JPS5833024A - Gas combustion controller - Google Patents

Abstract

PURPOSE:To prevent the temporary change of the supply quantity of gas upon switching burners by providing within a gas passage a passage control type proportional control valve, a branch pipe which distributes gas and an electromagnetic valve which opens and closes the gas passage. CONSTITUTION:Within gas passage, are provided a flow quantity control type proportional control valve PV, and a branch pipe Pr which distributes gas to a plurality of burners B1 and B2 on the downstream side of the control valve PV. Electromagnetic valves which open or close the gass passage in correspondence to the plurality of the burners B1 and B2 in the intermediate of the branch pipe Pr after branching. The control valve PV is provided with a valve body 4 having a variable sectional area of the passage, electrically driven parts 6-8, a primary pressure chamber 9 on the upstream side of the valve body 4 and a secondary pressure chamber 10 on the downstream side. A back pressure chamber 11 is provided on the opposite side to the passage of a diaphragm 5 moving in linkage with the valve body 4, and a communication pipe 15, communicating the low pressure part of the passage more downstream than the secondary pressure chamber 10 with the back pressure chamber 11 is provided. By this arrangement, the change of the temporary gas supply quantity at the time of switching the burner can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a capacity control means for fully automatically switching the burner between small capacity and high capacity in gas combustion equipment and further proportionally controlling the burner. Regarding manufacturing that prevents.

FIG. 1 is a system diagram of a gas water heater common to the present invention and a conventional example. Gas Q flows in the direction of the arrow through the source solenoid valve v0
．． The branch pipe PY is reached through the proportional control valve PV, and is divided into two routes, each connected to the first burner B1. The second burner B2 has a solenoid valve v1. Supplied via v2. Heat exchanger HE has water W
flows in the direction of the arrow, and there is a temperature sensor T near the heat exchanger outlet.
n is provided to detect the hot water temperature and input it to the electric control section C.

Signal processing, proportional control valve Pv, solenoid valve V. ,V.

Outputs an operation signal to v2. Then, proportional control valve pv, solenoid valve V11 &:
Control Lb ia valve v1. When V2 is oFp, combustion of ij bar stops.

The reason for dividing the burner into two is a well-known standard.

If the amount of gas supplied to the maximum combustion amount of the burner is reduced using the control valve, there will be a limit to the combustion range of the burner, such as backfire. This is an attempt to expand the width.

Here, in the conventional example, a pressure control type proportional control valve shown in FIG. 2 was used as the proportional control valve Pv.

In Fig. 2, 1 is a fluid inlet, 2 is an outlet, 3 is a valve seat,
A valve body 4 is fixed to the center of the diaphragm 5.

A plunger 7 is supported by a leaf spring 8 at the axis of the coil 6 so as to be able to move up and down without sliding. The lower end of the plunger 7 abuts against the center of the diaphragm 6, so that force is applied to the valve body 4.

In the above configuration, the pressure in the primary pressure chamber 9 on the upstream side above the valve body 4 is Pl, and the pressure in the secondary pressure chamber 1o on the downstream side of the valve body 4 is P2.
Let the pressure-receiving surface atSv of the valve body 4 and the pressure-receiving area of the diaphragm 6 be SD, and let F be the force acting on the valve body 4 by the drive unit consisting of the coil 6 and the plunger 7, etc., then depending on the force F generated by the electromagnetic drive unit, Can be changed.

In other words, by controlling the current flowing through the coil 6, the secondary pressure P2t can be controlled.

In other words, in the conventional pressure type proportional control valve shown in FIG. 2, the secondary pressure P2 is controlled by the force F acting on the valve body 4, regardless of the gas flow rate or the primary pressure.

Next, the operation of a conventional example in which the pressure type proportional control valve shown in FIG. 2 is used in the water heater shown in FIG. 1 will be explained with reference to the characteristic diagram of the conventional example shown in FIG. Here, for simplicity, we will explain the first burner B1 and the second burner B2.
are the same. : Now, let the combustion amount of the entire burner be Q, and burner B4. If each combustion lid of B2 is 9, the load on the water heater is large and the proportional valve coil current i (hereinafter referred to as proportional valve current) is the maximum current 5, and burners B1 and B2 each have a maximum combustion amount of 6. In other words, the combustion amount of the entire burner Q =
When the proportional current 1' is lowered from the combustion state at 01, it passes through the curve d and becomes Q=Q2 at h 1 '' 13.

Furthermore, when the load on the water heater becomes smaller, the solenoid valve v1 is closed, but at this moment, the secondary pressure P2 is constant in the pressure control type proportional control valve as described above. Moreover, the combustion amount Q of the entire burner becomes % from Q2 to Q3.

In other words, at this point, the burner combustion amount of the water heater changes discontinuously, and the hot water temperature described in FIG. 1 drops too much.

Then, the hot water temperature sensor Tn detects it and the proportional valve current i
is increased to 12 and Q=02. When the load further decreases, only burner B2 burns, and the proportional control valve reduces the amount of combustion, so that i=i and Q=03.

Conversely, even when the load increases, the solenoid valve v1 remains closed and the proportional valve current increases as the load increases, 1=12 TeQ=
02 To'! ') When Isofune v1 opens, Q=Q4, and the temperature of the hot water rises too much, which is detected by the temperature detector Tn, and the electric control unit C reduces the proportional valve current 1, and 1=i3.
Assuming that Q=03, burners B1 and B2 burn with a small flame, and as the load increases, the proportional valve current increases and i
: Maximum ability Q=Q1 with il.

Of course, when the water heater is actually used, the combustion amount Q2 constantly increases and decreases, so improving this discontinuous control has traditionally been an important issue.

The present invention connects the discontinuous control of the conventional example described above.

FIG. 4 shows an embodiment of a flow rate control type proportional control valve used in the present invention.

In Fig. 4, 1 is a fluid inlet, 2 is an outlet, 3 is a valve seat,
A valve body 4 is fixed to the center of the diaphragm 5.

A langeer 7 is supported on the axis of the coil 6 by a leaf spring 8 so as to be able to move up and down without sliding. The lower end of the plunger 7 is in contact with the center of the diaphragm 6, so that a force is applied to the valve body 4. The upstream side of the valve body 4 is a primary pressure chamber 9. The downstream side is the secondary pressure chamber 1o, and the secondary pressure chamber 10
A constriction part 13 made of oriice is provided further downstream of the
A low pressure section 14 is formed, and a communication passage 16 is provided between the low pressure section 14 and the back pressure chamber 11 to communicate with each other.

The operation of the flow rate control type proportional control valve in the configuration of the present invention described above will be described below. -Pressure of secondary pressure chamber 9 "eP1s secondary pressure chamber 1
0 pressure to B2. Pressure in the low pressure section 14 and back pressure chamber 11
3, and the pressure receiving area Isv of the valve body 4.

If the pressure-receiving area of the diaphragm 5 is SD, and the force exerted on the valve body 4 by the electromagnetic drive unit including the coil 6 and the plunger 7 is F, then B2-P3=-;

However, it is designed so that 5v=SD. However, the wires B2-B3 can be controlled and varied as desired in proportion to the force F that is generated by the electromagnetic drive and acts on the valve body 4.

Here, B2-B3 is the pressure difference between the upstream and downstream of the throttle section 13 due to the orifice, as described above. As is generally known, the pressure difference across the orifice that occurs when fluid flows through the orifice is a function of the flow rate of the fluid. In other words, due to the force F acting on the valve body 4! The fact that 1lP2-P3 is determined means that the flow rate is determined by F,
- It is unrelated to the pressure P1 of the next pressure chamber 9 and the ability of the burner whose combustion amount is controlled by this proportional control valve, that is, the diameter and number of burner nozzles.

Next, as an embodiment of the present invention, a case where the flow rate control type proportional control valve shown in FIG. 4 is used in the water heater shown in FIG. 1 will be explained with reference to FIG. 6, which is a characteristic diagram of the present invention.

As explained in the conventional example, the load on the water heater is sufficiently large for burner B.
1. From the state where B2 is burning at full capacity.

As the load becomes smaller, solenoid valve V closes and only burner B2 burns.1. Furthermore, the manner in which the combustion amount of burner B2 becomes smaller will be explained using FIG.

First, proportional valve current 1=11 and burner B1. B2 burns at full capacity and the gas flow rate is Q=Q.When the load becomes smaller and the proportional valve current decreases to t=i3, burners B4. The combustion amount of B2 also becomes small, and the total gas flow rate of B1°B2 becomes Q=02 through curve a. At this time, burner B1. The gas flow rate of each B2 is Q=Q3 when the flow rate is 1 through the curve a'.

゛When the solenoid valve V is closed, the first burner B is activated.

stops combustion, and only the second burner B2 continues combustion, but unlike the conventional example, the proportional valve current remains at 1 = i3, and the flow rate control type proportional control valve maintains the gas flow rate Q = 02 as described above. It works like flowing water. Therefore, the second burner B2 is operated by the solenoid valve v1.
When the solenoid valve v1 was open, combustion occurred at a gas flow rate of Q3, but the moment the solenoid valve v1 closed, combustion occurred at a gas flow rate of Q2.

Then, as the load becomes smaller, the proportional valve current further decreases, and the gas flow rate increases to 1 '' 14 and Q-
It becomes 03.

Conversely, when the load on the water heater increases, 1 = 43 and solenoid valve v1
opens, and at this moment the second burner B2 becomes Q=Q3, the first burner B also becomes Q-Q3, and the total gas flow rate of burners B1 and B2 becomes Q-02.

When the proportional valve current i further increases, each burner becomes a
Along the curve ', the gas flow rate to the burners B1 and 82 increases along the curve a, 1=i1 and Q=Q.

becomes.

In this way, according to the present invention, the solenoid valve v1 seen in the conventional example
Fig. 6 shows a practical embodiment of the present invention, and the opening/closing of the solenoid valve V explained with reference to Fig. with hysteresis,
In order to prevent frequent opening and closing of the solenoid valve v1, when the proportional valve current decreases, the solenoid valve v1 is closed at 1=i3L, and when the proportional valve current increases, the solenoid valve v1 is opened at '='3H. .

[Brief explanation of drawings]

FIG. 1 is a system diagram of a gas water heater common to the conventional example and the present invention, and FIG. 2 is a configuration diagram showing the principle of a pressure-controlled proportional control valve used in the conventional system. FIG. 3 is a characteristic diagram of the conventional example, and FIG. 4 is a system diagram of the present invention. FIG. 6 is an explanatory diagram of the operation of another embodiment of the present invention. Pv...Proportional control valve, B1. B2・River...Burna. Pr-...Branch pipe &vv'...Solenoid valve, 4
・g2...Valve body h6-8...-Electric drive unit,
9...-Secondary pressure chamber, 10...Secondary pressure chamber, 6...
...Diaphragm, 11 ...Back pressure chamber, 14
・・・・・・Low pressure part. R6...Communication path, 13...Aperture part. Turtle 1 Figure Mei 2 @ Turtle 3 Figure I4 Figure

Claims (3)

[Claims] (1) A valve body capable of varying the cross-sectional area of the flow path is provided in the gas flow passage 1, an electric drive unit that generates a force acting on the valve body, and a primary royal chamber on the upstream side of the valve body. A secondary royal chamber is provided on the downstream side of the valve body, and a back pressure chamber is provided on the opposite side of the flow path of the diaphragm linked with the valve body. A flow rate control type proportional control valve is provided with a communication valve to communicate with the flow rate control type proportional control valve, and a branch pipe for distributing gas to a plurality of burners is provided on the downstream side of the flow rate control type proportional control valve. A gas combustion control device equipped with a solenoid valve that opens and closes gas flow paths corresponding to multiple burners. (2) The gas combustion control device according to claim 1, wherein an orifice or nozzle is provided between the secondary royal family and the low pressure section. (3) Location where sufficient pressure drop due to piping resistance can be obtained-7
・、、、。 The gas combustion side and control device according to claim 1, wherein the low pressure section is a low pressure section.