JP2014173808A - Hot water supply apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a low-cost hot water supply apparatus capable of utilizing the existing hot water tank by avoiding a risk of running out of hot water without attaching a temperature detector and the like to the hot water tank.SOLUTION: A hot water supply apparatus is operated in such a manner that: water temperature is detected by a thermostat 21, the water flowing into a heat pump unit 2A which heats up water flowing therein from a hot water tank and returns the water to the hot water tank; operation of the heat pump unit 2A is stopped when the water is heated up to a predetermined temperature or more; and the heat pump unit 2A is turned on after a predetermined time has passed (for example, 6 hours) after stopping the operation of the heat pump unit 2A. By setting an operation interval of the heat pump unit 2A appropriately, a risk of running out of hot water can be avoided without attaching a temperature detector and the like to the hot water tank.

Description

  The present invention relates to a hot water supply apparatus using a heat pump, and more particularly, to a hot water supply apparatus that controls the operation interval of the heat pump to avoid the risk of hot water shortage.

  Recently, the use of hot water supply devices using heat pumps is expanding from the viewpoint of energy saving. This type of hot water supply device is a hot water storage tank, a water supply pipe that supplies low temperature water to the lower part of the hot water storage tank, connected to the hot water storage tank by piping, and heats the water from the lower part of the tank to form hot water (hot water). A heat pump unit including a heat pump device that returns to the top, a hot water supply pipe that supplies hot water stored in a hot water storage tank to the outside, and the like (see, for example, Patent Document 1). In this hot water supply device, when hot water in the hot water storage tank is used, low temperature water is supplied to the lower part of the tank according to the amount used, and the hot water storage tank has a high temperature water layer (hot water layer) and a low temperature water layer (water). Layer) and a mixed layer at the boundary between the two layers (a layer of lukewarm water in which hot water and water are mixed), the amount of low-temperature water increases as hot water is used, and the mixed layer moves to the top of the tank. Therefore, a temperature detector that also functions as a residual hot water detector is placed at the appropriate location in the hot water storage tank, and when the temperature detector detects a temperature lower than the predetermined hot water temperature, it is determined that the remaining amount of hot water is low, and the heat pump unit is installed. It operates to heat the water in the lower part of the hot water tank and return it to the upper part of the hot water tank to prevent the hot water from running out (hot water running out).

JP 2008-116131 A

  However, in the conventional control method in which the amount of hot water in the hot water storage tank is detected by a temperature detector or the like and the operation of the heat pump unit is controlled according to the detected state, this type of hot water supply device is used by using an existing tank. When constructing, it is necessary to attach a temperature detector etc. to the tank side. As a heat pump unit operation control system that does not require the temperature detector to be mounted on the tank side, for example, a timer system that operates the heat pump unit at a predetermined operation start time using a timer is conceivable. However, in this control method, when the amount of hot water used increases, hot water may run out before the operation start time of the heat pump unit.

  The present invention has been made paying attention to the above problems, and an object of the present invention is to provide a hot water supply apparatus that can avoid the risk of running out of hot water without attaching a temperature detector or the like to the hot water storage tank.

  For this reason, the hot water supply device of the present invention includes a hot water storage tank that stores high-temperature water supplied to the outside, a heat pump device that heats water that enters from the hot water storage tank and returns the water to the hot water storage tank, and a water temperature that enters the heat pump device. And a control means for controlling the heat pump device to stop when a detected water temperature of the temperature detecting device becomes equal to or higher than a predetermined water temperature, and to control the operation of the heat pump device after a predetermined time has elapsed since the heat pump device stopped. And.

  According to the hot water supply device of the present invention, when the water temperature in the hot water storage tank becomes equal to or higher than the predetermined water temperature, the heat pump device is operated and controlled after a predetermined time has elapsed since the heat pump device is stopped, so that the hot water storage tank is always hot water ( Since the heat pump device is stopped when it is full with hot water), set the specified time (operation interval) after the stop so that the heat pump device operates before the hot water (hot water) in the hot water storage tank runs out. By doing so, the risk of running out of hot water can be avoided without detecting the amount of hot water in the hot water storage tank. Therefore, the risk of running out of hot water can be avoided without attaching a temperature detector to the hot water storage tank, and it is possible to construct a hot water supply device using an existing hot water storage tank without installing a new hot water storage tank. Equipment can be provided.

1 is a schematic configuration diagram of a first embodiment of the present invention. It is a block diagram of the heat pump unit of 1st Embodiment same as the above. It is a time chart which shows the example of the driving | running | working interval control of 1st Embodiment same as the above. It is a block diagram of the heat pump unit of 2nd Embodiment of this invention. It is a time chart in the case of showing the driving interval control example by the time interval learning of 2nd Embodiment same as the above, and changing a driving interval short. It is a time chart when the driving interval control example by the time interval learning of 2nd Embodiment same as the above is shown, and a driving interval is changed long. It is a time chart in the case of showing the example of driving interval control by the time zone learning of 3rd Embodiment of this invention, and changing a driving interval short. It is a time chart in the case of showing the example of driving interval control by the time zone learning of 3rd Embodiment of this invention, and changing a driving interval short.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
Drawing 1 is a schematic structure figure of a 1st embodiment of a hot-water supply device of the present invention, and shows an example for apartment houses which can supply hot water to a plurality of dwelling units.
In FIG. 1, the hot water supply apparatus of the present embodiment includes a hot water storage tank 1, a heat pump unit 2, an electric heater 3, and a heater control unit 4.

  The hot water storage tank 1 stores high temperature water (for example, 65 ° C. hot water) heated by a heat pump device 2A (shown in FIG. 2) of the heat pump unit 2, and low temperature water (city water, etc.) is stored in the hot water storage tank 1. A water supply pipe 5 to be supplied to the lower part and a connection pipe 6 for introducing low-temperature water at the lower part of the hot water storage tank 1 into the water inlet part of the heat pump device 2A are connected to substantially the same height position near the bottom of the hot water storage tank 1. The hot water storage tank 1 includes a connection pipe 7 for returning the high temperature water (hot water) heated from the water outlet of the heat pump device 2A to the upper part of the hot water storage tank 1, and a hot water supply pipe for supplying the hot water in the hot water storage tank 1 to each household. 8 are connected to substantially the same height near the top of the hot water storage tank 1.

  The hot water supply pipe 8 is provided with a return pipe 8a for returning the water in the hot water supply pipe 8 to the upper part of the hot water storage tank 1 and a branch pipe 8b for supplying high temperature water in the hot water supply pipe 8 to each household. . The return pipe 8a is provided with a circulation pump 9 for circulating high-temperature water in the hot water storage tank 1 through the hot water supply pipe 8 and the return pipe 8a. Each branch pipe 8b is provided with a hot water supply valve 10 respectively. In FIG. 1, reference numeral 11 denotes a power supply line that supplies driving power for the heat pump unit 2 and the heater control unit 4.

As shown in FIG. 2, the heat pump unit 2 heats the low-temperature water entering from the hot water storage tank 1 through the connection pipe 6 and returns the high-temperature water (hot water) to the upper part of the hot water storage tank 1 through the connection pipe 7. A device 2A and a control device 2B as control means for controlling the driving of the heat pump device 2A are provided. In the heat pump device 2A, a compressor, a condenser (heat exchanger), an expansion valve, and an evaporator (heat exchanger) are interposed in a circulation path of a refrigerant (for example, CO ₂ ), and the heat of the air is obtained by the evaporator. The low temperature water taken in through the connecting pipe 6 from the lower part of the hot water storage tank 1 is heated by the condenser, and the hot water is returned to the upper part of the hot water tank 1 through the connecting pipe 7. The control device 2B controls the heat pump device 2A to stop when the temperature of the water entering the heat pump device 2A becomes equal to or higher than a predetermined water temperature, and controls the operation of the heat pump device 2A after a predetermined time has elapsed since the heat pump device 2A stopped. And a thermostat 21 which is a temperature detecting means, an operation unit 22, an OFF timer 23, and a control unit 24.

  The thermostat 21 detects the temperature of water entering the heat pump device 2A from the lower part of the hot water storage tank 1 through the connection pipe 6, and detects, for example, that the detected water temperature is equal to or higher than a predetermined water temperature (for example, 50 ° C.). Then it turns from on to off. In the present embodiment, the configuration in which the thermostat 21 is incorporated into the heat pump unit 2 as a part of the heat pump unit 2 is shown. However, the configuration in which the thermostat 21 is arranged outside the heat pump unit 2 and detects the water temperature in the connection pipe 6. But you can.

  The operation unit 22 sets the predetermined time (operation interval) from the operation stop of the heat pump device 2A by the control unit 24 to the operation start (operation).

  The OFF timer 23 measures the time from when the heat pump device 2 </ b> A stops operation until it starts operation.

  The control unit 24 controls the heat pump device 2A to stop when the detected water temperature of the thermostat 21 becomes equal to or higher than the predetermined water temperature, and operates the heat pump device 2A when the time of the OFF timer 23 reaches the predetermined time set by the operation unit 22. Control.

  The electric heater 3 is used as an auxiliary heat source when the heat capacity of the heat pump device 2A is insufficient, and is disposed in the vicinity of the water supply pipe 5 connected to the lower part of the hot water storage tank 1, and the heater controller 4 defines the heat pump device 2A. Independent drive control. If the electric heater 3 is arranged at the lower part of the hot water storage tank 1, a lot of hot water can be generated in the hot water storage tank 1 when the electric heater 3 is driven.

Next, operation | movement of the hot water supply apparatus of this embodiment is demonstrated.
When a power switch (not shown) is turned on and power is supplied to the heat pump unit 2 via the power line 11, the control device 2B operates the heat pump device 2A. By the operation of the heat pump device 2A, the low temperature water that has entered the heat pump device 2A from the lower part of the hot water storage tank 1 via the connection pipe 6 is heated, and the high temperature water is returned to the upper part of the hot water storage tank 1 via the connection pipe 7. And when the temperature of the water which enters into the heat pump device 2A from the connection pipe 6 becomes equal to or higher than the predetermined water temperature, the thermostat 21 is turned off from on. When the control unit 24 determines that the thermostat 21 has been turned off from on, the control unit 24 determines that the hot water storage tank 1 is fully filled with high-temperature water and has completed upwelling, and controls the heat pump device 2A to stop. At the same time, the OFF timer 23 is operated to start measuring the elapsed time after the heat pump device 2A is stopped.

  A predetermined time (for example, 6 hours) from the stoppage of operation of the heat pump device 2A to the start of operation is appropriately set in advance so that hot water does not run out in the operation unit 22, and the control unit 24 controls the predetermined time and the OFF timer 23. To determine whether or not the timing of the OFF timer 23 has reached a predetermined time. When the time measured by the OFF timer 23 reaches a predetermined time, the control unit 24 controls the operation of the heat pump device 2A and starts supplying hot water to the hot water storage tank 1 by the heat pump device 2A. Therefore, as shown in FIG. 3, the heat pump device 2 </ b> A repeatedly operates at an operation interval (6 hours in FIG. 3) preset by the operation unit 22.

  According to the hot water supply apparatus of this embodiment, the heat pump apparatus 2A is operated after a predetermined time has elapsed since the heat pump apparatus 2A stopped (that is, from the state where the hot water storage tank 1 is filled with high-temperature water). Since the operation interval is appropriately set so that the heat pump device 2A operates before the hot water in the hot water storage tank 1 runs out, the hot water storage tank 1 is not provided with a temperature detector or the like to monitor the remaining hot water amount. In both cases, the risk of running out of hot water can be avoided. For this reason, the risk of running out of hot water can be avoided without newly installing a temperature sensor or the like in the existing hot water storage tank, and a low-cost hot water supply system using an existing hot water storage tank can be shortened without installing a new hot water storage tank. Can be provided in a period.

  In addition, since the operation interval from when the heat pump device 2A is stopped to when the heat pump device 2A is operated can be arbitrarily changed within a range of 1 hour to 23 hours by the operation unit 22, for example, the amount of hot water used in the winter increases. In some cases, the operation interval is set short to avoid the risk of running out of hot water. When the amount of hot water used decreases during the summer, the operation interval of the heat pump device 2A is set so that the hot operation does not occur and the operation interval is set long. By reducing the frequency, power consumption can be reduced while avoiding the risk of running out of hot water.

  Further, since the hot water in the hot water storage tank 1 is circulated back to the hot water storage tank 1 through the hot water supply pipe 8 and the return pipe 8 by the circulation pump 9, hot water always flows in the hot water supply pipe 8. Therefore, when the hot water supply valve 10 is opened, high temperature water can be supplied immediately.

Next, 2nd Embodiment of the hot water supply apparatus of this invention is described.
The hot water supply device of the second embodiment is configured to variably control a predetermined time (operation interval) from when the heat pump device 2A is stopped to when it is operated based on the heat pump device operation time from the operation of the heat pump device 2A to the stop. .

  As shown in FIG. 4, the hot water supply apparatus of the present embodiment is different from the first embodiment in that an ON timer 25 and a storage unit 26 are added to the control device 2 </ b> B of the heat pump unit 2. Other configurations are the same as those in the first embodiment.

  The ON timer 25 measures the time from the start of operation of the heat pump device 2A to the stop of operation. The said memory | storage part 26 memorize | stores the operation time of 2 A of heat pump apparatuses timed by the ON timer 25. FIG. The control unit 24 variably controls a predetermined time (operation interval) from the stop of the heat pump device 2 </ b> A to the operation based on the history data of the heat pump device operation time stored in the storage unit 26.

  In the hot water supply apparatus of the present embodiment, the control unit 24 controls the operation of the heat pump device 2A at the predetermined time set by the operation unit 22 when the timing of the OFF timer 23 is set, and simultaneously operates the ON timer 25 to operate the heat pump device 2A. Start timing time. Thereafter, when the detected water temperature of the thermostat 21 becomes equal to or higher than the predetermined water temperature by the heating operation of the heat pump device 2A and the thermostat 21 is turned off from on, it is determined that the hot water storage tank 1 is filled with high-temperature water and the heat pump device 2A is The stop control is performed, and at the same time, the OFF timer 23 is operated to start measuring the elapsed time after the heat pump device 2A stops. Further, the control unit 24 causes the storage unit 26 to store the time measured by the ON timer 25 (heat pump device operation time) when the heat pump device 2A is stopped. Then, based on the history data of the heat pump device operation time stored in the storage unit 26, the operation interval of the heat pump device 2A is automatically set. As described above, the hot water supply apparatus of the present embodiment learns and automatically adjusts the operation interval at which hot water does not run out based on the stored history data of the heat pump apparatus operation time.

An example of automatic adjustment of the operation interval by the hot water supply apparatus of the present embodiment will be described with reference to the time charts of FIGS.
In the example of FIGS. 5 and 6, the operation interval from the stop of the heat pump device 2 </ b> A to the start of operation of the current heat pump device 2 </ b> A is automatically adjusted based on the previous (latest) heat pump device operation time stored in the storage unit 26. This is an example.

  FIG. 5 shows that when the previous (latest) heat pump device operation time stored in the storage unit 26 is longer than the normal operation time (for example, 3 hours), it is determined that the amount of hot water used is large, and the operation interval of the heat pump device 2A This is an example in which the operation interval is changed to be shorter (for example, 4 hours) than the operation interval (for example, 6 hours) set by the operation unit 22. In this case, as shown in FIG. 5A, the operation interval from the previous operation of the heat pump device 2A to the start of operation of the current heat pump device 2A is changed from 6 hours to 4 hours. As shown in the figure (B), there are cases where the operation interval of the heat pump device 2A not only this time but also later is changed to 4 hours, and both can be arbitrarily selected.

  6 shows that when the previous (latest) heat pump device operation time stored in the storage unit 26 is shorter than the normal operation time (for example, 3 hours), it is determined that the amount of hot water used is small, and the operation interval of the heat pump device 2A. Is longer than the operation interval (for example, 6 hours) set by the operation unit 22. In this case, as shown in FIG. 5A, when only the operation interval from the previous operation of the heat pump device 2A to the start of operation of the current heat pump device 2A is changed long, as shown in FIG. In addition to this time, there is a case where the operation interval of the heat pump device 2A thereafter is changed long, and both can be arbitrarily selected.

  The determination of whether the operation time is longer or shorter than the normal operation time may be performed in units of time, for example. Further, the adjustment of the operation interval may be performed by adjusting the operation interval shorter (or longer) by 1 hour if the operation time is longer (or shorter) by 1 hour than usual according to the length of the operation time. However, the adjustment interval of the operation interval may be set in advance regardless of the length of the operation time.

  The automatic adjustment control of the operation interval by the hot water supply apparatus of the present embodiment is not limited to the adjustment performed only by the previous operation time history as shown in FIGS. 5 and 6, but based on a plurality of operation time histories up to the previous time. Automatic adjustment control may be performed. For example, when the heat pump device operation time is longer (or shorter) than the normal operation time for a set number of times or more, it is determined that the hot water usage frequency is high (or low), and the interval until the current heat pump device operation is You may make it change shorter (or longer) than a normal driving | operation space | interval. Further, it may be determined that the hot water usage frequency is high (or low) based on the tendency of the operation time history of a predetermined number of times (for example, average operation time), and the operation interval may be changed short (or long). In such a case, for example, the number of operations and the number of operation days are determined and stored in the storage unit 26 as history information of the heat pump device operation time. The history information of the heat pump device operation time stored in the storage unit 26 may be sequentially updated every time the heat pump device operation time is measured.

  According to such a hot water supply apparatus, since the operation interval that does not cause hot water shortage is learned and automatically adjusted based on the past heat pump device operation time history, the risk of hot water shortage can be avoided and power consumption can be reduced. .

Next, a third embodiment of the hot water supply apparatus of the present invention will be described.
The hot water supply device of the third embodiment is configured to variably control the operation interval of the heat pump device 2A based on a heat pump device operation time history for each preset time zone. In addition, the structure of the hot water supply apparatus of this embodiment is the same as 2nd Embodiment, and only the variable control form of an operation interval differs.

  In the hot water supply apparatus of the present embodiment, for example, one day (24 hours) is set to 0 to 6 o'clock (midnight), 6 o'clock to 12 o'clock (morning), 12 o'clock to 18 o'clock (daytime), and 18 o'clock to 24 o'clock (night). ) Divided into four time zones. This is set by the operation unit 22, and the heat pump device operation time history for each time zone is stored in the storage unit 26. The control unit 24 variably controls the operation interval of the heat pump device 2 </ b> A for each time zone based on the history of the heat pump device operation time for each time zone stored in the storage unit 26.

An example of the automatic adjustment of the operation interval by the hot water supply apparatus of the present embodiment will be described with reference to the time charts of FIGS.
7 and 8 are examples of automatically adjusting the driving interval of the next day based on the driving time history of each time zone of the previous day, and FIG. 7 is an example of automatically adjusting the driving interval to be short. Is an example of automatically adjusting the operation interval longer.

  In FIG. 7, the operation time (heat pump device operation time from 9 o'clock in FIG. 7) in the time zone from 6 o'clock to 12 o'clock (morning) of the previous day stored in the storage unit 26 is from the normal operation time (for example, 3 hours). If it is long (for example, 5 hours), it is determined that the amount of hot water used in that time zone is large, and the operation interval immediately before the heat pump device operation in the time zone from 6:00 to 12:00 (morning) on the next day is normal (for example, 6 hours) Change to a shorter driving interval (eg 4 hours).

  In FIG. 8, the operation time in the time zone from 6:00 to 12:00 (morning) of the previous day stored in the storage unit 26 (the heat pump device operation time from 9:00 in FIG. 8) is more than the normal operation time (for example, 3 hours). If it is short (for example, 1 hour), it is determined that the amount of hot water used in that time period is small, and the operation interval immediately before the heat pump device operation in the time period from 6:00 to 12:00 (morning) on the next day is normal (for example, 6 hours) Change to a longer operating interval (eg, 8 hours).

  7 and 8 show an example in which the operation interval learning control based on the previous heat pump device operation time described in FIGS. 5A and 6A of the second embodiment is used together. .

  The hot water supply apparatus of the present invention is configured to be able to connect a signal line 30 of power supply information transmitted from the outside, such as an electric power company, as shown by a broken line in FIG. It is good also as a structure which connects the signal wire | line 30 and uses together the action | operation and stop control of 2 A of heat pump apparatuses based on the said electric power supply information. Here, the power supply information means, for example, that the power rate is set higher than usual when the power demand is high, and cheaper than normal when the power demand is low, or the power supply is stopped when the power demand is high. In other words, it means a contract that lowers the power charge on condition that it starts when power demand is low, and means control information such as the change of the power charge and the timing of stopping / starting power supply.

  As an example of using both the operation and stop control of the heat pump device 2A based on the power supply information, for example, before the predetermined time elapses after the operation of the heat pump device 2A is stopped until the next heat pump device operation starts. When the information indicating the cheaper charge or the start of power supply is input from the signal line 30 of the power supply, the heat pump device 2A is operated by the input of the power supply information regardless of the lapse of the predetermined time, and the heat pump is operated at the lower power charge than usual. Activate the device 2A. Thereby, a power charge can be reduced. In addition, for example, when the operation of the heat pump device 2A is stopped when the operation of the heat pump device 2A is stopped by inputting information indicating a higher charge or power supply stoppage than usual from the signal line 30 of the power supply information during the operation of the heat pump device 2A, It is determined that the amount of high-temperature water is small, and the predetermined time until the start of operation of the next heat pump device 2A is changed to be shorter than the normal set time in order to avoid the risk of running out of hot water. In addition, the control pattern at the time of using together the action | operation and stop control of 2 A of heat pump apparatuses based on electric power supply information is not restricted to these examples.

DESCRIPTION OF SYMBOLS 1 Hot water storage tank 2 Heat pump unit 2A Heat pump apparatus 2B Control apparatus 21 Thermostat 22 Operation part 23 OFF timer 24 Control part 25 ON timer 26 Storage part 30 Signal line

Claims (7)

A hot water storage tank for storing hot water to be supplied to the outside,
A heat pump device that heats water entering from the hot water storage tank and returns the water to the hot water storage tank;
Temperature detecting means for detecting the temperature of water entering the heat pump device;
Control means for controlling the stop of the heat pump device when the detected water temperature of the temperature detecting means is equal to or higher than a predetermined water temperature, and controlling the operation of the heat pump device after a predetermined time has elapsed since the stop of the heat pump device;
A hot water supply apparatus comprising:   The hot water supply apparatus according to claim 1, wherein the control unit is configured to be able to vary the predetermined time.   The hot water supply apparatus according to claim 2, wherein the control unit varies the predetermined time based on a heat pump apparatus operation time from an operation to a stop of the heat pump apparatus.   The hot water supply apparatus according to claim 3, wherein the control means stores the heat pump device operation time and varies the predetermined time based on the stored heat pump device operation time history.   The said control means memorize | stores the heat pump apparatus operating time for every preset time slot | zone, The said predetermined time is varied for every time slot | zone based on the memorize | stored heat pump apparatus operating time log | history for every said time slot | zone. 4. A hot water supply apparatus according to 4.   The hot water supply apparatus according to any one of claims 1 to 5, wherein the control means is configured to be able to control the operation and stop of the heat pump apparatus based on external power supply information.   The hot water supply apparatus according to any one of claims 1 to 6, further comprising a return pipe for returning water in the hot water supply pipe for supplying high-temperature water in the hot water storage tank to the outside to the hot water storage tank.