JPH0438194Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Technical Field) The present invention relates to a relatively large water heater that stores hot water by forming temperature stratification, such as a water heater that utilizes late-night electricity.

(Prior Art) Currently, various types of water heaters are provided as hot water storage type water heaters, ranging from relatively small capacity water heaters of up to 200 liters to large water heaters. When these are used as a heating method, there are so-called instant hot water storage systems that heat hot water with a burner, electric heater, etc. when hot water is dispensed for small capacities, and for large capacities that use late-night electricity as a fuel-saving type when not in use. Sometimes there is a central hot water storage system that stores a predetermined amount of hot water. In the instant type, it is heated (reheated) and refilled each time it is used, but it is not economical or
There is no major inconvenience in terms of convenience, and they are installed individually and widely used in general households. On the other hand, in cases where large quantities of water are used by a large number of people for commercial purposes, and where the amount of water used per day is approximately constant, it is economical to use a large water storage device all at once. Water heaters that store hot water and use it each time are commonly used. In this case, due to the heat retention and economic efficiency of water heaters, late-night electricity is used as a heat source, or hot water is stored by heating it indirectly with a heavy oil boiler, and in order to use high-temperature water sequentially,
Instead of stirring the hot water in the hot water storage tank to discharge the hot water, a method is used in which temperature stratification is formed and the hot water is discharged from the upper high temperature water.

However, in the case of levers, the amount of hot water dispensed per unit time generally tends to fluctuate, and, for example, it is likely that a large number of locations are used at the same time, or that only one location is used. Therefore, in order to accommodate any type of use, the hot water pipe from the tank is installed with a diameter larger than that of the branch pipes distributed to each location, and when a small amount of hot water is used, a portion of the hot water (excess hot water) is used.
A circulation method (return method) in which hot water is returned to the tank is sometimes used.

FIG. 4A shows an example of a conventional hot water storage type water heater using the above-mentioned hot water return method.
A heater 2 is provided at the inner bottom of the tank, a water supply pipe 3 is connected to the bottom of the tank, and a hot water tap 4 is connected to the top. 5 is a hot water return pipe connected to the upper part of the tank with a pump P interposed therebetween. The tip of the hot water return pipe 5, that is, the connection to the tank, is as shown in FIG. 4B.
It can be connected by opening directly into the upper part of the tank, or by extending a part of the tip into the tank and forming a large number of holes in the radial direction of the pipe as shown in Figure C. There is.

(Problem) In this conventional method (structure), when hot water is returned by pump operation, the hot water in the tank is agitated because the hot water is returned by spouting it toward the inside of the tank in Figure 4B. In severe cases where the temperature stratification is disturbed, the water temperature in various parts of the tank may become uniform. This is a serious problem in practical use because the relatively low temperature water at the bottom of the tank (compared to the hot water at the top) is mixed with the high temperature water at the top, resulting in a drop in the outlet temperature. Although the above-mentioned problems are alleviated to some extent in the structure shown in Fig. 4C, since the returned hot water flows along the inner wall of the tank, it ends up stirring the hot water inside the tank, so there is still a need for improvement. It was hot.

(Means for solving the problem) This proposal was proposed in view of the above-mentioned problems with the conventional structure.By improving the connection of the hot water return pipe to the hot water storage tank, the temperature stratification of the hot water in the tank is disturbed. The purpose of the present invention is to provide a hot water device that can be used more efficiently without causing problems.

(Embodiment) Fig. 1 shows a first embodiment of the present invention, in which a heater consisting of an electric heater or, in the case of indirect heating, a heating hot water coil or the like piped from the outside, is installed at the inner bottom of the hot water storage tank 11. 12 are arranged. A water supply pipe 13 is connected to the lower part of the tank, and a hot water outlet pipe 14 is connected to the upper part. Reference numeral 15 denotes a return pipe that branches off from a branch pipe section (not shown) leading to various locations with a pump P interposed therebetween, and returns surplus hot water to the tank. The hot water return pipe 15 once passes through the upper part of the inside of the hot water storage tank 11 and is connected to the hot water outlet pipe 14 at the outside of the tank. The penetrating portion is formed not only in the shape of a straight tube but also in the shape of a spiral tube or a finch tube so as to function as the heat exchange portion 15a.

In the above configuration, when the pump P is operated, hot water is passed through the return pipe 15 to the heat exchange section 15a inside the tank.
Although the returned hot water that has passed through the heat exchange section has a lower temperature than when it was discharged due to natural heat radiation on the way back before passing through the heat exchange section, it exchanges heat with the hot water in the tank in the heat exchange section and rises in temperature. It will merge with the hot water in the hot water supply pipe. However, the hot water in the tank is the return pipe 15.
It is in thermal contact with the returned hot water passing through the inside (heat exchange section 15a) and is not directly mixed with the returned hot water, so no mixing or stirring action occurs due to the returned hot water. Therefore, the temperature stratification within the tank is not disturbed. That is, when hot water is tapped, a mixture of the high temperature hot water at the top of the tank and the returned hot water whose temperature has been raised through heat exchange is always obtained, and excellent thermal efficiency can be achieved.

FIG. 2 shows another embodiment of the present invention, and FIG. 3 is an enlarged view of the X section in FIG. In this embodiment, when connecting the hot water outlet pipe 24 to the hot water storage tank 11, the base end is widened into a flap shape at the upper part of the inside of the tank, and the distal end 25a of the hot water return pipe 25 is exposed to the widened part 24a. It is opened.

In this case, when hot water is discharged, the returned hot water from the hot water return pipe 25 mixes with the hot water stored in the upper part of the tank, and is supplied after being subjected to heat exchange such as heating.

However, the return hot water is quickly guided to the hot water tap because the spouting part of the hot water return pipe opening expands downward in a floppy shape and faces the open hot water tap, and is similar to the heat exchanger of the first embodiment. This enables high-temperature hot water to be dispensed without disturbing temperature stratification.

(Effects) As detailed above, in this invention, the tip of the hot water return pipe passes through the upper part of the hot water storage tank and opens into the hot water tap that discharges the hot water in the tank, so the temperature of the hot water in the tank is stratified by the return of hot water into the tank. Therefore, hot water at the upper part of the tank can be obtained when hot water is dispensed, and a hot water storage type water heater which is extremely economical and practical can be provided.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a hot water system according to an embodiment of the present invention, FIG. 2 is a block diagram of a hot water system according to another embodiment of the present invention, and FIG. 3 is a diagram showing the section X in FIG. The enlarged views of FIGS. 4A, B, and C are diagrams showing an example of the configuration of a conventional water heating device. 1, 11... Hot water storage tank, 2, 12... Heater, 3, 13... Water supply pipe, 4, 14, 24... Hot water outlet pipe, 24a... Expansion part, 5, 15, 25... Hot water return pipe , 15a...heat exchange section, 25a...tip of hot water return pipe, P...pump.

Claims (1)

[Scope of Claim for Utility Model Registration] A water supply pipe is connected to the bottom of the hot water storage tank, a hot water outlet pipe and a hot water return pipe are connected to the top of the tank, and a heater is installed at the bottom of the hot water storage tank to stratify the temperature of the hot water inside the tank. In the hot water device for forming hot water and storing hot water, the hot water return pipe and the hot water outlet pipe are connected via a heat exchanger placed in the upper part of the same tank, and the heat exchanger connects the hot water outlet pipe to a downward direction. 1. A hot water storage type hot water device, characterized in that the opening is widened in the shape of a bulge, and the tip of the hot water return pipe is exposed at the bottom of the widened portion.