A gas supply system based on a low-calorific gas generator and a control method therefor

Abstract

The present application relates to the field of gas delivery system, in particular to a kind of based on low heat value gas generator's gas supply and distribution system, including gas generator, gas generator is connected by gas outlet three-way valve, and three-way valve is simultaneously connected vent pipe and booster fan, vent pipe connection igniting device, booster fan is connected gas combustion system by gas pipeline, gas combustion system is connected heat exchange furnace, the present application also discloses a kind of control method for the combustion application of gas supply and distribution system.The present application effectively solves the contradiction problem that low pressure, low heat value gas large flow distribution is given to gas combustion system stable combustion.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of gas delivery system, in particular to a gas supply and distribution system based on low-calorific value gas generator and a control method thereof. BACKGROUND

[0002] In a low-calorific value gas generator (such as a coal gasification furnace or a biomass gasification furnace using air as a catalyst) direct gas combustion system, due to the low calorific value and small pressure of the gas, the gas flow per unit time through the valve is large, so the valve diameter used in the gas supply and distribution system is generally large. However, the cost of commonly used large-diameter gate valves and butterfly valves is high, and the cost will be multiplied by every 50mm increase in the diameter of DN300 or more. Meanwhile, the difficulty and cost of making a three-way valve are also multiplied, and since the valve diameter is too large, the opening and closing power and structural strength of the valve are required to be higher, and it is more likely to be stuck due to tar bonding, which leads to difficulty in opening and causes operation and safety accidents.

[0003] Therefore, there is a need for a gas supply and distribution system with high reliability and a reasonable control method to improve the operation stability and safety of the existing low-calorific value gas generator gas supply and distribution system. SUMMARY

[0004] In order to solve the above-mentioned problems of the gas supply and distribution system, the present application designs a gas supply and distribution system based on a low-calorific value gas generator and a control method thereof, which solves the contradiction between the large flow of low-pressure and low-calorific value gas and the stable combustion of the combustion system. The specific technical scheme is as follows:

[0005] The present application discloses a gas supply and distribution system based on a low-calorific value gas generator, comprising a gas generator, wherein the gas generator is connected to a three-way valve through a gas outlet, and the three-way valve is connected to a vent pipe and a booster fan at the same time, the vent pipe is connected to an ignition device, the booster fan is connected to a gas combustion system through a gas pipeline, and the gas combustion system is connected to a heat exchange furnace.

[0006] Preferably, the three-way valve comprises a main valve body, one side of the main valve body is provided with an air inlet, and the two ends of the main valve body are connected to one end of a sub-valve body and an air outlet B respectively, the other end of the sub-valve body is provided with an actuator, one side of the sub-valve body is provided with an air outlet A, and the actuator is connected to a valve core arranged in the main valve body through a push-pull rod.

[0007] Further, the actuator is connected to a gas source processor through a solenoid valve.

[0008] Further, the connection between the main valve body and the sub-valve body and the connection between the main valve body and the air outlet B are both provided with sealing seat rings, and the connections are fixed through flanges.

[0009] Preferably, the connection between the auxiliary valve body and the actuator is fixed by a flange.

[0010] Preferably, the gas generator comprises a hopper, and the hopper is connected to the gas generator by a feeder.

[0011] The application also discloses a control method of the gas supply and distribution system, comprising the following steps.

[0012] The central control system receives the gas demand signal of the gas combustion system, and first detects the temperature signal and the pressure signal of the gas, monitors the gas temperature, the gas pressure and the oxygen content of the gas.

[0013] When the gas temperature, the gas pressure and the oxygen content of the gas all meet the standards, the central control system outputs an opening signal to the three-way valve, slowly opens the three-way valve, supplies the gas to the gas combustion system through the gas outlet A, and simultaneously makes the gas outlet B connected to the venting pipe of the three-way valve gradually close, so that the gas supply and distribution system is switched from the venting state to the complete combustion application state.

[0014] When the flame monitoring signal of the gas combustion system is normal, the central control system outputs a starting instruction to the booster fan, and the booster fan starts and the rotating speed gradually increases from 0 to a set lower limit rotating speed.

[0015] When the load of the heat exchange furnace changes, the gas generator is adjusted according to the corresponding load, and the central control system outputs a corresponding control signal to adjust the rotating speed of the booster fan, so that the rotating speed of the fan is adapted to the gas demand of the gas combustion system.

[0016] Preferably, the gas temperature is controlled at 100-200 DEG C in the case of suitable gas supply, the gas pressure is controlled at 1000-2000 Pa in the case of suitable gas supply, and the oxygen content of the gas is controlled at ≤3.5% according to the oxygen signal detected by the oxygen content meter.

[0017] Preferably, the lower limit rotating speed of the booster fan is 20% of the rated rotating speed, and the accelerating time of the booster fan is controlled at 5-10 s.

[0018] Preferably, the time consumed by the process of opening the three-way valve to fully open the gas outlet A is controlled at 8-10 s.

[0019] Compared with the prior art, the application has the following beneficial effects:

[0020] The present application adopts a new type of piston large-diameter three-way valve, which can realize mechanical linkage and interlocking of gas supply and venting, and the opening speed of the valve can be adjusted, which is beneficial to the safe operation of ignition combustion and ensures the safe and stable operation condition; the gas supply flow regulation is more accurate by the gas supply of the booster fan; when power failure occurs, the gas supply system can automatically stop gas supply, automatically stop the combustion in the furnace, and synchronously open the gas venting channel, ignite and burn in the air, which avoids the risk of system gas pressure soaring and ensures the safety of the system; the collection of multiple induction signals greatly improves the reliability of automatic control; the present application effectively solves the contradiction problem of stable combustion of low-pressure and low-calorific value gas large-flow distribution to the gas combustion system. BRIEF DESCRIPTION OF DRAWINGS

[0021] The present application will be further described in detail below in combination with the drawings and specific embodiments.

[0022] Fig. 1 is a structural schematic diagram of the gas supply and distribution system of the present application.

[0023] Fig. 2 is a structural schematic diagram of the three-way valve of the present application.

[0024] Fig. 3 is a flow chart of the control method of the gas supply and distribution system of the present application.

[0025] In the figure: 1, gas generator; 2, feeder; 3, solid fuel; 4, hopper; 5, gas outlet; 6, three-way valve; 7, venting pipe; 8, ignition device; 9, booster fan; 10, gas pipeline; 11, gas combustion system; 12, heat exchange furnace; 21, actuator; 22, auxiliary valve body; 23, push-pull rod; 24, sealing seat ring; 25, valve core; 26, main valve body; 27, gas inlet; 28, gas outlet A; 29, gas outlet B; 30, electromagnetic valve; 31, gas source processor. DETAILED DESCRIPTION

[0026] The present application will be further described in detail below in combination with the drawings and specific embodiments.

[0027] The present application provides an embodiment as follows:

[0028] Reference Figs. 1-2The application discloses a gas supply and distribution system based on a low-heat-value gas generator, which comprises the gas generator 1, the gas generator 1 comprises a hopper 4, the hopper 4 is connected with the gas generator 1 through a feeder 2, the gas generator 1 is connected with a three-way valve 6 through a gas outlet 5, the three-way valve 6 is simultaneously connected with a venting pipe 7 and a booster fan 9, the venting pipe 7 is connected with an ignition device 8, the booster fan 9 is connected with a gas combustion system 11 through a gas pipeline 10, and the gas combustion system 11 is connected with a heat exchange furnace 12.

[0029] The solid fuel 3 in the hopper 4 is added into the gas generator 1 through the feeder 2 to produce gas through a gasification reaction, the gas enters the three-way valve 6 through the gas outlet 5, the three-way valve 6 adopts a normally closed design for supplying the gas combustion system 11, when the three-way valve 6 has no opening signal, the gas is discharged to the air through the three-way valve 6 and the venting pipe 7, and the ignition device 8 ignites the tail gas to burn in the air, thereby ensuring the safety of the surrounding environment and reducing air pollution, when the three-way valve 6 is opened, the gas flows to the booster fan 9 through the three-way valve 6, is pressurized by the booster fan 9, and is sent to the control valve group of the gas combustion system 11 to be adjusted in pressure and flow, and is ignited and combusted by a burner to supply heat energy to the heat exchange furnace 12.

[0030] Preferably, the three-way valve 6 comprises a main valve body 26, one side of the main valve body 26 is provided with an air inlet 27, two ends of the main valve body 26 are connected with one end of a sub-valve body 22 and an air outlet B 29 respectively, the other end of the sub-valve body 22 is provided with an actuator 21, one side of the sub-valve body 22 is provided with an air outlet A 28, the actuator 21 is connected with a valve core 25 arranged in the main valve body 26 through a push-pull rod 23, and the actuator 21 is connected with a gas source processor 31 through an electromagnetic valve 30, the large-diameter low-cost piston type three-way valve 6 designed in the application can be flexibly and safely switched in the function switching process of controlling the gas supply and safe diffusion.

[0031] Further, the connection positions of the main valve body 26 and the sub-valve body 22 and the connection positions of the main valve body 26 and the air outlet B 29 are all provided with sealing seat rings 24, and the connection positions are fixed through flanges, and the connection position of the sub-valve body 22 and the actuator 21 is fixed through a flange.

[0032] Referring to Fig. 3 The application further discloses a control method of the gas supply and distribution system, which comprises the following steps.

[0033] The central control system receives the gas demand signal of the gas combustion system 11, first detects the temperature signal and the pressure signal of the gas, and monitors the gas temperature, the gas pressure and the oxygen content of the gas.

[0034] When the gas temperature, gas pressure and oxygen content of the gas all meet the standards, the central control system outputs an opening signal to the three-way valve 6, slowly opens the three-way valve 6, supplies the gas to the gas combustion system 11 through the gas outlet A28, and gradually closes the gas outlet B29 connected with the vent pipe 7 at the same time, so that the gas supply and distribution system is switched from the venting state to the complete combustion application state;

[0035] When the flame monitoring signal of the gas combustion system 11 is normal, the central control system outputs a starting instruction to the booster fan 9, the booster fan 9 starts, and the rotating speed gradually increases from 0 to a set lower limit rotating speed;

[0036] When the load of the heat exchange furnace 12 changes, the gas generator 1 is adjusted correspondingly, and the central control system outputs a corresponding control signal to adjust the rotating speed of the booster fan 9, so that the rotating speed of the fan is adapted to the gas demand of the gas combustion system 11, and the close cooperation between the gas supply and distribution system and the gas combustion system 11 achieves the good effects of safe combustion, stable load and reliable automatic control performance.

[0037] Preferably, the gas temperature is controlled at 100-200 DEG C under the condition of suitable gas supply, the gas pressure is controlled at 1000-2000 Pa under the condition of suitable gas supply, and the oxygen content is controlled at ≤3.5% according to the oxygen content signal detected by the oxygen content meter.

[0038] Preferably, the lower limit rotating speed of the booster fan 9 is 20% of the rated rotating speed, and the accelerating time of the booster fan 9 is controlled at 5-10 s.

[0039] Preferably, the time consumed from the opening of the three-way valve 6 to the full opening of the gas outlet A28 is controlled at 8-10 s.

[0040] The present application adopts a new type of piston type large-diameter three-way valve, which can realize the mechanical linkage and interlocking of gas supply and venting, and the speed of valve opening is adjustable, which is beneficial to the safe operation of ignition and combustion, ensures the safe and stable operation condition; the booster fan supplies the gas, so that the gas flow regulation is more accurate; when power failure occurs, the gas supply and distribution system can automatically stop the gas supply, automatically stop the combustion in the furnace, automatically switch to the venting port for safe air discharge, and ensure the safety of the system; the multiple induction signals are collected, which greatly improves the reliability of automatic control; and the present application effectively solves the contradiction problem of stable combustion of low-pressure and low-calorific value gas with large flow rate supplied to the gas combustion system.

[0041] The above embodiments are only illustrative of the principles of the present application and its effects, and are not intended to limit the present application. Any modification or change made by any person skilled in the art without departing from the spirit and scope of the present application shall be covered by the claims of the present application.

Claims

1. A control method for a gas supply system, the control method being applied to a gas supply system comprising a gas generator (1), characterized in that, The gas generator (1) is connected with a three-way valve (6) through a gas outlet (5), the three-way valve (6) is connected with a venting pipe (7) and a booster fan (9) simultaneously, the venting pipe (7) is connected with an ignition device (8), the booster fan (9) is connected with a gas combustion system (11) through a gas pipeline (10), and the gas combustion system (11) is connected with a heat exchange furnace (12). The three-way valve (6) comprises a main valve body (26), one side of the main valve body (26) is provided with an air inlet (27), and two ends of the main valve body (26) are connected with one end of a sub valve body (22) and an air outlet B (29) respectively, the other end of the sub valve body (22) is provided with an actuator (21), and one side of the sub valve body (22) is provided with an air outlet A (28), and the actuator (21) is connected with a valve core (25) arranged in the main valve body (26) through a push-pull rod (23). The control method comprises the following steps: The central control system receives a gas demand signal of the gas combustion system (11), first detects a temperature signal and a pressure signal of the gas, and monitors the gas temperature, the gas pressure and the oxygen content of the gas; When the gas temperature, the gas pressure and the oxygen content of the gas all meet the standards, the central control system outputs an opening signal to the three-way valve (6), slowly opens the three-way valve (6), supplies the gas combustion system (11) with the gas through the air outlet A (28), and gradually closes the air outlet B (29) connected with the venting pipe (7) of the three-way valve (6) at the same time, so that the gas supply and distribution system is switched from the venting state to the complete combustion application state; When the flame monitoring signal of the gas combustion system (11) is normal, the central control system outputs a starting instruction to the booster fan (9), and the booster fan (9) starts and the rotating speed gradually increases from 0 to a set lower limit rotating speed; When the load of the heat exchange furnace (12) changes, the gas generator (1) is adjusted correspondingly, and the rotating speed of the booster fan (9) is adjusted by the central control system to adapt to the gas demand of the gas combustion system (11).

2. The control method for a gas supply system according to claim 1, characterized by, The actuator (21) is connected with a gas source processor (31) through an electromagnetic valve (30).

3. The control method for a gas supply system according to claim 2, characterized by, The connection between the main valve body (26) and the sub valve body (22) and the connection between the main valve body (26) and the air outlet B (28) are both provided with sealing seat rings (24), and the connections are fixed through flanges.

4. The control method for a gas supply system according to claim 2, characterized by The connection between the sub valve body (22) and the actuator (21) is fixed through a flange.

5. The control method for a gas supply system according to claim 2, wherein The gas generator (1) comprises a hopper (4), and the hopper (4) is connected with the gas generator (1) through a feeder (2).

6. The control method for a gas supply system according to claim 1, wherein The gas temperature is controlled at 100-200 DEG C in the case of suitable gas supply, the gas pressure is controlled at 1000-2000 Pa in the case of suitable gas supply, and the oxygen content of the gas is controlled at ≤3.5% according to the oxygen signal detected by an oxygen meter.

7. The control method for a gas supply system according to claim 1, wherein The lower limit rotating speed of the booster fan (9) is 20% of the rated rotating speed, and the rotating speed increasing time of the booster fan (9) is controlled at 5-10 s.

8. The control method for a gas supply system according to claim 1, wherein The time for the three-way valve (6) to be opened to full opening of the air outlet A (28) is controlled to be 8-10 s.

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