JPH02178576A - Multi-heat pump hot water feeding system - Google Patents

Abstract

PURPOSE:To enable an additional heating of a bath tub to be carried out further enable a heat recovery to be attained from a remained hot water in the bath tub by a method wherein a first condensor outlet water temperature and a second condensor outlet water temperature become a predetermined temperature, respectively, and a hot water storing tank lower water temperature is compared with the second condensor outlet water temperature. CONSTITUTION:When it is judged that there is remained hot water in a bath tub by a hot water temperature and water pressure sensor 26, a second heat pump 9 is operated, a remained hot water within a bath tub 11 is applied as a heating source by an evaporator 12 and then the hot water fed is heated by a second condensor 13. The hot water fed passes from a lower part of a hot water storing tank 16 through a changing-over valve 19, a pump 17, a control valve 23 and a second condensor 13, and a control valve 23 is controlled by a controller 29 in such a way as the hot water shows a predetermined temperature by a temperature sensor 26. A flow rate of the hot water fed is adjusted. The fed hot water heated up to a specified temperature returns from the changing-over valve 20, a control valve 21 and a changing-over valve 18 to an upper part of the hot water storing tank 16. At this time, a result of sensing of the temperature sensor 25 is compared with a detected hot water temperature of a hot water temperature sensor 27 at the lower part within the hot water storing tank 16, and a flow rate of the hot water is adjusted in such a way as the temperature becomes lower than a lower part temperature within the hot water storing tank 16. Under this operation, it is possible to perform an additional heating with a heat pump device 9 having the hot water storing tank 16 as the heat source.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to residential hot water supply systems using heat pumps, and particularly to multi-heat pump hot water supply systems for collective housing.

BACKGROUND ART Conventionally, water heaters using heat pump devices have been known as devices that use electric power as a heating source for hot water in homes.

This uses a heat pump device to draw heat from outside air, allowing for highly efficient operation and energy savings, but the boiling temperature is 60-70°C, which is lower than other water heaters (e.g. electric water heaters have a boiling temperature of 85°C). Therefore, the capacity of the hot water storage tank will be large. Additionally, the heating capacity varies greatly due to the equipment price and electric capacity, and the system operates for long periods of time with a low heating amount and stores hot water in the hot water tank to withstand large loads. Also, with late-night electric water heaters, the water heated overnight must be stored for a long time.

The heat pump water heater, which is a hot water supply system using electricity as a heat source in an apartment complex, requires a large hot water storage tank.

Problems to be Solved by the Invention Water heaters that use late-night electricity must store high-temperature hot water for a long time, as mentioned above, and what is more? i/@
Since the hot water storage tank is set up in accordance with the maximum hot water load, an excessively large hot water storage tank is set up for most days, which results in a large installation space and a large amount of heat loss.

Furthermore, once the hot water runs out, there is no reheating function in the hot water tank, so you have to wait until the next morning to use the hot water.

Water heaters using heat pump devices save energy, but as mentioned above, their heating capacity is small and the boiling temperature is lower than that of electric water heaters, so the hot water storage tank capacity is larger than that of electric water heaters. - Once the hot water runs out, the hot water storage tank's reheating capacity is small, so there is a problem in that it takes a long time to wait until the water is boiled. Also, once the hot water in the bathtub has dropped, in order to reheat it, hot water is poured from the hot water storage tank, but since the boiling temperature of the hot water tank is not very high, a large amount of hot water must be poured. For example, in order to lower the temperature of 180 liters of hot water to 38°C and raise it to 42°C, 40 liters of hot water at 60°C is required. That much,
The capacity of the hot water storage tank must be increased, the cost of the equipment will be high, and the installation space will be large, making it impractical.

In apartment complexes, there is a problem in that each housing unit requires a large installation space for a hot water tank, regardless of whether the Cf, electric water heater, or heat pump device is used.

In view of the above-mentioned problems with conventional hot water supply systems, the present invention provides an energy-saving multi-heat pump hot water supply that enables reheating of the bathtub by installing a second heat pump device in the multi-heat pump hot water supply system, and recovers heat from the remaining hot water in the bathtub. The purpose is to provide a system.

Means for Solving the Problems The present invention provides a first heat pump device equipped with a compressor and an evaporator in the center, a hot water storage tank, a first condenser, and a pump, and a second condenser and a second heat pump device in the bathtub. of! A second heat pump device equipped with an evaporator installed to exchange heat with hot water is provided in each dwelling unit, and the first heat pump device and a first condenser provided in each dwelling unit are connected in parallel via refrigerant piping. a circuit forming a refrigerant circuit and connecting the lower part of the hot water storage tank, the pump, the first condenser, and the upper part of the hot water storage tank; and a circuit connecting the lower part of the hot water storage tank, the pump, the second condenser, and the upper part of the hot water storage tank; , a circuit connecting the lower part of the hot water storage tank, a pump, a first condenser and a second condenser in parallel, and an upper part of the hot water storage tank, the upper part of the hot water storage tank, the pump, the second condenser, and the lower part of the hot water storage tank. a circuit connecting the lower part of the hot water storage tank, a pump, a first condenser, and a first condenser outlet, one branching to the upper part of the hot water storage tank and the other to the lower part of the hot water storage tank via the second condenser. a control means configured to be able to switch between the connected circuit and the first condenser outlet water temperature and the second condenser outlet water temperature to a set temperature; a means for determining the presence or absence of residual hot water in the bathtub, a means for determining the presence or absence of residual hot water in the hot water storage tank, and a means for determining the end of bathing.

Effects The advantage of having each unit clustered together in an apartment complex is that the amount of hot water used per unit fluctuates widely on a daily basis, but when you add up the amount of hot water used by multiple units, it is averaged out. Incorporating the concept of simultaneous usage rate, in which the average required amount of hot water supply per hour per dwelling unit becomes smaller as the units are shifted from each other, the first heat pump device has a relatively small capacity when calculated per dwelling unit. A second heat pump system is installed in the center, and each dwelling unit is equipped with a small-capacity hot water tank, a heat exchanger with a large heating capacity, and a heat exchanger with a small heating capacity for the purpose of reheating the bathtub and recovering heat. The heat from the first heat pump device can be easily distributed to each dwelling unit in the required amount, and the second heat pump device can reheat the bathtub and recover heat. That is, after taking a bath, if there is hot water left in the bathtub and there is a request to heat the hot water tank, the second heat pump device is activated and recovers heat from the evaporator installed to exchange heat with the hot water in the bathtub. The second condenser can heat the hot water sent from the lower part of the hot water tank via the pump and store it in the hot water tank. Furthermore, when the amount of hot water remaining in the hot water storage tank is small, the first heat pump device is activated and the first condenser and second condenser reduce the amount of hot water in the hot water storage tank.
? j Heat hot and cold water in parallel. If there is no hot water remaining in the bathtub, the first heat pump device is activated and the hot water in the hot water storage tank is heated by the first condenser. If the temperature of the bathtub drops during bathing, a second heat pump device that uses the remaining hot water in the hot water storage tank as a heat source can be operated to reheat the hot water in the bathtub. At that time, if there is no remaining hot water above a certain level in the hot water storage tank, the first heat pump device is operated, the first condenser heats the hot water in the hot water storage tank, and some of the heated hot water is A second heat pump device is operated as a heat source, and heat is taken in from the second condenser to reheat the hot water in the bathtub.

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

In FIG. 1, reference numeral 1 denotes a first heat pump device, which includes a compressor 2, an evaporator 3 for pumping up heat from a waste heat source, an expansion valve 4, and a conduit 5 to form a refrigerant circuit. Heat from the first heat pump device 1 is supplied to each dwelling unit through a refrigerant pipe 7 via a refrigerant gas control valve 6,6'. 8 is a first condenser, which exchanges heat supplied from the first heat pump device 1 with hot water. 9 is a second heat pump device that includes a compressor 10, an evaporator 12 installed to exchange heat with the hot water in the bathtub 11, a second condenser 13 that exchanges heat with hot water, and an expansion valve 14. The four-way valve 15 is connected in a ring to form a refrigerant circuit. 16 is a hot water storage tank, and 17 is a pump. 18, 19, and 20 are switching valves that switch the hot water supply circuit, and 21, 22, and 23 are control valves that control the hot water supply flow rate. 24 is a temperature sensor that measures the outlet water temperature of the first condenser 8; 25 is a temperature sensor that measures the outlet water temperature of the second condenser 13; 26 is a water temperature sensor that measures the water temperature and water pressure in the bathtub 11; , a water pressure sensor. A plurality of hot water temperature sensors 27 are installed in the hot water storage tank 16 in the height direction to measure the amount of remaining hot water and the hot water temperature. 28 is a switch that notifies the end of bathing, and 29 is a controller that switches to the optimal operating mode based on the signals from each sensor. 30 is a hot water pipe, 31 is a faucet, and 32 is a city water pipe.

33 is a check valve.

Next, the operation of the configuration of this embodiment will be explained using FIGS. 2 to 6, and FIG. 7 shows a control flow diagram.

FIG. 2 is a system diagram when the first heat pump device 1 is operating to heat the hot water storage tank. Hot water temperature sensor 2 in the hot water tank 16
7 detects a drop in the hot water temperature, and when a heating request is issued from the controller 29 to the central first heat pump device 1, the first heat pump device 1 is activated and the control valve 6 is opened to increase the amount of heat to the first heat pump device 1. It is supplied to the condenser 8. If a heating request is issued from another dwelling unit, the control valve corresponding to that dwelling unit will be opened 6 degrees. Usually, the hot water storage tank 16 is heated by this hot water storage tank heating operation. As a result, by utilizing the concept of simultaneous usage rate, which is an advantage of apartment complexes, the first heat pump device in the center can be a heat pump device with a capacity smaller than the sum of the heating amounts of each dwelling unit, and the heat pump device with a large heating amount can be used. The first condenser 8 allows the hot water storage tank 16 to have a small capacity. Hot water is supplied from the bottom of the hot water storage tank 16 through the switching valve 19 and the pump 17.
, a control valve 22, and the first condenser 8, and as a means to set the temperature of the hot water to a set temperature, a controller 29 controls the control valve 22 to adjust the flow rate of the hot water so that the temperature reaches the set temperature using a temperature sensor 24. . Hot water heated to a constant temperature is
Returns from the switching valve 18 to the upper part of the hot water storage tank 16.

Figure 3 is a system diagram during heat recovery operation. This is because the controller 29 detects the completion of bathing by the water bath 28 as a means for determining the end of bathing, and furthermore, the hot water temperature sensor 27 in the hot water storage tank 16 detects the temperature below the set temperature, and serves as a means for determining whether or not there is hot water remaining in the bathtub 11. If it is determined that there is residual hot water based on the water temperature and water pressure determined by the water temperature and water pressure sensor 26, the second heat pump 9 is operated and the evaporator 12 uses the remaining hot water in the bathtub 11 as a heat source. The hot water is heated in the condenser 13.

Hot water is supplied from the lower part of the hot water storage tank 16 through a switching valve 19, a pump 17, a control valve 23, and a second condenser 13, and then a temperature sensor 25 serves as a means for determining that the hot water reaches the set temperature. The controller 29 controls the control valve 23 to adjust the flow rate of hot water. The hot water heated to a constant temperature returns to the upper part of the hot water storage tank 16 through the switching valve 20, the control valve 21, and the switching valve 18. This allows the bathtub l
When there is residual hot water in the bathtub 11, priority is given to recovering heat from the bathtub 11, allowing energy-saving operation.

FIG. 4 is a system diagram during simultaneous operation of hot water heating operation and heat recovery operation. This is because after bathing, the water temperature in the hot water storage tank 16 is low and there is a heating request, and the hot water temperature sensor 27, which is a means for determining whether there is any remaining hot water in the hot water storage tank 1G, detects the remaining hot water.
If the amount is below a certain level, the first heat pump device 1 and the second heat pump device 9 are operated simultaneously and the first condenser 8
Hot water is heated in parallel by the second condenser 13 and the second condenser 13. The hot water is branched into two from the lower part of the hot water storage tank 16 through a switching valve 19 and a pump 17. One side enters a control valve 22 and a first condenser 8, and is sent to a temperature sensor 24 to maintain a predetermined temperature. 29 controls the control valve 22 to adjust the flow rate of hot water. The other hot water enters the second condenser 13 through the control valve 23, and the controller 29 controls the control valve 23 to adjust the flow rate of hot water so that the temperature reaches a predetermined temperature using the temperature sensor 25.

Thereafter, it passes through the switching valve 20 and the control valve 21, merges with the hot water discharged from the first condenser 8, and returns to the upper part of the hot water storage tank 16 via the switching valve 18. With this operation, heat recovery from the bathtub 11 and heating of the hot water tank 16 by the first heat pump device 1 can be performed at the same time, making it possible to quickly boil the hot water tank 16 at the same time as energy-saving operation.

FIG. 5 is a system diagram during bath W: 11.0 reheating operation. During bathing, the water temperature and water pressure sensor 26 in the bathtub 1 detects a drop in the water temperature, and there is a certain amount of hot water remaining in the hot water tank 16, but the lower temperature of the hot water tank 16 drops and a heating request is made. Drive. First of all, the square well 15 of the second heat pump device 9 is replaced and the second condenser 13 is used as an evaporator.
The refrigerant circuit is configured such that the evaporator 11 acts as a condenser. Hot water is supplied from the top of the hot water tank 16 to the switching valve 1.
8, enters the evaporator 13 via the pump 17 and control valve 23,
It acts as a heat source for the second heat pump device 9, lowers the temperature, and returns to the lower part of the hot water storage tank 16 via the switching valve 20.19. At that time, the temperature comparison means of the controller 29 compares the detection result of the outlet temperature sensor 25 of the evaporator 13 with the hot water temperature detected by the hot water temperature sensor 27 in the lower part of the hot water storage tank 16, and the temperature in the lower part of the hot water storage tank 16 is lowered. The control valve 23 is controlled to adjust the flow rate of hot water. With this operation, reheating, which was previously only achieved with plug/V, is possible in the hot water storage tank 1.
This is realized by a second heat pump device 9 using a heat pump 6 as a heat source.

FIG. 6 is a system diagram during simultaneous operation of hot water heating operation and reheating operation. This starts when the water temperature in the bathtub 11 and the water pressure sensor detect a drop in the temperature while taking a bath, and the remaining hot water level in the hot water tank 16 is detected to be below a certain level by the temperature sensor 27. Do this. The first heat pump device 1 and the second heat pump device 9 are operated simultaneously, and the refrigerant circuit of the second heat pump device 9 is the same as that in FIG. 5. Hot water is heated from the lower part of the hot water storage tank 16 through the switching valve 19, pump 17, control valve 22, and first condenser 8 to a predetermined temperature by the temperature sensor 24 and control valve 22, and some of it passes through the switching valve 18. Hot water storage W! The remaining hot water enters the evaporator 13 via the control valve 21 and reverse valve 33, and the temperature sensor 25 controls the hot water temperature to be lower than that detected by the hot water temperature sensor 27 at the lower part of the hot water storage tank 16. The control valve 21 adjusts the flow rate of hot water, which acts as a heat source for the second heat pump 9 to lower its temperature. A portion of the water returns to the lower part of the hot water storage tank 16 via the switching valves 20 and 19, and a portion of the water is supplied to the pump 1 again.
7 to the first condenser 8.

As a result of this operation, when the remaining hot water in the hot water storage tank 16 is reduced to below a certain level, the second heat pump device 9 reheats the bathtub 11 using the heat from the first heat pump device 1 as a heat source, but the amount of heat generated by the first condenser 8 is Since this is larger, only the heat required for reheating can be sent to the second condenser 13, that is, the evaporator, and the remaining heat can be stored in the hot water storage tank 16.

As described above, the hot water supply system of the present invention has five operation modes, and includes a first heat pump device 1 and a second heat pump device 9, and a pump 17, a first condenser 8, and a second condenser 13. Control valve 21.22.23, switching valve 1B,
It is connected to the hot water storage tank 16 via 19.20 and a reverse IE valve 33, so that the optimum operation mode can be selected depending on the usage condition.

By doing so, there is no need to use hot water to reheat the bathtub 11, and heat can be recovered from the remaining hot water after bathing to heat the hot water tank 16, thereby enabling energy-saving operation. Furthermore,
The second heat pump device 9 has a refrigerant circuit completely separated from the first heat pump device 1, so different refrigerants can be used, and in particular, in reheating, a high boiling point refrigerant that can be operated at a high condensing temperature is used. It becomes possible. As explained above, the control functions of this system include a temperature control function by controlling the flow rate of water supply No. 7 at the condenser outlet in each operation mode, and a function to compare the temperature at the bottom of the hot water storage tank with the temperature at the second condenser outlet. It has a function to determine whether there is residual hot water based on the temperature and water pressure in the bathtub, a function to determine whether there is residual hot water based on the temperature and capacity in the hot water storage tank, and a function to determine when bathing is complete. Therefore, switching between each operation mode and controlling the temperature are a matter of course, and in addition, switching between the first heat pump device and the second heat pump device can be done without running out of hot water, in order to judge whether there is enough hot water left in the bathtub or hot water storage tank. You can do it more optimally.

As described in detail, the present invention enables reheating of a bathtub by installing a second heat pump device in a multi-heat pump hot water supply system, and can provide an energy-saving system in which heat can be recovered from the hot water remaining in the bathtub. . Furthermore, since the second heat pump device and the first heat pump device have separate refrigerant circuits, different refrigerants can be used. In addition, if the system control of the present invention is provided with a function to determine the presence or absence of remaining hot water in the bathtub and hot water storage tank, and a function to determine the end of bathing, switching between each operation mode will be more optimal without running out of hot water. It can be done.

[Brief explanation of the drawing]

Fig. 1 is a system diagram of a multi-heat pump hot water supply system according to an embodiment of the present invention, Figs. 2 to 6 are system diagrams of each operation mode of the system, and Fig. 7 is a control flow diagram of the same embodiment. be. 1... First heat pump device, 2... Compressor, 8
...first condenser, 9 second heat pump device, 13
...Second condenser, 16...Hot water tank, 17...Pump, 18.19.20---Switching valve, 6.21.
22.23...Control valve, 24.25...Temperature sensor 26...Water temperature, pressure sensor 27...Water temperature sensor 28...Switch, 29...Controller.

Claims (2)

[Claims] (1) A first heat pump device equipped with a compressor and an evaporator is installed in the center, and is equipped with a hot water tank, a first condenser, and a pump, and can exchange heat with the second condenser and hot water in the bathtub. A second heat pump device equipped with an evaporator provided in each dwelling unit is provided in each dwelling unit, and the first heat pump device and the first condenser provided in each dwelling unit are connected in parallel with refrigerant piping to form a refrigerant circuit. a circuit connecting the lower part of the hot water storage tank, a pump, a first condenser, and an upper part of the hot water storage tank; a circuit connecting the lower part of the hot water storage tank, the pump, the second condenser, and the upper part of the hot water storage tank; A circuit that connects the lower part, the pump, the first condenser, and the second condenser in parallel, and connects the upper part of the hot water storage tank, and the circuit that connects the upper part of the hot water storage tank, the pump, the second condenser, and the lower part of the hot water storage tank. and a circuit branching from the lower part of the hot water storage tank, a pump, a first condenser, and a first condenser outlet, one of which is connected to the upper part of the hot water storage tank, and the other is connected to the lower part of the hot water storage tank via a second condenser. A multi-heat pump hot water system characterized by a switchable configuration. (2) A control means that brings the first condenser outlet water temperature and the second condenser outlet water temperature to a set temperature, a means for comparing the lower water temperature of the hot water storage tank and the second condenser outlet water temperature, and residual hot water in the bathtub. A multi-heat pump hot water supply system characterized by comprising means for determining the presence or absence of residual hot water in the hot water storage tank, and means for determining the end of bathing.