Hot standby quick-start system of gas-fired boiler

Abstract

The hot standby quick start system comprises a temperature and pressure reduction system, a main adjusting system, an auxiliary adjusting system and a superheater adjusting system. The output end of the temperature and pressure reduction system communicates with the main adjusting system, the auxiliary adjusting system and the superheater adjusting system. A desuperheater and a pressure reducer are arranged in the temperature and pressure reduction system, so that the requirements of steam parameters of the hot standby quick-start system are met; the main adjusting system is provided with a second temperature transmitter and a main adjusting valve, and the steam inlet amount can be adjusted to meet the hot standby requirement according to the temperature index of the lower collecting box; the auxiliary adjusting system is provided with a third temperature transmitter and an auxiliary adjusting valve, the steam inlet amount can be adjusted according to the water side temperature index of the boiler barrel, and the hot standby requirement is met; the superheater adjusting system is provided with a fourth temperature transmitter and a superheating system adjusting valve, whether water is accumulated in the superheater or not can be judged according to the temperature index of the superheater, and the superheater is protected. Therefore, the fuel operation cost of a hot standby furnace of an enterprise boiler is reduced, the emission standard is met, and the requirements of hot standby and quick start within 5-10 minutes can be met.

Description

Technical Field

[0001] The present invention relates to the field of gas boilers with hot standby and quick start requirements, and in particular to a gas boiler hot standby quick start system, which is applied to industries such as petrochemical, papermaking, and pharmaceuticals. Background Art

[0002] In the fields of petrochemical, papermaking, pharmaceutical, etc., the process requires continuous supply of steam. At the same time, the steam supply often changes suddenly with the process requirements. Once the steam supply cannot match the process requirements, the entire process will be scrapped or even shut down, which will cause immeasurable losses. Nowadays, most companies consider setting up hot standby boilers, that is, when the main boiler is running, the hot standby boiler runs at a small load of 3% to 5% BMCR. When the main boiler has an accident, the hot standby boiler will start quickly in 5 to 10 minutes to the rated load to meet the process requirements. However, the long-term consumption of fuel costs in hot standby conditions will impose a great burden on enterprises. At the same time, in hot standby conditions, burner combustion will cause excessive NOx emissions due to high excess air coefficients and incomplete combustion. The above problems have always been problems that need to be solved in this field. Summary of the invention

[0003] In order to solve the above technical problems, the present invention designs a gas boiler hot standby quick start system, which can reduce the fuel operation cost of the enterprise's boiler hot standby furnace. The boiler emissions meet national standards and can meet the hot standby and 5-10 minutes quick start requirements.

[0004] The present invention adopts the following technical solution: A gas boiler hot standby quick start system comprises a temperature reduction and pressure reduction system, a main regulating system, an auxiliary regulating system and a superheater regulating system; the output end of the temperature reduction and pressure reduction system is respectively connected to the main regulating system, the auxiliary regulating system and the superheater regulating system; The temperature reduction and pressure reduction system comprises a shut-off valve 1, a temperature reducer, a pressure reducer, a temperature transmitter 1 and a pressure transmitter which are sequentially connected through pipelines. The temperature transmitter 1 and the pressure transmitter are respectively used to control the temperature reducer and the pressure reducer in linkage. The temperature reduction and pressure reduction system adjusts the steam pressure and temperature at the outlet of the temperature reduction and pressure reduction system through the pressure transmitter and the temperature transmitter 1 respectively. The main regulating system comprises a main regulating valve, a shut-off valve and a lower header which are connected in sequence through pipelines. A temperature transmitter is installed on the lower header. The temperature transmitter is used to control the main regulating valve in linkage. The main regulating system controls the opening of the main regulating valve through feedback from the temperature transmitter to control the amount of steam entering the lower header. The auxiliary regulating system comprises an auxiliary regulating valve, a shut-off valve and a boiler drum which are connected in sequence through pipelines. A temperature transmitter is installed on the boiler drum. The temperature transmitter is used to control the auxiliary regulating valve in linkage. The auxiliary regulating system controls the opening of the auxiliary regulating valve by feedback control of the temperature transmitter to control the amount of steam entering the boiler drum. The superheater regulating system comprises a superheater regulating valve, a shut-off valve 4 and a superheater which are connected in sequence through pipelines. The superheater is equipped with a temperature transmitter 4, which is used to control the superheater regulating valve in linkage. The superheater regulating system determines whether water accumulates in the superheater through feedback from the temperature transmitter 4, controls the opening of the superheater regulating valve to control the amount of steam entering the superheater, and protects the superheater. The lower header is connected to the boiler drum through a pipeline, and the boiler drum is connected to the superheater through a pipeline.

[0005] Preferably, a drum pressure indicator is installed on the drum.

[0006] Preferably, two shut-off valves are installed on both sides of the main regulating valve, and a bypass pipeline is connected in parallel on both sides of the pipeline connecting the main regulating valve and the two shut-off valves. Two shut-off valves are installed on the bypass pipeline.

[0007] Preferably, shut-off valves three are installed on both sides of the auxiliary regulating valve, and bypass pipelines two are connected in parallel on both sides of the pipeline connecting the auxiliary regulating valve and the two shut-off valves three, and two shut-off valves three are installed on the bypass pipeline two.

[0008] Preferably, four shut-off valves are installed on both sides of the superheating system regulating valve, and a bypass pipeline three is connected in parallel on both sides of the pipeline connecting the superheating system regulating valve and the two shut-off valves four, and two shut-off valves four are installed on the bypass pipeline three.

[0009] The beneficial effects of the present invention are as follows: (1) the present invention can dynamically select different process schemes according to the steam usage of the enterprise; (2) a desuperheater and a pressure reducer are arranged in the desuperheating and pressure reducing system to meet the steam parameter requirements of the hot standby quick start system; (3) the main regulating system is provided with a temperature transmitter and a main regulating valve, which can adjust the steam inlet amount according to the temperature index of the lower header to meet the hot standby requirement; (4) the auxiliary regulating system is provided with a temperature transmitter and an auxiliary regulating valve, which can adjust the steam inlet amount according to the water side temperature index of the boiler drum to meet the hot standby requirement; (5) the superheater regulating system is provided with a temperature transmitter and a superheater system regulating valve, which can judge whether the superheater has water accumulation according to the superheater temperature index to protect the superheater; (6) the desuperheating and pressure reducing system, the main regulating system, the auxiliary regulating system and the superheater regulating system are all equipped with shut-off valves for shutting off, bypassing and equipment maintenance, thereby further ensuring the stability of the hot standby quick start system. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 It is a structural schematic diagram of the present invention; In the figure: 100, temperature reduction and pressure reduction system, 200, main regulating system, 300, auxiliary regulating system, 400, superheater regulating system, 500, boiler drum pressure indicator, 101, desuperheater, 102, pressure reducer, 103, shut-off valve one, 104, pressure transmitter, 105, temperature transmitter one, 201, main regulating valve, 202, lower header, 203, temperature transmitter two, 204, shut-off valve two, 301, auxiliary regulating valve, 302, boiler drum, 303, temperature transmitter three, 304, shut-off valve three, 401, superheat system regulating valve, 402, superheater, 403, temperature transmitter four, 404, shut-off valve four. DETAILED DESCRIPTION

[0011] The technical solution of the present invention is further described in detail below through specific embodiments and in conjunction with the accompanying drawings: Example: Figure 1 As shown, a gas boiler hot standby quick start system includes a temperature reduction and pressure reduction system 100, a main regulating system 200, an auxiliary regulating system 300 and a superheater regulating system 400; the output end of the temperature reduction and pressure reduction system 100 is connected to the main regulating system 200, the auxiliary regulating system 300 and the superheater regulating system 400 respectively; The temperature reduction and pressure reduction system 100 comprises a shut-off valve 103, a temperature reducer 101, a pressure reducer 102, a temperature transmitter 105 and a pressure transmitter 104 which are sequentially connected through pipelines. The temperature transmitter 105 and the pressure transmitter 104 are respectively used to control the temperature reducer 101 and the pressure reducer 102 in linkage. The temperature reduction and pressure reduction system 100 adjusts the steam pressure and temperature at the outlet of the temperature reduction and pressure reduction system 100 through the pressure transmitter 104 and the temperature transmitter 105 respectively. The main regulating system 200 includes a main regulating valve 201, a shut-off valve 204 and a lower header 202 which are connected in sequence through pipelines. A temperature transmitter 203 is installed on the lower header 202. The temperature transmitter 203 is used to control the main regulating valve 201 in linkage. The main regulating system 200 controls the opening of the main regulating valve 201 through feedback from the temperature transmitter 203 to control the amount of steam entering the lower header 202. The auxiliary regulating system 300 includes an auxiliary regulating valve 301, a shut-off valve 304 and a drum 302 which are connected in sequence through pipelines. A temperature transmitter 303 is installed on the drum 302. The temperature transmitter 303 is used to control the auxiliary regulating valve 301 in linkage. The auxiliary regulating system 300 controls the opening of the auxiliary regulating valve 301 through feedback control of the temperature transmitter 303 to control the amount of steam entering the drum 302. The superheater regulating system 400 comprises a superheater regulating valve 401, a shut-off valve 404 and a superheater 402 which are connected in sequence through pipelines. The superheater 402 is equipped with a temperature transmitter 403. The temperature transmitter 403 is used to control the superheater regulating valve 401 in linkage. The superheater regulating system 400 determines whether water accumulates in the superheater 402 through feedback from the temperature transmitter 403, controls the opening of the superheater regulating valve 401 to control the amount of steam entering the superheater 402, and protects the superheater 402. The lower header 202 is connected to the boiler drum 302 through a pipeline, and the boiler drum 302 is connected to the superheater 402 through a pipeline.

[0012] The drum 302 is provided with a drum pressure indicator 500 .

[0013] Two shut-off valves are installed on both sides of the main regulating valve respectively, and a bypass pipeline is connected in parallel on both sides of the pipeline connecting the main regulating valve and the two shut-off valves. Two shut-off valves are installed on the bypass pipeline.

[0014] The two sides of the auxiliary regulating valve are respectively installed with shut-off valves three, and the two sides of the pipeline connecting the auxiliary regulating valve and the two shut-off valves three are connected in parallel with bypass pipeline two, and the two shut-off valves three are installed on the bypass pipeline two.

[0015] Four shut-off valves are installed on both sides of the superheating system regulating valve, and bypass pipelines are connected in parallel on both sides of the pipeline connecting the superheating system regulating valve and the two shut-off valves. Two shut-off valves are installed on the bypass pipeline.

[0016] like Figure 1 As shown, low-cost steam is converted into steam with demand parameters through the temperature reduction and pressure reduction system 100 and then enters the main regulating system 200, the auxiliary regulating system 300 and the superheater regulating system 400. The temperature reduction and pressure reduction system 100 adjusts the steam parameters at the outlet of the temperature reduction and pressure reduction system through the pressure transmitter 104 and the temperature transmitter 105; the steam of the main regulating system 200 is regulated to enter the lower header 202 to heat the boiler cold water through the main regulating valve 201; the steam of the auxiliary regulating system 300 is regulated to enter the boiler drum 302 to heat the boiler cold water through the auxiliary regulating valve 301; the steam of the superheater regulating system 400 is regulated to enter the superheater 402 through the auxiliary superheating system regulating valve 401.

[0017] In the temperature reduction and pressure reduction system 100, the temperature reducer 101 adjusts the outlet temperature of the temperature reduction and pressure reduction system through a temperature transmitter 105, and the pressure reducer 102 controls the outlet steam pressure of the temperature reduction and pressure reduction system through a pressure transmitter 104; The present invention mainly controls the temperature of temperature transmitter three 303 and temperature transmitter two 203 to make them equal to the saturation temperature corresponding to the set pressure, and then controls the pressure value of the drum pressure indication 500 to be equal to the set pressure, so as to meet the hot standby working conditions and prepare for quick start. At the same time, a superheater adjustment system 400 is set to judge whether the superheater has water accumulation according to the superheater temperature index to protect the superheater.

[0018] a. The main regulating system 200 controls the opening of the main regulating valve 201 according to the feedback of the temperature transmitter 203 to control the amount of steam entering the lower header 202; b. The auxiliary regulating system 300 controls the opening of the auxiliary regulating valve 301 according to the feedback of the temperature transmitter 3 303 to control the amount of steam entering the lower drum 302; c. The superheater regulating system 400 determines whether water accumulates in the superheater based on the feedback from the temperature transmitter 403, and controls the opening of the superheater regulating valve to control the amount of steam entering the superheater 402 to protect the superheater.

[0019] After adopting the hot standby quick start system of the gas boiler of the present invention, the pressure-bearing parts such as the drum 302 and the lower header 202 in the hot standby condition are heated evenly, and the drum pressure indicator 500 maintains the set pressure range, providing effective conditions for the rapid start of the boiler in 5 to 10 minutes; during the hot standby process, the burner is not started or started with a long open flame, and the NOx emission meets the standard requirements; at the same time, low-cost steam heating is adopted to significantly reduce the fuel operating cost.

[0020] There are two technical solutions to choose from according to the company's gas consumption: 1) Enterprise demand is saturated steam: The low-cost steam passes through the temperature and pressure reduction system 100 and enters the main regulating system 200 and the auxiliary regulating system 300 respectively. 2) Enterprise demand is superheated steam: The low-cost steam passes through the temperature reduction and pressure reduction system 100 and enters the main regulating system 200, the auxiliary regulating system 300 and the superheated steam regulating system respectively.

[0021] The above-described embodiment is only a preferred solution of the present invention and does not limit the present invention in any form. There are other variations and modifications without exceeding the technical solution described in the claims.

Claims

1. A gas boiler hot standby quick start system, characterized in that: It includes a temperature reduction and pressure reduction system, a main regulating system, an auxiliary regulating system and a superheater regulating system; the output end of the temperature reduction and pressure reduction system is connected to the main regulating system, the auxiliary regulating system and the superheater regulating system respectively; The temperature reduction and pressure reduction system comprises a shut-off valve 1, a temperature reducer, a pressure reducer, a temperature transmitter 1 and a pressure transmitter which are sequentially connected through pipelines. The temperature transmitter 1 and the pressure transmitter are respectively used to control the temperature reducer and the pressure reducer in linkage. The temperature reduction and pressure reduction system adjusts the steam pressure and temperature at the outlet of the temperature reduction and pressure reduction system through the pressure transmitter and the temperature transmitter 1 respectively. The main regulating system comprises a main regulating valve, a shut-off valve and a lower header which are connected in sequence through pipelines. A temperature transmitter is installed on the lower header. The temperature transmitter is used to control the main regulating valve in linkage. The main regulating system controls the opening of the main regulating valve through feedback from the temperature transmitter to control the amount of steam entering the lower header. The auxiliary regulating system comprises an auxiliary regulating valve, a shut-off valve and a boiler drum which are connected in sequence through pipelines. A temperature transmitter is installed on the boiler drum. The temperature transmitter is used to control the auxiliary regulating valve in linkage. The auxiliary regulating system controls the opening of the auxiliary regulating valve by feedback control of the temperature transmitter to control the amount of steam entering the boiler drum. The superheater regulating system comprises a superheater regulating valve, a shut-off valve 4 and a superheater which are connected in sequence through pipelines. The superheater is equipped with a temperature transmitter 4, which is used to control the superheater regulating valve in linkage. The superheater regulating system determines whether water accumulates in the superheater through feedback from the temperature transmitter 4, controls the opening of the superheater regulating valve to control the amount of steam entering the superheater, and protects the superheater. The lower header is connected to the boiler drum through a pipeline, and the boiler drum is connected to the superheater through a pipeline.

2. A gas boiler hot standby quick start system according to claim 1, characterized in that: A drum pressure indicator is installed on the drum.

3. A gas boiler hot standby quick start system according to claim 1, characterized in that: Two shut-off valves are installed on both sides of the main regulating valve respectively, and a bypass pipeline is connected in parallel on both sides of the pipeline connecting the main regulating valve and the two shut-off valves. Two shut-off valves are installed on the bypass pipeline.

4. A gas boiler hot standby quick start system according to claim 1, characterized in that: The two sides of the auxiliary regulating valve are respectively installed with shut-off valves three, and the two sides of the pipeline connecting the auxiliary regulating valve and the two shut-off valves three are connected in parallel with bypass pipeline two, and the two shut-off valves three are installed on the bypass pipeline two.

5. The gas boiler hot standby quick start system according to claim 1 is characterized in that: Four shut-off valves are installed on both sides of the superheating system regulating valve, and bypass pipelines are connected in parallel on both sides of the pipeline connecting the superheating system regulating valve and the two shut-off valves. Two shut-off valves are installed on the bypass pipeline.

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