JPS58200873A - Gas burner - Google Patents

Abstract

PURPOSE:To control a gas flow rate by sensing gas pressure by a gas pressure sensor, converting it to a current value by an electronic circuit, and driving a valve body with electromagnetic force. CONSTITUTION:A valve body 23 is forced down onto a valve seat 22 by plate springs 29, 30 and cuts out gas even in case of power failure. An electronic circuit 33 compares the pressure detected by a pressure sensor 31 with the set pressure and reduces the current of an electromagnetic coil 26 if said detected pressure is higher than the set one to reduce electromagnetic force, and thus the valve body 23 is pushed back to the valve seat 22 by the plate springs 29, 30 and stops at a point where they balance with each other. On the contrary, if the detected pressure is lower, the valve body 23 is opened, allowing more gas to flow. Accordingly, if the original gas pressure varies to increase the gas pressure in an inlet chamber 20, a volume of gas flowing through a valve gap increases and the pressure in an outlet chamber 21 also rises, so that the control circuit 33 operates so as to throttle a space between the valve body 23 and the vlave seat 22, allowing the pressure in the outlet chamber 21 to return to the original one.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a so-called electronic gas governor that realizes, by electronic control, a gas governor that performs stable combustion without transmitting fluctuations in source gas pressure to the burner in a gas combustion appliance.

Conventional gas combustion appliances are equipped with a gas governor device to prevent the amount of combustion from changing due to fluctuations in the original gas pressure.

Figure 5 shows a diagram of the principle of a gas instantaneous water heater. Gas is inlet 1
The gas flows in from the gas governor 2 and is burned in the burner 3. Water enters from the inlet 4 and absorbs the combustion heat of the burner 3 in the heat exchanger 5 to become hot water, which is then supplied from the faucet 6. 7 indicates an exhaust port. In this case, without the governor 2, if the gas pressure at the inlet 1 fluctuates, the water temperature at the faucet 6 will fluctuate, creating a risk of burns.
Gas governor 2 is definitely required.

FIG. 6 shows a schematic diagram of a conventional gas governor device 2. Gas flows from a person 18 to an outlet 19, and a well 1o and a valve seat 11 are provided in the middle. −・
The end of the diaphragm 12 is attached to the diaphragm 12 and is always urged downward by the spring 13. Now, when the gas pressure at the inlet 8 increases, the pressure in the chamber increases, and the diaphragm
The force P1 that raises the force upward increases and the force P of the spring 13 increases.
'jf10 is raised until 2 is balanced. This allows valve 1
The gap between the valve seat 11 and the valve seat 11 is narrow, increasing flow path resistance and preventing pressure rise in the chamber B.

Conversely, when the pressure in chamber A decreases, valve 10 is pushed down and the gap with valve seat 11 opens to prevent the pressure in chamber B from decreasing.

The gas pressure in the chamber B is controlled by the force P of the spring 13 by the screw 14.
Add or subtract 2.

In the gas governor device as described above, it is necessary for a person to manually adjust the setting of the gas pressure by turning the screw 14, which is particularly troublesome when changing the gas type. Furthermore, since the pressure regulation range of one gas governor is limited (limited by the diameter of the diaphragm 12, the force of the spring 13, etc.), it is difficult to regulate the pressure in a high range. There was also a need to replace it.

In addition, in recent years, devices have been released that control the combustion of burner 3 so that the hot water temperature of 16 reaches the desired temperature.

A diagram of this system is shown in FIG. 7. In this case, a gas distribution valve 16 is provided in the inner row downstream of the governor 2, and the outlet temperature is detected by a temperature sensor 17', and the temperature I pressure control circuit 18 controls the valve. 16. In this case, gas passage resistance increases, making it difficult to achieve the desired amount of combustion, and also increases costs. Furthermore, since the diaphragm 12 is generally made of a thin film made of a material such as rubber, if it breaks, the gas hole 16 will pass through the diaphragm 12.
Gas leaks into the outside air at ρ, which is dangerous. Also, at this time, the force P1 of the diaphragm disappears, and the force P2 of the spring 13
Since the gas is applied to valve 1o and valve 1o is fully open, high gas pressure is applied directly to the burner, and there is a risk of damaging the burner and heat exchanger. 3 or the gas hole 16, it is very dangerous as it may cause an explosion or death due to poisoning. Therefore, a main valve 19 is generally provided as shown in Fig. 7, which increases the passage resistance and increases the cost. There is.

The present invention eliminates the above-mentioned drawbacks of the conventional electronic gas governor, and provides an electronic gas governor that can accurately set gas pressure over a wide range, eliminate any concerns about gas leakage, and also doubles as a combustion sensitivity control function. The aim is to provide the following.

In order to achieve this object, the present invention detects gas pressure using a gas pressure sensor, converts it into a current value using an electronic circuit, and drives the electromagnetic force K, l according to this current value to generate a gas. This is a configuration that controls the current meter.

With this configuration, the gas pressure can be controlled with high accuracy, and since the gas pressure is adjusted by an electronic circuit, a wide adjustment range can be achieved. Furthermore, since there is no need to use a diaphragm, there is no need to worry about gas leakage.

At the same time, the electronic control circuit makes it possible to carry out various types of control, allowing for a wide range of applications such as, for example, by inputting a signal from a temperature sensor, it is easy to vary the combustion h'L and perform a temperature side valve.

Hereinafter, specific embodiments of the present invention will be explained according to the drawings. Note that parts in the middle of each figure or parts that operate the same are given the same numbers.

FIG. 1 is a sectional view showing a specific example of the configuration of the electronic gas governor of the present invention. Gas exits from the inlet chamber 20 and flows toward the -1 chamber 21 through a gap between the valve seat 22 and the IP pot body 23 provided on the way. Reference numeral 24 denotes a magnetic plunger made of a magnetic material, with the valve body 23 attached to one end, and a plunger end 25 made of a non-magnetic material attached to the other end. 26 is a hollow cylindrical electromagnetic coil included in a magnetic circuit 27, and the plungers 24 and 25 pass through the hollow cylindrical portion 28.

Further, the plunger 24.25 is connected to the hollow cylindrical portion 2 of the coil 26.
A plate spring 29.30 is used to hold the valve element 23 vertically movable without contacting the valve seat 22, and normally presses the valve body 23 against the valve seat 22.
A pressure sensor 31 for detecting gas pressure is provided in the 3.degree. outlet chamber 21 which is energized by the 3.degree. outlet chamber 21, and is connected to an electronic circuit 33 by a lead wire 32. Electronic circuit 33 is coupled to electromagnetic coil 26 by lead wire 34 and supplies coil current.

Reference numeral 35 indicates a source supply terminal for the 'multiplex circuit 330' IIj, and reference numeral 36 indicates a gas pressure control terminal for controlling the gas pressure set value by means of an external electric signal.

Next, the operation will be explained. Normally the valve body 23 is a plate spring 29.30
Since the valve seat 22 is pressed by the valve seat 22, the gas does not flow out into the outlet chamber 21. This also serves as the main cock 19 in FIG. 7, and shuts off the gas even in the event of a power outage. electronic circuit 3
When power is supplied to the outlet chamber 3 from the terminal 35, the pressure sensor 31 detects the pressure in the outlet chamber 21. Since the joint vent chamber 23 is closed, the pressure in the outlet chamber 21 is atmospheric pressure. If we consider the case where the gas is, for example, liquefied natural gas (LNG) -
・Generally, the gas pressure supplied to the burner is 1o○rnmH2n
It is necessary to keep it in moderation. For this reason, the electronic circuit 33 supplies the drive current for the coil 26 in the absence of pressure in the outlet chamber 21 .

As a result, an electromagnetic force is generated in the magnetic circuit 27, and the electromagnetic plunger 4 is attracted in the opposite direction against the force of the leaf spring 29. The valve body 23 is separated from the valve seat 22, and gas flows through the gap. This increases the gas pressure in the outlet chamber 21. Pressure sensor 31 detects this pressure and transmits it to electronic circuit 33. The electronic circuit 33 compares the detected pressure of the pressure sensor 31 with the set pressure (100 mmH2o), and reduces the current of the electromagnetic coil 26 if the detected pressure is higher. As a result, the electromagnetic force also decreases, and the valve body 23 is pushed back to the valve seat 22 by the force of the leaf springs 29 and 30, and comes to rest at a point where the electromagnetic force and the force of the leaf springs 29 and 30 are balanced. On the contrary, detection 11-.

If the force is low, the valve body will be opened further to allow more gas to flow.

In other words, the gap between the valve body 23 and the valve seat 22 is controlled so that the gas pressure in the outlet chamber 21 is always 100 mmH2°. Therefore, for example, when the source gas pressure fluctuates and the gas pressure in the inlet chamber 2o increases, the gas flow rate flowing through the gap increases and the pressure in the outlet chamber 31 also increases by 1. It operates to narrow the gap between the valve seat 22 and restore the pressure in the outlet chamber 21 to its original state.

Figure 2 shows its control characteristics. The horizontal axis P3 indicates the original gas pressure, that is, the pressure in the inlet chamber 2o, and the vertical axis P4 indicates the gas pressure in the outlet chamber 21. Kin'ai gas pressure P3 is the set gas pressure P'(
Here, if the pressure is lower than 100 mmH2o), the gas pressure P4 increases according to the original gas pressure P3, as shown by the X-ray in the figure. Here, the areas where the X-ray is more gently sloped than the Z line, which is the original gas pressure P3 - output gas pressure P4, are the valve body 23 and the valve seat 22.
There is a pressure drop due to passage resistance. When the source gas pressure P3 rises above the set gas pressure P', the outlet gas pressure P4 is fixed at P' by the operation of the valve body 23 described above (Y line). As described above, combustion equipment is designed so that F is used heavily in the Pa section where governor characteristics occur.

Y1 to Y3 in the diagram indicate the characteristics when the gas pressure set value P' is changed, and values such as Y1 to Y3 can be selected to arbitrary values by adjusting the electronic control circuit described later.

FIG. 3 is a circuit diagram showing a specific example of the control circuit section 33. The circuit operates by being supplied with a DC power source 37 through a terminal 36. Resistors 38 and 39 generate potential /h via power supply 37. Also, resistance 40° pressure sensor 31. A divided potential eb is obtained by a variable resistor 41. Here, it is assumed that the pressure sensor 31 uses a pressure sensor using piezoresistance or the like, and its resistance value changes depending on the pressure. The potentials la and lb are inverted and amplified f by an operational amplifier 42 (hereinafter referred to as an operational amplifier) and resistors 43 and 44. , the output of the operational amplifier 42 is connected to the base of the transistor 450, the emitter is connected to the negative terminal of the power source 37 through the resistor 46, and the collector is connected to the positive terminal of the power source 37 through the electromagnetic coil 26. The potential et is a value Ip that is approximately halfway between the value at which the current in the electromagnetic coil 26 starts to open the valve body 23 and the value at which the valve body 23 fully opens. ). The resistance value of the spinal pressure sensor 31 is at potential 6.
When a=lb, the operation of the operational amplifier 42 yields k=lb=71! c, the coil 26 receives a current I
It stabilizes by flowing p. Next, when the original gas pressure P3 rises, the gas flow will start if the gap between the body 23 and the valve seat 22 is the same.
, ;.

increases, and the pressure at the pressure sensor 31 rises 3. This causes the resistance of the pressure sensor 31 to increase, causing the electric f1 seal lb
rises. Since the operational amplifier 42 is an inverting amplification circuit (11 paths), the potential /c is lowered by a voltage obtained by amplifying the potentials 1b-1h with an amplification factor of the ratio of the resistors 43 and 44.

As a result, the current flowing through the coil 26 decreases to reduce the gas flow by 1 ft, and the pressure sensor 31 operates to return to the original gas pressure. /Jll to increase the gas pressure.

(However, only when it is between Pa in Fig. 2). In this way, the pressure sensor 31 operates so that the detected pressure is always constant. The gas governor 1 functions exactly the same as the conventional gas governor explained in FIG. The variable resistor 41 is for adjusting the gas pressure, and adjusts Y in FIG. 2 to Y1 to Y3.

This is to be adjusted when the set pressure P' differs due to conversion of gas type or equipment. For example, if the resistance of the variable resistor 41 is increased, the resistance value of the pressure sensor 31 needs to be reduced by the increase in the variable resistor 41 in order to reach the potential lb24a. For Kosai 1, the set value of the gas pressure has decreased by that amount. In this way, the gas pressure can be easily adjusted to any desired value using only the variable resistor 41.

In the figure, 47 indicates a diode for absorbing back electromotive force of the electromagnetic coil 26.

This system realizes the system shown in FIG. 7, in which the control valve 169 and the main valve 19 shown in FIG. 7 are unnecessary and the gas governor 2 is replaced with the electronic gas governor of the present invention.

In the explanation of FIG. 3, it was mentioned that the force of the gas 11 can be arbitrarily varied by the variable resistor 41. This is to vary the combustion amount of the gas burner 3, and this is applied to the combustion amount control by taking advantage of Lfi.It also operates as a gas governor and has a structure that can absorb fluctuations in the source gas pressure.

The left side 33 in FIG. 4 shows the circuit for controlling the gas force constant as explained in FIG. Here, unlike the method of setting the gas pressure using a variable resistor 41 connected in series with the pressure sensor 31 as shown in FIG. Action is the third
As shown in the figure, it works so that 'rlq'=c, and when nothing is connected to the external terminal 36, it works as the same gas governor as in FIG.

This circuit detects the temperature using the temperature control circuit 18i and the temperature sensor 17, and controls the fuel F'U iI'x (gas pressure) so that the temperature reaches the set temperature. The temperature sensor 17 will be explained here using an example in which a negative temperature-sensitive resistance element (thermistor) is included. Divided potential l of temperature sensor 17 and resistor 49
The reference potential 1f divided by d and resistor 50.61 is amplified by operational amplifier 62 and resistors 53' and 64, and its output potential g
g is input from the terminal 36 to the resistor 66. When the water supply temperature is low in the water heater of the younger brother 7, the resistance of the temperature IW sensor 17 is large, the potential jd is high, and the output type 1\reg is also high. Since the potential (h' changes according to the potential eg, 7!a'
It also becomes more expensive.

In order for the stiffness to be ``city level lb 2 la'', pressure sensor 3 is required.
This means that the resistance value of 1 increases (pressure increases), which means that the pressure gradient setting value increases. Conversely, when the temperature of the temperature sensor 17 increases, the potential ld decreases and 7! Since a' also decreases, the set pressure also decreases, and the combustion i of the burner 3 also decreases. In this way, the set value of the gas pressure is automatically and steplessly controlled f7 according to the temperature of the temperature sensor 17. At the same time, when the original gas pressure fluctuates even if the pressure sensor 31C signal is the same l1la', the valve body 23 is controlled to prevent the gas pressure fluctuation. The temperature setting value can be set by a variable resistor 56 connected in series with the temperature [W sensor 17], and gas type switching can be adjusted by a variable resistor 41'. No matter how low the temperature of the temperature sensor 17 is, the potential 7
The maximum value of jh' determined by the resistor 56 is determined by the variable resistor 41' and is cut at the maximum gas pressure setting value (maximum combustion amount) so that Ig does not exceed the power supply voltage 37.

In this example, the temperature control circuit was explained, but a circuit designed according to the pressure or combustion state (flame state and exhaust gas components) may be connected to the terminal 36, or a timer circuit or the like may be used to burn for a certain period of time upon ignition)11- A sequence circuit may be connected, such as a slow ignition operation in which the ignition is throttled down to eliminate ignition noise, or a sequence circuit in which the ignition is extinguished after a certain period of time.

Here, although the valve body 23 is controlled steplessly in FIG. 1, it may be controlled in multiple stages, and it is also possible to control the gas pressure by controlling the valve body 23 on/off and varying its operating cycle. It is clear that the same effect can be obtained by using a motor or other drive method other than the electromagnetic method shown in the figure. It can also be widely applied to various gas appliances other than water heaters.

As described above, the electronic gas governor of the present invention has the following effects.

1. Just like a conventional governor, it is connected to a gas circuit and operates as a governor simply by applying power. By designing the gain of the amplifier circuit, etc., it is possible to obtain highly accurate governor control performance. Pressure adjustment can also be achieved over a wide range using only the electronic circuit section.

2. Unlike conventional gas governors, the structure does not use a diaphragm, so there is no risk of gas leakage due to damage to the diaphragm.

3. It also has a gas closing function, which is difficult to do with conventional gas governors, and is safe because it closes the gas when the power is turned off.

4. It is possible to add various control functions by simply inputting an external signal to the gas pressure control terminal, and it can be applied not only as a simple gas governor but also as an actuator for controlling the amount of combustion.

As described above, it has many effects and is an industrial value dog.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing an example of an electronic gas governor according to the present invention, FIG. 2 is a diagram of its operating characteristics, FIG. A circuit diagram showing an example, Fig. 5 is a system diagram of a general water heater, and Fig. 6 is a conventional gas gas! Fig. 7 is a 7-stem diagram of a conventional water heater with temperature control. 2o... Gas inlet chamber, 21... Gas outlet chamber, 22... Valve seat, 23... Valve body,
24... Single magnetic plunger, 25... Plunger end, 26... Electromagnetic coil, 27...
...Magnetic circuit, 29.30...Plate/(ne (elastic body), 31...Pressure sensor, 33...
Electronic control circuit, 36...Gas pressure control terminal, 41
゜41'...Variable resistor (gas EE setting section). Name of agent: Patent attorney Toshio Nakao and one other person.
Figure 1? 0 222' Fig. 2 Fig. 3 -PJ 5 Fig. 5 q 16 Fig. 10 // Fig. 7

Claims (2)

[Claims] (1) A gas population chamber, a gas outlet chamber, a valve seat provided in the middle of a gas passage from the gas inlet chamber to the outlet chamber, a valve body disposed opposite to the valve seat, and the valve body. - a magnetic plunger formed of a non-magnetic material and having a /ζ plunger end attached to the other end; an electromagnetic coil movably penetrating the magnetic plunger into a hollow cylindrical portion; The outlet chamber includes an elastic body on a magnetic circuit including an electromagnetic coil that urges the valve body in a direction to press the valve seat and at the same time holds the magnetic plunger so that it does not come into contact with the electromagnetic coil. A gas governor is provided with a pressure sensor that detects gas pressure, and has an electronic control circuit that controls a current value flowing through the electromagnetic coil according to the output of the pressure sensor. (2) The electronic control circuit is configured to energize the electromagnetic coil so that the pressure detected by the pressure sensor becomes the pressure set by the gas pressure setting section, and the gas pressure setting section varies the gas pressure set value by an external electric signal. The gas governor according to claim 1, further comprising a gas pressure control terminal.