JPS60200042A - Heat pump type hot water supplier - Google Patents

Abstract

PURPOSE:To reduce a decreasing in efficiency of a heat pump when a simultaneous operation of a heater and a heat pump is performed by a method wherein a cylinder of hot water storing reservoir with an open top end and an open bottom end thereof is placed on an outer circumference of the heater in the longitudinal hot water reservoir and a connection pipe for the heat pump device is placed at the lower part of the hot water reservoir. CONSTITUTION:Hot water heated by a water heat exchanger 4 is flowed into the lower part of the hot water reservoir 1 and the water in the hot water reservoir 1 is heated under a natural convection caused by a flating force. According flow of convection is formed from the lower opening of the longitudinal cylinder 7 to the upper opening thereof by an electric heater 7, a hot water heated by an electric heater 3 is accumulated at the upper part of a hot water reservoir 1 with a less convection of heating flow caused by the heat pump 2 while the layered temperature flow is being made. Therefore, since the intermediate part and the lower part of the hot water reservoir show a substantial uniform temperature and it is made possible to perform an operation of the heat pump without being affected by the electric heater.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an improvement in a heat pump water heater that heats water in a hot water storage tank and supplies hot water using a heat pump, particularly one having an auxiliary electric heater.

Conventional configuration and its problems In this type of conventional heat pump water heater system, the heat pump's hourly heating capacity is smaller than that of kerosene boilers, etc., and its capacity is particularly affected by the outside air temperature. In order to guarantee the boiling temperature in winter, an electric heater 3 is inserted into the lower part of the hot water tank 1 as shown in FIG.
A connecting pipe 5.5' having a pump 6 on its way to the water heat exchanger 4 heated by the water is connected to the lower part of the hot water tank 1, and these heat pump device 2 and electric heater 3 can be operated simultaneously in severe cold. I was using it. Figure 5 shows the state of convection in the hot water storage tank in this case, and it is clear from this that the water heated by the heat pump and the water heated by the electric heater do not mix completely. Convection flows inside, and the temperature is uniformly adjusted.

Figure 6 shows that when the heat pump and heater heat at the same time,
That is, it shows the difference in cop of the heat pump between parallel operation and when heater heating is performed after heat pump heating, that is, series operation. Boil the initial water temperature to 1 and the end temperature to TH.
If the heating capacity of the heat pump and heater is simple and special, then in the case of parallel operation, the average heating temperature of the heat pump is (TO + TH) as shown by the solid line in Figure 6.
/2. In addition, in the case of series operation, if the heat pump heats from To to TR first, and then the heater heats from TR to °rH, as shown by the dashed line in Figure 6, the heating capacity of the heat pump and heater are equal, so TH -TR
=TR-To, and 1=To+Tu/2. The average heating temperature of the heat pump is (TO+TR)/2, and as is clear, (TO+TH)/2>(T.

+TR)/2. Due to the nature of heat pumps, the higher the condensing temperature, that is, the heating temperature, the lower the COP. Therefore, in the operation of the heat pump and heater, the coP is worse when the heat pump and heater are heated simultaneously than when they are heated in series over time. As described above, when a heat pump and a heater are operated simultaneously, there is generally a drawback that the efficiency of the heat pump decreases due to the effect of the heater.

OBJECTS OF THE INVENTION The present invention has been made to solve such conventional problems, and an object of the present invention is to reduce the decrease in efficiency of the heat pump when the heat pump and heater are operated simultaneously.

Structure of the Invention In order to achieve this object, the present invention provides a vertically long cylinder that is opened and covered near the top and bottom of the vertical hot water storage tank on the outer periphery of an electric heater that hangs down from the top of the vertical hot water storage tank,
Two connecting pipes to the water heat exchanger heated by the heat pump device are provided at the bottom of the hot water storage tank. With this configuration, the water heated by the electric heater and the water heated by the heat pump are separated as a whole, although there is some mixing, so the effect of the heater on the heat pump is small, and the CoP of the heat pump can be high even when operated simultaneously. effective.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. 1 and 2.

In FIG. 1, 1 is an insulated vertical hot water storage tank, 2 is a heat pump device, and although the internal structure is omitted, a refrigeration cycle is constituted by a compressor, an air heat exchanger, a fan, an expansion valve, etc. The water heat exchanger 4 constitutes a part of the refrigeration cycle, and functions as a condenser that exchanges heat between the refrigerant and water. 5 is a connecting pipe connected to the lower part of the hot water storage tank 1 and sent to the water heat exchanger 4, and has a circulation pump 6 in the middle thereof. 5' is also water heat exchanger 4
This is a return connecting vibe that sends heated water from the hot water storage tank 1 to the hot water storage tank 1. 3
is an electric heater and is inserted hanging down from the top of the hot water tank 1. Reference numeral 7 is a vertically elongated cylinder which is provided on the outer periphery of the stain heater 3 so as to be open near the top and bottom of the hot water tank 1, respectively. 8 is a hot water outlet pipe, and 9 is a water supply pipe. 10 is a convection prevention plate made of punched metal or the like and supports the vertically long cylinder 7. Note that the same members as in FIGS. 3 and 4 are given the same numbers.

In the above configuration, as shown in FIG. 2, hot water heated by the water heat exchanger 4 in simultaneous operation of the electric heater and the heat pump flows into the lower part of the hot water tank 1 and heats the water in the hot water tank 1 by natural convection due to buoyancy. do. At this time, hot water tank 1
The influence of convection on the upper part is reduced by the convection prevention plate 10. On the other hand, another convection is formed by the electric heater 7 from the lower opening of the vertically long cylinder 7 to the upper opening, and the electric heater 3 The high-temperature water heated by the heat sink accumulates while creating temperature stratification. Therefore, as shown in Figure 3, high temperature hot water is formed in the upper part of the temperature profile diagram of the hot water storage tank, and the temperature in the middle and lower parts of the hot water storage tank is almost uniform and can be maintained at a temperature that is not affected by the electric heater. It is.

In other words, in simultaneous operation of the electric heater and the heat pump, heating by the heat pump can be achieved without the influence of the electric heater, making it possible to increase the coefficient of performance of the heat pump.

Effects of the Invention As described above, the heat pump water heater of the present invention provides the following effects.

(1) Since the outer periphery of the electric heater is covered with a vertical cylinder that is open near the top and bottom of the hot water tank, the electric heater generates convection that is different from the convection of heat pump heating, and there is no temperature stratification at the top of the hot water tank. This has the effect of increasing the coefficient of performance of the heat pump when the electric heater and heat pump are operated simultaneously.

@) The convection prevention plate supports the vertically long cylinder and has the effect of weakening the effect of convection caused by heat pump heating in the upper part of the hot water storage tank and reducing mixing with hot water heated by the electric heater.

The present invention can be used not only in heat pump water heaters, but also in heating/cooling water heaters using heat pumps, solar heat utilization equipment, etc., which have a hot water storage tank that operates the main heat source unit and electric heater at the same time. Needless to say, it is a thing.

[Brief explanation of drawings]

Fig. 1 is a configuration diagram of a heat pump water heater according to an embodiment of the present invention, Fig. 2 is a sectional view showing the state of hot water in the hot water storage tank, and Fig. 3
The figure is a temperature profile diagram in the hot water storage tank, Figure 4 is a configuration diagram of a conventional heat pump water heater, Figure 5 is a sectional view showing the state of hot water in the conventional hot water storage tank, and Figure 6 is the heating state. FIG. 1. Hot water storage tank, 2. Heat pump device, 3. Electric heater, 4... water heat exchanger, 5.5'... connecting pipe,
7. Vertical cylinder, 10. Convection prevention plate. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 3 Figure 1 degree - Figure 4 Figure 5 Figure 61! ! □Time

Claims (1)

[Claims] (1) A hot water storage tank, an electric heater hanging down from the top of the hot water storage tank, a vertically elongated cylinder that covers the outer periphery of the electric heater with openings near the top and bottom of the hot water storage tank, and a lower part of the hot water storage tank. A heat pump water heater that connects a pair of connecting pipes to a water heat exchanger that is heated by a heat pump device. ? ) The heat pump water heater according to claim 1, wherein the vertically elongated cylinder is supported by a convection prevention plate provided at an intermediate position of the hot water storage tank.