A deep thermal-electric decoupling system for industrial steam supply and its use method

Abstract

The present invention discloses a deep thermoelectric decoupling system for industrial steam supply, including a boiler, a high-pressure cylinder, a medium-pressure cylinder, a low-pressure cylinder, a condenser and an ejector, and connected through a temperature and pressure reduction unit, a throttling adjustment unit, a heating unit, a shutoff unit and a check unit. At the same time, the present invention also discloses a method for using the deep thermoelectric decoupling system for industrial steam supply. The present invention can achieve stable and continuous industrial steam supply within a large adjustment range of power generation load, achieve matching operation of unit power generation load and power grid dispatching, and meet the industrial steam supply operation requirements of large unit-type generator sets.

Description

Technical Field

[0001] The invention relates to a thermoelectric decoupling system, in particular to an industrial steam supply deep thermoelectric decoupling system and a use method, belonging to the technical field of cogeneration of heat and power. Background Art

[0002] Large thermal power generating units generally adopt a unit system, that is, the steam turbine generator corresponds to the boiler one by one. Compared with the main pipe system of most thermal power plants in industrial parks, this configuration has good controllability and economy in pure condensing power generation, but there are many problems when it is used as a thermal power plant to supply steam to industrial enterprises.

[0003] Due to the high steam pressure, industrial steam supply is generally extracted from several places such as high-pressure cylinder exhaust, reheater outlet or superheater outlet (new steam). However, no matter where the steam is extracted, it will bring about the problem of boiler reheater and superheater load matching. The superheater steam comes from the boiler drum. In principle, the flow of steam is equal to the feed water volume. The reheater steam comes from the exhaust steam of the high-pressure cylinder of the steam turbine, which is equal to the new steam volume minus the extraction steam of the high-pressure heat recovery heater, the shaft seal extraction steam, the main valve leakage, etc. Under the condition of pure condensing power generation, it can be basically considered that the steam flow through the reheater is in a fixed proportional relationship with the steam flow through the superheater. In other words, if steam is extracted from the high-pressure cylinder exhaust or the superheater outlet for industrial steam supply, the steam flow through the reheater will inevitably decrease, making the ratio of the steam flow through the reheater to the steam flow through the superheater unbalanced. The heat exchange area, layout position, etc. of the reheater and superheater are designed when the boiler is built, and cannot be adjusted and changed at will. If the steam flow through the reheater is reduced, it will inevitably cause the reheater to overheat, and cause high temperatures on subsequent heating surfaces such as economizers and air preheaters, affecting the safety of the boiler.

[0004] If industrial steam is extracted from the reheater outlet, although the load matching problem of the steam flow through the reheater and superheater is avoided, it will cause a mismatch in the steam inlet to the high-pressure cylinder and the medium-pressure cylinder of the steam turbine.

[0005] When steam flows in the steam turbine, it will generate axial force on the turbine rotor. Under normal circumstances, the steam intake of the high-pressure cylinder and the intermediate-pressure cylinder of the steam turbine is in a fixed proportional relationship. In addition, by designing the shaft bosses of different sizes at the inlet and exhaust ports, and designing the reaction degrees of the moving blades of the high-pressure cylinder and the intermediate-pressure cylinder with different designs, under purely condensing conditions, the high-pressure cylinder and the intermediate-pressure cylinder can ensure axial thrust balance under any load conditions. Therefore, if steam is extracted from the reheater outlet for heating, the steam flow through the high-pressure cylinder will be greater than the steam flow through the intermediate-pressure cylinder, thereby causing axial thrust imbalance. Extracting steam from the high-pressure cylinder exhaust port will also cause this phenomenon. The axial thrust imbalance of the high-pressure cylinder and the intermediate-pressure cylinder will cause high temperature of the thrust bearing, which will lead to a safety accident of the steam turbine.

[0006] In addition, the extraction pressure at the high-pressure cylinder exhaust, reheater outlet and other places is closely related to the load of the turbine: the lower the turbine load, the lower the extraction pressure. For industrial steam supply pressure requirements greater than 1.8MPa, the high-pressure cylinder exhaust pressure cannot be met when the turbine load is lower than 60% for most turbines. In other words, if a stable industrial steam supply is maintained, the load of the turbine unit for extraction steam heating must be maintained at a high level, but this will be restricted by the power grid. For example, during the off-peak period at night, in order to balance the supply and demand of the power grid, the turbine power generation load is often controlled below 40%.

[0007] Therefore, there are major problems in converting large unit-type power generating units into industrial heating units, especially when the heating load is large. Therefore, in order to fundamentally solve the problem of large-scale industrial steam supply for large unit-type thermal power units and achieve deep thermal and electrical decoupling, it is necessary to develop new technologies and methods. Summary of the invention

[0008] The technical problem to be solved by the present invention is to overcome the above-mentioned deficiencies in the prior art and provide an industrial steam supply deep thermal-electric decoupling system.

[0009] To solve the above problems, the present invention adopts the following technical solution: an industrial steam supply deep thermoelectric decoupling system, including a boiler, a high-pressure cylinder, a medium-pressure cylinder, a low-pressure cylinder, a condenser and an ejector, and connected through a temperature and pressure reduction unit, a throttling adjustment unit, a heating unit, a shutoff unit and a check unit.

[0010] The following is a further optimization of the above scheme by the present invention: the temperature reduction and pressure reduction unit includes a temperature reduction and pressure reduction device a, a temperature reduction and pressure reduction device b, a temperature reduction and pressure reduction device C, and a temperature reduction and pressure reduction device d;

[0011] The throttling regulating unit includes a throttling regulating valve A, a throttling regulating valve D, a throttling regulating valve F, a throttling regulating valve C, and a throttling regulating valve L;

[0012] The shutoff unit includes a shutoff valve E, a shutoff valve I, a shutoff valve J, a shutoff valve B, a shutoff valve G, a shutoff valve H, a shutoff valve M, a shutoff valve K, a shutoff valve A, a shutoff valve B, a shutoff valve C, a shutoff valve D, and a shutoff valve F;

[0013] The check unit includes a first check valve, a second check valve, a third check valve, and a fourth check valve;

[0014] The heating unit includes heater I, heater II, and shaft seal heater;

[0015] The boiler includes a reheater and a superheater.

[0016] Further optimization: the reheater is connected with a shut-off valve A, a shut-off valve B, a shut-off valve I, a throttling regulating valve D, and a temperature and pressure reducing device d. The shut-off valve A is connected to the temperature and pressure reducing device C, the shut-off valve B is connected to the temperature and pressure reducing device b, the shut-off valve I is connected to the ejector, the ejector is connected to the shut-off valve J, the shut-off valve J8 is connected to the medium-pressure cylinder, the ejector is connected to the shut-off valve C and the throttling regulating valve C, the second check valve is connected to the shut-off valve C, the throttling regulating valve C is connected to the shut-off valve B, the shut-off valve B is connected to the third check valve, the third check valve is connected to the reheater, the throttling regulating valve D is connected to the first check valve, the first check valve is connected to the high-pressure cylinder, the first check valve and the steam inlet of the high-pressure cylinder are connected to the superheater through the throttling regulating valve A, the shut-off valve D is connected between the throttling regulating valve A and the third check valve, the temperature and pressure reducing device a is connected between the shut-off valve D and the third check valve, the shut-off valve B and the first The three check valves are connected to the high-pressure cylinder, the temperature and pressure reducing device d is connected to the shut-off valve E, the shut-off valve E is connected to the medium-pressure cylinder through the throttling regulating valve F, the fourth check valve is connected between the shut-off valve E and the throttling regulating valve F, the fourth check valve is connected to the shut-off valve B, the shut-off valve H and the throttling regulating valve C through the shut-off valve G, the shut-off valve C is connected to the low-pressure cylinder, the low-pressure cylinder is connected to the condenser, the condenser is connected to the throttling regulating valve L and the shaft seal heater, a condensate pump is arranged between the shaft seal heater and the condenser, the shaft seal heater is connected to the heater I through the three-way valve, the heater I is connected to the low-pressure heat recovery heating system through the shut-off valve F, the heater I is connected to the shut-off valve K through the shut-off valve M, the shut-off valve M and the shut-off valve K are connected to the exhaust port of the medium-pressure cylinder, the shut-off valve K is connected to the condenser through the throttling regulating valve L, the heater I is connected to the deaerator through the heater II, and the heater II is connected to the shut-off valve H.

[0017] At the same time, the present invention also discloses a method for using an industrial steam supply deep thermal-electric decoupling system, which is divided into an ejection operation mode and a joint adjustment operation mode according to the power generation load.

[0018] Further optimization: In the ejector operation mode, the throttling control valve A is closed, the desuperheating and pressure reducing valve a is opened, and the new steam is bypassed to the reheater through desuperheating and pressure reducing to balance the amount of circulating steam between the reheater and the superheater; at this time, the high-pressure cylinder inlet steam is drawn from the reheater and enters the high-pressure cylinder through the throttling control valve D and the first check valve; the high-pressure cylinder exhaust pressure is low and cannot flow into the reheater. At this time, the shut-off valve B is opened, and a part of it flows to the low-pressure cylinder through the throttling control valve C, and a part of it enters the heater II through the shut-off valve H to heat the condensate, and the shut-off valve G is closed; the high-pressure steam on the reheater side is prevented from flowing back through the third check valve, and the medium-pressure cylinder inlet steam is introduced from the reheater through the shut-off valve E and the throttling control valve F; the medium-pressure cylinder exhaust steam, a part of it is ejected and pressurized and discharged to the low-pressure cylinder through the ejector, and the other part is led to the heater I through the shut-off valve M to heat the condensate; the driving steam of the ejector is drawn from the output steam of the reheater and supplied after desuperheating and pressure reducing.

[0019] Further optimization: In the joint operation mode, the throttling control valve A is opened, and new steam enters the high-pressure cylinder; because the high-pressure cylinder inlet steam pressure is higher than the reheater output pressure at this time, the first check valve is closed to prevent new steam from entering the reheater; the shut-off valve B is closed, the high-pressure cylinder exhaust steam pressure increases, and enters the reheater through the third check valve; the intermediate-pressure cylinder inlet steam is still drawn from the reheater, the shut-off valve J, shut-off valve K, and shut-off valve M are closed, the intermediate-pressure cylinder exhaust steam all enters the low-pressure cylinder, and the ejector stops working; the desuperheater and pressure reducer a is opened, and new steam enters the reheater.

[0020] Further optimization: A method for deep thermoelectric decoupling in the ejection operation mode, comprising the following steps:

[0021] 1) By reducing the temperature and pressure of new steam, the new steam is bypassed to the reheater inlet to achieve steam flow balance between the reheater and the superheater;

[0022] 2) The steam source of the high-pressure cylinder is adjusted from fresh steam to the reheater output steam. Due to the significant reduction in the inlet pressure, the steam flow rate of the high-pressure cylinder is greatly reduced according to the Flugel formula, thereby reducing the work done by the high-pressure cylinder;

[0023] 3) In order to make the high-pressure cylinder exhaust smoothly, the high-pressure cylinder exhaust steam is discharged to the low-pressure cylinder;

[0024] 4) After the steam inlet volume and pressure of the high-pressure cylinder are reduced, in order to balance the axial thrust of the intermediate-pressure cylinder and the high-pressure cylinder, a throttling regulating valve F is installed at the input end of the intermediate-pressure cylinder to adjust the steam inlet pressure and flow of the intermediate-pressure cylinder;

[0025] 5) In order to make the exhaust of the intermediate pressure cylinder smooth, the exhaust steam of the intermediate pressure cylinder is lifted by the ejector and then introduced into the low pressure cylinder;

[0026] 6) In order to ensure the normal operation of the load (steam-driven feedwater pump, deaerator), steam is drawn from the outlet of the reheater and supplied after being desuperheated and decompressed;

[0027] 7) Industrial steam supply load is adjusted through the temperature and pressure reducer b;

[0028] 8) The power generation load is adjusted through the throttling regulating valve D, throttling regulating valve F and ejector. When the power generation load requirement increases, the throttling regulating valve D is opened to increase the steam inlet to the high-pressure cylinder. At the same time, the throttling regulating valve F is adjusted to achieve axial thrust balance, and the ejector is adjusted to ensure that the steam inlet and exhaust pressure ratio of the intermediate pressure cylinder is within the required range of the intermediate pressure cylinder;

[0029] 9) When the power generation load requirement decreases, the throttling control valve D is closed, and the throttling control valve F and the ejector are adjusted at the same time.

[0030] Further optimization: The method of deep thermal-electric decoupling in the joint operation mode includes the following steps:

[0031] 1) By reducing the temperature and pressure of new steam, the new steam is bypassed to the reheater to achieve steam flow balance between the reheater and the superheater;

[0032] 2) The steam source of the high-pressure cylinder is adjusted from the reheater output end to the new steam. Due to the significant increase in the inlet pressure, the steam flow rate of the high-pressure cylinder is greatly increased according to the Flugel formula, thereby increasing the work done by the high-pressure cylinder;

[0033] 3) The industrial steam supply load is adjusted through the temperature and pressure reducer b; the power generation load is adjusted through the throttling control valve A. When the power generation load requirement increases, the throttling control valve A is opened to increase the steam inlet to the high-pressure cylinder. In order to achieve the axial thrust balance between the high-pressure cylinder and the medium-pressure cylinder, the throttling control valve F is adjusted at the same time;

[0034] 4) When the power generation load requirement is reduced, the throttle regulating valve A is closed, and the throttle regulating valve F is adjusted to achieve axial thrust balance between the high-pressure cylinder and the medium-pressure cylinder;

[0035] 5) The high-pressure cylinder exhaust pressure is regulated by the temperature and pressure reducer a to maintain the ratio of the high-pressure cylinder exhaust pressure to the pressure after the high-pressure cylinder regulating stage between 0.45-0.55.

[0036] Further optimization: Switching from the ejection operation mode to the joint debugging operation mode includes the following steps:

[0037] 1) Adjust the temperature and pressure reducer d so that the opening of the throttling control valve F reaches 100%, and the temperature and pressure reducer d is used to balance the axial thrust of the high-pressure cylinder and the medium-pressure cylinder;

[0038] 2) Open the shut-off valve G and gradually open the regulating valve A at the same time to increase the high-pressure cylinder steam inlet pressure, and adjust the high-pressure cylinder steam inlet and exhaust pressures through the throttling regulating valve C to maintain the ratio of the high-pressure cylinder exhaust pressure to the pressure after the regulating stage at 0.4-0.45;

[0039] 3) If the difference between the high-pressure cylinder inlet steam temperature and the intermediate-pressure cylinder inlet air temperature exceeds 30°C, the intermediate-pressure cylinder inlet steam temperature shall be appropriately reduced through the temperature and pressure reducer d;

[0040] 4) Open the shut-off valve K and maintain the ratio of the exhaust steam pressure to the inlet steam pressure of the intermediate pressure cylinder at 0.23-0.27 through the throttling regulating valve L;

[0041] 5) Adjust the boiler load to keep the new steam pressure stable; when the high-pressure cylinder exhaust pressure is higher than the reheater input pressure, shut-off valve B is closed;

[0042] 6) When the exhaust pressure of the intermediate pressure cylinder is higher than the inlet pressure of the low pressure cylinder, the shut-off valve I, shut-off valve J, shut-off valve M, shut-off valve K and three-way valve are closed.

[0043] Further optimization: Switching from the joint debugging operation mode to the ejection operation mode includes the following steps:

[0044] 1) Gradually close the throttling regulating valve A, and at the same time open the shut-off valve B, shut-off valve K, and regulating valve D;

[0045] 2) The throttling regulating valve C is used to match and adjust the steam inlet and exhaust pressures of the high-pressure cylinder to maintain the ratio of the high-pressure cylinder exhaust pressure to the pressure after the regulating stage at 0.4-0.45;

[0046] 3) The throttling regulating valve L is used to adjust the steam inlet and exhaust pressures of the intermediate pressure cylinder to maintain the ratio of the exhaust pressure of the intermediate pressure cylinder to the steam inlet pressure at 0.23-0.27;

[0047] 4) Increase the opening of the desuperheater and pressure reducer a to maintain the reheater output pressure stable;

[0048] 5) Increase boiler output and maintain stable new steam pressure;

[0049] 6) After the throttling regulating valve A is completely closed, open the shut-off valve J and shut-off valve I, start the ejector, and at the same time open the shut-off valve M, shut-off valve H, and the three-way valve, and start the heater I and heater II;

[0050] 7) While maintaining the ratio of the exhaust pressure of the intermediate pressure cylinder to the inlet pressure not lower than 0.23 and not higher than 0.27, gradually close the throttling control valve L.

[0051] The above scheme reduces the output power of the high-pressure cylinder by reducing the steam inlet pressure of the high-pressure cylinder; achieves axial thrust balance between the high-pressure cylinder and the intermediate-pressure cylinder by adjusting the steam inlet pressure of the intermediate-pressure cylinder; achieves balance between the boiler reheater and the superheater by bypassing the new steam after cooling and reducing the pressure; achieves smooth exhaust of the intermediate-pressure cylinder by heating the condensate and the ejector; and achieves smooth exhaust of the high-pressure cylinder by passing the exhaust steam of the high-pressure cylinder to the low-pressure cylinder. By adopting the above technical measures, the present invention can achieve stable and continuous industrial steam supply within a large adjustment range of power generation load, achieve matching operation of the unit power generation load and power grid dispatching, and meet the industrial steam supply operation requirements of large-scale unit-type generator sets.

[0052] The present invention is further described below in conjunction with the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] Figure 1 It is a flow chart of the present invention in an embodiment;

[0054] Figure 2 It is a flow chart of the ejection operation mode in the embodiment of the present invention;

[0055] Figure 3 This is a flow chart of the joint debugging operation mode in an embodiment of the present invention.

[0056] In the figure: 1. desuperheater C, 2. throttling control valve A, 3. throttling control valve D, 4. desuperheater d, 5. throttling control valve F, 6. shut-off valve E, 7. shut-off valve I, 8. shut-off valve J, 9. desuperheater b, 10. ejector, 11. medium-pressure cylinder, 12. medium-pressure cylinder exhaust port, 13. low-pressure cylinder, 14. low-pressure cylinder steam inlet, 15. desuperheater a, 16. reheater outlet, 17. superheater, 18. reheater, 19. reheater inlet, 20. high-pressure cylinder, 21. high-pressure cylinder exhaust port, 22. high-pressure cylinder steam inlet 1. The steam inlet of the intermediate pressure cylinder is as follows: 2. The steam inlet of the intermediate pressure cylinder is as follows: 2. The steam inlet of the intermediate pressure cylinder is as follows: 3. The steam inlet of the intermediate pressure cylinder is as follows: 4. The steam inlet of the intermediate pressure cylinder is as follows: 5. The steam inlet of the intermediate pressure cylinder is as follows: 6. The steam inlet of the intermediate pressure cylinder is as follows: 7. The steam inlet of the intermediate pressure cylinder is as follows: 8. The steam inlet of the intermediate pressure cylinder is as follows: 9. The steam inlet of the intermediate pressure cylinder is as follows: 10. The steam inlet of the intermediate pressure cylinder is as follows: 11. The steam inlet of the intermediate pressure cylinder is as follows: 12. The steam inlet of the intermediate pressure cylinder is as follows: 13. The steam inlet of the intermediate pressure cylinder is as follows: 14. The steam inlet of the intermediate pressure cylinder is as follows: 15. The steam inlet of the intermediate pressure cylinder is as follows: 16. The steam inlet of the intermediate pressure cylinder is as follows: 17. The steam inlet of the intermediate pressure cylinder is as follows: 18. The steam inlet of the intermediate pressure cylinder is as follows: 19. The steam inlet of the intermediate pressure cylinder is as follows: 20. The steam inlet of the intermediate pressure cylinder is as follows: 21. The steam inlet of the intermediate pressure cylinder is as follows: 22. The steam inlet of the intermediate pressure cylinder is as follows: 23. The steam inlet of the intermediate pressure cylinder is as follows: 24. The steam inlet of the intermediate pressure cylinder is as follows: 25. The steam inlet of the intermediate pressure cylinder is as follows: 26. The steam inlet of the intermediate pressure cylinder is as follows: 27. The steam inlet of the intermediate pressure cylinder is as follows: 28. The steam inlet of the intermediate pressure cylinder is as follows: 29. The steam inlet of the intermediate pressure cylinder is as follows: 30. The steam inlet of the intermediate DETAILED DESCRIPTION

[0057] Examples, such as Figure 1-3As shown, an industrial steam supply deep thermal-electric decoupling system includes a boiler, a reheater 18 and a superheater 17 are arranged on the boiler, a reheater outlet 16 and a reheater inlet 19 are arranged on the reheater 18, the reheater outlet 16 is connected to a shut-off valve A36, a shut-off valve B37, a shut-off valve I7, a throttling regulating valve D3, and a temperature reducing and pressure reducing device d4 through a pipeline, the other end of the shut-off valve A36 is connected to a temperature reducing and pressure reducing device C1 through a pipeline, the other end of the temperature reducing and pressure reducing device C1 is connected to a small steam turbine and a deaerator, the other end of the shut-off valve B37 is connected to a temperature reducing and pressure reducing device b9 through a pipeline, the steam output by the temperature reducing and pressure reducing device b9 is used for industrial steam supply, the other end of the shut-off valve I7 is connected to an ejector 10 through a pipeline, and the ejector 10 is provided with two input ends and one output end Ends, one of the input ends is connected to the shut-off valve I7, the other input end (low-pressure ejector end) is connected to one end of the shut-off valve J8, the other end of the shut-off valve J8 is connected to the intermediate-pressure cylinder exhaust port 12 on the intermediate-pressure cylinder 11 and the second check valve 42 through a pipeline, the output end of the ejector 10 is connected to one end of the shut-off valve C38 and the throttling regulating valve C28 respectively, the other end of the second check valve 42 is connected to the other end of the shut-off valve C38, the other end of the throttling regulating valve C28 is connected to one end of the shut-off valve B24 through a pipeline, the other end of the shut-off valve B24 is connected to one end of the third check valve 43 through a pipeline, the other end of the third check valve 43 is connected to the reheater inlet 19 through a pipeline, the other end of the throttling regulating valve D3 is connected to one end of the first check valve 41, The other end of the first check valve 41 is connected to the high-pressure cylinder steam inlet 22 on the high-pressure cylinder 20 through a pipeline, the first check valve 41 and the high-pressure cylinder steam inlet 22 are connected to the output end of the superheater 17 through the throttling regulating valve A2, a shut-off valve D39 is connected between the throttling regulating valve A2 and the third check valve 43 through a bypass pipeline, a temperature reducing and pressure reducing device a15 is connected between the shut-off valve D39 and the third check valve 43, the shut-off valve B24 and the third check valve 43 are connected to the high-pressure cylinder exhaust port 21 on the high-pressure cylinder 20, the other end of the temperature reducing and pressure reducing device d4 is connected to one end of the shut-off valve E6 through a pipeline, the shut-off valve E6 is connected to the intermediate-pressure cylinder steam inlet 23 on the intermediate-pressure cylinder 11 through the throttling regulating valve F5, and the shut-off valve E6 and the throttling regulating valve F5 are connected through a communication pipeline. There is a fourth check valve 44, which is connected to the shutoff valve B24, the shutoff valve H26 and the throttling regulating valve C28 through the shutoff valve G25. The end of the shutoff valve C38 away from the second check valve 42 is connected to the low-pressure cylinder steam inlet 14 on the low-pressure cylinder 13. The low-pressure cylinder 13 is connected to a condenser 35, and the condenser 35 is connected to a throttling regulating valve L32 and a shaft seal heater 34. A condensate pump is provided between the shaft seal heater 34 and the condenser 35. The shaft seal heater 34 is connected to a heater I30 through a three-way valve 33. The heater I30 is connected to a low-pressure heat recovery heating system through a shutoff valve F40. The heater I30 is connected to a shutoff valve K31 through a shutoff valve M29. The shutoff valve M29 and the shutoff valve K31 are connected to the medium-pressure cylinder exhaust port 12.The shutoff valve K31 is connected to the condenser 35 through the throttling regulating valve L32, the heater I30 is connected to the deaerator through the heater II27, and the heater II27 is also connected to the shutoff valve H26.

[0058] The first check valve 41 is open in the direction from the reheater outlet 16 to the high-pressure cylinder steam inlet 22, and closed in the opposite direction;

[0059] The second check valve 42 is open in the direction from the medium pressure cylinder exhaust port 12 to the low pressure cylinder inlet port 14, and closed in the opposite direction;

[0060] The third check valve 43 is open in the direction from the high-pressure cylinder exhaust port 21 to the reheater inlet 19, and closed in the opposite direction;

[0061] The fourth check valve 44 is open in the direction from the high-pressure cylinder exhaust port 21 to the medium-pressure cylinder steam inlet port, and is closed in the opposite direction.

[0062] The temperature reducing and pressure reducing device a15, the temperature reducing and pressure reducing device b9, the temperature reducing and pressure reducing device C1 and the temperature reducing and pressure reducing device d4 constitute a temperature reducing and pressure reducing unit.

[0063] The throttle regulating valve A2, the throttle regulating valve D3, the throttle regulating valve F5, the throttle regulating valve C28 and the throttle regulating valve L32 constitute a throttle regulating unit.

[0064] The shut-off valve E6, shut-off valve I7, shut-off valve J8, shut-off valve B24, shut-off valve G25, shut-off valve H26, shut-off valve M29, shut-off valve K31, shut-off valve A36, shut-off valve B37, shut-off valve C38, shut-off valve D39, and shut-off valve F40 constitute a shut-off unit.

[0065] The first check valve 41 , the second check valve 42 , the third check valve 43 , and the fourth check valve 44 constitute a check unit.

[0066] The heater I 30 , the heater II 27 , and the shaft seal heater 34 constitute a heating unit.

[0067] At the same time, the present invention also discloses a method for using an industrial steam supply deep thermal-electric decoupling system. According to the relationship between the power generation load and the steam supply load, through the switching of the above-mentioned connecting pipes and valves, the system is divided into an induced operation mode and a joint operation mode to meet the deep thermal-electric decoupling requirements.

[0068] When the power generation load is low, the ejection operation mode is adopted:

[0069] At this time, the throttling regulating valve A2 on the new steam pipeline is closed, the desuperheater a15 and the shut-off valve D39 are opened, and the new steam is bypassed to the reheater inlet 19 through desuperheating and decompression to balance the circulating steam volume between the reheater 18 and the superheater 17;

[0070] At this time, the steam inlet of the high-pressure cylinder 20 is drawn out from the reheater outlet 16 pipeline, and enters the high-pressure cylinder 20 through the throttling regulating valve D3 and the check valve 41; the exhaust pressure of the high-pressure cylinder 20 is low and cannot flow into the reheater inlet 19. At this time, the shut-off valve B24 is opened, and part of it flows to the low-pressure cylinder 13 through the throttling regulating valve C28, and part of it enters the heater II 27 through the shut-off valve H26 to heat the condensate, and the shut-off valve G25 connected to the connecting pipeline between the medium-pressure cylinder steam inlet 23 is closed; the check valve 43 between the high-pressure cylinder exhaust port 21 and the reheater inlet 19 prevents the high pressure on the reheater 18 side from Steam reflux, steam inlet to the intermediate pressure cylinder 11, introduced from the reheater outlet 16 pipeline through the shut-off valve E6 and the throttling regulating valve F5; the exhaust steam of the intermediate pressure cylinder 11, a part of which is ejected and pressurized through the ejector 10, and discharged to the low pressure cylinder 13 from the low pressure cylinder steam inlet 14, and the other part is led to the heater I30 through the shut-off valve M29 to heat the condensate; the driving steam of the ejector 10 is drawn from the steam at the reheater outlet 16, the industrial steam is drawn from the reheater 18 outlet 16 pipeline and supplied after being cooled and reduced in pressure, and the steam used by the small steam turbine and the deaerator is drawn from the reheater outlet 16 pipeline and supplied after being cooled and reduced in pressure C1;

[0071] In this operation mode, boiler feed water enters the boiler, and new steam is finally produced by the superheater 17. The throttling control valve A2 is closed, so all the new steam enters the reheater inlet 19 through the shut-off valve D39 and the desuperheater a15; the steam is heated by the reheater 18 and discharged to the reheater outlet 16; the steam at the reheater outlet 16 is divided into five parts, one part is supplied to the small steam turbine and deaerator through the desuperheater C1, one part is supplied to the industrial steam supply through the desuperheater b9, one part is supplied to the ejector 10 through the shut-off valve I7, one part is supplied to the intermediate pressure cylinder 11 through the desuperheater d4, and the last part is supplied to the high pressure cylinder 20 through the throttling control valve D3;

[0072] The steam at the reheater outlet 16 enters the high-pressure cylinder 20 through the throttling regulating valve D3, the check valve 41 and the high-pressure cylinder steam inlet 22, pushing the high-pressure cylinder 20 to do work. The exhaust steam at the high-pressure cylinder exhaust port 21 is divided into two streams through the shut-off valve B24, one stream is discharged to the low-pressure cylinder 13 through the throttling regulating valve C28, and the other stream is supplied to the heater II 27 through the shut-off valve H26 to heat the condensate. The steam at the reheater outlet 16 enters the medium-pressure cylinder 11 through the temperature and pressure reducer d4, the shut-off valve E6, and the throttling regulating valve F5, pushing the medium-pressure cylinder 11 to do work. The exhaust steam of the medium-pressure cylinder 11 The steam is divided into two streams through the two intermediate pressure cylinder exhaust ports 12. One stream is ejected and pressurized to the low pressure cylinder 13 through the shut-off valve J8, and the other stream is supplied to the heater I 30 through the shut-off valve M29 to heat the condensate. The steam from the ejector 10 and the exhaust steam from the high pressure cylinder 20 from the throttling regulating valve C28 merge into the low pressure cylinder 13, pushing the low pressure cylinder 13 to do work. The exhaust steam from the low pressure cylinder 13 enters the condenser 35 to condense into condensate, enters the shaft seal heater 34, and then is heated by the heater I 30 and the heater II 27, and sent to the deaerator to complete the steam-water process.

[0073] In this operating mode, the principle method of deep thermal and electrical decoupling is as follows: by reducing the temperature and pressure of new steam, the new steam is bypassed to the reheater inlet 19 to achieve steam flow balance between the reheater 18 and the superheater 17; the steam source of the high-pressure cylinder 20 is adjusted from the new steam to the reheater outlet 16 (the hot section of the reheated steam). Since the inlet pressure is greatly reduced, according to the Flugel formula, the steam flow of the high-pressure cylinder 20 will also be greatly reduced, thereby reducing the work done by the high-pressure cylinder 20; in order to make the high-pressure cylinder 20 exhaust smoothly, the exhaust steam of the high-pressure cylinder 20 is discharged to the low-pressure cylinder 13; after the steam intake and steam pressure of the high-pressure cylinder 20 are reduced, in order to balance the axial thrust between the intermediate-pressure cylinder 11 and the high-pressure cylinder 20, a throttling regulating valve F5 is installed at the steam inlet of the intermediate-pressure cylinder 11 to adjust the steam intake pressure and flow of the intermediate-pressure cylinder 11; in order to make the intermediate-pressure cylinder 11 The exhaust steam is smooth, and the exhaust steam of the intermediate pressure cylinder 11 is lifted by the ejector 10, and then introduced into the low pressure cylinder 13, or used to heat the condensate; in order to ensure the normal operation of the steam-driven feed water pump and the deaerator, steam is drawn out from the reheater outlet 16 and supplied after being cooled and reduced in pressure; the industrial steam supply load is adjusted by the cooling and pressure reducing device b9; the power generation load is adjusted by the throttling regulating valve D3, the throttling regulating valve F5 and the ejector 10. When the power generation load requirement is increased, the throttling regulating valve D3 is opened to increase the steam intake of the high pressure cylinder 20, and the throttling regulating valve F5 is adjusted at the same time to achieve axial thrust balance, and the ejector 10 is adjusted to ensure that the steam intake and exhaust pressure ratio of the intermediate pressure cylinder 11 is within the required range of the intermediate pressure cylinder 11; when the power generation load requirement is relatively low, the throttling regulating valve D3 is closed, and the throttling regulating valve F5 and the ejector 10 are adjusted at the same time.

[0074] When the power generation load is high, the joint operation mode is adopted:

[0075] At this time, the throttling regulating valve A2 on the new steam pipeline is opened, and the steam inlet to the high-pressure cylinder 20 comes from the new steam; since the steam inlet pressure of the high-pressure cylinder 20 is higher than the pressure at the reheater outlet 16, the check valve 41 after the throttling regulating valve D3 is closed to prevent the new steam from entering the reheater outlet 16 pipeline; the shut-off valve B24 at the high-pressure cylinder exhaust port 21 is closed, and the exhaust pressure of the high-pressure cylinder 20 increases and enters the reheater inlet 19 through the check valve 43; the steam inlet to the intermediate-pressure cylinder 11 is still drawn from the reheater outlet 16, and the shut-off valve J8, shut-off valve K31, and shut-off valve M29 connected to the intermediate-pressure cylinder exhaust port 12 are closed, and the exhaust steam of the intermediate-pressure cylinder 11 all enters the low-pressure cylinder 13, and the ejector 10 stops working; the temperature and pressure reducing device a15 and the shut-off valve D39 are still open, bypassing part of the new steam to the reheater inlet 19;

[0076] In this operation mode, boiler feed water enters the boiler, and new steam is finally produced by the superheater 17. The throttling control valve A2 is opened, so part of the new steam enters the high-pressure cylinder 20 and pushes the high-pressure cylinder 20 to do work, and part of it passes through the temperature-reducing and pressure-reducing device a15 to enter the reheater inlet 19; at this time, the shut-off valve B24 is closed, and the exhaust steam of the high-pressure cylinder 20 all enters the reheater inlet 19; the steam is heated by the reheater 18 and discharged to the reheater outlet 16; the steam output from the reheater outlet 16 is divided into two parts, one part is supplied to the industrial steam supply through the temperature-reducing and pressure-reducing device b9, and the other part is supplied to the medium-pressure cylinder 11 through the temperature-reducing and pressure-reducing device d4, the shut-off valve E6, and the throttling control valve F5 and pushes the medium-pressure cylinder 11 to do work, and the exhaust steam of the medium-pressure cylinder 11 is discharged to the low-pressure cylinder 13, pushing the low-pressure cylinder 13 to do work, and the exhaust steam of the low-pressure cylinder 13 enters the condenser 35 to condense into condensate, enters the shaft seal heater 34, and then passes through the original low-pressure heat recovery heating system of the steam turbine to complete the steam-water cycle;

[0077] In this operation mode, the principle method of deep thermal-electric decoupling is: by reducing the temperature and pressure of new steam, the new steam is bypassed to the inlet of the reheater 18 to achieve the steam flow balance between the reheater 18 and the superheater 17; the steam source of the high-pressure cylinder 20 is adjusted from the reheater outlet 16 (the hot section of the reheated steam) to the new steam. Since the inlet pressure is greatly increased, according to the Flugel formula, the steam flow of the high-pressure cylinder 20 will also be greatly increased, thereby increasing the work done by the high-pressure cylinder 20; the industrial steam supply load is adjusted by the temperature and pressure reducer b9; the power generation load is adjusted by the throttling control valve A 2 is adjusted. When the power generation load requirement is higher, the throttling regulating valve A2 is opened to increase the steam inlet to the high-pressure cylinder 20. In order to achieve the axial thrust balance between the high-pressure cylinder 20 and the medium-pressure cylinder 11, the throttling regulating valve F5 is adjusted at the same time. When the power generation load requirement is reduced, the throttling regulating valve A2 is closed, and the throttling regulating valve F5 is adjusted at the same time to achieve the axial thrust balance between the high-pressure cylinder 20 and the medium-pressure cylinder 11. The exhaust steam pressure of the high-pressure cylinder 20 is adjusted by the temperature and pressure reducer a15 to maintain the ratio of the exhaust steam pressure of the high-pressure cylinder 20 to the pressure after the high-pressure cylinder 20 adjustment stage between 0.45-0.55.

[0078] Switch from joint debugging mode to ejection mode:

[0079] In the joint operation mode, when the power generation load continues to decrease so that the exhaust steam pressure of the high-pressure cylinder 20 cannot meet the industrial steam supply requirements, it is necessary to switch to the ejector operation mode;

[0080] At this time, gradually close the throttle regulating valve A2, and open the shut-off valve B24, shut-off valve K31, and throttle regulating valve D3. The throttle regulating valve C28 is used to match and adjust the steam inlet and exhaust pressures of the high-pressure cylinder 20, and the ratio of the exhaust pressure of the high-pressure cylinder 20 to the pressure after the regulating stage is maintained at 0.4-0.45. The throttle regulating valve L32 is used to match and adjust the steam inlet and exhaust pressures of the intermediate-pressure cylinder 11, and the ratio of the exhaust pressure of the intermediate-pressure cylinder 11 to the steam inlet pressure is maintained at 0.23-0.27; at the same time, increase (increase) the opening of the temperature and pressure reducer a15 to maintain the pressure of the intermediate-pressure cylinder 11. The pressure at the outlet 16 of the heater is stable, and the boiler output is increased to maintain the new steam pressure stable; after the throttling regulating valve A2 is completely closed, the shut-off valve J8 and the shut-off valve I7 are opened, the ejector 10 is turned on, and the shut-off valve M29, the shut-off valve H26, and the three-way valve 33 are opened at the same time, and the heater I30 and the heater II27 are started. Under the condition that the ratio of the exhaust pressure to the inlet pressure of the intermediate pressure cylinder 11 is maintained at not less than 0.23 and not more than 0.27, the throttling regulating valve L32 is gradually closed. At this point, the joint operation mode is switched to the ejector operation mode.

[0081] Switch from the ejection operation mode to the joint debugging operation mode:

[0082] In the ejection operation mode, when the throttling control valve D3 is fully opened and still cannot meet the power generation load increase requirements, it is necessary to switch to the joint adjustment operation mode;

[0083] At this time, adjust the temperature and pressure reducer d4 so that the opening of the throttling control valve F5 reaches 100%, and the temperature and pressure reducer d4 is used to implement the balance adjustment of the axial thrust of the high-pressure cylinder 20 and the intermediate-pressure cylinder 11; open the shut-off valve G25, and at the same time gradually open the throttling control valve A2 to increase the steam inlet pressure of the high-pressure cylinder 20, and adjust the steam inlet and exhaust pressure of the high-pressure cylinder 20 through the throttling control valve C28 to maintain the ratio of the exhaust pressure of the high-pressure cylinder 20 to the pressure after the regulating stage at 0.4-0.45; at this time, if the difference between the steam inlet temperature of the high-pressure cylinder 20 and the air inlet temperature of the intermediate-pressure cylinder 11 is large (generally controlled within 30°C), the Pass through the desuperheater and pressure reducer d4 to appropriately reduce the inlet steam temperature of the intermediate pressure cylinder 11; open the shut-off valve K31, and maintain the ratio of the exhaust pressure to the inlet steam pressure of the intermediate pressure cylinder 11 between 0.23 and 0.27 through the throttling regulating valve L32; adjust the boiler load to maintain a stable new steam pressure; when the exhaust steam pressure of the high pressure cylinder 20 is higher than the pressure of the reheater inlet 19, close the shut-off valve B24; when the exhaust steam pressure of the intermediate pressure cylinder 11 is higher than the inlet steam pressure of the low pressure cylinder 13, close the shut-off valve I7, shut-off valve J8, shut-off valve M29, and shut-off valve K31, and close the three-way valve 33, and the system completes the switching of the joint debugging operation mode.

[0084] During the switching process between the above two operating modes, the principle method of deep thermoelectric decoupling is: by cooling and reducing the pressure of new steam, the new steam is bypassed to the reheater inlet 19 to achieve steam flow balance between the reheater 18 and the superheater 17; after the steam inlet volume and steam pressure of the high-pressure cylinder 20 are changed, in order to balance the axial thrust between the intermediate-pressure cylinder 11 and the high-pressure cylinder 20, the temperature and pressure reducer d4 adjusts the steam inlet pressure and flow of the intermediate-pressure cylinder 11; in order to ensure the normal operation of the steam-driven feed water pump and the deaerator, steam is drawn out from the reheater outlet 16 and supplied after cooling and pressure reduction; the industrial steam supply load is adjusted by the temperature and pressure reducer b9.

[0085] For example:

[0086] Taking a subcritical 330MW×2 generating units of a power plant as an example, the rated operating mode parameters of the boiler are: new steam volume 1059t / h, new steam temperature 537℃, new steam pressure 16.7MPa; reheat steam temperature 537℃, reheat steam pressure 3.9MPa; industrial steam supply pressure is 2.8MPa, and industrial steam supply volume is 400t / h.

[0087] During the peak period of power consumption in the daytime, if the grid dispatch requires the power generation load of a single unit to be higher than 160MW (about 48% of the rated power generation load of the unit), and the industrial steam supply of 400t / h is met, the two units need to operate in the deep thermal-electric decoupling operation mode;

[0088] At this time, the throttling regulating valve A2 is adjusted according to the power generation load to adjust the steam entering the high-pressure cylinder 20; the temperature and pressure reducing device a15 is adjusted according to the exhaust pressure of the high-pressure cylinder 20, and the exhaust steam pressure of the high-pressure cylinder 20 is adjusted; in order to achieve the axial thrust balance between the high-pressure cylinder 20 and the intermediate-pressure cylinder 11, the steam inlet pressure of the intermediate-pressure cylinder 11 is adjusted by starting the throttling regulating valve F5 at the same time; the shut-off valve B24, the shut-off valve G25, the shut-off valve I7, the shut-off valve H26, the shut-off valve M29, the shut-off valve K31, and the shut-off valve J8 are closed, and the temperature and pressure reducing device c1 is closed; the three-way valve 33 is closed, and the condensate comes out of the shaft seal heater 35 and enters the original steam turbine low-pressure heat recovery heating system;

[0089] In this operation mode, boiler feed water enters the boiler, and new steam is finally produced by the superheater 17. The throttling regulating valve A2 is opened, so part of the new steam enters the high-pressure cylinder 20 to push the high-pressure cylinder 20 to do work, and part passes through the temperature-reducing and pressure-reducing device a15 to enter the reheater inlet 19; at this time, the shut-off valve B24 is closed, and the exhaust steam of the high-pressure cylinder 20 all enters the reheater inlet 19; the steam is heated by the reheater 18 and discharged to the reheater outlet 16; the steam at the reheater outlet 16 is divided into two parts, one part is supplied to the industrial steam supply through the temperature-reducing and pressure-reducing device b9, and the other part is supplied to the medium-pressure cylinder 11 through the temperature-reducing and pressure-reducing device d4 and the shut-off valve E6, pushing the medium-pressure cylinder 11 to do work, and the exhaust steam of the medium-pressure cylinder 11 is discharged to the low-pressure cylinder 13, pushing the low-pressure cylinder 13 to do work, and the exhaust steam of the low-pressure cylinder 13 enters the condenser 35 to condense into condensate, enters the shaft seal heater 34, and then enters the original low-pressure heat recovery heating system of the turbine through the three-way valve 33 to complete the steam-water cycle;

[0090] In the joint operation mode, the industrial steam supply of a single unit is maintained at 200t / h, the unit power generation load can be adjusted between 160-282MW, and the boiler load is adjusted within the range of 70-100%. When the industrial steam supply of a single unit is 200t / h and the power generation load is 160MW (corresponding to a load rate of about 48%), the boiler load is 70%;

[0091] When the grid dispatching requires the power generation load of a single unit to be less than 160MW, the unit needs to switch from the joint operation mode to the ejection operation mode;

[0092] At this time, close the throttling regulating valve A2, and open the shut-off valve B25, shut-off valve K31, throttling regulating valve D3, shut-off valve J8, and shut-off valve I7 at the same time, open the ejector 10, open the shut-off valve M29, shut-off valve H26, and three-way valve 33, start the heater I30, heater II27, start the throttling regulating valve C28, and throttling regulating valve L32; maintain the pressure at the outlet 16 of the reheater stable, increase (increase) the opening of the temperature reducing and pressure reducing device a15, and increase the boiler output to maintain the new steam pressure stable; after the throttling regulating valve A2 is completely closed, gradually close the throttling regulating valve L32 while maintaining the ratio of the exhaust pressure of the intermediate pressure cylinder 11 to the inlet pressure not less than 0.23 and not more than 0.27;

[0093] In this operating mode, boiler feed water enters the boiler and new steam is finally produced by the superheater 17. The throttling control valve A2 is closed, so all the new steam passes through the desuperheater a15 to enter the reheater inlet 19; the steam is heated by the reheater 18 and discharged to the reheater outlet 16; the steam at the reheater outlet 16 is divided into five parts, one part is supplied to the small steam turbine and deaerator through the desuperheater c1, one part is supplied to the industrial steam supply through the desuperheater b9, one part is supplied to the ejector 10 through the shut-off valve I7, one part is supplied to the intermediate pressure cylinder 11 through the desuperheater d4, and the last part is supplied to the high pressure cylinder 20 through the throttling control valve D3; the steam at the reheater outlet 16 enters the high pressure cylinder 20 through the throttling control valve D3, pushes the high pressure cylinder 20 to do work, and the exhaust steam of the high pressure cylinder 20 is divided into two streams after passing through the shut-off valve B24, one part It is discharged to the low-pressure cylinder 13 through the throttling regulating valve C28, and the other stream is supplied to the heater II 27 through the shut-off valve H26 to heat the condensate; the steam at the reheater outlet 16 enters the medium-pressure cylinder 11 through the desuperheater and pressure reducer d4, the shut-off valve E6, and the throttling regulating valve F5, pushing the medium-pressure cylinder 11 to do work, and the exhaust steam of the medium-pressure cylinder 11 is divided into two streams, one of which is pressurized and discharged to the low-pressure cylinder 13 through the shut-off valve J8 and the ejector 10, and the other is supplied to the heater I 30 through the shut-off valve M29 to heat the condensate; the steam from the ejector 10 and the exhaust steam of the high-pressure cylinder 20 from the throttling regulating valve C32 are combined and enter the low-pressure cylinder 13, pushing the low-pressure cylinder 13 to do work, and the exhaust steam of the low-pressure cylinder 13 enters the condenser to condense into condensate, enters the shaft seal heater 34, and then is heated by the heater I 30 and the heater II 27, and sent to the deaerator to complete the steam-water process.

[0094] In the ejection operation mode, the industrial steam supply of a single unit can be adjusted within the range of 0-600t / h, so only one generator set is needed to meet the industrial steam supply requirements. Under the condition that the industrial steam supply of a single unit is 400t / h, the power generation load of a single unit can be adjusted between 56-121MW, and the boiler load can be adjusted within the range of 80-100%. When the industrial steam supply of a single unit is 400t / h and the power generation load is 56MW, the boiler load is 80%;

[0095] If the industrial steam supply of a single unit is still maintained at 200t / h, the unit's power generation load can be adjusted between 56-160MW, and the boiler load can be adjusted within the range of 60%-100%. When the industrial steam supply of a single unit is 200t / h and the power generation load is 56MW (corresponding to a load rate of about 17%), the boiler load is 60%.

[0096] In the ejection operation mode, if the power grid dispatching requires the power generation load of a single unit to be increased to more than 160MW, it is necessary to switch to the joint operation mode;

[0097] At this time, adjust the temperature and pressure reducer d4 so that the opening of the throttling control valve F5 reaches 100%, and the temperature and pressure reducer d4 is used to implement the balance adjustment of the axial thrust of the high-pressure cylinder 20 and the intermediate-pressure cylinder 11; open the shut-off valve G25, and at the same time gradually open the throttling control valve A2 to increase the steam inlet pressure of the high-pressure cylinder 20, and adjust the steam inlet and exhaust pressure of the high-pressure cylinder 20 through the throttling control valve C28 to maintain the ratio of the exhaust pressure of the high-pressure cylinder 20 to the pressure after the regulating stage at 0.4-0.45; at this time, if the difference between the steam inlet temperature of the high-pressure cylinder 20 and the air inlet temperature of the intermediate-pressure cylinder 11 is large (more than 30°C), the temperature and pressure reducer d4 is used to adjust the steam inlet and exhaust pressure of the high-pressure cylinder 20. The decompressor d4 appropriately reduces the steam inlet temperature of the intermediate pressure cylinder 11; opens the shut-off valve K31, and maintains the ratio of the exhaust pressure to the inlet pressure of the intermediate pressure cylinder 11 at 0.23-0.27 through the throttling regulating valve L32; adjusts the boiler load to maintain a stable new steam pressure; when the exhaust pressure of the high pressure cylinder 20 is higher than the pressure of the reheater inlet 19, the shut-off valve B24 is closed; when the exhaust pressure of the intermediate pressure cylinder 11 is higher than the inlet pressure of the low pressure cylinder 35, the shut-off valve I7, shut-off valve J8, shut-off valve M29, and shut-off valve K31 are closed, and the condensate three-way valve 33 is closed, and the system completes the switch to the joint debugging operation mode.

[0098] The above scheme reduces the output power of the high-pressure cylinder 20 by reducing the steam inlet pressure of the high-pressure cylinder 20; achieves axial thrust balance between the high-pressure cylinder 20 and the intermediate-pressure cylinder 11 by adjusting the steam inlet pressure of the intermediate-pressure cylinder 11; balances the boiler reheater 18 and the superheater 17 by bypassing the new steam after cooling and reducing the pressure; achieves smooth exhaust of the intermediate-pressure cylinder 11 by heating the condensate and the ejector 10; and achieves smooth exhaust of the high-pressure cylinder 20 by passing the exhaust steam from the high-pressure cylinder 20 to the low-pressure cylinder 13. By adopting the above technical measures, the present invention can achieve stable and continuous industrial steam supply within a large adjustment range of power generation load, achieve matching operation of the unit power generation load and power grid dispatching, and meet the industrial steam supply operation requirements of large-scale unit-type generator sets.

[0099] The basic principles and main features of the present invention and the advantages of the present invention are shown and described above. For those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic features of the present invention. Therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present invention is limited by the attached claims rather than the above description. Therefore, it is intended to include all changes within the meaning and scope of the equivalent elements of the claims in the present invention, and any figure marks in the claims should not be regarded as limiting the claims involved.

Claims

1. A method for using an industrial steam supply deep thermal and electrical decoupling system, characterized in that: It includes a boiler, a high-pressure cylinder, an intermediate-pressure cylinder, a low-pressure cylinder, a condenser and an ejector, and is connected through a temperature and pressure reduction unit, a throttling adjustment unit, a heating unit, a shutoff unit and a check unit; The temperature reduction and pressure reduction unit includes a temperature reduction and pressure reduction device a, a temperature reduction and pressure reduction device b, a temperature reduction and pressure reduction device C, and a temperature reduction and pressure reduction device d; The throttling regulating unit includes a throttling regulating valve A, a throttling regulating valve D, a throttling regulating valve F, a throttling regulating valve C, and a throttling regulating valve L; The shutoff unit includes a shutoff valve E, a shutoff valve I, a shutoff valve J, a first shutoff valve B, a shutoff valve G, a shutoff valve H, a shutoff valve M, a shutoff valve K, a shutoff valve A, a second shutoff valve B, a shutoff valve C, a shutoff valve D, and a shutoff valve F; The check unit includes a first check valve, a second check valve, a third check valve, and a fourth check valve; The heating unit includes heater I, heater II, and shaft seal heater; The boiler comprises a reheater and a superheater; The reheater is connected with a shutoff valve A, a second shutoff valve B, a shutoff valve I, a throttling regulating valve D, and a temperature and pressure reducing device d. The shutoff valve A is connected to the temperature and pressure reducing device C, the second shutoff valve B is connected to the temperature and pressure reducing device b, the shutoff valve I is connected to the ejector, the ejector is connected to the shutoff valve J, the shutoff valve J is connected to the medium-pressure cylinder, the ejector is connected to the shutoff valve C and the throttling regulating valve C, the second check valve is connected to the shutoff valve C, the throttling regulating valve C is connected to the first shutoff valve B, the first shutoff valve B is connected to the third check valve, the third check valve is connected to the reheater, the throttling regulating valve D is connected to the first check valve, the first check valve is connected to the high-pressure cylinder, the first check valve and the steam inlet of the high-pressure cylinder are connected to the superheater through the throttling regulating valve A, the shutoff valve D is connected between the throttling regulating valve A and the third check valve, the temperature and pressure reducing device a is connected between the shutoff valve D and the third check valve, the first shutoff valve B and the third The check valve is connected to the high-pressure cylinder, the temperature and pressure reducing device d is connected to the shut-off valve E, the shut-off valve E is connected to the medium-pressure cylinder through the throttling regulating valve F, the shut-off valve E and the throttling regulating valve F are connected with a fourth check valve, the fourth check valve is connected with the first shut-off valve B, the shut-off valve H and the throttling regulating valve C through the shut-off valve G, the shut-off valve C is connected to the low-pressure cylinder, the low-pressure cylinder is connected to the condenser, the condenser is connected to the throttling regulating valve L and the shaft seal heater, a condensate pump is arranged between the shaft seal heater and the condenser, the shaft seal heater is connected to the heater I through the three-way valve, the heater I is connected to the low-pressure heat recovery heating system through the shut-off valve F, the heater I is connected to the shut-off valve K through the shut-off valve M, the shut-off valve M and the shut-off valve K are connected to the exhaust port of the medium-pressure cylinder, the shut-off valve K is connected to the condenser through the throttling regulating valve L, the heater I is connected to the deaerator through the heater II, and the heater II is connected to the shut-off valve H; According to the power generation load, it is divided into ejection operation mode and joint operation mode.

2. The method for using the industrial steam supply deep thermal-electric decoupling system according to claim 1, characterized in that: In the ejector operation mode, the throttling control valve A is closed, the desuperheating and pressure reducing valve a is opened, and the new steam is bypassed to the reheater through desuperheating and pressure reducing to balance the amount of circulating steam between the reheater and the superheater; at this time, the high-pressure cylinder inlet steam is drawn from the reheater and enters the high-pressure cylinder through the throttling control valve D and the first check valve; the high-pressure cylinder exhaust pressure is low and cannot flow into the reheater, at this time, the first shut-off valve B is opened, a part of it flows to the low-pressure cylinder through the throttling control valve C, and a part of it enters the heater II through the shut-off valve H to heat the condensate, and the shut-off valve G is closed; the high-pressure steam on the reheater side is prevented from flowing back through the third check valve, and the medium-pressure cylinder inlet steam is introduced from the reheater through the shut-off valve E and the throttling control valve F; the medium-pressure cylinder exhaust steam, a part of it is ejected and pressurized and discharged to the low-pressure cylinder through the ejector, and the other part is led to the heater I through the shut-off valve M to heat the condensate; the driving steam of the ejector is drawn from the output steam of the reheater and supplied after desuperheating and pressure reducing.

3. The method for using the industrial steam supply deep thermal-electric decoupling system according to claim 1 is characterized in that: In the joint operation mode, it is characterized by: the throttling regulating valve A is opened, and new steam enters the high-pressure cylinder; because the high-pressure cylinder inlet steam pressure is higher than the reheater output pressure at this time, the first check valve is closed to prevent new steam from entering the reheater; the first shut-off valve B is closed, the high-pressure cylinder exhaust steam pressure increases, and enters the reheater through the third check valve; the medium-pressure cylinder inlet steam is still drawn from the reheater, the shut-off valve J, shut-off valve K, and shut-off valve M are closed, the medium-pressure cylinder exhaust steam all enters the low-pressure cylinder, and the ejector stops working; the temperature and pressure reducer a is opened, and new steam enters the reheater.

4. The method for using the industrial steam supply deep thermal-electric decoupling system according to claim 2 is characterized in that: The method of deep thermal and electrical decoupling in the ejection operation mode comprises the following steps: 1) By reducing the temperature and pressure of new steam, the new steam is bypassed to the reheater inlet to achieve steam flow balance between the reheater and the superheater; 2) The steam source of the high-pressure cylinder is adjusted from fresh steam to the reheater output steam. Due to the significant reduction in the inlet pressure, the steam flow rate of the high-pressure cylinder is greatly reduced according to the Flugel formula, thereby reducing the work done by the high-pressure cylinder; 3) In order to make the high-pressure cylinder exhaust smoothly, the high-pressure cylinder exhaust steam is discharged to the low-pressure cylinder; 4) After the steam inlet volume and pressure of the high-pressure cylinder are reduced, in order to balance the axial thrust of the intermediate-pressure cylinder and the high-pressure cylinder, a throttling regulating valve F is installed at the input end of the intermediate-pressure cylinder to adjust the steam inlet pressure and flow of the intermediate-pressure cylinder; 5) In order to make the exhaust of the intermediate pressure cylinder smooth, the exhaust steam of the intermediate pressure cylinder is lifted by the ejector and then introduced into the low pressure cylinder; 6) In order to ensure normal operation of the load, steam is drawn out from the outlet of the reheater and supplied after being desuperheated and decompressed; 7) Industrial steam supply load is adjusted through the temperature and pressure reducer b; 8) The power generation load is adjusted through the throttling regulating valve D, throttling regulating valve F and ejector. When the power generation load requirement is higher, the throttling regulating valve D is opened wider to increase the steam inlet to the high-pressure cylinder. At the same time, the throttling regulating valve F is adjusted to achieve axial thrust balance, and the ejector is adjusted to ensure that the steam inlet and exhaust pressure ratio of the intermediate pressure cylinder is within the required range of the intermediate pressure cylinder; 9) When the power generation load requirement is relatively low, the throttling regulating valve D is closed, and the throttling regulating valve F and the ejector are adjusted at the same time.

5. The method for using the industrial steam supply deep thermal-electric decoupling system according to claim 3 is characterized by: The method of deep thermal-electric decoupling in the joint operation mode comprises the following steps: 1) By reducing the temperature and pressure of new steam, the new steam is bypassed to the reheater to achieve steam flow balance between the reheater and the superheater; 2) The steam source of the high-pressure cylinder is adjusted from the reheater output end to the new steam. Due to the significant increase in the inlet pressure, the steam flow rate of the high-pressure cylinder is greatly increased according to the Flugel formula, thereby increasing the work done by the high-pressure cylinder; 3) The industrial steam supply load is adjusted through the temperature and pressure reducer b; the power generation load is adjusted through the throttling control valve A. When the power generation load requirement increases, the throttling control valve A is opened to increase the steam inlet to the high-pressure cylinder. In order to achieve the axial thrust balance between the high-pressure cylinder and the medium-pressure cylinder, the throttling control valve F is adjusted at the same time; 4) When the power generation load requirement is reduced, the throttle regulating valve A is closed, and the throttle regulating valve F is adjusted to achieve axial thrust balance between the high-pressure cylinder and the medium-pressure cylinder; 5) The high-pressure cylinder exhaust pressure is regulated by the temperature and pressure reducer a to maintain the ratio of the high-pressure cylinder exhaust pressure to the pressure after the high-pressure cylinder regulating stage between 0.45-0.

55.

6. The method for using the industrial steam supply deep thermal-electric decoupling system according to claim 1, characterized in that: Switching from the ejection operation mode to the joint debugging operation mode includes the following steps: 1) Adjust the temperature and pressure reducer d so that the opening of the throttling control valve F reaches 100%, and the temperature and pressure reducer d is used to implement the balance adjustment of the axial thrust of the high-pressure cylinder and the medium-pressure cylinder; 2) Open the shut-off valve G and gradually open the regulating valve A at the same time to increase the high-pressure cylinder steam inlet pressure, and adjust the high-pressure cylinder steam inlet and exhaust pressures through the throttling regulating valve C to maintain the ratio of the high-pressure cylinder exhaust pressure to the pressure after the regulating stage at 0.4-0.45; 3) If the difference between the high-pressure cylinder inlet steam temperature and the intermediate-pressure cylinder inlet air temperature exceeds 30±1℃, the intermediate-pressure cylinder inlet steam temperature shall be appropriately reduced through the temperature and pressure reducer d; 4) Open the shut-off valve K and maintain the ratio of the exhaust steam pressure to the inlet steam pressure of the intermediate pressure cylinder at 0.23-0.27 through the throttling regulating valve L; 5) Adjust the boiler load to keep the new steam pressure stable; when the high-pressure cylinder exhaust pressure is higher than the reheater input pressure, the first shut-off valve B is closed; 6) When the exhaust pressure of the intermediate pressure cylinder is higher than the inlet pressure of the low pressure cylinder, the shut-off valve I, shut-off valve J, shut-off valve M, shut-off valve K and three-way valve are closed.

7. The method for using the industrial steam supply deep thermal-electric decoupling system according to claim 1, characterized in that: Switching from the joint debugging operation mode to the ejection operation mode includes the following steps: 1) Gradually close the throttling regulating valve A, and at the same time open the first shut-off valve B, shut-off valve K, and regulating valve D; 2) The throttling regulating valve C is used to match and adjust the steam inlet and exhaust pressures of the high-pressure cylinder to maintain the ratio of the high-pressure cylinder exhaust pressure to the pressure after the regulating stage at 0.4-0.45; 3) The throttling regulating valve L is used to adjust the steam inlet and exhaust pressures of the intermediate pressure cylinder to maintain the ratio of the exhaust pressure of the intermediate pressure cylinder to the steam inlet pressure at 0.23-0.27; 4) Increase the opening of the desuperheater and pressure reducer a to maintain the reheater output pressure stable; 5) Increase boiler output and maintain stable new steam pressure; 6) After the throttling regulating valve A is completely closed, open the shut-off valves J and I, start the ejector, and at the same time open the shut-off valves M, H, and the three-way valve, and start the heaters I and II; 7) While maintaining the ratio of the exhaust pressure of the intermediate pressure cylinder to the inlet pressure of the steam not lower than 0.23 and not higher than 0.27, gradually close the throttling control valve L.

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