JPS60191126A - Burner - Google Patents

Abstract

PURPOSE:To form the air flow and the gas flow into laminar flows and to make constant the air-fuel ratio at the time of low TDR to obtain a constantly stable combustion by forming a gas nozzle, a primary air damper, and a secondary air damper by minute pipes. CONSTITUTION:The primary damper 11 is poistioned at the upstream of a mixing pipe 3, and the secondary air damper 12 is located at a position where primary air and secondary air can be divided from each other between a secondary air port 6 and a combustion fan 1. The gas pressuer is fed back from the upstream of the primary air damper 12 to an air-fuel ratio controller 10 and the primary air pressure from the upstream of the primary air damper 11 thereto. Further, the gas nozzle 2, the primary air damper 11 and the secondary air damper 12 are formed by minute pipes so that respective flows thereof are all formed into laminar flows. As a result, particularly the unstable combustion state such as generations of back fire, yellow tip and CO at the time of TDR can be prevented.

Description

[Detailed description of the invention] Field of application for short-term transportation The present invention relates to a household appliance that uses a combustion fan to burn combustion gas under high load, such as when turning gas to the right. related to combustion equipment.

Structure of a conventional example and its problems FIG. 1 shows a conventional example of a water heater. 1 is a combustion fan, 2 is a gas nozzle, 3 is an M joint pipe, 4 is a mixing chamber, 5 is a flame port, 6 is a secondary air port, 7 is a combustion chamber, 8 is a heat exchanger, 9 is an exhaust chamber, 10 is It is an air-fuel ratio control device. The combustion air sent by the combustion fan 1 is divided into primary air and secondary air, and the secondary air is sucked into the mixing pipe S by the gas ejected from the force nozzle 2 L, where it is uniformly mixed in the mixing chamber 4. After 7 hours, it is ejected from the flame port 5. Secondary air is blown out from the secondary air port 6,
High-load combustion occurs inside the air-fuel mixture and the combustion chamber 7.

The combustion scum is heat exchanged with water in a heat exchanger 8, the heated water is used for hot water supply, and the non-gas scum is discharged to the outside from the exhaust chamber 9.

Additionally, the sludge pressure upstream of the nozzle 2 and the primary air pressure upstream of the mixing pipe 3 are fed back to the air-fuel ratio control device 10, and when the gas amount changes and the sludge pressure changes, the fan wind foot is changed. CC air pressure and force pressure are controlled so that they are always equalized.

In FIG. 3, the problems of the C conventional example will be explained. In the vertical axis of FIG. 3, m is the air-fuel ratio, PA is the temporary air ratio, and the horizontal axis TDR is the throttle ratio. As is clear here, it can be seen that in the conventional example, the primary air ratio PA and the air-fuel ratio m increase at low TDR.

In addition, the primary air-fuel ratio PA may also decrease depending on the gas quality, which has a serious adverse effect on combustion stability at low TDR.

OBJECT OF THE INVENTION The present invention solves the problems of the conventional technology.
The purpose is to keep the primary air ratio PA and air-fuel ratio m constant even during R, and to always achieve stable combustion.

Structure of the Invention In order to achieve this object, the present invention comprises a primary air damper formed by a fine tube and a secondary air damper so as to make the air flow entirely laminar in order to divide the combustion air into primary air and secondary air. a secondary air damper, a gas nozzle formed by a fine tube so that all the fuel gas flow is laminar, a mixing pipe located downstream of the gas nozzle, a flame port for spouting the air-fuel mixture, and spouting the secondary air. It consists of a secondary air port and an air-fuel ratio control device that equalizes the gas pressure upstream of the gas nozzle and the air pressure upstream of the primary air damper.

With this configuration, the flow of air and gas becomes laminar in any case, and the flow structure does not change from turbulent to laminar at low TDR as in the conventional case, and the primary air ratio PA and air-fuel ratio m It remains constant in both cases. Therefore, low T
Combustion is stable even during DR.

DESCRIPTION OF EMBODIMENTS FIG. 2 shows an embodiment in which the present invention is applied to a water heater. In the drawings, the same numbers as in FIG. 1 are given to the first members. 11 is a primary air damper, and 12 is a secondary air damper. The primary air damper 11 is located upstream of the mixing tube. The primary air damper 11 may be located in the gap between the mixing tube 3 and the gas nozzle 2.

The secondary air damper is located between the secondary air port 6 and the combustion fan 1, and is located at a location where primary air and secondary air can be divided. The gas pressure is fed back to the air-fuel ratio control device 10 from upstream of the gas nozzle 2, and the primary air pressure is fed back from the upstream of the primary air damper 11. Further, the gas nozzle 2, the primary air damper 11, and the secondary air damper 12 are formed of fine tubes so that their respective flows are all laminar.

With this configuration, the flow structure does not change from turbulent flow to laminar flow at low TDR as in the conventional case, and the flow becomes laminar in either case. In the case of laminar flow, if the flow rate is Q, the proportionality constant K, and the pressure difference ΔP, then Q=KΔP (1) As shown in equation (1), the flow rate Q is one-dimensionally proportional to the pressure difference ΔP. Therefore, the primary air PA and the air-fuel ratio m are constant in all cases as shown in FIG.

Such air-fuel ratio control can prevent combustion instability phenomena such as back, yellow, and CO generation, especially at low TDR.

Effect of the invention The configuration of the present invention has the following effects.

(1) By forming the gas nozzle and the primary air damper with fine tubes, the primary air ratio PA is always constant even if the TDR changes.

(2) By forming the secondary air damper with a fine tube, the air-fuel ratio m remains constant even if the TDR changes.

(3) Since the primary air PA and the air-fuel ratio m are kept constant, it is possible to prevent unstable combustion when back, yellow, and CO occur, especially at low TDR.

[Brief explanation of the drawing]

Figure 1 is a front sectional view showing a conventional example of a water heater;
The figure is a front sectional view of a water heater showing one embodiment of the present invention.
The figure is a characteristic diagram showing the relationship between the primary air ratio, air-fuel ratio, and TDR. 1...Fuel fan, 2...Gas nozzle, 3...Mixing pipe,
5...flame port, 6...secondary air port, 10...air-fuel ratio control device, 11...primary air damper, 12...secondary air damper. One person's name: Benkonju Naka [Toshi! (Yuka 1 person 1st figure 1 figure 2

Claims (1)

[Claims] Combustion fan and converts combustion air into primary air and secondary air 7
A secondary air damper and a secondary air damper are formed by microtubes to make the air flow all laminar. The removed gas nozzle, the mixing pipe located downstream of the J-marked gas nozzle, the flame port that spouts out the mixture q, the secondary air port that spews out secondary air, the gas pressure upstream of the gas nozzle, and the air upstream of the primary air damper. A combustion device consisting of a pressure and an air-fuel ratio control device that equalizes the pressure.