A joint operation control system and method based on garbage gasification coupled with coal-fired power generation

Abstract

The present invention relates to a joint operation control system based on garbage gasification coupled with coal-fired power generation, comprising: a garbage gasification system and a gasification combustible gas coupled with a coal-fired system; the garbage gasification system comprises a garbage bin, a feeder, a gasifier, a blower, a gas cooler, a gas induced draft fan, a first electric regulating valve and a first stop valve. The beneficial effects of the present invention are as follows: the present invention designs two coupling branches to serve as a backup for each other, which can ensure that the gasification combustible gas generated by the garbage gasification system can be switched and balanced at any time under the premise of the normal economic operation of the two boilers, ensuring that the gasifier is in the best operating condition; the present invention is provided with an emergency shut-off valve, which is used to realize the emergency cutting off of the gasification combustible gas coupled with the coal-fired system pipeline and the emergency shutdown of the gasifier when the two coal-fired boilers fail to shut down at the same time or the gasification system equipment fails, so as to fully ensure the safety and stability of the gasification system and the coal-fired boiler.

Description

Technical Field

[0001] The present invention relates to a resource processing technology for solid wastes such as refuse-derived fuels and combustible general industrial waste, and in particular to a joint operation control system based on waste gasification coupled with coal-fired power generation. Background Art

[0002] At present, there are many studies on waste gasification power generation in China, and there are also several patents involving waste gasification coupled coal-fired power generation. When coal-fired boilers are selected as power generation devices for waste gasification combustible gas, since the large coal-fired units to which the coal-fired boilers belong are all provincially coordinated units, there are large fluctuations in daily operating loads. When the coupled coal-fired boilers adjust their loads according to the requirements of the provincial coordinated regulation, if the waste gasification system is not timely and reasonably coordinated and operated, once the proportion of gasified combustible gas exceeds the normal proportion range, it will have a certain impact on the operation of the coal-fired boiler. According to the "Technical Evaluation Report on the Blending of Gasification Gas in Thermal Power Plants" compiled by the Department of Thermal Engineering of Tsinghua University in March 2016, referring to biomass gasification technology, for low calorific value gasification gas, under BMCR conditions, when 10% calorific value ratio gasification gas is blended, various performance indicators can ensure the normal operation of the boiler.

[0003] During the normal operation of the coal-fired unit, as the social electricity demand changes, the operating load rate of the coal-fired unit will change accordingly, and the corresponding operating load of its coal-fired boiler also needs to be adjusted in time. If this control strategy is not implemented, in order to ensure the normal operation of the coupled coal-fired unit, once the load fluctuation of the coal-fired unit makes the actual gasified combustible gas blended at this time exceed the reasonable blending ratio of the coal-fired boiler, the garbage gasification system can only stop running, otherwise it will have a great impact on the economic operation of the coal-fired boiler. Summary of the invention

[0004] The purpose of the present invention is to overcome the deficiencies in the prior art and to provide a joint operation control system and method based on garbage gasification coupled with coal-fired power generation. When the operating load of the coal-fired boiler changes, the garbage gasification system can be operated under joint adjustment to ensure that the ratio of gasified combustible gas to coal is always in the optimal range without affecting the normal operation of the coal-fired boiler, thereby ensuring the safe and stable operation of the coupled coal-fired unit.

[0005] The combined operation control system based on garbage gasification coupled with coal-fired power generation includes a garbage gasification system and a gasification combustible gas coupled with a coal-fired system;

[0006] The garbage gasification system comprises a garbage bin, a feeder, a gasifier, a blower, a gas cooler, a gas induced draft fan, a first electric regulating valve and a first stop valve, the inlet of the gasifier is connected to the outlet of the feeder and the outlet of the blower respectively, the outlet of the gasifier is connected to the gas inlet of the gas cooler, and the gas outlet of the gas cooler is connected to the gasification combustible gas coupled coal-fired system through the gas induced draft fan, the first electric regulating valve and the first stop valve in sequence;

[0007] The gasification combustible gas coupled coal-fired system includes a coupling branch 1 and a coupling branch 2, wherein the coupling branch 1 includes a first emergency shut-off valve, a second electric regulating valve, a second stop valve, a first one-way check valve and a first coal-fired boiler, and the coupling branch 2 includes a second emergency shut-off valve, a third electric regulating valve, a third stop valve, a second one-way check valve and a second coal-fired boiler; the outlet of the first stop valve of the garbage gasification system is divided into two paths and is respectively connected to the first emergency shut-off valve of the coupling branch 1 and the second emergency shut-off valve of the coupling branch 2; in the coupling branch 1, the first emergency shut-off valve, the second electric regulating valve, the second stop valve, the first one-way check valve and the first coal-fired boiler are connected in sequence; in the coupling branch 2, the second emergency shut-off valve, the third electric regulating valve, the third stop valve, the second one-way check valve and the second coal-fired boiler are connected in sequence.

[0008] Preferably, the inlet of the feeder is connected to the outlet of the garbage bin, and the outlet of the feeder is connected to the feed inlet of the gasifier.

[0009] Preferably, the gasifier is a fixed bed gasifier or a fluidized bed gasifier.

[0010] Preferably, the gas induced draft fan is an explosion-proof axial flow fan.

[0011] Preferably, the first coal-fired boiler and the second coal-fired boiler are large pulverized coal boilers with subcritical or higher parameters.

[0012] The control method of the joint operation control system based on garbage gasification coupled with coal-fired power generation is as follows: the garbage gasification system gasifies garbage at high temperature to generate gasified combustible gas, and then the gasified combustible gas is cooled by a gas cooler, and then sent to the gasified combustible gas coupled with coal-fired system through a pipeline by a gas induced draft fan, and finally enters the coal-fired boiler through various valves for coupled combustion with coal powder; the garbage gasification system realizes variable operating condition adjustment of the gasifier operation by means of frequency conversion adjustment of the feeder and the blower, and at the same time realizes synchronous adjustment of the flow rate of the gasified combustible gas by means of the first electric regulating valve; during normal operation, the second stop valve and the first one-way check valve of the coupling branch one and the third stop valve and the second one-way check valve of the coupling branch two are always in the open state; through the operation of the second electric regulating valve and the third electric regulating valve, the coupling branch one and the coupling branch two of the gasified combustible gas coupled with coal-fired system are in a one-operation-one-standby operation mode.

[0013] As a preference: the feeder is controlled by a variable frequency motor.

[0014] As a preference: the blower is controlled by a variable frequency motor.

[0015] Preferably, the gas cooler cools the gasified combustible gas to a temperature of 400-500°C using a cooling medium.

[0016] The adjustment method of the joint operation control system based on garbage gasification coupled with coal-fired power generation is as follows: when the joint operation control system based on garbage gasification coupled with coal-fired power generation has the following operating conditions, the adjustment method of the control system is as follows:

[0017] 1) When the peak load of the coal-fired units in joint operation is frequently adjusted, the coupling branch 1 is in operation and the coupling branch 2 is on standby, the standby coupling branch 2 is started by opening the second emergency shut-off valve and the third electric regulating valve, and the combustible gas flow is distributed by online adjusting the operation of the second electric regulating valve and the third electric regulating valve, so that the garbage gasification system always operates in the best working condition;

[0018] 2) When the joint operation coal-fired boiler has a planned shutdown or a fault shutdown, after the system receives the shutdown signal of the first coal-fired boiler, the first emergency shut-off valve and the second electric regulating valve are automatically closed, and at the same time, the second emergency shut-off valve and the third electric regulating valve are automatically opened, and the gasified combustible gas is introduced into the coupling branch 2, and the gasification coupling combustion is carried out with the second coal-fired boiler on the coupling branch 2;

[0019] 3) When the two coupled coal-fired boilers are shut down due to a planned shutdown or a fault at the same time, the gasification combustible gas coupled coal-fired system is cut off by controlling each electric regulating valve and the emergency shut-off valve, the feeder and the blower stop running, and the electric regulating valve and the emergency shut-off valve are closed.

[0020] The beneficial effects of the present invention are:

[0021] 1. The present invention can realize the joint operation control between the garbage gasification system and the gasification combustible gas coupled coal-fired system by controlling the opening of the electric regulating valve, the motor frequency of the feeder and the motor frequency of the blower, so as to ensure that the garbage gasification system can switch the coupling branches in time according to the load fluctuation of the coal-fired boiler and the operating conditions of the two coal-fired boilers at any time, thereby greatly improving the operating hours of the garbage gasification system.

[0022] 2. The present invention adopts the mutual backup design of two coupling branches to ensure that the two boilers can operate normally and economically respectively, and the gasification combustible gas generated by the garbage gasification system can be switched and balanced at any time to ensure that the gasifier is in the best operating condition.

[0023] 3. The present invention can make the gasified combustible gas generated by the garbage gasification system always maintain the optimal coal-fired coupling combustion ratio, thereby achieving the optimal garbage gasification thermal efficiency and coupled power generation efficiency.

[0024] 4. By setting an emergency shut-off valve, the present invention can realize the emergency cutting off of the gasification combustible gas coupled with the coal-fired system pipeline and the emergency shutdown of the gasifier when two coal-fired boilers fail and shut down at the same time or the gasification system equipment fails, thereby fully ensuring the safety and stability of the gasification system and the coal-fired boiler. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a schematic diagram of the joint operation control system based on garbage gasification coupled with coal-fired power generation;

[0026] Figure 2 This is a control flow chart taking the initial coupling branch 1 as an example of operation and coupling branch 2 as standby.

[0027] Explanation of the accompanying drawings: garbage bin 1, feeder 2, gasification furnace 3, blower 4, gas cooler 5, gas induced draft fan 6, first electric regulating valve 7, first stop valve 8, first emergency shut-off valve 9, second electric regulating valve 10, second stop valve 11, first one-way check valve 12, first coal-fired boiler 13, second emergency shut-off valve 14, third electric regulating valve 15, third stop valve 16, second one-way check valve 17, second coal-fired boiler 18. DETAILED DESCRIPTION

[0028] The present invention is further described below in conjunction with embodiments. The description of the following embodiments is only used to help understand the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principles of the present invention, several improvements and modifications may be made to the present invention, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

[0029] The said combined operation control system based on garbage gasification coupled with coal-fired power generation controls the garbage feed amount and gasification agent feed amount of the garbage gasification system according to the operating load fluctuation of the coal-fired boiler, and finally controls the gas production of the garbage gasification system to match the optimal coupling and blending ratio of the coal-fired boiler, so as to realize stable and efficient garbage gasification coupled with coal-fired power generation technology. At the same time, the control system can realize the emergency backup branch switching when the combined operation coal-fired boiler fails and shuts down, and timely cuts off the gasification combustible gas pipeline and garbage feed amount when the gasification system equipment fails and shuts down, so as to ensure the safety of the coal-fired unit and the garbage gasification system.

[0030] Embodiment 1

[0031] The first embodiment of the present invention provides a coordinated operation control system based on garbage gasification coupled with coal-fired power generation, including a garbage gasification system and a gasification combustible gas coupled with a coal-fired power generation system.

[0032] The garbage gasification system includes a garbage bin 1, a feeder 2, a gasifier 3, a blower 4, a gas cooler 5, a gas induced draft fan 6, a first electric regulating valve 7 and a first stop valve 8. The inlet of the feeder 2 is connected to the outlet of the garbage bin 1, the outlet of the feeder 2 is connected to the feed inlet of the gasifier 3, the inlet of the gasifier 3 is connected to the outlet of the feeder 2 and the outlet of the blower 4 respectively, the outlet of the gasifier 3 is connected to the gas inlet of the gas cooler 5, and the gas outlet of the gas cooler 5 is connected to the gasification combustible gas coupled coal-fired system through the gas induced draft fan 6, the first electric regulating valve 7 and the first stop valve 8 in sequence. The gasifier 3 body is a fluidized bed gasifier. The gas induced draft fan 6 is an explosion-proof axial flow fan. The first coal-fired boiler 13 and the second coal-fired boiler 18 are large pulverized coal boilers with subcritical and above parameters.

[0033] The gasification combustible gas coupled coal-fired system comprises a coupling branch 1 and a coupling branch 2, wherein the coupling branch 1 comprises a first emergency shut-off valve 9, a second electric regulating valve 10, a second stop valve 11, a first non-return valve 12 and a first coal-fired boiler 13, and the coupling branch 2 comprises a second emergency shut-off valve 14, a third electric regulating valve 15, a third stop valve 16, a second non-return valve 17 and a second coal-fired boiler 18. The outlet of the first stop valve 8 of the garbage gasification system is divided into two paths and connected to the first emergency shut-off valve 9 of the coupling branch 1 and the second emergency shut-off valve 14 of the coupling branch 2 respectively. In the coupling branch 1, the first emergency shut-off valve 9, the second electric regulating valve 10, the second stop valve 11 and the first non-return valve 12 are connected in sequence, and finally connected to the first coal-fired boiler 13; in the coupling branch 2, the second emergency shut-off valve 14, the third electric regulating valve 15, the third stop valve 16 and the second non-return valve 17 are connected in sequence, and finally connected to the second coal-fired boiler 18.

[0034] Embodiment 2

[0035] The second embodiment of the present invention provides a control method for a joint operation control system based on garbage gasification coupled with coal-fired power generation. The garbage gasification system gasifies garbage at high temperature to generate gasified combustible gas. After that, the gasified combustible gas is cooled to 400-500°C by a gas cooler, and then sent to the gasified combustible gas coupled with the coal-fired system through a pipeline by a gas induced draft fan, and finally enters the coal-fired boiler after passing through various valves for coupled combustion with coal powder. The garbage gasification system can realize variable operating condition adjustment of the gasifier operation by means of variable frequency adjustment of the feeder and the blower, and at the same time, the first electric regulating valve can be used to realize synchronous adjustment of the flow rate of the gasified combustible gas. During normal operation, the second stop valve 11 and the first one-way check valve 12 of the coupling branch one and the third stop valve 16 and the second one-way check valve 17 of the coupling branch two are always in the open state. When the garbage gasification system is operating normally, through the operation of the second electric regulating valve, the third electric regulating valve, etc., the coupling branch 1 and the coupling branch 2 of the gasification combustible gas coupling coal-fired system are in a one-operation-one-standby operation mode, that is, when the coupling branch 1 is operating, the coupling branch 2 is not ventilated with gasification combustible gas, and when the coupling branch 2 is operating, the coupling branch 1 is not ventilated with gasification combustible gas, and the coupling branch is adjusted and switched at any time or emergency shutdown is performed according to the operating status of the coal-fired boiler. The feeder 2 is controlled by a variable frequency motor, and the blower 4 is controlled by a variable frequency motor.

[0036] Embodiment 3

[0037] The third embodiment provides a control method for a joint operation control system based on waste gasification coupled with coal-fired power generation. When the joint operation control system based on waste gasification coupled with coal-fired power generation has the following operating conditions, the control system is mainly adjusted as follows:

[0038] 1) When the peak load of the coal-fired units in joint operation is frequent, the spare coupling branch can be started at any time to balance the combustible gas, ensuring the normal and stable operation of the two coal-fired units and the garbage gasification system always operating in the best working condition. Once the coal-fired units in joint operation have the problem of frequent peak load, the spare coupling branch 2 (or coupling branch 1) can be started by operating the second emergency shut-off valve 14 (or the first emergency shut-off valve 9) and the third electric regulating valve 15 (or the second electric regulating valve 10), and the combustible gas flow rate can be distributed by online adjusting the operation of the second electric regulating valve 10 and the third electric regulating valve 15, ensuring that the garbage gasification system always operates in the best working condition without affecting the normal operation of the first coal-fired boiler 13 and the second coal-fired boiler 18.

[0039] 2) When the coal-fired boiler in joint operation has a planned shutdown or a fault shutdown, taking coupling branch one as an example, after the system receives the shutdown signal of the first coal-fired boiler 13, the first emergency shut-off valve 9 and the second electric regulating valve 10 are quickly and automatically closed, and at the same time, the second emergency shut-off valve 14 and the third electric regulating valve 15 are quickly and automatically opened (or the second emergency shut-off valve 14 and the third electric regulating valve 15 are quickly and automatically opened, followed by the second electric regulating valve 10 being quickly and automatically closed, and finally the first emergency shut-off valve 9 is quickly and automatically closed), and the gasified combustible gas is introduced into coupling branch two, and gasification coupled incineration is carried out with the second coal-fired boiler 18 on coupling branch two.

[0040] 3) When the two coupled coal-fired boilers are shut down due to a planned shutdown or a fault at the same time, the gasified combustible gas coupled coal-fired system will be cut off by controlling each electric regulating valve and emergency shut-off valve, and the feeder, blower, electric regulating valve and emergency shut-off valve will be immediately activated to ensure that the overall system safety is not affected.

Claims

1. A joint operation control system based on garbage gasification coupled with coal-fired power generation, characterized by: It includes garbage gasification system and gasification combustible gas coupled coal-fired system; The garbage gasification system comprises a garbage bin (1), a feeder (2), a gasifier (3), a blower (4), a gas cooler (5), a gas induced draft fan (6), a first electric regulating valve (7) and a first stop valve (8); the inlet of the gasifier (3) is connected to the outlet of the feeder (2) and the outlet of the blower (4) respectively; the outlet of the gasifier (3) is connected to the gas inlet of the gas cooler (5); the gas outlet of the gas cooler (5) is connected to the gasification combustible gas coupled coal-fired system through the gas induced draft fan (6), the first electric regulating valve (7) and the first stop valve (8) in sequence; The gasification combustible gas coupled coal-fired system comprises a coupling branch 1 and a coupling branch 2, wherein the coupling branch 1 comprises a first emergency shut-off valve (9), a second electric regulating valve (10), a second stop valve (11), a first one-way check valve (12) and a first coal-fired boiler (13), and the coupling branch 2 comprises a second emergency shut-off valve (14), a third electric regulating valve (15), a third stop valve (16), a second one-way check valve (17) and a second coal-fired boiler (18); the outlet of the first stop valve (8) of the garbage gasification system is divided into two outlets. They are respectively connected to the first emergency shut-off valve (9) of coupling branch one and the second emergency shut-off valve (14) of coupling branch two; in coupling branch one, the first emergency shut-off valve (9), the second electric regulating valve (10), the second stop valve (11), the first one-way check valve (12) and the first coal-fired boiler (13) are connected in sequence; in coupling branch two, the second emergency shut-off valve (14), the third electric regulating valve (15), the third stop valve (16), the second one-way check valve (17) and the second coal-fired boiler (18) are connected in sequence.

2. The combined operation control system based on garbage gasification coupled with coal-fired power generation according to claim 1 is characterized by: The inlet of the feeder (2) is connected to the outlet of the garbage bin (1), and the outlet of the feeder (2) is connected to the feed inlet of the gasifier (3).

3. The combined operation control system based on garbage gasification coupled with coal-fired power generation according to claim 1 is characterized by: The gasifier (3) is a fixed bed gasifier or a fluidized bed gasifier.

4. The combined operation control system based on garbage gasification coupled with coal-fired power generation according to claim 1 is characterized by: The gas induced draft fan (6) is an explosion-proof axial flow fan.

5. The combined operation control system based on garbage gasification coupled with coal-fired power generation according to claim 1 is characterized by: The first coal-fired boiler (13) and the second coal-fired boiler (18) are large pulverized coal boilers with subcritical parameters or above.

6. A control method for the joint operation control system based on garbage gasification coupled with coal-fired power generation as claimed in claim 1, characterized in that: The garbage gasification system gasifies garbage at high temperature to generate gasified combustible gas, and then the gasified combustible gas is cooled by a gas cooler (5), and then sent to the gasified combustible gas coupled coal-fired system by a gas induced draft fan (6) through a pipeline, and finally enters the coal-fired boiler after passing through various valves to be coupled with coal powder for combustion; the garbage gasification system realizes variable operating condition adjustment of the gasification furnace (3) by means of frequency conversion adjustment of a feeder (2) and a blower (4), and simultaneously realizes synchronous adjustment of the flow rate of the gasified combustible gas by means of a first electric regulating valve (7); during normal operation, the second stop valve (11) and the first non-return valve (12) of the coupling branch one and the third stop valve (16) and the second non-return valve (17) of the coupling branch two are always in an open state; through the operation of the second electric regulating valve (10) and the third electric regulating valve (15), the coupling branch one and the coupling branch two of the gasified combustible gas coupled coal-fired system are in a one-operation-one-standby operation mode.

7. The control method of the joint operation control system based on garbage gasification coupled with coal-fired power generation according to claim 6 is characterized by: The feeder (2) is controlled by a variable frequency motor.

8. The control method of the joint operation control system based on garbage gasification coupled with coal-fired power generation according to claim 6 is characterized by: The blower (4) is controlled by a variable frequency motor.

9. The control method of the joint operation control system based on garbage gasification coupled with coal-fired power generation according to claim 6 is characterized by: The gas cooler (5) uses a cooling medium to cool the gasified combustible gas to 400-500°C.

10. A method for adjusting the joint operation control system based on garbage gasification coupled with coal-fired power generation as claimed in claim 1, characterized in that: When the following operating conditions occur in the joint operation control system based on garbage gasification coupled with coal-fired power generation, the adjustment method of the control system is: 1) When the peak load of the coal-fired unit in joint operation is frequently adjusted, the coupling branch 1 is in operation and the coupling branch 2 is in standby mode, the standby coupling branch 2 is started by opening the second emergency shut-off valve (14) and the third electric regulating valve (15), and the flow rate of the combustible gas is distributed by online adjusting the operation of the second electric regulating valve (10) and the third electric regulating valve (15), so that the garbage gasification system always operates in the best working condition; 2) When the joint-operation coal-fired boiler has a planned shutdown or a fault shutdown, after the system receives a shutdown signal from the first coal-fired boiler (13), the first emergency shut-off valve (9) and the second electric regulating valve (10) are automatically closed, and at the same time, the second emergency shut-off valve (14) and the third electric regulating valve (15) are automatically opened, and the gasified combustible gas is introduced into the coupling branch 2, and gasified coupled combustion is performed with the second coal-fired boiler (18) on the coupling branch 2; 3) When the two coupled coal-fired boilers are simultaneously shut down due to a planned shutdown or a fault, the gasified combustible gas coupled coal-fired system is cut off by controlling each electric regulating valve and the emergency shut-off valve, the feeder (2) and the blower (4) stop running, and the electric regulating valve and the emergency shut-off valve are closed.

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