JPH0343559Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a water heater for producing hot water for use in baths, etc.

Conventional technology A conventional water heater has a heat transfer tube installed inside, and heats the water by passing water through the heat transfer tube and flowing a heating medium around the outer circumference, or conversely, passes the heating medium through the heat transfer tube and heats the outer circumference. Most are indirect heating systems that heat water. On the other hand, as a method for directly heating water with a heating medium, there is a submerged combustion method.

Problems to be Solved by the Invention Among the conventional water heaters, those using the indirect heating method described above have low heat transfer efficiency because heat is transferred through heat transfer tubes. On the other hand, in the above-mentioned submerged combustion method, water is directly heated with a heating medium, so the heat transfer efficiency is good, but since the combustion exhaust gas outlet is sealed with water, the exhaust gas pressure is high enough to resist this water seal. The combustion air must be forced through, and positive pressure equal to the water seal head is applied to the combustion chamber, making the device large and complicated to operate.

The object of the present invention is to provide a highly efficient water heater using a direct heating method in which water and a heating medium are brought into direct contact.

Means for Solving the Problems In order to solve the above problems, the direct heating water heater of the present invention has a hot water chamber at the bottom of the water heater body.
A burner that injects fuel gas downward is installed near the center of the upper lid, a combustion tube is installed vertically around the burner, and an intermediate wall is placed concentrically between the combustion tube and the side wall of the water heater body. A water chamber is provided in the upper part between the combustion tube and the intermediate wall, and a gas-liquid contact chamber is formed in the lower part. an opening through which water flows down in a film form, a combustion exhaust gas outlet is provided in the lower part and the bottom of the combustion cylinder, and an exhaust gas flow path is provided between the side wall of the water heater main body and the intermediate wall;
This water heater is characterized by an exhaust port provided at the top of the water heater body.

Effect With the above configuration, when fuel gas is combusted in the burner, the exhaust gas is injected into the gas-liquid contact chamber from the combustion exhaust gas injection hole provided at the lower part of the combustion tube. At the same time, water flows down the outer surface of the combustion tube and the inner surface of the intermediate wall in a film form from the opening provided at the bottom of the water chamber, and after being preheated by the radiated heat of the combustion tube, it comes into direct contact with the exhaust gas ejected from the exhaust gas outlet. The water is heated with high efficiency and stored in the hot water chamber at the bottom. The exhaust gas becomes cold and is discharged from the upper exhaust port.

Embodiment An embodiment of the present invention will be described based on the drawings.
FIG. 1 is a schematic vertical sectional view of a direct heating water heater according to an embodiment of the present invention. In FIG. 1, a water heater main body 1 has a lid 2 attached to its upper part and a hot water chamber 3 formed in its lower part. A burner 4 is installed near the center of the upper lid body 2 so as to inject downwardly fuel gas supplied from a fuel gas supply pipe 5 through a valve 5a. 6 is an igniter, and 7 is a fire detector. A combustion tube 8 having a length close to a predetermined liquid level in the hot water chamber 3 at the bottom is vertically installed on the lower surface of the lid body 2 surrounding the burner 4, and has a length extending from approximately the center to the entire lower circumference and the bottom. A combustion exhaust gas ejection hole 10 is provided to eject combustion exhaust gas 9 generated when combustion gas is combusted by the burner 4 in the combustion tube 8 . Between the combustion tube 8 and the side wall 1a of the water heater main body 1, an intermediate wall 11 having substantially the same length as the combustion tube 8 is vertically installed concentrically at a predetermined interval.
A water chamber 1 is provided in the upper part between the combustion tube 8 and the intermediate wall 11.
2 is provided, and a gas-liquid contact chamber 13 is formed below it. Openings 15a and 15b are provided at the bottom of the water chamber 12 to allow water to flow down in a film form along the outer surface of the combustion tube 8 and the inner surface of the intermediate wall 11 to form water films 14a and 14b. Intermediate wall 11
and the side wall 1a of the water heater main body 1 is the exhaust gas flow path 1.
6, and an exhaust port 17 is provided at the upper end of the side wall 1a. 18 is a demister. A hot water circulation pipe 20 is provided between the hot water chamber 3 and the water chamber 12 via a pump 19. 21 is a temperature controller, and 22 is a pressure sensor. Also hot water room 3
includes a water supply pipe 22, a hot water supply pipe 23 and a return pipe 24.
is installed.

When producing hot water using the direct heating type water heater configured as described above, first, the water is pumped by the pump 19.
The hot water is sent from the hot water chamber 3 to the water chamber 12 via the hot water circulation pipe 20. The water in the water chamber 12 flows through the bottom opening 15a,
The water flows down from 15b as water films 14a and 14b along the outer surface of the combustion tube 8 and the inner surface of the intermediate wall 11, and flows into the hot water chamber 3 from the lower ends of the combustion tube 8 and the intermediate wall 11. Thus, water is distributed between hot water chamber 3 and water chamber 1.
It cycles between 2 and 2. Next, the valve 5a is opened to supply fuel gas from the fuel gas supply pipe 5 to the burner 4, and the igniter 6 ignites it to cause combustion. As a result of the combustion, the combustion tube 8 is heated, and the combustion exhaust gas is ejected from the combustion exhaust gas outlet 10 in the lower part of the combustion tube 8 into the gas-liquid contact chamber 13 . On the other hand, water films 14a and 14b flowing down from the water chamber 12 along the outer surface of the combustion tube 8 and the inner surface of the intermediate wall 11 are preheated by the heat dissipated by the combustion tube 8, and then are ejected from the combustion exhaust gas injection hole 10. It is heated extremely efficiently by direct contact with the generated exhaust gas, and flows down to the hot water chamber 3 as hot water. The exhaust gas exchanges heat with water, becomes low temperature, and is discharged to the outside from the exhaust port 17 via the exhaust gas flow path 16. As described above, the hot water in the hot water chamber 3 is circulated between the hot water chamber 12 via the pump 19 and the hot water circulation pipe 20, and its temperature is gradually raised. The temperature is controlled by intermittent operation.

Hot water is obtained in the above manner, but since the water is in the form of a film and comes into direct contact with the high-temperature combustion exhaust gas, heat transfer is extremely efficient and fuel consumption can be reduced by approximately 30% compared to conventional indirect heating methods. In addition, compared to conventional submerged combustion methods, the pressure of the exhaust gas is lower because it comes into contact with a film of water, forced ventilation is not necessarily required, the equipment is simple and compact, and it is easy to operate. Furthermore, since there are no complicated heat transfer tubes, maintenance and repair such as cleaning of water scale etc. is easy. Although the hot water obtained absorbs combustion exhaust gas components, water quality test results show that it is harmless to the human body, although it depends on the composition of the fuel gas, and hot water that has absorbed _CO2 also has the effect of promoting blood circulation. , suitable for bath use.

Effects of the invention According to the direct heating type water heater of this invention, the water flows down in a film form and comes into direct contact with the combustion exhaust gas, so the heat transfer efficiency is extremely good and the fuel consumption is significantly lower than that of conventional water heaters. The pressure of the exhaust gas may be low, there is no need for forced ventilation, the device can be downsized, and it has special effects such as being easy to operate, maintain, repair, etc.

[Brief explanation of the drawing]

FIG. 1 is a schematic vertical sectional view showing an embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Water heater main body, 2... Lid body, 3... Hot water chamber, 4... Burner, 8... Combustion tube, 10... Combustion exhaust gas nozzle, 11... Intermediate wall, 12... Water chamber,
13... Gas-liquid contact chamber, 14a, 14b... Water film,
15a, 15b...opening, 16...exhaust gas flow path, 17...exhaust port.

Claims (1)

[Scope of utility model registration request] A hot water chamber is provided at the bottom of the water heater body, a burner that injects fuel gas downward is installed near the center of the upper lid, a combustion tube is installed vertically around the burner, and the combustion tube and the water heater are installed vertically around the burner. An intermediate wall is provided vertically concentrically between the side wall of the main body, a water chamber is provided in the upper part between the combustion tube and the intermediate wall, and a gas-liquid contact chamber is formed in the lower part, and a gas-liquid contact chamber is formed at the bottom of the water chamber. Openings are provided along the outer surface of the combustion tube and the inner surface of the intermediate wall to allow water to flow down in the form of a film, and combustion non-gas ejection holes are provided at the lower and bottom portions of the combustion tube, and the side wall of the water heater main body and the intermediate A direct heating type water heater characterized by having an exhaust gas flow path between the wall and the water heater, and an exhaust port provided at the top of the water heater body.