speed of the outdoor fan according to the operating frequency of the compressor and the outdoor temperature after the start of the hot water storage operation.

【0017】

According to the inventions according to claims 2 and 3, the compressor, the pump, and the outdoor fan all have variable capacities, and the opening degree of the flow control valve can be controlled, and these are used when the hot water storage operation of the heat pump water heater is started. And, when the hot water storage temperature stabilizes due to the continuation of the hot water storage operation, the control is optimized by controlling with the capacity suitable for each operating condition, so only this hot water storage operation is used to store hot water in the hot water storage tank. The temperature of the hot water can be raised to the high temperature of the target temperature, and the hot water storage operation efficiency can be improved.

【0018】

According to the invention of claim 4, when the controller receives the hot water storage operation stop command signal from the hot water storage tank controller or the remote controller, the hot water storage operation is stopped or the water temperature detection value detected by the water temperature sensor is used. The heat pump water heater according to any one of claims 1 to 3, wherein the heat pump water heater has a function of stopping the hot water storage operation based on the above.

【0019】

According to the present invention, the hot water storage operation is automatically stopped by the hot water storage operation stop signal from the hot water storage tank controller or the remote controller, or when the detection value of the water temperature sensor in the hot water storage tank detects a predetermined hot water storage temperature. Can be done.

【0020】

According to the invention of claim 5, the controller stops the operation of the pump and opens the on-off valve of the bypass path to perform the defrosting operation, and after the defrosting operation is completed, the controller operates the defrosting operation. It is characterized by providing a means for setting a target value of the initial operating frequency of the compressor when returning to the hot water storage operation to a value obtained by multiplying the operating frequency before the start of the defrosting operation by a predetermined coefficient. The heat pump water heater according to any one of claims 1 to 4.

【0021】

According to the present invention, by opening the on-off valve of the bypass path by the controller, the high-temperature and high-pressure gaseous refrigerant from the compressor is bypassed by the water heat exchanger and directly introduced into the outdoor air heat exchanger. Since it is defrosted by heating, the defrosting can be performed in a short time (quick defrosting). Further, since this defrosting operation is not defrosting by so-called reverse defrosting in the refrigeration cycle, the water heat exchanger does not act as an evaporator (cooler) to cool the hot water storage unlike the reverse defrosting. Therefore, the temperature of the hot water can be raised quickly and with high efficiency.

【0022】

Furthermore, when returning from the hot water storage operation to the hot water storage operation, the compressor is operated at a frequency that is a multiplier of the operating frequency before the start of the defrosting operation, so that the temperature of the hot water storage is raised. It can be done quickly.

【0023】

The invention of claim 6 is the heat pump water heater according to any one of claims 1 to 5, wherein the controller is installed in a case accommodating at least the refrigeration cycle.

【0024】

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of the present invention will be described with reference to FIGS. 1 to 8. In these figures, the same or corresponding parts are designated by the same reference numerals.

【0025】

FIG. 1 is a block diagram showing an overall configuration of a heat pump water heater 21 according to an embodiment of the present invention. The heat pump water heater 21 includes a water circuit 31 that circulates water in the direction of the arrow in the figure, and a heat pump type refrigeration cycle 41 that circulates a refrigerant as a heating medium for heating the water circulating in the water circuit 31 in the direction of the arrow in the figure. It has.

【0026】

In the refrigeration cycle 41, the number of revolutions (rotational speed) per unit time can be freely controlled by controlling the operating frequency with an inverter (not shown), and the capacity of the compressor 42 is variable. The heat exchange pipe 43a, the flow control valve 44, which is an expansion valve with adjustable flow rate consisting of an electric valve, etc., and the air heat exchanger 45 installed outdoors, etc., are sequentially connected by the refrigerant pipe 46 in this order to circulate the refrigerant. It constitutes a loop. Further, the discharge side of the compressor 42 and the refrigerant inlet side of the air heat exchanger 45 are communicated with each other by a defrosting bypass path 47, and a defrosting by an electromagnetic two-way valve or the like is provided in the middle of the defrosting bypass path 47. It is equipped with a bypass valve 48.

【0027】

Further, the air heat exchanger 45 is provided with an outdoor fan 45a having a variable capacity for promoting heat exchange between air and the refrigerant, while the water heat exchanger 43 is provided with the condensation temperature (heat exchange intermediate temperature) Tc of the refrigerant. The condensate temperature sensor 43c for detecting the above is provided, and the heat exchange outlet water temperature sensor 43d for detecting the water outlet temperature Twout is provided in the water circuit 31 near the outlet side of the water heat exchanger 43. Further, the outdoor air heat exchanger 45 has a refrigerant evaporation temperature T._EThe evaporation temperature sensor 45b for detecting the temperature, the outdoor temperature sensor 45c for detecting the outdoor temperature, and the suction temperature sensor 42a for detecting the suction temperature Ts are provided on the suction side of the compressor 42.

【0028】

Then, these suction temperature sensor 42a, evaporation temperature sensor 45b, condensation temperature sensor 43c, compressor 42, expansion valve 44, defrost bypass valve 48, and outdoor fan 45a are electrically connected to the controller 49 by a signal line (not shown). ing.

【0029】

On the other hand, the water circuit 31 is located above the hot water storage tank 32 on the water outlet side of the primary side heat exchange pipe 43a through which the refrigerant of the water heat exchanger 43 passes and the secondary side heat exchange pipe 43b through which heat exchangeable water passes. While the water inlet / outlet 32a that doubles as the water inlet and the hot water supply port is connected by the water pipe 33a, the suction port of the pump 34 with variable flow rate is connected to the water outlet 32b at the bottom of the hot water storage tank 32 by the water pipe 33b. Is connected to the water inlet of the primary side heat exchanger 43b of the water heat exchanger 43 by a water pipe to form a closed loop that circulates the hot water (or water storage) in the hot water storage tank 32 in the direction of the arrow in the figure. doing. The pump 34 has the ability to make a round of the hot water (water) in the hot water storage tank 32 during the hot water storage operation, for example, in about 8 hours at midnight when the electricity rate is cheap.

【0030】

In the hot water storage tank 32, one branch end of the bifurcated branch pipe connected to the hot water inlet / outlet 32a above the hot water storage tank 32 is connected to the outlet water channel side of the water heat exchanger 43, while the other branch end is connected to the hot water supply pipe 35. On the other hand, at the bottom of the hot water storage tank 32, a water receiving port 32c connected to the water supply pipe 36 and a water outlet 32b for storing water or supplying hot water in the hot water storage tank 32 are formed, and the water pipe 33b is formed at the water outlet 32b. It is connected to the suction port of the pump 34 via.

【0031】

Further, a bottom water temperature sensor 37 for detecting the temperature Twin of the water storage (including hot water storage) in the hot water storage tank 32 is provided at the bottom of the hot water storage tank 32.

【0032】

The hot water storage tank 32 configured in this way is housed in the hot water storage tank casing 38a and is configured in the hot water storage tank 38, and the hot water storage tank controller 39 which is a hot water storage tank controller is arranged in the hot water storage tank casing 38a. .. The hot water storage tank controller 39 is composed of, for example, a microprocessor or the like, and is configured to freely communicate with the remote controller 50 such as a control signal in both directions. For example, when receiving a hot water storage operation start command signal from the remote controller 50, or a hot water storage tank. When the time (for example, 11:00 pm) when the midnight time zone when the electricity charge is cheaper is started by the built-in clock of the controller 39, the hot water storage operation start command signal is displayed via a signal line (not shown) or infrared rays, etc. It is configured to wirelessly transfer or transmit to control 49. In addition, the hot water storage tank controller 39 has a function of transferring the water temperature detection value Twin read from the bottom water temperature sensor 37 to the controller 49.

【0033】

The controller 49 is composed of a microprocessor and the like, and is arranged in the heat source machine casing 51a. The heat source machine casing 51a contains, inside, each device constituting the refrigeration cycle 41 such as the compressor 42 and the outdoor air heat exchanger 45, and the water heat exchanger 43, the pump 34, and the water pipe 33 of the water circuit 31. A part of it is housed in the heat source machine 51. The heat source machine 51 is connected to the hot water storage tank 38 via a pair of water pipes 33a and 33b.

【0034】

The controller 49 is electrically connected to the suction side temperature sensor 42a, the condensation temperature sensor 43c, the heat exchange outlet water temperature sensor 43d, the evaporation temperature sensor 45b, and the outdoor temperature sensor 45c by signal lines (not shown), and detects each of these sensors. While reading the values, they are electrically connected to the pump 34, the inverter (not shown) of the compressor 42, the outdoor fan 45c, and the defrost bypass valve 48 by signal lines (not shown), and are configured to control these appropriately.

【0035】

That is, the controller 49 circulates the hot water (including water storage) in the hot water storage tank 32 to the water circuit 31 by the water supply of the pump 34, heats it by the water heat exchanger 43, raises the temperature to the target temperature, and raises the temperature in the hot water storage tank 32. Frost occurred in the various control functions required to execute the hot water storage operation that is stored in the hot water storage operation and waits for the next hot water supply operation, and in the outdoor air heat exchanger 45 that acts as an evaporator (cooler) due to this hot water storage operation. Occasionally, it is equipped with various control functions necessary to switch the hot water storage operation to the defrosting operation for defrosting this frost formation. That is, the controller 49 sets the hot water storage temperature in the hot water storage tank 32 to a predetermined value by setting the inlet water temperature of the water heat exchanger 43 to a predetermined value, and the hot water storage in the hot water storage tank 32 reaches the predetermined temperature. A compressor 42, an operation mode control means for switching the hot water storage operation to the defrosting operation when frost is formed on the hot water storage operation mode for raising the temperature and the outdoor air heat exchanger 45 acting as an evaporator during the hot water storage operation. Compressor control means for controlling operation, pump control means for controlling operation of pump 34, flow control valve control means for controlling the opening degree of flow control valve 44, and outdoor fan control means for controlling operation of outdoor fan 45a, respectively. I have.

【0036】

FIG. 2 shows each control means of the controller 49 at each stage from the start of the hot water storage operation to the stop after the stable time at which the hot water storage temperature (Twout) is almost stable (constant) at the set value. , The timing chart when controlling the operation of the compressor 42, the pump 34, the flow rate control valve 44, and the outdoor fan 45a is shown.

【0037】

That is, when the operation mode control means of the controller 49 receives a hot water storage operation start command signal from, for example, the remote controller 50 in which the hot water storage operation start operation is performed, or the hot water storage tank controller 39 that clocks a predetermined midnight time. , As shown in FIG. 1, close the defrost bypass valve 48, start the operation of the compressor 42, the water heat exchanger 43, and the outdoor fan 45a, and set the inlet water temperature of the water heat exchanger 43 to a predetermined value. By doing so, the target value of the boiling temperature of the hot water is set and the hot water storage operation is started.

【0038】

The initial frequency Hz at the start of operation of the compressor 42 is obtained from the following equation (1) by the compressor control means.

【0039】

[Number 1]

Hz = -2 * Twin + 90 ...... (1) However, Twin: Water temperature detection value by the bottom water temperature sensor 37 That is, the compressor control means reads the water temperature detection value from the bottom water temperature sensor 37, and when the water temperature detection value is, for example, 6 ° C, the initial frequency Hz is 78 Hz according to the following equation (2).

【0040】

[Number 2]

-2 × 6 + 90 = 78 (Hz) ...... (2) [0041]

This initial frequency is gradually increased at predetermined time intervals, for example, every minute, based on the water temperature detection value Twin that gradually rises as the hot water storage operation progresses, and one of the release conditions at the start of the next operation is satisfied. After judging that, the operation is performed at a constant frequency. The conditions for canceling the operation at the start of operation are that 10 minutes have passed since the start of operation and (AND) the super heat amount TSH> set super heat amount TSHO-1 of the refrigeration cycle 41 is satisfied, and 20 minutes have passed since the start of operation. There are cases and cases. Here, the super heat amount TSH and the setting TSHO are as follows.

【0042】

That is, the super heat amount TSH can be obtained by the following equation (3).

【0043】

[Number 3]

<img file="JP2002243276A_D0001.tif" />【0044】

On the other hand, the set super heat amount TSHO is set as shown in Table 1 below, for example, according to the actual operating frequency of the compressor 42.

【0045】

[table 1]

<img file="JP2002243276A_D0002.tif" />【0046】

Then, when the compressor control means detects that the above-mentioned operation start release condition is satisfied during the hot water storage operation, the compressor control means shifts to the stable control shown in FIG.

【0047】

That is, the compressor control means has a deviation E and a change amount ΔE (this time Twout) between the heat exchange outlet water temperature Twout and the set temperature Tsc as shown in the following equation (4) every predetermined control time (for example, 60 seconds). (Difference between the value of Twout and the value of Twout 60 seconds before the previous time) is calculated, and the value obtained from the control rule table shown in Table 2 below is multiplied by 0.5 from these E and ΔE to correct the frequency command signal fi. And correct the current frequency command signal fi.

【0048】

[Number 4]

<img file="JP2002243276A_D0003.tif" />【0049】

[Table 2]

<img file="JP2002243276A_D0004.tif" />【0050】

Then, as shown in the following equation (5), the correction value Δfi (n) obtained this time is added to the previous frequency command fi (n-1) to obtain the current frequency command signal fi (n).

【0051】

[Number 5]

<img file="JP2002243276A_D0005.tif" />【0052】

Further, the frequency command signal fi is corrected every 60 seconds, for example. That is, as shown in FIG. 3, the deviation E is constantly read by the controller 49, but the frequency command correction is performed every 60 seconds according to the control output table according to the change amount ΔE determined every 60 seconds and the deviation E at that time. Determine the quantity Δfi (n). However, when the set temperature is changed, it is controlled by the frequency command correction amount Δfi (n) obtained based on the deviation E ́ at that time and the change amount ΔE ́ from the previous time to the time when the set temperature is changed. ..

【0053】

On the other hand, as shown in FIG. 2, the pump control means uses the pump 34 in a stepwise manner such that the discharge flow rate of the pump 34 is 0.2 L / min, 0.6 L / min, 1.0 L / min at predetermined time intervals (for example, 1 minute). After that, the pump is operated at a constant flow rate such as 1.0 L / min, including when it is stable.

【0054】

At the start of the hot water storage operation, the flow control valve disclosure control means applies a predetermined number of control pulses to the flow control valve 44, controls the opening degree to a predetermined initial opening degree, and continues the initial opening degree for a predetermined time. After that, until stable, super heat control is performed so that the amount of super heat TSH in the refrigeration cycle 41 becomes constant at a predetermined value.

【0055】

Further, the flow control valve opening control means sets the opening of the flow control valve 44 as a deviation SH from the set value (opening) for each control time TM as shown in Table 3 below, and a deviation between the previous deviation and the current deviation. It is corrected based on the deviation ΔSH of. This deviation SH is obtained by the following (6) and (7), and Table 3 shows 11 × 7 elements with SH of -5 to 5 and ΔSH of -3 to 3.

【0056】

[Number 6]

<img file="JP2002243276A_D0006.tif" />【0057】

[Table 3]

<img file="JP2002243276A_D0007.tif" />【0058】

The opening control time TM of the flow rate control valve 44 is set as shown in Table 4 below, for example, according to the actual operating frequency (Hz) of the compressor 42.

【0059】

[Table 4]

<img file="JP2002243276A_D0008.tif" />【0060】

Then, the outdoor fan control means of the controller 49 operates (ON) the outdoor fan 45a when the compressor 42 is operating (ON), and also stops the operation of the outdoor fan 45a when the compressor 42 is stopped (OFF). .. In addition, the outdoor fan control means has a function of controlling the rotation speed (rpm) of the outdoor fan 45a according to the operating frequency of the compressor 42 and the outdoor temperature (outside air temperature) Tout. The fan taps f1 to f8 of the outdoor fan 45a at the time are as shown in Table 5 below, and as shown in Table 6, the fan taps are preset according to the detected value of the outside air temperature Tout. In Table 6, the rotation speed (rpm) of the outdoor fan 45a when the operating frequency of the compressor 42 is 24 to 54 Hz is as shown in Table 7 below, for example.

【0061】

[Table 5]

<img file="JP2002243276A_D0009.tif" />【0062】

[Table 6]

<img file="JP2002243276A_D0010.tif" />【0063】

[Table 7]

<img file="JP2002243276A_D0011.tif" />【0064】

Then, when the controller 49 receives a boiling stop command signal from at least one of the hot water storage tank controller 39 and the remote controller 50, or when it is determined that the detected value detected by the bottom water temperature sensor 37 has reached the set value. , It has a function to stop the hot water storage operation. That is, as shown in FIG. 2, the controller 49 has a function of stopping each operation of the compressor 42, the pump 34, and the outdoor fan 45a, and controlling the flow rate control valve 44 to the stop opening degree to stop the hot water storage operation. ing.

【0065】

FIG. 4 shows a state in which the set value Tsc of the hot water storage temperature is controlled stepwise by the controller 49 in conjunction with the rise or fall of the inlet water temperature Twin detected by the bottom water temperature sensor 37 during the hot water storage operation. The middle-up arrow indicates the temperature rise of the inlet water temperature Twin, and the downward arrow indicates the temperature decrease.

【0066】

For example, if the controller 49 detects that the Twin of the water heat exchanger 43 has dropped from 19 ° C to 18 ° C during the hot water storage operation, the hot water storage temperature set value Tsc is controlled from 78 ° C to 81 ° C. On the other hand, when the inlet water temperature Twin rises from 19 ° C to 20 ° C, the hot water storage temperature set value Tsc is controlled from 81 ° C to 78 ° C. Therefore, stable control can be performed without significantly changing the operating frequency of the compressor 42.

【0067】

Then, when the hot water storage operation is continued, hot water having a set temperature (for example, 87 ° C) gradually accumulates in the hot water storage tank 32 from above, and a predetermined set water temperature (for example, 30 °) is accumulated by the bottom water temperature sensor 37. When C) is reached, it is determined that the inside of the hot water storage tank 32 is almost filled with hot water storage at the hot water storage set temperature (87 ° C), and the hot water storage operation is stopped.

【0068】

Figure 5 shows the changes in the heat exchange outlet temperature (hot water storage temperature) Twout, heat exchange intermediate temperature (condensation temperature) Tc, bottom water temperature Twin, and super heat amount TSH from the start to the end of this hot water storage operation. After the start, the hot water storage set temperature (for example, 87 ° C) can be stored in the hot water storage tank 32 in a short time while the condensation temperature, that is, the heat exchange intermediate temperature Tc is maintained at about 60 ° C. Shown.

【0069】

FIG. 6 shows the refrigerant of the refrigeration cycle 41 during the defrosting operation of the heat pump water heater 21 configured in this way and the water circulation direction of the water circuit 31 with arrows.

【0070】

That is, during the hot water storage operation, the outdoor air heat exchanger 45 acts as a refrigerant evaporator and is installed outdoors. Therefore, depending on the condition of the outside air temperature Tout detected by the outdoor temperature sensor 45c, the outdoor air heat exchanger 45c may be used. Frost formation occurs and the heat exchange capacity is reduced. Therefore, the controller 49 switches from the hot water storage operation to the defrosting operation when it is determined by the reduction amount detection method that the defrosting start condition is satisfied. This decrease detection method is the outdoor heat exchange temperature (evaporation temperature) detected by the outdoor temperature sensor 45c when the operation time of the compressor 42 accumulated from the start of stable hot water storage or the end of the previous defrosting operation reaches a predetermined time. Detected value) Defrosting conditions are determined based on TE and its decrease TEO.

【0071】

That is, the amount of decrease in TEO is first detected, and there are the following two methods for detecting it.

【0072】

(1) First, after the hot water storage operation is started, the outdoor heat exchange temperature (evaporation temperature) TE is detected for 5 minutes from the time when the predetermined time (for example, 5 minutes) elapses after the above-mentioned operation start release condition is satisfied, and the TE is detected. The lowest value is TEO.

【0073】

(2) Alternatively, after the completion of defrosting, the minimum value of the evaporation temperature TE detected in 5 minutes from 10 minutes after the completion of defrosting to 15 minutes is defined as TEO.

【0074】

Table 8 below shows the defrosting execution conditions as zones A, B, and C based on these evaporation temperature detection values TE and TEO, and each of these zones A to C is the evaporation temperature detection value TE shown in FIG. It is calculated based on the elapsed time from the end of the previous defrosting operation.

【0075】

[Table 8]

<img file="JP2002243276A_D0012.tif" />【0076】

Therefore, for example, when the evaporation temperature detection value TE is -20 ° C or less, it belongs to Zone B in Table 8. Therefore, as shown in Table 8, the defrosting operation starts after, for example, 30 minutes have passed since the end of the previous defrosting operation. It will be operated for about 4 minutes.

【0077】

Then, when this defrosting start condition is satisfied, the controller 49 opens the defrosting bypass valve 48, and the high-temperature and high-pressure gaseous refrigerant discharged from the compressor 42 is sent to the water heat exchanger 43 and the flow control valve. 44 is bypassed and introduced directly into the air heat exchanger 45 through the defrost bypass path 47, where the air heat exchanger 45 is heated by the heat of condensation of the condensing liquid refrigerant, and the frost is heated and melted to defrost. It is designed to do. This defrosting operation is continued until it is determined by the controller 49 that the defrosting end condition described later is satisfied.

【0078】

In this defrosting completion detection means, the detection temperature of the suction side temperature of the compressor 42 detected by the suction temperature sensor 42a continues for 80 seconds at, for example, 2.5 ° C or higher, or the detection temperature becomes 5 ° C or higher. Alternatively, if the defrosting operation continues for 10 minutes or more, it is judged that the defrosting operation has been completed, and after that judgment, the defrosting bypass valve 48 is closed again to defrost as shown in FIG. It is configured to return from operation to hot water storage operation again.

【0079】

FIG. 8 is a timing chart showing the control by the controller 49 during the defrosting operation of the heat pump water heater 21. That is, when the controller 49 determines that the above defrosting start condition is satisfied, the defrosting bypass valve 48, which has been fully closed so far, is opened as a frosting detection after a predetermined time (for example, 20 seconds) from the frosting detection. While the valve (ON) is turned on, the operation of the pump 34 and the outdoor fan 45a during operation is stopped (OFF), the operating frequency of the compressor 42 is operated at the predetermined defrosting operating frequency Hz, and the flow control valve 44 is opened. The degree is controlled to a predetermined defrosting opening degree to perform the above-mentioned constant control of the amount of super heat. If the operation of the compressor 42 is stopped due to some abnormality during this defrosting operation, the counting of the defrosting operation time is stopped.

【0080】

Then, this defrosting operation is performed when a predetermined time, for example, 10 minutes has passed after the start, or when the suction temperature detection value TS detected by the suction temperature sensor 42a establishes TS 5 ° C, or 5 When ° C TS 3 ° C continues for 80 seconds, it is judged that the defrosting end condition is satisfied, and the defrosting operation is terminated.

【0081】

As shown in FIG. 8, the defrosting operation is terminated by closing the defrosting bypass valve 48 and restarting the operations of the pump 34 and the outdoor fan 45a, and after the defrosting operation is completed, the hot water storage operation is resumed. At this time, the outdoor fan 45a is operated at a constant rotation speed (rpm) from the start of the hot water storage operation, but the pump 34 and the compressor 42 increase the operating frequency by a predetermined frequency every predetermined time (for example, 1 minute elapses). Let me. The initial target operating frequency of the compressor 42 after the end of the defrosting operation is a value obtained by multiplying the frequency before the start of the defrosting operation by a predetermined coefficient (for example, 0.9). Since the hot water storage operation is restarted by setting the target frequency high in this way, the hot water stored at the hot water storage set temperature (for example, 87 ° C.) can be stored in the hot water storage tank 32 in a short time.

【0082】

Next, the operation of the heat pump water heater 21 configured in this way will be described.

【0083】

First, as shown in FIG. 1, when the refrigeration cycle 41 side is operated to store hot water, the high-temperature and high-pressure gaseous refrigerant compressed by the compressor 42 passes through the primary side heat exchange pipe 43a of the water heat exchanger 43 to condense and liquefy. The heat is dissipated, and the heat of condensation (heat dissipation) heats the water passing through the secondary heat exchange tube 44b of the water heat exchanger 44.

【0084】

On the other hand, the liquid refrigerant condensed and liquefied by the water heat exchanger 43 is depressurized when passing through the flow control valve 44 having a predetermined opening, and the flow rate of the refrigerant is appropriately controlled to the flow rate and flows into the air heat exchanger 45. , Here it evaporates, absorbs heat from the outside air, returns to the compressor 42 in the state of a gaseous refrigerant, is returned from the suction side, is compressed again by the compressor 42, flows into the water heat exchanger 43, and is condensed. It is liquefied and the heat of condensation heats the water flow of the secondary side heat exchange pipe 43b, and by repeating this, the water flow of the secondary side heat exchange pipe 43b of the water heat exchanger 43 is gradually heated to high temperature water. ..

【0085】

The hot water (hot water) heated by the water heat exchanger 43 exits from the water outlet, is supplied into the hot water supply tank 32, and is supplied and stored from the water inlet / outlet 32a above the water outlet 32a.

【0086】

Further, the hot water stored in the hot water supply tank 32 is sucked into the pump 34 having a variable flow rate from the water outlet 32b at the bottom, and after being boosted here, again in the secondary heat exchange pipe 43b of the water heat exchanger 43. When water is passed, it is heated again by the heat of condensation of the high-temperature and high-pressure gaseous refrigerant that passes through the primary side heat exchange pipe 43a to further raise the hot water temperature and enter the hot water supply tank 32, and the hot water above it. It is supplied from the doorway 32a. Hereinafter, when the hot water storage temperature in the hot water storage tank 32 is gradually raised to the target temperature by repeating this, the hot water storage operation is stopped to prepare for the hot water supply operation. Then, during the hot water supply operation, the hot water supply in the hot water supply tank 33 is supplied to the hot water supply section via the hot water supply pipe 35.

【0087】

During such hot water storage operation, the air heat exchanger 45 is installed outdoors and acts as an evaporator (cooler), so that frost may occur on the air heat exchanger 45. At this time, if it is determined that the defrosting start condition is satisfied by the controller 49, the defrosting bypass valve 48 is opened by the controller 49 to switch from the hot water storage operation to the defrosting operation.

【0088】

Then, the high-temperature and high-pressure gaseous refrigerant from the compressor 42 bypasses the water heat exchanger 43 and directly flows into the air heat exchanger 45 to condense and dissipate heat. It can be defrosted by heating the frost formation and melting the frost here.

【0089】

Further, the refrigerant condensed by the air heat exchanger 45 is returned to the compressor 42 from the suction side thereof, and the frost formation of the air heat exchanger 45 is defrosted by repeating this. At this time, if the controller 49 determines that the above defrosting end condition is satisfied, the controller 49 closes the defrosting bypass valve 48 to end the defrosting operation, and returns the refrigeration cycle 41 to the hot water storage operation again.

【0090】

By returning to the hot water storage operation, the above hot water storage operation is repeated again, and when the temperature of the hot water stored in the hot water storage tank 32 reaches a predetermined value, a predetermined setting is made by the bottom water temperature sensor 37 that detects the inlet water temperature of the water heat exchanger 43. Since the temperature (for example, 30 ° C) Twin is detected, it is judged that the hot water stored in the hot water storage tank 33 has reached the predetermined set temperature (for example, 87 ° C), and the compressor 42, the pump 34, and the outdoor fan 45a are operated. To end the hot water storage operation and wait for the hot water supply operation.

【0091】

[Effect of the invention]

As described above, the present invention measures the start time of the midnight time zone in which the electricity charge preset by the hot water storage tank controller is cheaper or by performing the necessary operation for starting the hot water storage operation with the remote controller. When a hot water storage operation start command signal is given to the controller from these remote controllers or the hot water storage tank controller, the hot water storage operation in which the temperature has been raised to a predetermined boiling temperature can be started.

【0092】

In addition, the compressor, pump, and outdoor fan all have variable capacities, and the opening of the flow control valve can be controlled freely. When the hot water storage operation of the heat pump water heater starts, the hot water storage temperature is stabilized by continuing the hot water storage operation. When it is stable, the control is optimized by controlling it with the capacity suitable for each operating condition, so the temperature of the hot water stored in the hot water storage tank can be boiled up to the target temperature only by this hot water storage operation. The hot water storage operation efficiency can be improved.

【0093】

Further, the hot water storage operation can be automatically stopped by the hot water storage operation stop signal from the hot water storage tank controller or the remote controller, or when the detection value of the water temperature sensor in the hot water storage tank detects a predetermined hot water storage temperature.

【0094】

Furthermore, by opening the on-off valve of the bypass path with a controller, the high-temperature and high-pressure gaseous refrigerant from the compressor is bypassed by the water heat exchanger and directly introduced into the outdoor air heat exchanger for heating and removal. Since it frosts, the defrosting can be performed in a short time (quick defrosting). Further, since this defrosting operation is not defrosting by so-called reverse defrosting in the refrigeration cycle, the water heat exchanger does not act as an evaporator (cooler) to cool the hot water storage unlike the reverse defrosting. Therefore, the temperature of the hot water can be raised quickly and with high efficiency.

【0095】

Furthermore, when returning from the hot water storage operation to the hot water storage operation, the compressor is operated at a frequency that is a multiplier of the operating frequency before the start of the defrosting operation, so that the temperature of the hot water storage is raised. It can be done quickly.

[Simple explanation of drawings]

[Figure 1]

The block diagram which shows the state at the time of the hot water storage operation of the heat pump water heater which concerns on one Embodiment of this invention.

[Figure 2]

A timing chart showing a control method during hot water storage operation of the heat pump water heater shown in FIG.

[Fig. 3]

The figure which shows the relationship between the deviation E and the change amount ΔE between the heat exchange outlet water temperature and the set temperature for each control time (60 seconds) required by the controller of the heat pump water heater shown in FIG.

[Fig. 4]

The schematic diagram which shows the state which controls the hot water storage temperature target value Tsc according to the change of the water temperature detection value Twin detected by the bottom water temperature sensor shown in FIG.

[Fig. 5]

The graph which shows each change of the heat exchange outlet temperature Twout, the heat exchange intermediate (condensation) temperature Tc, the hot water storage tank bottom water temperature Twin, and the super heat amount TSH from the start to the stop of the hot water storage operation of the heat pump water heater shown in FIG.

[Fig. 6]

The block diagram which shows the state at the time of the defrosting operation of the heat pump water heater shown in FIG.

[Fig. 7]

A timing chart showing each of the multiple defrosting operation zones of the heat pump water heater shown in Fig. 1.

[Fig. 8]

A timing chart showing a control method during defrosting operation of the heat pump water heater shown in Fig. 1.

[Fig. 9]

The block diagram which shows the structure of the conventional heat pump water heater.

[Fig. 10]

A graph showing changes in the water temperature in the hot water storage tank and the condensation temperature of the conventional heat pump water heater shown in Fig. 9 in comparison.

[Explanation of symbols]

21 heat pump water heater 31 water circuit 32 Hot water storage tank 32a water entrance 32b water outlet 32c water receiving port 33,33a, 33b Water piping 34 pump 35 hot water supply pipe 36 Water supply pipe 37 Bottom water temperature sensor 38 Hot water tank 38a Hot water tank casing 41 Refrigeration cycle 42 compressor 42a Suction temperature sensor 43 Water heat exchanger 43c Condensation temperature sensor 44 Flow control valve 45 Air heat exchanger 45a outdoor fan 45b Evaporation temperature sensor 46 Refrigerant piping 47 Defrost Bypass Road 48 Defrost Bypass Valve 49 controller 50 remote controller 51 Heat source machine 51a Heat source casing