JPS6120453Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a hot water supply device, and particularly to a hot water supply device using a hot water storage method.

A hot water storage system uses hot water heated in a heat exchanger to store hot water in a hot water storage tank with a heat-retaining structure installed above it using natural circulation force, and is easy to handle. Because hot water can be easily obtained in large quantities, it is rapidly becoming available in ordinary households.

FIG. 1 is a cross-sectional view of the main parts of an example of a water heater using a hot water storage method using natural circulation, which has been commonly used in the past. A hot water storage tank 3 that is covered with a heat retaining structure is housed therein. A hot water outlet 4 is provided directly above the hot water storage tank 3, and a water supply port 5 is provided on the side surface of the lower part. Further, inside the casing 1 and directly below the hot water storage tank 3, a heating section 9 constituted by a blower 6, a burner 7, and a heat exchanger 8 is provided. The heat exchanger 8 has a water supply port provided at its lower side connected to the bottom of the hot water storage tank 3 via a water supply pipe 10, and a hot water outlet provided at the top thereof connected to the bottom of the hot water storage tank 3. It is connected to a tap pipe 11 that extends through the tap hole 4 to just below the tap hole 4. Note that the upper end surface of the tapping pipe 11 is closed, and a large number of pores 12 are provided on the peripheral surface of the end portion. In this case, the heat exchanger 8 is constituted by a collection of a large number of pipes having a large number of heat absorbing fins, as shown in FIG.
4 and the heat exchange section 15 located between the heat exchange section 1 and the heat exchange section 1
5 and a bypass pipe 16 that bypasses the outlet 14.
The temperature control valve 17 is located at the temperature control valve 17 and opens when the temperature exceeds the set temperature.

In the water heater having the heat exchanger configured as described above, the blower 6 is operated when the hot water storage tank 3, heat exchanger 8, water supply pipe 10, and hot water outlet pipe 11 are all filled with water. When the burner 7 is combusted while blowing air sucked in from the intake port 18, high-temperature gas resulting from the combustion is exhausted from the exhaust port 19 via the heat exchanger 8. In this case, since the heat exchange section 15 of the heat exchanger 8 is constituted by a collection of a large number of pipes having heat absorption fins, the water filled in the pipes is heated and turned into hot water. Rise and rise. When the temperature of the hot water heated in the heat exchange section 15 and flowing toward the upper outlet 14 reaches a predetermined set temperature, the temperature control valve 17 is opened. As a result, the heat exchange section 15
The heated water is sent out from the outlet 14 by its buoyant force, guided to the upper part of the hot water storage tank 3 via the outlet pipe 11, and released into the surrounding area through the pores 12 provided around it. The hot water is sent into the hot water storage tank 3 without causing any disturbance. in this case,
Since the hot water storage tank 3 is filled with water, the hot water sent out from the hot water tap 11 moves upward and is stored sequentially downward from the top of the hot water storage tank 3. Further, as the water in the heat exchanger 15 is heated and moved to the hot water storage tank 3, the cold water at the bottom of the hot water storage tank 3 is supplied to the water supply port 13 of the heat exchanger 8 via the water supply pipe 10. Ru.

By performing these operations in sequence, the water filled in the hot water storage tank 3 undergoes natural circulation via a path passing through the heat exchanger 8, and along with this, the water is boiled by the heat exchanger 8. The heated water is sequentially stored in the hot water storage tank 3.

However, in the water heater with the above configuration, the temperature sensing part 20 of the temperature control valve 17 is integrated and only detects the temperature in the vicinity, and this temperature sensing part uses a wax element or the like. The response is delayed because it converts temperature changes into mechanical changes. As a result, if miniaturization is promoted by reducing the internal hot water storage capacity of the heat exchanger compared to the burner capacity, a boiling phenomenon will occur inside the heat exchanger due to the response delay of the temperature control valve. Shorten the life of the heat exchanger. Further, in such a state, when the temperature control valve opens, the amount of circulating water increases rapidly, and as a result, the temperature of the hot water rapidly decreases, so the temperature control valve closes again. Therefore, the temperature control valve enters an oscillating state in which it repeatedly opens and closes, resulting in a shortened lifespan. Furthermore, if the temperature control valve is removed, the temperature of the hot water sent from the hot water outlet of the heat exchanger to the hot water storage tank will fluctuate greatly due to fluctuations in the water supply temperature and heating capacity. The thermal energy held in the hot water becomes less and the amount of stored hot water cannot be used effectively.

Therefore, an object of the present invention is to provide a water heater that can provide a stable hot water temperature even when the water supply temperature fluctuates.

In order to achieve such an object, the water heater according to the present invention is such that the temperature sensing part of the temperature control valve provided at the hot water outlet of the heat exchanger is provided near the water supply port of the heat exchanger. Hereinafter, the water heater according to the present invention will be described in detail with reference to the drawings.

FIG. 3 is a cross-sectional view of essential parts showing an embodiment of a heat exchanger used in a water heater according to the present invention,
The same parts as in FIG. 2 are designated by the same symbols, and detailed explanation thereof is omitted. In the figure, 21 is an outlet provided on the upper extension of the bypass pipe 16,
This outlet 21 is provided with a temperature control valve 22 . In this case, the temperature control valve 22 includes a valve section 24 biased in the closing direction by a spring 23 and a temperature sensing section 25 that controls the opening amount of the valve section 24 . The temperature sensing portion 25 is constructed of a wax element as in the conventional case, and is provided in a portion close to the water supply port 13. Therefore, the valve portion 24
is controlled in accordance with the temperature of water supplied to the water supply port 13, and opens slightly when the water supply temperature is 5° C., and as the water supply temperature rises, the opening amount increases.

In a water heater having a heat exchanger equipped with a temperature control valve configured as described above, when a burner (not shown) is operated to supply high-temperature combustion gas to the heat exchange section 15 of the heat exchanger, the internal The water is heated and moves upwards. In this case, the valve portion 24 of the temperature control valve 22 provided at the tap water outlet 21 has an opening amount corresponding to the water supply temperature by the temperature sensing portion 25 provided at the water supply port 13. Therefore, the amount of water flowing through the heat exchange section 15 corresponds to the temperature of the water supply. In other words, when the water supply temperature is low, the amount of circulation decreases, and when the temperature of the water supply rises, the amount of circulation increases. As a result, assuming that the amount of heat generated by the burner and the efficiency of the heat exchange section are fixed, the amount of temperature increase will increase when the amount of circulation is small, and the amount of temperature increase will decrease when the amount of circulation is large. As a result, the hot water temperature of the heat exchanger remains constant regardless of the water supply temperature.

In addition, in the above embodiment, a case was explained in which the temperature sensing part of the temperature control valve was provided near the water supply port via the bypass pipe, but in this case, the temperature control valve was heated in the heat exchange part. This is done to make it less susceptible to the effects of hot water, and is not limited to this.

As explained above, the water heater according to the present invention is
The temperature sensing part of the temperature control valve installed at the hot water outlet of the heat exchanger is placed close to the water supply port of the heat exchanger to detect the temperature of the water supply. The opening amount of the valve changes in accordance with the water supply temperature, which has the excellent effect of always storing hot water at a constant temperature regardless of the water supply temperature.

[Brief explanation of the drawing]

Figure 1 is a cross-sectional view of a conventional water heater, Figure 2 is a cross-sectional view of a main part of the heat exchanger in Figure 1, and Figure 3 is a cross-sectional view of a main part of the heat exchanger in Figure 1.
The figure is a sectional view of a main part of an embodiment of a heat exchanger used in a water heater according to the present invention. 13...Water supply port, 15...Heat exchange section, 16...
Bypass pipe, 21... Outlet, 22... Temperature control valve, 23... Spring, 24... Valve part, 25... Temperature sensing part. The same symbols are used for the same parts in the figures.

Claims (1)

[Scope of utility model registration request] In a hot water supply device that supplies hot water heated through an on-off valve disposed at a hot water outlet of the heat exchanger to a hot water storage tank provided above the hot water using natural circulation force, the heat exchanger a valve provided at the outlet of the heat exchanger, and a temperature-sensing section that is placed close to the water supply port of the heat exchanger and that detects the temperature of the water supply to the heat exchanger and adjusts the opening amount of the valve. A water heater characterized by the following features: