JPH0151728B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a gas heater that measures heating by burning an air-fuel mixture on the surface of a flame port made of a heat-resistant wire mesh.

This type of gas heater described above introduces a mixture of gas fuel and combustion air into a cylindrical or hemispherical flame port made of heat-resistant wire mesh, and burns it on the surface of the flame port to form warm air. The heat dissipated by infrared radiation from the flame opening, which is a wire mesh, lowers the flame temperature and produces less nitrogen oxides (NOx), which are considered harmful during combustion. However, when the amount of combustion per unit area of the wire mesh that makes up the flame port decreases, the flame cools down to an extreme degree, and the combustion of the air-fuel mixture becomes incomplete, resulting in unburned gas (HC) and carbon monoxide. The problem is that the combustion exhaust gas contains a large amount of (CO) and other substances. Furthermore, even if the amount of combustion becomes too large, the temperature of the air-fuel mixture rises too much, leading to flashback and thermal deterioration of the flame nozzle. That is, in this type of gas heater, the range of stable combustion is narrow, so the range of adjustment of the combustion amount is very narrow.

The present invention provides flame ports made of heat-resistant wire mesh for the main and auxiliary burners in a single combustion space, thereby making it possible to widen the range of adjustment of the combustion amount and providing high combustion stability. The purpose is to provide gas heaters.

Next, the configuration of the present invention will be specifically described based on embodiments shown in the drawings.

The gas heater as an application example of the present invention shown in the drawings generates warm air using a dual combustor 3 in which a main burner 1 and a sub-burner 2 are combined, and uses a built-in blower 4 to blow the warm air indoors. This is used to measure room heating. The duplex combustor 3 has a mixture forming part 5A that forms a mixture of gas fuel and combustion air, and a flame port 6A made of a cylindrical heat-resistant wire mesh connected to the mixture forming part 6A of the main burner 1. In the combustion space S surrounded by the main burner 1, a hemispherical flame port 6B made of a heat-resistant wire mesh and connected to a mixture forming part 5B separate from the main burner 1 is arranged. Outside the flame port 6A of the main burner 1, an outer cylinder 7 made of a heat-resistant metal is formed with a space as a mixture passage around the outer periphery of the main burner 1.
is provided. This outer cylinder 7 is the air-fuel mixture forming part 5
The air-fuel mixture forming part 5 forms a part of the air-fuel mixture A at the upper end.
It is connected to the suction pipe 8 which is the main body of A. Outer tube 7
The flame port 6A of the main burner 1 is open downward, and the flame port 6B of the sub burner 2 is arranged in a downward convex spherical shape at the upper end of the flame port 6A of the main burner 1. There is. This flame port 6 of sub-burner 2
B communicates with the air mixing section 5B of the main burner 1, in which components other than the suction pipe 9 are included. The suction pipes 8 and 9 of the main burner 1 and the sub-burner 2 are arranged close to each other, and the fuel nozzle 1, which is the terminal part of the fuel supply system 10, is connected to the open end of each suction pipe 8, 9 of the main burner 1 and the sub-burner 2.
1 is coming one by one. The fuel supply system 10 branches into a main burner supply system 10A and a sub-burner supply system 10B downstream of the governor 12, and the sub-burner supply system 10B has a bypass 14 for small input that straddles the input switching valve 13. It is configured. A solenoid valve 15 is inserted into the main burner supply system 10A on the upstream side of the combustion nozzle 11. Further, the sub-burner supply system 10B is provided with a solenoid valve 16 at its most upstream portion to open and close the sub-burner supply system 10B. In addition, the reference numeral 17 in the figure indicates a flame detection electrode for detecting the ionic current of the flame from the lower end of the outer cylinder 7.
Reference numeral 8 denotes an ignition electrode, 19 a gas sensor such as a Sn02 element for detecting combustible gases such as Co and H2 in the combustion exhaust gas, and 20 a sensor such as zirconia for detecting oxygen concentration.

That is, in the gas heater of this example, gas fuel is supplied to the auxiliary burner 2 without passing through the bypass 14 and ignited with a large input, and then gas fuel is supplied to the main burner 1 to cause the main burner 1 to perform combustion operation. At the same time, after the main burner 1 and the auxiliary burner 2 enter the simultaneous combustion state, a small input is applied to the auxiliary burner 2 through the gas fuel bypass 14 to cause the flame port 6A of the main burner 1 to exceed the heat resistant temperature. It is possible to avoid this. and,
For example, the combustion amount of auxiliary burner 2 is 1000/500Kcal hr
If the main burner 1 is 2500Kcal hr, then the simultaneous combustion of the main and sub burners will burn 3000Kcal hr, and the combustion amount of the sub burner 2 alone will be 1000Kcal hr and 500Kcal hr.
Two types of combustion amount can be selected depending on the heating load. In other words, the combustion amount can be adjusted over a wide range. In particular, in this example, the main burner 1 is installed downward, so the combustion space S
The buoyancy of the combustion gas generated in Since the flame outlet 6A is cooled by contacting with the fuel, overheating of the flame port 6A and temperature rise of the air-fuel mixture can also be suppressed. The combustion amount can be adjusted by turning the main burner 1 on and off, by providing a bypass or a continuously variable valve in the main burner supply system 9A, or by a combination of these. It's okay.

As is clear from the above description based on the embodiments, the gas heater of the present invention is provided with flame ports made of heat-resistant wire mesh for the main and sub burners in a single combustion space, and individually provided for the main and sub burners. Since it is designed to supply gas fuel, the overall combustion amount can be adjusted over a wide range by combining the combustion amounts of the main and sub burners, resulting in a wide range of stable combustion and a smaller combustion space. Since the buoyancy of the combustion gas acts in the opposite direction to the open side, the combustion gas is appropriately contained and the stability of combustion is increased.

[Brief explanation of drawings]

The drawing is a system diagram showing the configuration of a gas heater as an application example of the present invention. 1...Main burner, 2...Sub burner, 3...Combustor, 5A, 5B...Mixture forming section, 6A, 6B...
...flame port, 7...outer cylinder, 8, 9...suction pipe, 10...
...Fuel supply system, 11...Fuel nozzle, S...Combustion space.

Claims (1)

[Claims] 1. A mixture forming part that forms a mixture of gas fuel and combustion air, a cylindrical outer cylinder that connects downward to this mixture forming part, and an inner part that is provided inside this outer cylinder and is made of a cylindrical heat-resistant wire mesh. a main burner with a oriented burner;
The auxiliary burner is installed at the top of the combustion space that opens downward and is surrounded by the main burner's flame port, and the downward flame port made of heat-resistant wire mesh is connected to a mixture forming part that is separate from the main burner. A gas heating system comprising a dual-type combustor, and a fuel supply system that supplies gas fuel individually to the main burner and auxiliary burner of this combustor, and is configured to allow input to the auxiliary burner to be switched in magnitude. Machine.