JP5210906B2 - Water heater - Google Patents

Description

  The present invention relates to a hot water supply apparatus that includes a plurality of heat pump units and has a relatively large-scale hot water supply capability.

  A commercial hot water supply system that has a relatively large-scale hot water storage function and bath warming and warming function has a separate hot water heater (boiler) for shower hot water and a heat source machine (boiler) for warming and warming the bathtub. Most of them are installed. However, when such different hot water supply devices are set, there is a problem that the installation cost increases and the installation space becomes wide.

  Therefore, as a hot water supply apparatus that supplies a relatively large amount of hot water in a hospital, a welfare facility for the elderly, a hotel, or the like, for example, as disclosed in [Patent Document 1], a heat pump type hot water supply apparatus (hot water supply system) that supplies hot water using a heat pump. )It has been known.

  This hot water supply device includes a plurality of heat pump units, a sealed tank, and an open tank, and performs hot water storage operation by switching the number of operating heat pump units as required according to the amount of hot water, mainly during midnight power hours. . Then, a hot water supply circulation path connected to the hot water tap is formed, the hot water staying in this circulation path is kept at a predetermined temperature or higher, and hot water at a desired temperature is always obtained.

JP 2007-205698 A

  By the way, in the hot water supply apparatus described above, a plurality of temperature sensors are provided at predetermined intervals along the depth direction inside the sealed tank. The control means (system controller) that receives the detection signals from these temperature sensors controls the opening degree of the flow rate adjusting valve provided in the hot water supply pipe line that connects the sealed tank and the open tank.

By throttling the flow rate adjustment valve, the amount of hot water supplied from the sealed tank to the open tank is reduced, the amount of hot water stored in the sealed tank is increased, and the amount of cold water stored is reduced. If the flow regulating valve is opened, the phenomenon is reversed. In any case, the boundary layer between hot water and cold water in the sealed tank is always set to be located at the center in the depth direction of the sealed tank.
That is, high temperature hot water is always stored in about half of the sealed tank so that the high temperature hot water produced by the heat pump unit can be supplied to a stable hot water discharge open type tank.

  However, when the supply of hot water from the closed tank to the open tank is stopped, high-temperature hot water is radiated from the upper half of the closed tank, which increases the amount of heat that is wasted. The result is that energy is consumed.

  The present invention has been made in consideration of the above-mentioned circumstances, and the object of the present invention is to cope with large-capacity hot water supply and to suppress the heat radiation amount in the closed tank, and to be excellent in energy saving. It is intended to provide a hot water supply device.

  In order to solve the above problems and achieve the object, the hot water supply apparatus of the present invention generates cold water having a predetermined temperature by heating cold water supplied in a plurality of heat pump units, and is generated in a sealed tank by the heat pump unit. Hot water is stored, hot water supplied from the closed tank is stored in an open tank connected to the closed tank via a hot water supply pipe, and released from the closed tank by a flow rate adjusting valve provided in the hot water supply pipe. Control means for controlling the supply amount of hot water led to the mold tank, arranging a plurality of temperature sensors at predetermined intervals along the depth direction inside the sealed mold tank, and receiving a detection signal of this temperature sensor, When starting up the heat pump unit or when the number of heat pump units operating varies, the boundary layer between the hot water and cold water inside the sealed tank is positioned near the center in the depth direction of the sealed tank. During operation so that the boundary layer is positioned at an upper portion of the sealed tank, to control the opening of flow control valve.

  According to the present invention, while maintaining the original purpose of supplying hot water at an appropriate temperature to an open tank, the amount of heat released from the sealed tank can be suppressed, and a water heater excellent in energy saving can be provided. .

The schematic block diagram of the hot-water supply apparatus based on one embodiment of this invention. The schematic block diagram of the heat source machine which comprises the hot-water supply apparatus based on the embodiment. The schematic block diagram of the sealed tank which comprises the hot-water supply apparatus based on the embodiment. The figure explaining the operation state of the hot-water supply apparatus based on the embodiment. The conceptual diagram at the time of normal operation of the heat-source equipment based on the embodiment, and the conceptual diagram at the time of defrost operation. The schematic block diagram of the sealed tank which comprises the hot-water supply apparatus based on the embodiment.

  FIG. 1 is a schematic configuration diagram of a hot water supply apparatus 1 according to an embodiment of the present invention, and FIG. 2 is a schematic configuration of a heat source machine (heat pump unit) 2 used in the hot water supply apparatus 1 and incorporating a heat pump type hot water supply apparatus. FIG.

  The hot water supply device 1 is connected to a plurality of heat source devices 2 that generate hot water, each of which is high-temperature water having a predetermined temperature, and in parallel with these heat source devices 2 via a hot water supply pipe 13. A sealed tank 3 for storing hot water to be supplied to 13 is provided.

  Further, the hot water supply device 1 is connected to the sealed tank 3 via the hot water supply pipe 4, and an open type tank 5 for accumulating and storing hot water supplied from the sealed type tank 3, and one end of the open type tank 5. Is connected, and a hot water supply line 7 for supplying hot water stored in the open tank 5 by a hot water supply pump 6 is provided.

  Furthermore, the hot water supply device 1 stays in the hot water supply circuit 8 connected to the hot water supply line 7, the hot water supply circuit 10 that connects the hot water supply valve 8 and the circulation pump 9, and the hot water supply circuit 10. A reheating device 11 that is a heat pump type hot water supply device for holding hot water at a predetermined temperature or higher is provided.

  The heat pump type hot water supply apparatus incorporated in the heat source unit 2 is operated at a three-phase 200V, and includes a compressor 2a, a water heat exchanger 2b, a decompression mechanism 2c, and a heat source side heat exchanger 2d. And these components communicate with each other via a refrigerant pipe.

  The water heat exchanger 2b is connected to a water supply line 12 whose inlet side is connected to the sealed tank 3 via a three-way valve 2e and a pump 2f, and a hot water supply line 13 whose outlet side is connected to the sealed tank 3. And via a three-way valve 2g.

  The three-way valves 2e and 2g are set to maintain the above-described communication state as normal switching postures, and are switched according to conditions. Further, the sealed tank 3 is connected to a water supply introduction path 14 extending from a water receiving tank 15 as a water source in order to supply cold water to the hot water supply device 1.

FIG. 3 is a schematic configuration diagram of the sealed tank 3.
The sealed tank 3 is provided with four pipe connection ports.
That is, the cold water supply port 3a for supplying cold water from the water receiving tank 15 shown in FIG. 1 with the pressure reducing valve 14a and the cold water supply port 3a for supplying cold water, and the closed tank 3 through the water supply line 12 are connected. A cold water supply port 3 b for supplying cold water to the heat source device 2 is provided.

  Furthermore, each heat source unit 2 communicates with the hot water supply pipe line 13, and a hot water supply port 3 c for supplying hot water generated in each heat source unit 2 to the sealed tank 3 and an open type from the sealed type tank 3. A hot water supply port 3 d that communicates with the tank 5 via the hot water supply pipe 4 and supplies hot water to the open tank 5.

  In addition, a plurality of, for example, five temperature sensors T 1, T 2, T 3, T 4, and T 5 are provided in the sealed tank 3 at predetermined intervals along the depth direction of the sealed tank 3. Here, the temperature sensor T1 is at the shallowest position (uppermost part), the temperature sensor T5 is at the deepest position (lowermost part), and the temperature sensor T3 is located at substantially the center of the sealed tank 3 in the depth direction.

  The detection signals of these temperature sensors T1 to T5 are sent to the system controller (control means) 16 shown in FIG. 1, and the system controller 16 uses hot water in the sealed tank 3 based on the detected temperature information of these temperature sensors T1 to T5. Calculate temperature and amount of hot water storage.

  The system controller 16 controls the flow rate adjustment valve 13 a according to the amount of hot water stored in the sealed tank 3 to adjust the amount of hot water supplied to the open type tank 5. Specific control of the amount of hot water stored in the sealed tank 3 will be described later.

  In addition, a large number of hot water taps 8 connected to a hot water supply line 7 for supplying hot water in the open tank 5 by the operation of the hot water supply pump 6 are arranged in units of one floor in a hot water supply device installation place such as a hotel or a hospital. Hot water faucets and hot water taps for bathtubs. These hot water taps 8 are attached to a hot water supply circulation path 10 that is piped in an annular shape.

  Although hot water is supplied from the open tank 5 to the hot water supply circuit 10, the hot water remains in the hot water supply circuit 10 when the hot water tap 8 is not used for a long time. For this reason, the temperature of the hot water decreases with time, and when it is used, there is a problem that hot water does not come out until high temperature hot water is supplied from the open tank 5.

  However, the hot water supply circulation path 10 includes a circulation pump 9 and a reheating device 11 using a heat pump hot water supply device. Although not shown, a temperature sensor near the hot water inlet of the reheating device 11 detects the hot water temperature in the hot water supply circuit 10 and sends a detection signal to the system controller 16.

  When the system controller 16 determines that the temperature detected by the temperature sensor is lower than the predetermined temperature, the system controller 16 controls the reheating device 11 to reheat the hot water. For this reason, the hot water supply circuit 10 is always in a state where the required hot water temperature is maintained, and hot water can be instantaneously supplied from the hot water tap 8.

  The system controller 16 is connected to control devices such as the heat source device 2, the tank unit 17, and the open tank 5 through a communication line. It is provided in the vicinity of the sealed tank 3 and includes an operation switch to control the entire hot water supply system. The sealed tank 3 and the system controller 16 are housed in a housing and constitute a tank unit 17.

  The heat pump hot water supply device incorporated in the reheating device 11 is a normal one similar to the hot water supply device of the heat source unit 2 and has a control means, all of which include a compressor, a water heat exchanger, a pressure reduction mechanism, and a heat source (not shown). A side heat exchanger is provided and communicated sequentially through the refrigerant pipe.

The hot water supply apparatus 1 configured as described above operates as described below. Here, the case where the tapping temperature is 65 ° C. will be described as an example.
As shown in FIG. 4, the system controller 16 issues an operation command to each heat source device 2. At this time, the flow rate adjustment valve 13a is in a closed state. Cold water is supplied from the water receiving tank 15 to the sealed tank 3 through the water supply introduction path 14, and further, cold water is guided from the sealed tank 3 to the water supply pipe 12.

  Here, in the normal operation state shown in FIG. 5, water is supplied from the water supply pipe 12 to the water heat exchanger 2b of each heat source device 2 through the three-way valve 2e and the pump 2f. In each heat source unit 2, heat pump operation is performed, and the cold water led to the water heat exchanger 2b absorbs the heat of condensation of the refrigerant led to the water heat exchanger 2b and is heated to become hot water. .

  The high temperature hot water led out from the water heat exchanger 2 b is led from the three-way valve 2 g to the hot water supply pipe 13 and supplied to the sealed tank 3. All the hot water heated by the respective heat source devices 2 is led to the sealed tank 3 and stored.

  In the closed tank 3, cold water is introduced from the lower end surface and supplied from the lower end surface. On the other hand, hot water heated to a predetermined temperature is supplied from the upper end surface. The sealed tank 3 is filled with cold water and hot water, and pressure (water pressure) is applied to each other and to the inner wall of the sealed tank 3. Cold water and hot water do not circulate in the closed tank 3 and therefore do not mix.

  There is a boundary layer in which cold water and hot water are in contact with each other at one location in the depth direction inside the sealed tank 3. While constant water pressure is always applied from the water receiving tank 15 through the water supply introduction path 14, the sealed tank 3 and the open tank 5 are communicated by the hot water supply pipe 4, and the flow rate is adjusted in the hot water supply pipe 4. A valve 13a is provided.

  Therefore, the hot water stored in the sealed tank 3 can be supplied to the open tank 5 by opening the flow rate adjusting valve 13a. And the boundary layer position of the cold water in the sealed tank 3 and a hot water is moved to an up-down direction by adjusting the opening amount of the flow regulating valve 13a at this time.

  In a state where the hot water supplied from the sealed tank 3 is filled in the open tank 5, the system controller 16 stores and calculates temperature detection signals sent from the temperature sensors T1 to T5 provided in the sealed tank 3.

  When the temperature detected by the temperature sensor T3 provided at the center in the depth direction of the sealed tank 3 is T3 ≧ 65 ° C., the flow rate adjustment valve 13a is opened to a certain degree of opening. The detected temperature of the temperature sensor T4 provided at a position one step lower (deeper) than the temperature sensor T3 moves the flow rate adjustment valve 13a in the closing direction when T4 ≧ 65 ° C.

  The detected temperature of the temperature sensor T2 provided at a position one step higher (shallow) than the temperature sensor T3 is moved in the direction of closing the flow rate adjustment valve 13a when T2 <65 ° C. When the detected temperature of the temperature sensor T5 provided at the lowest (deepest) position is T5 ≧ 65 ° C., the flow rate adjustment valve 13a is fully opened, and the detected temperature of the temperature sensor T1 provided at the uppermost (shallowest) position is The flow rate adjustment valve 13a is fully closed at T1 ≦ 65 ° C.

  By such an operation, basically, the opening degree of the flow rate adjusting valve 13a is adjusted so that 65 ° C. hot water is always present at the positions of the temperature sensors T2 to T4. All of the hot water boiled by each heat source device 2 can be supplied to the open tank 5, and the same amount of hot water as that supplied to the sealed tank 3 can be supplied to the open tank 5.

The hot water supplied to the open tank 5 is supplied from the hot water tap 8 via the hot water supply pump 6 and the hot water supply circulation path 10 in response to a hot water supply request for opening the hot water tap 8.
Then, until hot water is finished and the next hot water supply request is made, hot water stays in the hot water supply circulation path 10, and a temperature sensor (not shown) detects that the hot water has become lower than a predetermined temperature. Is sent to the system controller 16.

  The system controller 16 operates the reheating device 11 to heat the hot water remaining in the hot water supply circulation path 10 and keep it at a predetermined temperature or higher. Therefore, even if there is a long time until hot water supply is finished and the hot water tap 8 is opened next time, hot water having a predetermined temperature or higher is always supplied.

  As described above, the hot water boiled by the heat source device 2 is supplied to the sealed tank 3, and hot water is stored in the sealed tank 3. When hot water of a predetermined temperature or higher is stored in the sealed tank 3, the hot water is supplied to the open tank 5 and stored in the open tank 5.

  Therefore, even if the heat source device 2 is not of a large capacity, the system can be supported by connecting a plurality of units in parallel according to the capacity of the hot water supply device 1. For this reason, using the standardized heat source unit 2, a system with a wide capacity from a relatively small system corresponding to an apartment house to a large-scale hot water supply device for hotels, hospitals, factories, etc. It can be configured.

  Since the open tank 5 is provided, it can be easily installed on the rooftop of a building, has high safety, and can easily supply hot water to each floor. Since the heat source unit 2 constitutes a heat pump type hot water supply device, it is excellent in energy saving. The hot water supply device 1 is easy to install, can supply a large volume of hot water, and is excellent in energy saving.

  It is necessary to boil hot water with a plurality of heat source units 2 and supply the heated tank 5 in a stable state. Therefore, as described above, by adjusting the opening degree of the flow rate adjusting valve 13a based on the detected temperature information of the plurality of temperature sensors T1 to T5, the boundary layer position of the cold water and hot water in the sealed tank 3 is appropriately moved. .

  In other words, when the operation of the hot water supply device 1 is started, that is, when the heat source unit 2 that is a heat pump unit is started up and when the number of operating heat source units 2 varies, the system controller 16 determines the position of the boundary layer in the sealed tank 3. Of the flow rate adjustment valve 13a is controlled so as to be placed in the vicinity of the approximate center in the depth direction of the tank (approximately the mounting position of the temperature sensor T3).

  Further, when the operation as the hot water supply device 1 is in a stable state, the system controller 16 moves the boundary layer in the sealed tank 3 to the uppermost position (substantially attached position of the temperature sensor T1). The opening degree of 13a is controlled.

  That is, when the hot water supply device 1 is started up or when the number of operating heat source units 2 varies, the amount of hot water led to the open tank 5 varies greatly, and the movement of the flow rate adjustment valve 13a varies greatly. Resulting in.

  Even in such a case, the opening degree of the flow rate adjusting valve 13a is controlled so as to be approximately near the center in the depth direction of the sealed tank 3 so that cold water does not go to the open tank 5. Therefore, hot water can be stably supplied from the sealed tank 3 to the open tank 5 even at the time of startup or when the number of operating units varies.

  When hot water supply is continued in a stable state as the hot water supply device 1, the boundary layer is moved to the upper part in the depth direction in the sealed tank 3, so that most of the sealed tank 3 becomes a low temperature part, The heat loss from the sealed tank 3 can be reduced.

  In particular, when the outside air temperature is lowered, for example, in the severe winter season, frost adheres to the heat source side heat exchanger 2d that evaporates the refrigerant in the heat source unit 2 constituted by the heat pump unit, and if left as it is, the heat exchange efficiency is lowered. As a result, hot water at a predetermined temperature cannot be obtained. Therefore, in order to melt the frost adhering to the heat source side heat exchanger 2d, it is necessary to perform a defrosting operation in the heat source device 2.

  The defrosting operation is not necessarily performed after confirming that frost has adhered to the heat source side heat exchanger 2d, and frost has adhered to the heat source side heat exchanger 2d in advance with respect to the system controller 16. Easy conditions may be determined, and the defrosting operation may be started immediately after the information is obtained.

  For example, the information that the outside air temperature is equal to or lower than a predetermined temperature and the operation of the heat source unit 2 has been continued for a predetermined time or more in this state is confirmed in advance, and the defrosting operation is started when certain conditions are met. At this time, the control is performed such that the position of the boundary layer in the sealed tank 3 is moved downward in accordance with the number of heat source units 2 that defrost.

  That is, as described above, the system controller 16 performs control to move the boundary layer position to the upper part in the depth direction of the closed tank 3 during the stable period of the hot water supply operation. If the defrosting operation is simultaneously performed on the heat source devices 2 in the state as they are, the amount of hot water supplied from the sealed tank 3 is insufficient, and cold water may be supplied.

  Therefore, as described above, when the number of the heat source devices 2 entering the defrosting is small, the boundary layer position may not be changed so much, but the boundary layer position is controlled to be a deeper position as the number increases.

  As a result, even if many heat source units 2 start the defrosting operation all at once, hot water is reliably supplied from the sealed tank 3 to all the heat source units 2 and the defrosting operation is completed. Efficient defrosting using high-temperature hot water is possible after minimizing the heat loss from the heat source unit 2.

  FIG. 6 shows the flow of hot water during the actual defrosting operation. The three-way valves 2e and 2g are switched, and the heat source unit 2 is set to the reverse cycle. The heat source side heat exchanger 2d is configured as a condenser and the water heat exchanger 2b is configured as an evaporator.

  By driving the pump 2f in this state, high-temperature hot water stored in the sealed tank 3 is guided from the hot water supply line 13 to the water heat exchanger 2b via the three-way valve 2g, and is supplied to the water heat exchanger 2b. The led refrigerant is heated. The refrigerant whose temperature has risen is led to the heat source side heat exchanger 2d via the decompression device 2c shown in FIG. 2, and here, the heat of condensation is generated to melt the attached frost.

  The hot water led to the water heat exchanger 2b and heat-exchanged with the low-temperature refrigerant is reduced in temperature and converted into low-temperature water, and returns to the sealed tank 3 via the three-way valve 2e and the water supply pipe 12. Thus, an efficient defrosting operation is basically performed using the hot water at the top of the sealed tank 3. Since the defrosting operation is completed in a relatively short time, even if the hot water in the sealed tank 3 is used, the hot water supply device 1 is not hindered.

  When the defrosting operation is completed, the system controller 16 returns to the state when the hot water supply operation is stable. Specifically, the opening degree of the flow rate adjustment valve 13a is adjusted to move the boundary layer between hot water and cold water inside the sealed tank 3 to the upper part (for example, the temperature sensor T2orT1) to increase the amount of cold water. Reduce heat dissipation.

Further, the system controller 16 not only performs the defrosting operation on the heat source unit 2 but also depends on the conditions of the outside air temperature and the operation duration time described above, and simply, during the stable operation as the hot water supply device 1, You may make it perform control which determines the boundary layer position of the sealed tank 3 with ambient temperature.
In other words, instead of detecting the prior information that the heat source device 2 enters the defrosting operation, the system controller 16 receives the detection signal of the outside air temperature sensor 20 shown in FIG. It has a function of changing the position of the boundary layer when the operation is stable.

  For example, when the outside air temperature is 7 ° C. or higher, the system controller 16 adjusts the opening of the flow rate adjustment valve 13a so that the boundary layer is aligned with the temperature sensor T1 mounting position provided at the uppermost portion of the closed tank 3. That is, if the outside air temperature is 7 ° C. or higher, it is determined that frost does not adhere to the heat source side heat exchanger 2d of the heat source device 2, and the hot water supply device 1 is in a stable operation state.

When the outside air temperature is equal to or lower than 7 ° C., the system controller 16 adjusts the opening of the flow rate adjustment valve 13a so that the boundary layer is aligned with the temperature sensor T2 mounting position provided next to the closed tank 3. That is, if the outside air temperature becomes 7 ° C. or lower, it is expected that frost will adhere to the heat source side heat exchanger 2d of the heat source device 2, and the position of the boundary layer is lowered to prepare for the defrosting operation.

  Note that the present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. Various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the above-described embodiments.

  2 ... Heat source machine (heat pump unit), 3 ... Sealed tank, 4 ... Hot water supply line, 5 ... Open tank, 13a ... Flow rate adjusting valve, T1-T5 ... Temperature sensor, 16 ... System controller (control means), 20 ... Outside air temperature sensor.

Claims (3)

A plurality of heat pump units that heat the supplied cold water and generate hot water of a predetermined temperature;
A sealed tank for storing hot water generated by these heat pump units;
An open type tank that is connected to the sealed tank via a hot water supply pipe and stores hot water supplied from the sealed tank,
A flow rate adjusting valve that is provided in a hot water supply line that communicates between the sealed tank and the open tank, and that controls the amount of hot water led from the sealed tank to the open tank;
A plurality of temperature sensors arranged at predetermined intervals along the depth direction in the sealed tank;
When the detection signals of these temperature sensors are received, the boundary layer between the hot water and cold water inside the sealed tank is located near the center in the depth direction of the sealed tank when the heat pump unit starts up or when the number of operating heat pump units fluctuates. Control means for controlling the opening of the flow regulating valve so that the boundary layer is positioned above the sealed tank during normal operation;
A hot water supply apparatus comprising: Further, the control means includes
In the defrosting operation of the heat pump unit, the position of the boundary layer between the hot water and the cold water inside the sealed tank is controlled to move downward according to the number of heat pump units performing the defrosting operation. The hot water supply apparatus according to claim 1. Further, the control means includes
2. An outside temperature detection signal from a sensor for detecting outside temperature is received, and control is performed to move the position of the boundary layer between hot water and cold water inside the sealed tank according to the outside temperature. Water heater.

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