Comprehensive utilization device for conversion and gasification waste heat

Abstract

The utility model discloses a conversion and gasification waste heat comprehensive utilization device, which is characterized in that conversion gas enters a secondary conversion furnace for chemical reaction to release heat, and then enters a low-pressure steam generator for heat exchange with boiler water to produce 0.5 MPa saturated steam. After heat exchange, the converted gas enters a boiler feed water preheater to exchange heat with boiler feed water, the boiler feed water after heat exchange enters a low-pressure steam generator, the converted gas enters a first desalted water heater to exchange heat with normal-temperature desalted water, and hot desalted water after heat exchange enters a gasification deaerator. One path of low-pressure flash steam discharged from the top of the gasification low-pressure flash separator enters the gasification deaerator, the other path of low-pressure flash steam enters the generator set for power generation, during normal production, the third regulating valve is in a closed state, and all the gasification low-pressure flash steam is used for power generation. The conversion low-grade chemical reaction waste heat is used for heating the desalted water of the gasification deaerator, the gasification low-pressure flash steam is reduced and used for heating the desalted water of the gasification deaerator, the generating capacity of the gasification low-pressure flash steam is improved, and comprehensive utilization of conversion and gasification waste heat is achieved.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the field of waste heat utilization, and relates to a comprehensive utilization device for shift and gasification waste heat. BACKGROUND

[0002] There are more low-grade chemical reaction waste heat in shift in synthetic ammonia production process, which is difficult to utilize, and many enterprises take away the waste heat through circulating water cooling, causing energy waste. The gasification low-pressure flash steam has a pressure of 0.15 MPa and a temperature of 126 DEG C, and some domestic enterprises use part of the gasification low-pressure flash steam to heat desalted water in a gasification deaerator and generate power. It is necessary to study how to use the shift low-grade chemical reaction waste heat to heat desalted water in the gasification deaerator, improve the power generation capacity of the gasification low-pressure flash steam, and make contribution to energy saving and emission reduction and sustainable development. CONTENT OF THE UTILITY MODEL

[0003] The utility model aims at providing a comprehensive utilization device for shift and gasification waste heat, which comprises the following steps: shift gas enters a second shift converter to generate chemical reaction, releases heat, and then enters a low-pressure steam generator to exchange heat with boiler water to produce 0.5 MPa saturated steam. After heat exchange, the shift gas enters a boiler feed water preheater to exchange heat with boiler feed water, and the heat-exchanged boiler feed water enters the low-pressure steam generator, and the shift gas enters a first desalted water heater to exchange heat with normal-temperature desalted water, and the heat-exchanged hot desalted water enters the gasification deaerator. The gasification low-pressure flash steam separator top low-pressure flash steam enters the gasification deaerator in one way and enters a power generator set to generate power in another way, and when in normal production, the adjusting valve three is in a closed state, and the gasification low-pressure flash steam is used for power generation.

[0004] A first desalted water heater is arranged between the low-pressure steam generator and the second desalted water heater to produce 105 DEG C hot desalted water which enters the gasification deaerator. The heat-exchanged pipe material of the first desalted water heater is made of 321 stainless steel.

[0005] An adjusting valve one is arranged at the shift gas inlet and outlet of the first desalted water heater, and a remote temperature table one is arranged at the desalted water outlet pipeline, and the remote temperature table one is controlled to 105 DEG C by adjusting the opening degree of the adjusting valve one.

[0006] A remote temperature table two is arranged at the gasification deaerator outlet pipeline, and an adjusting valve three is arranged from the gasification low-pressure flash steam separator top to the gasification deaerator, and when the production load is low and the shift waste heat is insufficient, the remote temperature table two is controlled to 105 DEG C by adjusting the opening degree of the adjusting valve three.

[0007] A pipeline is arranged from the gasification low-pressure flash steam separator top low-pressure flash steam to a low-pressure flash condenser and a separator, and the gas bottom liquid phase is discharged to a gasification ash water tank. When the power generator set is faulty, the adjusting valve four can be immediately closed and the adjusting valve eight is opened to prevent overpressure of the gasification low-pressure flash steam separator.

[0008] Adjusting valve six and adjusting valve seven are arranged at the circulating water inlet pipeline of the low-pressure flash condenser and the generator set; adjusting valve six is opened and adjusting valve seven is closed when the generator set is normally operated; adjusting valve six is immediately closed and adjusting valve seven is opened when the generator set is in failure, so that the circulating water consumption is reduced.

[0009] Adjusting valve five and the steam pipeline from the low-pressure shift steam generator to the generator set are arranged; when the production load is low and the low-pressure flash steam of the gasification is insufficient to maintain the minimum load operation of the generator set, adjusting valve five is opened, 0.5MPa saturated steam is appropriately supplemented, and the start-stop times of the generator set are reduced.

[0010] In the device of the technical scheme, the shift gas enters the second shift furnace and is reacted into shift gas, and then enters the low-pressure steam generator to exchange heat with the boiler water to generate 0.5MPa saturated steam. After heat exchange, the shift gas enters the boiler feed water preheater to heat the 103℃ boiler feed water to 130℃, and the heated boiler feed water enters the low-pressure steam generator. The shift gas enters the first desalted water heater to heat the normal-temperature desalted water to 105℃, and the heated hot desalted water enters the gasification deaerator, and the shift gas continues to enter the second desalted water heater to heat the normal-temperature desalted water to 95℃, and the heated hot desalted water is sent to the boiler for use. The low-pressure flash steam at the top of the gasification low-pressure flash separation device all enters the generator set to generate electricity, and the condensate generated after electricity generation is sent to the gasification ash water tank.

[0011] 1. The low-grade chemical reaction waste heat of shift is used to heat the desalted water of the gasification deaerator, and the low-pressure flash steam of the gasification is all used for power generation, so that the power generation capacity is improved, and the comprehensive utilization of the waste heat of shift and gasification is realized.

[0012] 2. The waste heat of shift chemical reaction is realized to be used for steam generation, heating of boiler feed water, heating of gasification deaerator water and heating of boiler deaerator water in sequence, so that the cascade utilization of the waste heat of chemical reaction is realized.

[0013] 3. The adjusting valve of the circulating water inlet pipeline of the low-pressure flash condenser and the generator set is arranged, so that the circulating water consumption is not increased after the device is transformed.

[0014] 4. The steam pipeline from the low-pressure shift steam generator to the generator set and the adjusting valve are arranged, so that the long-period stable operation of the generator set is realized, and the faults and damages of the generator set caused by frequent start-stop are avoided. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 A schematic diagram of a shift and gasification waste heat comprehensive utilization device.

[0016] In the figure: the second shift converter 1, the low-pressure steam generator 2, the boiler feed water preheater 3, the first desalted water heater 4, the second desalted water heater 5, the gasification deaerator 6, the gasification low-pressure flash separation device 7, the low-pressure flash condenser 8, the separator 9, the grey water tank 10, the generator set 11, the regulating valve one 12, the remote temperature gauge one 13, the remote temperature gauge two 14, the regulating valve three 15, the regulating valve five 16, the regulating valve four 17, the regulating valve six 18, the regulating valve seven 19, the regulating valve eight 20. DETAILED DESCRIPTION

[0017] The technical solutions in the embodiments of the utility model will be clearly and completely described in combination with specific embodiments of the utility model. The embodiments are only a part of the embodiments of the utility model, not all the embodiments. Based on the embodiments in the utility model, all the other embodiments obtained by the ordinary skilled in the art without creative work belong to the protection scope of the utility model.

[0018] Embodiment 1

[0019] The utility model will be further explained in combination with the embodiments.

[0020] A kind of shift and gasification waste heat comprehensive utilization device, the outlet of second shift converter 1 is connected with the inlet of low-pressure steam generator 2, the outlet of low-pressure steam generator 2 is connected with the inlet of boiler feed water preheater 3, the outlet of boiler feed water preheater 3 is connected with the inlet of first desalted water heater 4, the outlet of first desalted water heater 4 is connected with the inlet of gasification deaerator 6;

[0021] Gasification low-pressure flash separation device 7 top outlet is connected with another inlet of gasification deaerator 6 and generator set 11 respectively.

[0022] Another outlet of first desalted water heater 4 is also connected with the inlet of second desalted water heater 5, so that the hot desalted water prepared enters gasification deaerator 6.

[0023] Adjusting valve one 12 is arranged at the inlet and outlet of shift gas of first desalted water heater 4, and remote temperature gauge one 13 is arranged at the outlet pipeline of desalted water.

[0024] Remote temperature gauge two 14 is arranged at the outlet pipeline of gasification deaerator 6, and adjusting valve three 15 is arranged from the top of gasification low-pressure flash separation device 7 to gasification deaerator 6.

[0025] The low-pressure flash gas pipeline of the top of gasification low-pressure flash separation device 7 is sequentially connected with low-pressure flash condenser 8 and separator 9, and the liquid phase pipeline at the bottom of separator 9 is connected with gasification grey water tank 10.

[0026] Adjusting valve six 18 and adjusting valve seven 19 are arranged at the circulating water inlet pipeline of low-pressure flash condenser 8 and generator set 11.

[0027] The shift low-pressure steam generator 2 is connected to the generator set 11 through a steam pipeline, and an adjusting valve five 16 is arranged on the steam pipeline.

[0028] The shift gas entering the second shift furnace 1 is chemically reacted to become 236°C shift gas, and then enters the low-pressure steam generator 2 to exchange heat with 125°C boiler water from the boiler feed water preheater 3 to produce 0.5 MPa saturated steam. After the heat exchange, the temperature of the shift gas is reduced to 170°C, and then the shift gas enters the boiler feed water preheater 3 to heat 70 m 3 / h, 103°C boiler feed water to 125°C. The heated boiler feed water enters the low-pressure steam generator 2. After the heat exchange, the 158°C shift gas enters the first desalted water heater 4, and by adjusting the opening degree of the adjusting valve one 12, 60 m 3 / h normal temperature desalted water is heated to 105°C. After the heat exchange, the 140°C shift gas continues to enter the second desalted water heater 5 to heat 150 m 3 / h normal temperature desalted water to 95°C. After the heat exchange, the 60°C shift gas is sent to the subsequent process for further treatment.

[0029] Example 2

[0030] The device of example 1 is used to perform the following process: the adjusting valve four 17 is opened, and the adjusting valve eight 20 is closed. The 0.15 MPa, 126°C, 16 t / h low-pressure flash gas from the top of the gasification low-pressure flash separator 7 all enters the generator set 11 to generate electricity. After the electricity generation, the condensate is pumped to the gasification ash water tank 10 for recycling. When the synthetic ammonia production load is reduced due to some factors, the remote temperature table one 13 displays a value lower than 100°C, and the adjusting valve one 12 is completely closed. The adjusting valve three 15 is slowly opened to add low-pressure flash gas to the gasification deaerator 6. When the remote temperature table two 14 displays a value greater than 100°C, the adjusting valve four 17 is closed to ensure that the outlet gas phase pressure of the gasification low-pressure flash separator 7 is about 0.15 MPa. When the adjusting valve four 17 is continuously closed, and the low-pressure flash gas heat is lower than the minimum load of the generator set 11, the adjusting valve five 16 is slowly opened to supplement part of the 0.5 MPa saturated steam, and the generator set 11 is operated at the minimum load.

[0031] When the generator set 11 is malfunctioned and stopped, the adjusting valve seven 19 and the adjusting valve eight 20 are opened first, and then the adjusting valve four 17 and the adjusting valve six 18 are closed to keep the pressure of the gasification low-pressure flash separator 7 stable, which does not affect the safe and stable operation of the gasification.

Claims

1. A device for comprehensive utilization of waste heat from conversion and gasification, characterized in that, The outlet of the second-stage furnace (1) is connected to the inlet of the low-pressure steam generator (2), the outlet of the low-pressure steam generator (2) is connected to the inlet of the boiler feedwater preheater (3), the outlet of the boiler feedwater preheater (3) is connected to the inlet of the first demineralized water heater (4), and the outlet of the first demineralized water heater (4) is connected to the inlet of the gasification deaerator (6). The top outlet of the gasification low-pressure flash separator (7) is connected to the other inlet of the gasification deaerator (6) and the generator set (11).

2. The device for comprehensive utilization of waste heat from conversion and gasification according to claim 1, characterized in that, The other outlet of the first demineralized water heater (4) is also connected to the inlet of the second demineralized water heater (5), so that the produced hot demineralized water enters the gasification deaerator (6).

3. The device for comprehensive utilization of waste heat from conversion and gasification according to claim 1, characterized in that, The first demineralized water heater (4) is equipped with a regulating valve (12) at the inlet and outlet of the change gas, and a remote temperature gauge (13) is installed on the demineralized water outlet pipeline.

4. The device for comprehensive utilization of waste heat from conversion and gasification according to claim 1, characterized in that, A remote temperature gauge 2 (14) is installed on the outlet pipeline of the gasification deaerator (6), and a regulating valve 3 (15) is installed from the top of the gasification low-pressure flash separator (7) to the gasification deaerator (6).

5. The device for comprehensive utilization of waste heat from conversion and gasification according to claim 1, characterized in that, The low-pressure flash vapor pipeline at the top of the gasification low-pressure flash separator (7) is connected in sequence to the low-pressure flash condenser (8) and the separator (9), and the liquid phase pipeline at the bottom of the separator (9) is connected to the gasification ash water tank (10).

6. The device for comprehensive utilization of waste heat from conversion and gasification according to claim 5, characterized in that, Regulating valve six (18) and regulating valve seven (19) are installed on the circulating water inlet pipelines of the low-pressure flash condenser (8) and generator set (11).

7. The device for comprehensive utilization of waste heat from conversion and gasification according to claim 1, characterized in that, The low-pressure steam generator (2) is connected to the generator set (11) via a steam pipeline, and a regulating valve (16) is installed on the steam pipeline.

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