Steam turbine industrial heat supply and water supplement utilization system and method

Abstract

The invention discloses a steam turbine industrial heat supply and water supplement utilization system and method, a condenser in the system is connected with an industrial heat supply and water supplement pipeline provided with a heat supply and water supplement valve, the system further comprises two oil coolers, a water inlet of one oil cooler is connected with the industrial heat supply and water supplement pipeline through a water supplement water inlet pipe, and a water outlet of the other oil cooler is connected with a water supplement water outlet pipe. A water replenishing water outlet pipe is connected between a water outlet of the oil cooler and the final-stage low-pressure heater, an inlet valve is mounted on the water replenishing water inlet pipe, and an outlet valve is mounted on the water replenishing water outlet pipe; a water inlet of the other oil cooler is connected with a cooling water inlet pipe, and a water outlet is connected with a cooling water outlet pipe; according to the method, through operation data collection, thermodynamic calculation and check, valve pipeline design, heat balance modification, pipeline valve installation, control logic formulation and step-by-step switching of a cooling medium to industrial heat supply and water supplement, it is ensured that the temperature of an outlet of an oil cooler is stable, and original cooling water is stopped or reduced. The problems that an existing steam turbine industrial heat supply system is insufficient in heat energy utilization and heavy in environment burden are solved.

Description

Technical Field

[0001] The invention relates to the technical field of industrial heating steam turbine generator sets, and in particular to a steam turbine industrial heating water supplement utilization system and method. Background Art

[0002] In industrial heating systems, the traditional process of making-up water treatment is to return the make-up water to the condenser. However, due to the pressure difference in this process, the make-up water will flash inside the condenser. In order to deal with this problem, additional steam extraction is usually required for heating and deoxygenation. This additional heating step not only significantly increases energy consumption, but also directly leads to a decline in the economy of the entire system. At the same time, during the operation of the unit, the two oil coolers of the unit are connected to cooling water respectively, that is, the oil return process of the lubricating oil relies on separate cooling water for cooling. After absorbing the heat released by the oil cooler, the cooling water will directly discharge this heat to the external environment, which means that the heat energy contained in the return oil has not been effectively recycled. What is more serious is that the continuous use of cooling water not only consumes a large amount of plant electricity, but also aggravates the heat emission to the environment, forming a dual problem of energy waste and environmental burden. Summary of the invention

[0003] The purpose of the present invention is to provide a steam turbine industrial heating water utilization system, which can solve the problems of insufficient thermal energy utilization and heavy environmental burden in the existing steam turbine industrial heating system.

[0004] In order to solve the above problems, the technical solution adopted by the present invention is: this steam turbine industrial heating water supply utilization system includes a condenser, a condensate pump, a shaft seal heater and a final low-pressure heater connected in sequence, the leakage of the self-sealing system is respectively connected to the final low-pressure heater and the shaft seal heater, the condenser is connected to the industrial heating water supply pipeline, and the industrial heating water supply pipeline is equipped with a heating water supply valve; it also includes two oil coolers, the water inlet of one oil cooler is connected to the industrial heating water supply pipeline through a water supply inlet pipe, a water supply outlet pipe is connected between the water outlet of the oil cooler and the final low-pressure heater, the water supply inlet pipe is equipped with an inlet valve, and the water supply outlet pipe is equipped with an outlet valve; the water inlet of the other oil cooler is connected to the cooling water inlet pipe, and the water outlet is connected to the cooling water outlet pipe.

[0005] Another object of the present invention is to provide a method for utilizing industrial heating water for a steam turbine, comprising the following steps: a) Collect the operating data of the steam turbine unit lubricating oil system and industrial heating water supply system, including the lubricating oil inlet temperature, oil return temperature, flow rate, and industrial water supply temperature and flow rate; b) Based on the collected data, perform thermal calculation and verification on the oil cooler to determine the heat exchange effect when using industrial heating feed water as the cooling medium; c) Based on the results of thermal calculation and verification, design and select the inlet and outlet valves and pipelines for industrial heating water supply to ensure the flow and pressure requirements after the system transformation; d) Carry out heat balance modification calculation of the unit and calculate the change of steam extraction volume of the steam turbine after the feed water temperature of the heat recovery system increases; e) Install pipes and valves according to the above-mentioned steam turbine industrial heating water utilization system; f) Formulate control logic to automatically switch and control the opening of each valve according to the heating water supply flow and the oil temperature at the oil cooler outlet to ensure that the oil cooler outlet temperature remains within the set range; g) When the unit is put into operation, the cooling medium of the oil cooler is gradually switched according to the changes in the industrial heating feed water flow rate, until the industrial heating feed water is completely used as the cooling medium, and the use of the original cooling water is stopped or reduced.

[0006] In the technical scheme of the above-mentioned method for utilizing water replenishment for workers in the steam turbine industry, a more specific technical scheme may also be: the data collected in step a) includes the theoretical boundary requirements that the inlet oil temperature of the oil cooler does not exceed 65°C, the outlet oil temperature is maintained at 38~45°C, the oil volume is 570m³ / h, and the water volume is 800m³ / h.

[0007] In some possible implementation schemes, the thermal calculation verification in step b) includes calculating the heat exchange efficiency and heat exchange amount of the lubricating oil at a high temperature through a certain amount of make-up water to the target temperature.

[0008] In some possible implementation schemes, the valve and pipeline selection in step c) is calculated based on the industrial heating water inlet and outlet water flow, temperature and pressure, according to the water supply flow rate standard, and the valves and pipelines of corresponding specifications are selected according to the calculation results.

[0009] In some possible implementation schemes, the control logic formulation in step f) includes taking the oil cooler outlet temperature as the target value, and realizing automatic regulation of the heating water supply flow rate and the oil cooler outlet oil temperature by coordinated control of relevant valves.

[0010] In some possible implementation schemes, in step g), when the unit is put into operation, before the heating make-up water flow rate reaches the set value, the industrial heating heating make-up water inlet valve and outlet valve and the oil inlet valve and oil outlet valve of the corresponding oil cooler are closed, and the inlet and outlet valves of the other oil cooler are fully opened to use the original cooling water for cooling; when the heating make-up water flow rate reaches the set value, gradually switch to using industrial heating make-up water as the cooling medium, and adjust the use of the original cooling water until the original cooling water is completely stopped.

[0011] Another object of the present invention is to provide a control device for a steam turbine industrial heating and water supply utilization system, which is used to implement any of the methods described above, including a data acquisition module, a calculation module, a control logic module and an execution module. The data acquisition module is used to collect operating data of the lubricating oil system and the industrial heating and water supply system, the calculation module is used to perform thermal calculation verification and unit thermal balance modification calculation, the control logic module is used to formulate and execute control logic, and the execution module is used to switch and control related valves according to the control logic.

[0012] Due to the adoption of the above technical scheme, the present invention has the following beneficial effects compared with the prior art: the present invention utilizes the temperature difference between the unit lubricating oil return oil and the industrial heating make-up water, and replaces one cooling water in the original oil cooler with industrial heating make-up water to achieve cooling of the lubricating oil and heating of the industrial make-up water at the same time; it can not only increase the temperature of the industrial make-up water in the process of absorbing the heat of the lubricating oil, but also reduce the dependence on additional heating energy, thereby reducing the use of heat recovery extraction steam, improving the unit output or increasing the heating supply, and effectively reducing heat consumption; at the same time, during the operation, the cooling water of the original oil cooler can be stopped or partially put into use, which not only reduces the consumption of factory electricity, but also reduces the heat emission to the environment, achieving the dual goals of efficient utilization of thermal energy and energy conservation and emission reduction. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 This is a schematic diagram of the steam turbine industrial heating and water supply utilization system.

[0014] Figure 2 It is a circuit principle block diagram of the control device of the steam turbine industrial heating and water supply utilization system.

[0015] Explanation of the accompanying drawings: 1. Condenser; 2. Condensate pump; 3. Oil seal heater; 4. Final low-pressure heater; 5. Heating water supply outlet valve; 6. First oil cooler; 7. First oil inlet valve; 8. Second oil inlet valve; 9. Second oil cooler; 10. Cooling water outlet valve; 11. Cooling water inlet valve; 12. Second oil outlet valve; 13. First oil outlet valve; 14. Heating water supply inlet valve; 15. Heating water supply valve; 16. Industrial heating water supply pipeline; 17. Water supply inlet pipe; 18. Water supply outlet pipe; 19. Cooling water inlet pipe; 20. Cooling water outlet pipe; 21. Data acquisition module; 22. Calculation module; 23. Control logic module; 24. Execution module. DETAILED DESCRIPTION

[0016] The present invention will be further described below in conjunction with the accompanying drawings: Figure 1The steam turbine industrial heating water supply utilization system shown includes a condenser 1, a condensate pump 2, a shaft seal heater 3, a final low-pressure heater 4, a self-sealing system, an oil cooler, a cooling water pipeline and an industrial heating water supply pipeline 16. The condenser 1, the condensate pump 2, the shaft seal heater 3 and the final low-pressure heater 4 are connected in sequence. The leakage of the self-sealing system is respectively connected to the shaft seal heater 3 and the final low-pressure heater 4. The shaft seal heater 3 is connected to the condenser through a return pipe, and the drain outlet of the final low-pressure heater 4 is connected to the condenser 1 through a drain pipe. When working, the condenser 1 receives the exhaust gas of the steam turbine and condenses it. The condensate pump 2 extracts the condensate in the condenser 1 and sends it to the shaft seal heater 3. The condensate is heated by the shaft seal leakage to increase the water temperature. The final low-pressure heater 4 further heats the condensate to prepare for boiler feed water. The condenser 1 is connected to the industrial heating water supply pipeline 16, and a heating water supply valve 15 is installed on the industrial heating water supply pipe 16. The system has two oil coolers connected to the lubricating oil system in parallel, one of which is cooled by industrial heating water supply, and the other is cooled by the original cooling water system. The two oil coolers are respectively the first oil cooler 6 and the second oil cooler 9. The water inlet of the first oil cooler 6 is connected to the industrial heating water supply pipeline 16 through the water supply inlet pipe 17. The heating water supply valve 15 is arranged between the water supply inlet pipe 17 and the condenser 1. The water outlet of the first oil cooler 6 is connected to the final low-pressure heater 4 with a water supply outlet pipe 18. The water supply inlet pipe 17 is equipped with a heating water supply inlet valve 14, and the water supply outlet pipe 18 is equipped with a heating water supply outlet valve 5. The water inlet of the second oil cooler 9 is connected to the cooling water inlet pipe 19, and the water outlet is connected to the cooling water outlet pipe 20. The cooling water inlet pipe 19 is equipped with a cooling water inlet valve 11, and the cooling water outlet pipe 20 is equipped with a cooling water outlet valve 10. The lubricating oil inlets of the first oil cooler 6 and the second oil cooler 9 are connected to oil pumps respectively, and their lubricating oil outlets are connected to bearings respectively. The lubricating oil inlets of the first oil cooler 6 and the second oil cooler 9 are respectively equipped with a first oil inlet valve 7 and a second oil inlet valve 8, and the lubricating oil outlets of the first oil cooler 6 and the second oil cooler 9 are respectively equipped with a first oil outlet valve 13 and a second oil outlet valve 12.

[0017] The method for utilizing industrial heating water supply for steam turbine provided by the present invention comprises the following steps: a) Collect the operating data of the steam turbine unit lubricating oil system and industrial heating water supply system, including the lubricating oil inlet temperature, oil return temperature, flow rate, and industrial water supply temperature and flow rate. The theoretical boundary requirement of the lubricating oil flow rate is 570m³ / h, and the theoretical boundary requirement of the industrial heating water supply flow rate is 800m³ / h. The purpose of data collection is to be used for temperature matching calculation to ensure that the water supply matches the oil temperature and meets the requirement of the oil temperature at the outlet of the oil cooler after heat exchange cooling (38~45°C); b) Based on the collected data, the oil cooler is thermally calculated and checked to determine the heat exchange effect when industrial heating feed water is used as the cooling medium; the calculation process includes the calculation of the high-temperature lubricating oil through a certain amount of feed water to the target temperature to ensure that the modified system can meet the safety and economic requirements of the unit operation; c) Design and select the inlet and outlet valves and pipelines for industrial heating water supply according to the results of thermal calculation verification to ensure the flow and pressure requirements after the system transformation; the selection basis includes the inlet and outlet water supply flow, temperature and pressure, and the calculation is carried out according to the water supply flow rate standard, and the valves and pipelines of corresponding specifications are matched and selected to ensure the flow and pressure control accuracy of the system; d) Carry out heat balance modification calculation of the unit, calculate the change of steam extraction volume of the steam turbine after the feed water temperature of the heat recovery system increases, and the reduction of heat consumption of the unit; e) Install pipes and valves according to the above-mentioned steam turbine industrial heating water utilization system; f) Formulate control logic to automatically switch and control the opening of each valve according to the heating water supply flow and the oil temperature at the oil cooler outlet to ensure that the oil cooler outlet temperature remains within the set range; the control logic module automatically adjusts the opening of each valve according to the oil temperature at the oil cooler outlet and the industrial heating water supply flow; the control logic formulation includes taking the oil cooler outlet temperature as the target value, and realizing automatic adjustment of the heating water supply flow and the oil temperature at the oil cooler outlet by coordinating the control of related valves to ensure the stability and controllability of the oil cooler outlet temperature; g) When the unit is put into operation, according to the change of industrial heating water flow, gradually switch the cooling medium of the oil cooler until the industrial heating water is completely used as the cooling medium, and at the same time stop or reduce the use of the original cooling water to reduce the power consumption of the plant and the heat emission to the environment. The specific operation is as follows: ① Before the heating water supply flow reaches the set value (such as 30% of the cooling water flow required by the oil cooler), close the heating water supply inlet valve and the heating water supply outlet valve, the first oil inlet valve and the first oil outlet valve of the first oil cooler, fully open the heating water supply valve (15), the second oil inlet valve, the second oil outlet valve, the cooling water inlet valve and the cooling water outlet valve of the second oil cooler. At this time, the second oil cooler of the unit is still cooled by the original cooling water, and the first oil cooler is not put into operation. It is worth mentioning that the set value should be able to avoid excessive water supply, which will cause the oil temperature at the outlet of the oil cooler to be too low, affecting the safe operation of the unit; ② When the heating water supply flow reaches the set value, gradually close the original cooling water system and switch to the industrial heating water supply cooling mode. During the switching process, dynamically adjust the ratio of the industrial heating water supply flow and the original cooling water flow according to the change of the oil temperature at the outlet of the oil cooler. Specifically, close the heating water supply valve, fully open the heating water supply outlet valve and the heating water supply inlet valve 14, gradually open the first oil inlet valve and the first oil outlet valve of the first oil cooler, and at the same time reduce the second oil inlet valve, the second oil outlet valve, the cooling water inlet valve, and the cooling water outlet valve of the second oil cooler 9. The adjustment process is based on meeting the oil temperature requirement of the outlet main pipe of the oil cooler; at this time, the second oil cooler 9 of the unit is cooled with the original cooling water and the oil intake is gradually reduced, and the first oil cooler 6 is gradually put into operation to increase the cooling oil volume; ③ When the industrial heating water supply flow reaches the cooling water flow required by the oil cooler, the original cooling water system is completely closed, and the oil cooler is completely cooled by the industrial heating water supply. Specifically, close the heating water supply valve 15, fully open the heating water supply outlet valve 5 and the heating water supply inlet valve 14, the first oil inlet valve 7, and the first oil outlet valve 13 of the first oil cooler 6, and at the same time close the second oil inlet valve, the second oil outlet valve, the cooling water inlet valve, and the cooling water outlet valve of the second oil cooler 9. The adjustment process is based on meeting the oil temperature requirements of the oil cooler outlet main pipe; at this time, the second oil cooler 9 of the unit is out of operation, the original cooling water is stopped, and the first oil cooler 6 is running at full load. If the outlet oil temperature of the oil cooler is low, gradually open the heating water supply valve 15, gradually increase the industrial heating water supply flow, and reduce the cooling amount of the water supply entering the first oil cooler until the outlet oil temperature returns to the normal range.

[0018] The present invention also provides a control device for a steam turbine industrial heating and water supply utilization system, which is used to implement the above method. Figure 2 As shown, the control device includes a data acquisition module 21, a calculation module 22, a control logic module 23 and an execution module 24. The data acquisition module 21 is used to collect operating data of the lubricating oil system and the industrial heating water supply system; the calculation module 22 is used to perform thermal calculation verification and unit thermal balance modification calculation; the control logic module 23 is used to formulate and execute control logic to automatically adjust the opening of each valve according to the oil temperature at the outlet of the oil cooler and the industrial heating water supply flow rate; the execution module 24 is used to switch and control related valves according to the control logic to achieve automatic adjustment of the outlet temperature of the oil cooler.

[0019] The purpose of the present invention is to utilize the temperature difference between the unit lubricating oil return temperature and the industrial heating feed water, and replace the original cooling water of one oil cooler with the industrial heating feed water. The lubricating oil cooling makes the industrial feed water absorb heat and increase the temperature at the same time, thereby reducing the amount of heat recovery steam extraction, increasing the unit output or heating supply, and reducing heat consumption. At the same time, the original cooling water of the oil cooler can be stopped or partially put into use during operation, thereby reducing the power consumption of the plant, reducing the heat emission to the environment, and saving energy and protecting the environment.

Claims

1. A steam turbine industrial heating and water supply utilization system, comprising a condenser, a condensate pump, a shaft seal heater and a final low-pressure heater connected in sequence, wherein the leakage of the self-sealing system is respectively connected to the final low-pressure heater and the shaft seal heater, characterized in that: The condenser is connected to an industrial heating water supply pipeline, and a heating water supply valve is installed on the industrial heating water supply pipeline; it also includes two oil coolers, wherein the water inlet of one oil cooler is connected to the industrial heating water supply pipeline through a water supply inlet pipe, and a water supply outlet pipe is connected between the water outlet of the oil cooler and the final low-pressure heater, an inlet valve is installed on the water supply inlet pipe, and an outlet valve is installed on the water supply outlet pipe; the water inlet of the other oil cooler is connected to the cooling water inlet pipe, and the water outlet is connected to the cooling water outlet pipe.

2. A method for using water to replenish steam turbine industrial workers, characterized in that The following steps are involved: a) Collect the operating data of the steam turbine unit lubricating oil system and industrial heating water supply system, including the lubricating oil inlet temperature, oil return temperature, flow rate, and industrial water supply temperature and flow rate; b) Based on the collected data, perform thermal calculation and verification on the oil cooler to determine the heat exchange effect when using industrial heating feed water as the cooling medium; c) Based on the results of thermal calculation and verification, design and select the inlet and outlet valves and pipelines for industrial heating water supply to ensure the flow and pressure requirements after the system transformation; d) Carry out heat balance modification calculation of the unit and calculate the change of steam extraction volume of the steam turbine after the feed water temperature of the heat recovery system increases; e) Install pipes and valves in the steam turbine industrial heating water supply and utilization system according to claim 1; f) Formulate control logic to automatically switch and control the opening of each valve according to the heating water flow and the oil temperature at the oil cooler outlet to ensure that the oil cooler outlet temperature remains within the set range; g) When the unit is put into operation, the cooling medium of the oil cooler is gradually switched according to the changes in the industrial heating feed water flow rate, until the industrial heating feed water is completely used as the cooling medium, and the use of the original cooling water is stopped or reduced.

3. The method for utilizing water for workers in the steam turbine industry according to claim 2, characterized in that: The data collected in step a) include theoretical boundary requirements that the oil temperature at the inlet of the oil cooler does not exceed 65°C, the outlet oil temperature is maintained at 38~45°C, the oil volume is 570m³ / h, and the water volume is 800m³ / h.

4. The method for utilizing water for workers in the steam turbine industry according to claim 2, characterized in that: The thermal calculation verification in step b) includes calculating the heat transfer efficiency and heat transfer amount of the lubricating oil with high temperature through a certain amount of water replenishment to the target temperature.

5. The method for utilizing water for workers in the steam turbine industry according to claim 2, characterized in that: The valve and pipeline selection in step c) is calculated according to the water supply inlet and outlet flow, temperature and pressure of the industrial heating water supply, according to the water supply flow rate standard, and the valves and pipelines of corresponding specifications are selected according to the calculation results.

6. The method for utilizing water for workers in the steam turbine industry according to claim 2, characterized in that: The control logic formulation in step f) includes taking the oil cooler outlet temperature as the target value and realizing automatic regulation of the heating water supply flow rate and the oil cooler outlet oil temperature by coordinated control of relevant valves.

7. The method for utilizing water for workers in the steam turbine industry according to claim 2, characterized in that: In step g), when the unit is put into operation, before the heating make-up water flow rate reaches the set value, the industrial heating heating make-up water inlet valve and outlet valve and the oil inlet valve and oil outlet valve of the corresponding oil cooler are closed, and the inlet and outlet valves of the other oil cooler are fully opened to use the original cooling water for cooling; when the heating make-up water flow rate reaches the set value, gradually switch to using industrial heating make-up water as the cooling medium, and adjust the use of the original cooling water at the same time until the original cooling water is completely stopped.

8. A control device for a steam turbine industrial heating water supply and utilization system, used to implement the steam turbine industrial worker water supply and utilization method according to any one of claims 2 to 7, characterized in that: It includes a data acquisition module, a calculation module, a control logic module and an execution module. The data acquisition module is used to collect the operating data of the lubricating oil system and the industrial heating and water supply system. The calculation module is used to perform thermal calculation verification and unit thermal balance modification calculation. The control logic module is used to formulate and execute control logic. The execution module is used to switch and control related valves according to the control logic.

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