JPS5924135A - Heat pump type hot-water device - Google Patents

Abstract

PURPOSE:To improve operating efficiency while guaranteeing the amount of hot- water surely by a method wherein the operation of the device is controlled so as to minimize the operation of an auxiliary heater by detecting an outdoor temperature and the amount of remaining hot-water. CONSTITUTION:Upon both of the single operation of the heat pump or the operation of the same in parallel with an auxiliary heater 10, the hot-water is reserved in keeping the temperature of the hot-water flowing into a hot-water reserving tank 7 in constant. In case the outdoor temperature is higher than a set value, a switch 14' is being opened, and when the switch 19 is put ON, a compressor 1, a fan 5 and a pump 9 are conducted and the hot-water is reserved by flowing circulating water above a hot-water reserving tank 7 into the top of the tank 7 after it is heated to the temperature of hot-water by a condenser 2. In case the outdoor temperature is lowr than the set value, the switches 14', 15' are being closed, therefore, a heating capacity is obtained by the parallel operation of the compressor 1, the fan 5, the pump 9 and the heater 10 and a heating load may be satisfied. When the remaining water is existing more than a predetermined amount, the switch 15' is closed but the switch 14' is opened, therefore, only the heat pump is operated.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a heat pump hot water system equipped with an auxiliary heater, and more particularly to control of the operation of the auxiliary heater.

Conventional Structure and Problems In conventional heat pump water heaters equipped with an auxiliary heater, the operation of the auxiliary heater is mostly controlled manually and by detecting outside air temperature. The heating capacity of the heat pump decreases as the outside temperature drops, so if you select it manually, it is difficult to select the right timing. and reduce operating efficiency, and
The problem is that the auxiliary heater is not selected to operate even when the outside temperature is low, resulting in a shortage of hot water. In addition, when detecting the outside temperature, the amount of hot water is guaranteed, but if there is a large amount of remaining hot water, the heating load is small, so even though the heat pump alone can provide sufficient capacity, an auxiliary heater may be needed unnecessarily. It has the disadvantage of being driven.

Purpose of the Invention The present invention eliminates the above-mentioned drawbacks by providing an operation control method that minimizes the operation of the auxiliary heater by detecting the outside air temperature and the amount of remaining hot water, thereby ensuring a reliable amount of hot water. The aim is to improve operating efficiency.

Structure of the Invention In order to achieve this object, the present invention provides a heat source enthalpy detection sensor for a heat pump and a remaining hot water amount detection sensor in a hot water storage tank. By controlling the auxiliary heater to operate only in the following cases, even when the heat source enthalpy decreases, the auxiliary heater does not operate unnecessarily when there is a large amount of hot water remaining, making the heat pump highly efficient. It is operated by only one person, greatly improving efficiency.

DESCRIPTION OF EMBODIMENTS Fig. 1 shows an embodiment of the system according to the present invention, Fig. 2 shows an embodiment of an electric circuit diagram, and Fig. 3 shows a graph for explaining the operation of the present invention. I explain.

In FIG. 1, 1 is a compressor, 2 is a condenser, 3 is an expansion valve, 4 is an evaporator, 5 is a fan, and 6 is an accumulator, which constitute an air source heat pump. On the other hand, 7 is a hot water storage tank, 8 is a water circulation circuit between the condenser 2, 9 is a pump, 10 is an auxiliary heater (auxiliary heater) disposed downstream of the condenser 2, and 11 is a water circulation circuit between the condenser 2 and the condenser 2. A hot water supply pipe 12 is a water supply pipe, which connects a hot water storage tank 7, a condenser 2, and an auxiliary heater 1.
0 and the water supply function from the hot water storage tank 7 to the hot water supply pipe 11 by water supply from the water supply pipe 12.

Furthermore, 13 is a hot water temperature sensor flowing into the hot water storage tank 7, which controls the amount of circulating water by operating the rotation speed A of the pump. It stores hot water while keeping the temperature of the inflowing hot water constant. 14 is a remaining hot water amount detection sensor, which is disposed at a position in the hot water storage tank 7 that corresponds to a predetermined remaining hot water amount position. Reference numeral 16 denotes a heat source enthalpy detection sensor, which in this embodiment is replaced by an outside air temperature sensor. 16 is a suction water temperature detection sensor of the pump 9. In the electrical circuit schematic diagram of FIG.
is a switch that opens and closes according to the signal from the outside temperature controller 16;
16' is a switch that opens and closes according to the signal from the suction water temperature detection unit 16 of the pump 9, 1 is a high pressure switch of the heat pump,
18 is an overheat prevention switch for the heater 10, and 19 is an on/off switch for the system.

In the configurations shown in FIGS. 1 and 2 above, the driving operation will be explained.

First, if the outside temperature is higher than the set value, switch 14
' is open, and when switch 19 is turned on, compressor 1. The fan 6 and the pump 9 are energized, and the circulating water from the lower part of the hot water storage tank 7 is heated by the condenser 2 to become hot water and flow into the top to be stored. At this time, in order to keep the temperature of hot water flowing into the hot water tank 7 constant and guarantee hot water supply in response to fluctuations in outside air conditions and changes in water supply temperature, the hot water temperature detector 13 operates the pump 9 to control the amount of circulating water. . Therefore, the heating capacity of the heat pump decreases, but when the water supply temperature is low, the amount of circulating water decreases, and the heating capacity is large, but when the water supply temperature is high, the amount of circulating water increases. The hot water flows in from the upper part of the hot water storage tank 7, and due to the difference in specific gravity in the hot water storage tank 7, hot water is stored from the upper part.As the hot water storage tank 7 becomes full, the water temperature at the inlet of the pump 90 rises. When the temperature reaches the set temperature or higher, the switch 16' is opened and the operation is terminated. Next, when the outside air temperature 'ra is lower than the set value, the heating capacity of the heat pump decreases as shown in FIG. Therefore, in such a case, the auxiliary heater 1o is operated in parallel. In FIG. 2, switches 14' and 15' are closed, so compressor 1. Fan 5. Pump 9. By operating the heater 10 in parallel, 81
A heating capacity of ~C1 is obtained, and heating loads E and F can be satisfied.

Next, even when the outside air temperature Ta is lower than the set temperature, the heating load when a predetermined amount of hot water remains is X' to F' in Figure 3.
Therefore, the heating capacities B and C of the heat pump alone are sufficient. Therefore, when the outside temperature is lower than a predetermined value and the amount of remaining hot water is above a predetermined value, the switch 15' is closed but the switch 14' is open, so only the heat pump is operated, and unnecessary auxiliary heaters are not used. 10 operations are not performed, allowing highly efficient operation.

Effects of the Invention As described above, in a heat pump water heater that heats water in a hot water tank using the condensed heat of the heat pump and an auxiliary heater, the heat source enthalpy is reduced by the heat pump's heat source enthalpy detection sensor and the remaining hot water amount detection sensor in the hot water storage tank. When the heating capacity of the heat pump decreases and the amount of remaining hot water is small and the heating load increases, the heat pump and auxiliary heater operate in parallel to produce sufficient heating capacity to fully satisfy the large heating load, and the enthalpy of the heat source decreases, increasing the heating capacity of the heat pump. Even if the heat pump decreases, when there is a large amount of remaining hot water and the heating load is small, it is necessary to control the operation so that only the highly efficient heat pump is operated instead of operating an inefficient and unnecessary auxiliary heater, which increases the operating efficiency. There is. In actual use, the amount of remaining hot water frequently falls below a predetermined value, so this has a great effect.

In this embodiment, the auxiliary heater is shown outside the hot water storage tank, but the same effect can be obtained even if it is placed inside the hot water storage tank. Furthermore, in the case of a water heat source, water temperature can be used as a substitute for heat source entarbi detection. Although this embodiment describes an example of the inflow hot water temperature control method, it is clear that other methods such as the constant flow circulation method (Fig. 1) and the heat exchanger method buried in the hot water storage tank can also achieve the same function. .

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a heat pump water heater according to an embodiment of the present invention, FIG. 2 is an electric circuit diagram thereof, and FIG. 3 is a heating capacity characteristic diagram. 1... Compressor, 2... Condenser, 3...
...Expansion valve, 4...Evaporator, 7...
・Hot water tank, 10...Auxiliary heater, F4...
・Remaining hot water amount detection sensor, 15...Heat source enthalpy detection sensor. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 3
−11−→−Ta

Claims (1)

[Claims] A means for heating water in the hot water storage tank using the condensing heat of the heat pump and an auxiliary heater is provided, and the heat pump has a heat source enthalpy detection sensor and a remaining hot water amount detection sensor in the hot water storage tank, and the heat source enthalpy is below a predetermined value and the hot water storage tank is heated. A heat pump water heater that operates the auxiliary heater only when the amount of hot water remaining in the tank is below a predetermined value.