JPS59122845A - Hot-water boiler - Google Patents

Abstract

PURPOSE:To prevent a pipe-type heat exchanger from dew-condensating by a method wherein low temperature water preheated at the lower part of a boiler casing is supplied to the pipe-type heat exchanger. CONSTITUTION:A pipe-type heat exchanger 5, which consists in winding a pipe equipped with fins 6 in a coil inclined over the wound range thereof along an inner shell 1, is arranged in the upper part of a flue duct 4 formed of the inner shell 1. The hot water inlet 7 of the pipe-type heat exchanger is open at the intermediate part of a boiler casing 3, while its hot water outlet 8 is open at the upper end of the boiler casing 3. Due to the structure just mentioned above, low temperature water preheated at the lower part of the boiler casing 3 is supplied to the pipe-type heat exchanger 5, resulting in preventing combustion gas from being cooled down to its dew point and consequently preventing dew-condensating from occurring. In addition, because the low temperature water, which has heated until it reaches the intermediate part of the boiler casing 3, is supplied to the pipe-type heat exchanger 5, no boiling occurs in the pipe-type heat exchanger 5.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a hot water boiler having a heat exchanger with high thermal efficiency and high reliability.

Structure of the conventional example and its problems As a conventional example, there is Japanese Utility Model Publication No. 64-9268, but since the pipe type heat exchanger is installed in series with the can body, hot water is overheated in the pipe type heat exchanger. Boiling is likely to occur, and since the pipe heat exchanger is installed at the bottom of the can, freezing accidents may occur because the inside of the pipe heat exchanger is most likely to be cooled by draft when the operation is stopped. Ta.

The object of the invention is to eliminate the above-mentioned drawbacks of the conventional example, improve thermal efficiency, and at the same time prevent boiling and freezing due to overheating.

Structure of the Invention In order to achieve this object, the present invention provides a pipe heat exchanger with fins at the top of the smoke inside the can consisting of an inner shell and an outer shell, and a hot water outlet pipe and a water supply pipe at the upper and lower ends of the can. At the same time, the inlet of the pipe heat exchanger is opened in the middle part of the can body,
The outlet faces the hot water supply port of the can body, and the pipe heat exchanger is wound along the body of the can body so that it is wound in a coil shape and the entire winding part has an inclination, thereby improving thermal efficiency and reliability. It is something to be measured.

DESCRIPTION OF EMBODIMENTS The present invention will be described with reference to FIG. 1. Reference numeral 1.2 is an inner shell and an outer shell that constitute the can body 3, and 4 is a flue formed by the inner shell 1. . Reference numeral 6 denotes a pipe heat exchanger having fins 6 which are wound in a coil shape along the inner shell 1 above the flue 4 and whose entire winding group is inclined. The type lower opens at the middle part of the can body 3, and the hot water outlet 8 opens at the upper end of the can body 3. 9 is a water supply pipe provided at the lower part of the can body 3; 10 is a hot water outlet pipe provided at the upper end of the can body 3, facing the hot water outlet 8 of the pipe type heat exchanger 6 and having a gap 11; be. 12 is the combustion chamber 13 at the bottom of the flue 4
A burner installed in the fuel spray nozzle 14. Air blowing column 16
．． A middle cylinder 17 having a flame hole 16, an auxiliary combustion cylinder 18 for evaporating fuel, and a burner ring 19 for promoting mixing of fuel and air.
It consists of etc. 20 is a top plate having an exhaust port 21.

Next, to explain the present invention in detail, the combustion air is supplied to the blower column 1.
6, the flame is supplied into the combustion chamber 13 from the flame hole 16 of the middle cylinder 17. On the other hand, the fuel is pressure-injected into the combustion chamber 13 from the nozzle 14, and when ignited by an appropriate method, the sprayed fuel oil mixes with combustion air and burns in the upper part of the combustion chamber 13. The high temperature combustion exhaust gas generated in this way is sent to the flue 4.
is raised to perform heat exchange with the inner wall 1 of the can body 3.

Thereafter, it comes into contact with a pipe heat exchanger 5 provided above the flue 4 and exchanges heat with the pipe heat exchanger 6. The exhaust gas is then exhausted from the exhaust port 21 to the outside of the column.

On the other hand, since water is supplied from the water supply pipe 9, first the can body 3
A portion of the preheated feed water is heated to some extent through heat exchange and then supplied to the pipe heat exchanger 6 from the hot water lower of the pipe heat exchanger 6 where it is heated to a high temperature and then sent to the hot water outlet 8. It is first released into the can body 3. The remaining preheated supply water rises in the can body 3 as it is, undergoes heat exchange, merges with the high-temperature water that has passed through the pipe heat exchanger 6, and is supplied from the hot water tap 10.

In this way, the pipe-type heat exchanger 6 is supplied with low-temperature water that has been preheated at the lower part of the can body 3, and when the combustion exhaust gas is cooled to the dew point temperature in the pipe-type heat exchanger 6, there is no condensation. There's nothing to do. In addition, since the heated low temperature water is supplied to the middle part of the can body 3, the pipe type heat exchanger 5
It does not boil at all.

When the operation is stopped, the temperature of the canned water in the pipe type heat exchanger 6 is significantly lower than that in the can body 3, but since the entire winding part is sloped, the temperature of the canned water in the pipe type heat exchanger 6 is significantly lower than that in the can body 3. Hot water lower, can body 3. Hot water outlet8. Natural circulation is performed in the order of the pipe type heat exchanger 6, and since the pipe type heat exchanger 6 is provided at the upper part of the flue 4, there is no chance of local freezing.

Effects of the invention (1) Condensation of exhaust gas and boiling of hot water due to overheating can be prevented. Since the pipe-type heat exchanger is supplied with low-temperature water that has been preheated at the bottom of the can, the exhaust gas is not cooled to the dew point temperature and is not overheated and therefore does not boil.

(2) Since local cooling is eliminated, freezing can also be prevented.

The pipe heat exchanger is installed in the flue and has natural circulation with the can body, eliminating local cooling.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a main part showing the overall structure of the present invention, and FIG. 2 is a sectional view taken along the line BK in FIG. 1. 1...Inner shell, 2...Outer shell, 3...
... Can body, 4 ... Flue, 6 ... Pipe heat exchanger, 6 ... Fin, 7 ... Inlet, 8 ...・・Outlet, 9・・・・Water pipe, 1o・
... Hot water pipe. Name of agent: Patent attorney Toshio Nakao and 1 other person W4
1 @ 21 'Ia2 figure Δ64

Claims (2)

[Claims] (1) A pipe heat exchanger with fins is provided at the upper part of the flue inside the can body consisting of an inner shell and an outer shell, and a hot water outlet pipe and a water supply pipe are provided at the upper and lower ends of the can body, and at the same time at the inlet of the pipe heat exchanger. A hot water boiler with an opening in the middle of the can body and an outlet facing the hot water supply opening of the can body. (2) The hot water boiler according to claim 1, wherein the pipe heat exchanger is wound in a coil along the body of the can, and at the same time, the entire winding group has an inclination.