JPS59122844A - Water heater - Google Patents

Abstract

PURPOSE:To reduce the generation of noise due to vapor bubbles by a structure wherein a furnace is located nearer to the liquid level than a smoke tube bundle in order to make shallower the depth of liquid at the position, where vapor bubbles are produced, at the early stage during operation. CONSTITUTION:The furnace 5A of a heat exchanger 5 for heating heat transfer fluid is located near to the liquid level of a liquid well part 1B and yet a smoke tube bundle 5B is located at the underside of the furnace 5A. The smoke tube bundle 5B consists in dividing into an upper stage smoke tube bundle 5a, to the one end of which an exhaust port 4a located opposite to the burner 3 of the furnace 5A is connected, and a lower stage smoke tube bundle 5b, the one end side of which is connected through a passage 6 located outside an enclosed container 1 to the other end side of the upper stage smoke tube bundle 5a and at the same time the other end side of which is connected to the lower end part of an exhaust pipe 7 disposed upright along the outer sidewall of the enclosed container 1. Accordingly, because the shallow depth of liquid prevents the boiling point of the liquid from rising, the generation of noise due to vapor bubbles can be suppressed in spite of the generation of bubbles by the heating of liquid at the wall surface of the furnace 5A.

Description

DETAILED DESCRIPTION OF THE INVENTION According to the present invention, a heat exchanger for water heating is inserted and installed in an upper steam chamber in a closed container, and a furnace and a group of smoke pipes are installed in a lower heat medium liquid reservoir in the closed container. Concerning a hot water heater in which a heat exchanger for heating a heat medium liquid is inserted and installed.

In this type of hot water heater, a configuration in which the furnace and a group of smoke pipes are vertically stacked is adopted for the purpose of reducing the width and making it convenient to carry indoors. For hot water heaters in which the heat exchanger for heating the heat medium liquid is configured such that the smoke tube group is located near the liquid level and the furnace is located below the smoke tube group,
It had the following drawbacks.

In other words, in a hot water heater, steam bubbles are formed by heating the heat medium liquid, and these steam bubbles have a vapor pressure equal to the vapor pressure in the steam chamber plus the head pressure corresponding to the liquid depth at the point where they are generated. , and due to the temperature difference between it and the heating medium liquid by a sub-cooling amount corresponding to the liquid depth, heat is taken away and condensation failure occurs. Such condensation failure of vapor bubbles is
The larger the liquid depth at which steam bubbles are generated, the lower the temperature of the heating medium liquid is at the beginning of operation, and the lower the vapor pressure of the steam chamber and the steam bubbles, the more frequently and actively the steam bubbles are generated. On the other hand, in the early stages of operation, the heating of the heat medium by the heat exchanger is generally performed at a ratio of 60% to the furnace and 40% to the smoke pipe group.
Steam bubbles are first generated on the furnace wall.

Therefore, when the furnace is placed below the smoke pipe group like in a conventional hot water heater, the liquid depth at the point where steam bubbles are generated increases at the beginning of operation, so the condensation and destruction of steam bubbles becomes active. Moreover, it occurs in a short period of time, and the liquid splashes back onto the furnace wall due to the condensation breakage of the steam bubbles, causing intense noise. This is particularly noticeable in hot water heaters where the pressure inside the closed container is set below atmospheric pressure and the steam bubbles generated are much larger than in the case of heating under normal pressure.

The purpose of the invention is to eliminate such conventional drawbacks.The characteristic structure of the hot water heater according to the invention taken to achieve the above purpose is that the heat exchanger for heating the heat medium liquid is connected to the furnace of the hot water heater. It is located near the liquid level of the liquid reservoir, and the smoke pipe group is located below the furnace.

The effects of the characteristic configuration of the present invention described above are as follows.

In other words, by locating the furnace closer to the liquid surface than the smoke tube group, the liquid depth at the point where steam bubbles are generated can be reduced in the early stages of operation, thereby suppressing the boiling point rise and reducing the temperature difference between the steam bubbles and the heat transfer liquid. By making the size small, the condensation destruction of steam bubbles can be suppressed, and if the heating continues, steam bubbles will occur even on the walls of the smoke pipes, which have a large liquid depth. Since the heat medium liquid temperature is increased and the vapor pressure in the steam chamber and in the steam bubbles is increased, the temperature difference between the steam bubbles and the heat medium liquid is small, and condensation destruction of the steam bubbles can be suppressed.

The effects of the above action are as follows.

In other words, while the overall width can be reduced to make it easier for people to enter the room, the condensation destruction of vapor bubbles is always suppressed, even if the pressure inside the closed container is below atmospheric pressure.
Even in a hot water heater that generates very large steam bubbles, it is possible to reduce noise generation caused by the steam bubbles condensing and breaking and the heating medium liquid rebounding on the heating surface of the furnace wall or the wall of the smoke tube group.

Hereinafter, embodiments of the configuration of the present invention will be described based on the drawings.

A closed container (υ) is provided in which the heat transfer liquid is sealed in such a state that the internal pressure is maintained below atmospheric pressure. In addition to inserting and installing the exchangers (2) and (2'), a burner (3) is inserted into the heat medium liquid reservoir (IB) in the sealed container (1).
) The furnace (5A) and smoke pipe group (5
A reduced pressure hot water heater is constructed by inserting and installing a heat converter (5) for heating a heat medium liquid consisting of B).

The heat exchanger (5) for heating the heat medium liquid has a furnace (5A) located near the liquid level of the liquid reservoir (IB), and a smoke pipe group (5B).
) is located below the furnace (5A).

The smoke pipe group (5B) is a burner (
3), the upper smoke pipe group (6a) is connected at one end to the exhaust port (4a) located on the opposite side, and the closed container (υ) is connected to the other end of the upper smoke pipe group (5a). The lower smoke pipe group (5b
) and is divided into two parts.

(8), (91 is a hatch for cleaning smoke pipes.

In the above embodiment configuration, the furnace (5A) and the smoke pipe group (
Using the wall surface of 5B) as a heat transfer heating surface, the heat medium liquid is heated and evaporated, and the heat exchanger (2), (
2'), the steam condenses and liquefies and drips back into the liquid reservoir (IB), while the water is heated. Since heating of the heat medium liquid by the furnace (5) is carried out at a ratio of 60% for the furnace (5A) and 40% for the smoke tube group (5B), in the initial stage of operation, the heating medium is first heated by the wall surface of the furnace (5A). Steam bubbles are generated, but the boiling point rise is suppressed due to the small liquid depth of the furnace (5A), that is, the small liquid depth where steam bubbles are generated, and the temperature is reduced by the subcooling of the steam bubbles and heat transfer liquid. Since the difference is small, the condensation destruction of steam bubbles is suppressed, and the generation of noise mainly caused by the condensation destruction of steam bubbles and the liquid rebounding on the heating surface, the tab 9, and the wall surface of the furnace (6A) is suppressed. By the time steam bubbles are actively generated by heating on the wall surface of the smoke tube group (5B), the temperature of the heat medium liquid increases due to the convection of the heat medium liquid due to heating of the heat medium liquid by the furnace (5A). increases, and the vapor pressure in the steam chamber (IA) and the vapor pressure in the generated vapor bubbles increase accordingly, so regardless of the depth of the liquid where vapor bubbles are generated, the heat transfer liquid and vapor bubbles due to subcooling will increase. As the temperature difference between the temperature and the

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view, and FIG. 2 is a sectional view taken along the line 1--2 in FIG. (1)... Sealed container, (2)... Heat exchanger for water heating, (IA)... Steam chamber, (IB)
...Lower heat medium liquid reservoir section,

[5A]...Furnace, (5B)...Smoke pipe group, (5)...
Heat exchanger for heating heat medium liquid.

Claims (1)

[Claims] ■ A water heating heat exchanger (2) is inserted and installed in the upper S steam chamber (IA) in the closed container (1), and the lower heating medium in the closed container (1) is installed. A furnace (5
In a hot water heater in which a heat exchanger (5) for heating a heat medium liquid is inserted and installed, the heat exchanger (5) for heating a heat medium liquid is inserted into the furnace (5A ) is located near the liquid level of the liquid tank m (IB), and the smoke pipe group (5B) is located below the furnace (5A). The hot water heater according to claim 0, wherein the smoke pipe group (5B) is divided into two stages, upper and lower. ■ The hot water heater cell according to claim (1) or claim (2), wherein the pressure inside the closed container (1) is below atmospheric pressure.