JPS61114045A - Heat pump type hot-water supply device - Google Patents

Abstract

PURPOSE:To improve the thermal conductivity of a heat exchanger, enable to miniaturize the titled device and reduce the radiation loss thereof by a method wherein a heat exchanger arranged in a hot-water tank is made as a double pipe structure, a hot-water in the hot-water tank is circulated through an inner pipe of the heat exchanger. CONSTITUTION:A heat exchanger 14 having a double pipe structure is arranged in a hot-water tank 3. By driving a circulating pump 7, a hot-water 17 is raised in temperature by the condensing heat of a refrigerant 15 flowing through an inner pipe 18 of the heat exchanger 14. The heat exchanged hot-water 17 is introduced into a circulating pump 7 via a outlet pipe 24, then discharged via an upper part 19 in the hot-water tank 3 or via a discharging piping 25 as shown by an arrow mark B. By protruding an upper header 20 of the heat exchanger 14 to the outside of the hot-water tank 3, the number of piping penetrating holes arranged on the hot-water tank 3 can be decreased.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a heat pump water heater that stores hot water in a hot water storage tank using condensation heat of a heat pump system.

[Conventional technology]

Conventionally, this type of heat pump water heater has broadly classified into two methods for heating hot water using a condenser. One is a method in which a heat exchanger, which is a condenser, is installed outside the hot water storage tank, and the refrigerant and hot water in the hot water storage tank are guided to the heat exchanger by a circulation pump, and the heat exchanger is a double layered heat exchanger. A pipe structure is used. The other method is to place a heat exchanger inside the hot water tank and heat the hot water inside the tank.

FIG. 5 is a system diagram showing a conventional heat pump water heater in which a heat exchanger is disposed outside a hot water storage tank. This is disclosed, for example, in Japanese Utility Model Application No. 58-167862, etc. In the figure, l is a compressor that compresses and circulates the refrigerant, and 2 is installed outside the hot water storage tank 3. 4 is a refrigerant throttling mechanism,
5 is a refrigerant evaporator, 6 is a blower disposed opposite to the refrigerant evaporator 5, and the compressor 1. Heat exchanger 2. Together with the throttling mechanism 4 and the refrigerant evaporator 5, it constitutes a refrigeration cycle. 1 is a circulation pump connected between the lower part 8 of the hot water storage tank 3 and the heat exchanger 2; 9ti is the hot water outlet lO at the upper end of the hot water storage tank 3;
A hot water supply pipe connected to the heat exchanger 2 is connected to the heat exchanger 2, and a hot water outlet 11 is attached to the end. 12 is a running water supply port connected to the lower end of the hot water storage tank 3.

In the water heater constructed as described above, the pressure 1
When the compressor 1 and the circulation f5-''''77 are operated, the temperature of hot water in the hot water storage tank 3 rises, and heated hot water is supplied from the hot water supply pipe 9 through the hot water outlet 11. That is,
The hot water in the hot water tank 3 guided to the heat exchanger 2 by the circulation pump 7 is heated by the heat of condensation of the refrigerant when passing through the heat exchanger 2, and is returned to the hot water tank 3 again. By repeating this circulation cycle, the hot water in the hot water storage tank 3 reaches a predetermined temperature, and the heated hot water can be received from the hot water outlet II.

At this time, the flow of hot water in the hot water storage tank 3 becomes a so-called piston flow, and the heated hot water is stored in the upper part of the hot water storage tank 3, and the hot water outlet pipe of the heat exchanger 2 is connected to the hot water supply pipe 9. As soon as the device is started, heated hot water can be supplied from the upper part of the hot water storage tank 3 or directly from the heat exchanger 2, making it possible to cope with sudden hot water supply loads.

In addition, since the hot water is forcibly circulated through the circulation pump, the heat exchange form in the heat exchanger 2 is a forced convection method, which has good heat exchange performance (heat transfer coefficient), and the heat exchanger 2 It is possible to downsize the

Also, Figure 6 shows a heat exchanger installed inside the hot water tank.
7h, the same reference numerals as in FIG. 5 indicate corresponding parts having the same functions. 13 in the figure is hot water storage tank 3
This is a heat exchanger installed at the bottom of the

In this conventional example, since the heat exchanger 13 is disposed at the lower part of the hot water storage tank 3, a circulation pump for forcibly circulating hot water is not necessary. That is, the flow of hot water in the hot water storage tank 3 becomes natural convection, and the hot water can be uniformly heated throughout the hot water storage tank 3. The hot water heated in the hot water storage tank 3 is supplied from the hot water supply pipe 9 through the hot water outlet 11. In this way, since the heat exchanger 18 is placed directly inside the hot water tank 8 to heat hot water, the installation space for the heat exchanger 13 is not required within the system casing, and as mentioned above, the circulation pump Since this is not necessary, power consumption can be saved, and there is no need for piping outside the hot water storage [3], making it possible to reduce the dispersion heat loss.

[Problem that the invention seeks to solve]

However, the conventional heat pump water heaters shown in FIGS. 5 and 6 above each have problems in terms of installation space and heat radiation loss. In other words, in the case where the heat exchanger 2 is installed outside the hot water storage tank 3, installation space is required for the heat exchanger 2 and the circulation pump 7, and there is a problem in that hot water piping is also required. There were problems in that the heat radiation loss from the outer surface of the vessel 2 and the piping was large, the power consumption associated with the operation of the circulation pump 1 was large, and the operating performance (total performance coefficient) of the system was reduced. In addition, in the case where the heat exchanger 13 is disposed inside the hot water storage tank 3, if the temperature of the hot water in the hot water storage tank 3 is low, the temperature will not rise sufficiently during a short time hot water supply operation and the temperature will not reach the temperature that can be used for hot water supply. However, there was a problem in that it was unable to cope with sudden hot water supply loads.

This invention focused on the problems of these conventional products, took advantage of the advantages of each, and at the same time eliminated the disadvantages.The installation space is small, heat radiation loss is reduced, and sudden hot water supply loads can be avoided. The present invention provides a heat pump water heater that can also be used.

Means for Solving Problem C] In a heat pump water heater, a heat exchanger serving as a refrigerant condenser is disposed inside a hot water storage tank, and hot water is supplied from a hot water supply pipe connected to the hot water storage tank. A heat exchanger is formed by arranging an inner pipe with one end open in a hot water storage tank inside an outer pipe through which refrigerant circulates, and the hot water supplied to the heat exchanger from the other end of the inner pipe A circulation pump is provided that sucks in the hot water and discharges it into the hot water storage tank.

[Effect]

The hot water in the hot water storage tank is guided by the circulation pump to the inner pipe of the heat exchanger, and as it passes through the inner pipe, its temperature is raised by the heat of condensation of the refrigerant passing through the outer pipe. In addition, since the temperature inside the hot water storage tank can be raised by directly touching the outer pipe, thermal efficiency is good and it is possible to cope with sudden hot water supply loads. Since the heat exchanger is installed inside the hot water storage tank, the installation space is small and heat radiation loss is also reduced.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings. Note that the corresponding i portions having the same functions as those of the conventional example described above are given the same reference numerals, and redundant explanations will be omitted.

FIG. 1 is a system diagram showing a first embodiment of the present invention. In the figure, 14 is a refrigerant condenser disposed inside the hot water storage tank 3, which is a heat exchanger having a double tube structure, and its detailed structure is shown in FIG. That is, in this heat exchanger, an inner tube 18 through which hot water 17 circulates is concentrically arranged inside an outer tube 16 through which refrigerant 15 circulates. A header part 20 located at the upper part 19 and lower part 8 in the hot water storage tank 3
The outer tube 16 and the inner tube 18 are branched at ゜2N,
An inlet portion 22 for hot water 17 that opens into the hot water storage tank 3 is provided at one end of the inner pipe 18 branched from the header portion 21 of the lower portion 8 . Furthermore, fins 23 are formed around the outer circumference of the outer tube 16, and the thus formed heat exchanger I4 is wound spirally and placed inside the hot water storage tank 3 as described above. ing.

7 is a circulation pump installed outside the hot water storage tank 3, the suction side is connected to the other end of the inner pipe 18 branched from the header section 20 of the heat exchanger 14 by a hot water outlet pipe 24, and the discharge side is connected to the discharge side. Outlet section 2 of piping 25 1. ,,.

6 is arranged at the upper part 19 of the hot water storage tank 3. Further, a refrigerant inlet pipe 27 connected to the outer pipe 16 branched from the header section 20 is integrally connected to a refrigerant discharge pipe 28 connected to the compressor 1, and an outer pipe branched from the header section 21 of the lower part 8. Refrigerant outlet 1 connected to pipe 16! F29 is connected to the aperture mechanism 4. 30 is a refrigerant suction pipe interposed between the compressor 1 and the refrigerant evaporator 5.

In the heat pump water heater configured as described above, when the compressor 1 and the circulation pump 7 are driven, the temperature of the hot water in the hot water storage tank 3 rises, and the heated hot water is supplied from the hot water outlet 11. First, the refrigerant 15 is compressed by driving the compressor 1, and this refrigerant 15 is sent to the heat exchanger 14 in the hot water storage tank 3 through the discharge pipe 28. The refrigerant 15 that has passed through the outer tube 16 of the heat exchanger 14 is then passed through the outlet tube 29 into the throttle mechanism 4.
The refrigerant is guided to the refrigerant evaporator 5 to be evaporated. Thereafter, the refrigerant returns to the compressor 1 through the suction pipe 30, and this refrigerant cycle is repeated.

On the other hand, the hot water 17 in the hot water storage tank 3 is driven by the circulation pump 7.
As shown by arrow A, the refrigerant is sucked in from the inlet portion 22, passes through the inner tube 18 of the heat exchanger 14, and is heated by the heat of condensation of the refrigerant 15. The heat-exchanged hot water 17 enters the circulation pump 7 through the outlet pipe 24 and is discharged to the upper part 19 in the hot water storage tank 3 as shown by arrow B.

Here, in the heat exchanger 14 described above, since the refrigerant 15 is flowing through the outer tube 16, the hot water 17 in the hot water storage tank 3 is heated around the outer circumference of the outer tube 16, and heat exchange occurs in a state of natural convection. will be held. At this time, the fins 23 are formed around the outer circumference of the outer tube 16, and the heat exchanger 14 is spirally wound, so that the hot water 11 in the hot water storage tank 3 is efficiently The temperature is heated well and evenly.

In addition, the hot water 11 forcibly circulated through the inner pipe 18 of the heat exchanger 14 by the circulation pump 7 undergoes heat exchange in a forced convection state, and the heated hot water 17 is returned to the upper part 19 of the hot water storage tank 3. , the flow fdJ of the hot water 17 in the hot water storage tank 3 is in a piston flow state.

In this way, since the heat exchanger 14 with the double-pipe structure is arranged inside the hot water tank 3, the inner surface of the outer pipe 16 and the inner pipe! Heat exchange is performed on both sides of the outer surface of the heat exchanger 8 in a natural convection state and a forced convection state, respectively, so that a large heat transfer area of the heat exchanger 14 can be obtained. Therefore, the heat exchanger 14 can be downsized, and since it is disposed inside the hot water storage tank 3, the installation space is reduced accordingly, and extra piping is not required, and heat radiation loss is reduced. That is, since the efficiency of the heat exchanger 14 is improved, it can be made smaller, that is, the length can be shorter than in the past, and thereby the piping resistance is also reduced. Also,
Since the amount of heat exchange in the above forced convection state is about A of the total heat exchange amount (natural convection and forced convection), the amount of hot water 17 circulated by the circulation pump 1 is compared to the conventional example (see Figure 5). It can be made as small as a fishing machine, and the capacity of the circulation pump 7 can be extremely reduced. Furthermore, the circulation pump 7 sucks the heated hot water 11 from the inner pipe 18 and returns it to the upper part 19 of the hot water storage tank 3, so when hot water supply operation is started, the sufficiently heated hot water 17 is immediately pumped from the hot water outlet II. This makes it easier to deal with sudden hot water supply loads.

FIG. 3 is a system diagram showing a second embodiment of the invention. In this embodiment, the discharge pipe 25 of the circulation pump 1 is connected to the hot water supply pipe 9 outside the hot water storage tank 3, and the hot water 11 sucked by the circulation bonga passes through the hot water supply pipe 9 as shown by arrow C and is stored in the hot water supply pipe 9. It is returned to the upper part 19 of the tank 3.

With this configuration, the hot water 17 to the hot water storage tank 3 is reduced.
Also, the number of piping through holes that serve as inlets and outlets for the refrigerant 15 can be reduced, resulting in labor savings in manufacturing.

Further, FIG. 4 shows a third embodiment of the present invention.

In this embodiment, the outer pipe 16 of the heat exchanger 14 and the circulation pump 7
The upper header part 2'0 branches from the inner pipe 18 connected to the upper header part 2'0.
protrudes outside the hot water tank 3, and the second embodiment (third embodiment)
The discharge piping 25 of the circulation pump 7 is connected to the hot water supply piping 9 in the same way as in the case shown in FIG.

In such a configuration, the number of piping penetration holes provided in the hot water storage tank 3 can be further reduced.1)
Furthermore, when refrigerant leaks from the header section 20 during operation, it is easy to find and repair the damaged location.

〔Effect of the invention〕

As explained above, according to the present invention, a heat exchanger with a double pipe structure is disposed inside a hot water storage tank, and hot water in the hot water storage tank is circulated through the entire inner pipe of the heat exchanger by a circulation pump. As a result, the heat exchanger has good heat transfer efficiency and can be made smaller. In addition, piping can be omitted when the heat exchanger is installed outside the hot water storage tank, which reduces the installation space, reduces heat radiation loss, and improves system efficiency. It has the effect of improving operating performance, and can also cope with sudden hot water supply loads.
The effect is that the volume of the circulation pump can also be reduced.

[Brief explanation of drawings]

FIG. 1 is a system diagram showing a first embodiment of the present invention;
FIG. 2 is a partial cross-sectional view showing the detailed structure of the heat exchanger shown in FIG. The system diagrams shown in Figures 5 and 6 are system diagrams showing conventional examples.
Figure 5 is a diagram showing an example in which a heat exchanger is installed outside the hot water storage tank.
FIG. 6 is a diagram showing an example in which a heat exchanger is disposed inside the hot water storage tank. 3...Hot water storage tank 1...Circulation pump 8...Lower part of the hot water tank 9...Hot water supply piping 14... Heat exchanger 15 which is a refrigerant condenser...
... Refrigerant 16 ... Outer pipe 17 ... Hot water 18 ... Inner pipe 19 ... Upper part of hot water tank 20.21 ... Header section 25...Discharge piping 26...Exit section Note that the same reference numerals in the drawings indicate corresponding parts having the same function.

Claims (4)

[Claims] (1) In a heat pump water heater in which a heat exchanger serving as a refrigerant condenser is disposed inside a hot water storage tank and hot water is supplied from a hot water supply pipe connected to the hot water storage tank, the heat exchanger is connected to a refrigerant. The heat exchanger consists of an outer pipe that circulates, and an inner pipe that is placed inside the outer pipe and has one end opened in the hot water storage tank, and sucks hot water that has been heat exchanged from the other end of the inner pipe of the heat exchanger. A heat pump water heater characterized by being provided with a circulation pump that discharges water into a storage tank. (2) A patent characterized in that one end of the inner pipe of the heat exchanger that opens into the hot water storage tank is arranged at the bottom of the hot water storage tank, and the outlet of the discharge pipe of the circulation pump is arranged at the top of the hot water storage tank. A heat pump water heater according to claim 1. (3) The heat pump water heater according to claim 1, wherein the discharge pipe of the circulation pump is connected to the hot water supply pipe outside the hot water storage tank. (4) The heat exchanger is a heat pump according to claim 1, characterized in that a part where the outer pipe and the inner pipe connected to the circulation pump diverge protrudes outside the hot water storage tank. Water heater.