Vacuum pump efficiency-increasing vacuumizing cooling device and method and condensing steam turbine unit

Abstract

The invention relates to a vacuum pump efficiency-increasing vacuumizing cooling device and method and a condensing steam turbine unit. The device comprises an air exhaust pipeline system, a surface heat exchanger, a cooling medium supply unit, a bypass adjusting mechanism and a drainage unit. Two ends of the pumping pipeline system are respectively connected with a condenser and a vacuum pump; the surface type heat exchanger is connected in series in the air exhaust pipeline system and is positioned between an air exhaust pipe of the condenser and an inlet of the vacuum pump; the cooling medium supply unit comprises a condensation water supplementing tank, a condensation water conveying pump, a condenser water supplementing pipeline and a first electric adjusting door. The bypass adjusting mechanism is connected to the two ends of the surface type heat exchanger in parallel and comprises a bypass pipeline and a second electric adjusting door arranged on the bypass pipeline. And one end of the drainage unit is connected with the bottom of the surface heat exchanger, and the other end is connected into a condenser hot well for draining condensed water in the surface heat exchanger. Efficient operation of the vacuumizing device can be achieved, the economical efficiency and safety of operation of the condensing unit are improved, and the operation reliability is ensured.

Description

Technical Field

[0001] This invention belongs to the technical field of auxiliary equipment for condensing steam turbine units, and particularly relates to a vacuum pump efficiency improvement vacuum cooling device, method, and condensing steam turbine unit. Background Technology

[0002] During the operation of a condensing steam turbine unit, the efficiency of the condenser vacuum system plays a crucial role in the overall economy and safety of the unit. Especially in the high-temperature environment of summer, the temperature of both closed-loop and open-loop circulating cooling water rises significantly, directly causing the temperature of the mixed gas at the inlet of the vacuum system to rise accordingly. This temperature increase severely reduces the effective suction capacity of the vacuum pump, significantly decreasing its efficiency, which in turn leads to a decrease in the condenser vacuum level, increased heat consumption for power generation, and a decline in economic efficiency. Simultaneously, an unstable vacuum level also increases the safety risks such as deformation and vibration of the turbine's low-pressure cylinder, threatening the safe operation of the unit.

[0003] Currently, there are various solutions in the industry to address the above problems, but all of them have obvious shortcomings: Increasing the flow rate of closed-loop cooling water: This solution is limited by the capacity of the circulating water system. In summer, the cooling capacity is easily saturated and cannot effectively reduce the gas temperature. At the same time, increasing the flow rate will increase the energy consumption of the water pump, which will reduce the overall economic efficiency of the unit.

[0004] Using air-cooled coolers: their cooling effect is greatly affected by the ambient temperature. When the outdoor temperature is high in summer, the cooling efficiency drops sharply and it is difficult to meet the cooling demand. In addition, additional equipment such as fans are required, which not only takes up a lot of space, but also increases the cost of equipment purchase and subsequent maintenance.

[0005] Replacing with a high-power vacuum pump: The initial investment cost is high, and it does not fundamentally solve the problem of "high-temperature gas damaging the pump body's lifespan". In long-term operation, the pump body wears out quickly, the frequency of replacement and maintenance increases, and the operating cost rises significantly. Summary of the Invention

[0006] The purpose of this invention is to provide a vacuum pump efficiency improvement and vacuum cooling device, method, and condensing steam turbine unit. By connecting a surface heat exchanger in series in the original extraction pipeline and using condenser makeup water as the cooling medium, the high-temperature mixed gas entering the vacuum pump is cooled. This solves the problem of reduced vacuum pump efficiency caused by excessively high inlet temperature and high cooling water temperature in the condensing steam turbine unit production process, achieving efficient operation of the vacuum device, improving the economy and safety of condensing unit operation, and simultaneously setting a bypass adjustment mechanism to ensure operational reliability.

[0007] This invention provides a vacuum pump efficiency improvement and vacuum cooling device, including a vacuum pipeline system, a surface heat exchanger, a cooling medium supply unit, a bypass adjustment mechanism, and a condensate drain unit; The extraction pipeline system is connected to the condenser and vacuum pump of the condensing steam turbine unit at both ends, and is used to provide a transport channel for the high-temperature mixed gas extracted from the condenser. The surface heat exchanger is connected in series in the air extraction pipeline system, located between the condenser air extraction pipe and the vacuum pump inlet, at a distance of ≥1.5m from the vacuum pump inlet; The cooling medium supply unit includes a condensate water tank, a condensate delivery pump, a condenser water supply pipeline, and a first electric regulating valve. One end of the condenser water supply pipeline is connected to the condensate water tank, and the other end is connected to the cooling side inlet of the surface heat exchanger via the condensate delivery pump. The cooling side outlet of the surface heat exchanger is connected to the condenser via the first electric regulating valve. The cooling medium is condenser water. The bypass regulating mechanism is connected in parallel to both ends of the surface heat exchanger, and includes a bypass pipe and a second electric regulating valve provided on the bypass pipe; The condensate draining unit includes a liquid level sensor, an automatic condensate draining valve, and a manual condensate draining valve for the cooler. One end of the condensate draining unit is connected to the bottom of the surface heat exchanger, and the other end is connected to the hot water well of the condenser, for draining the condensate in the surface heat exchanger.

[0008] Furthermore, the surface heat exchanger is a shell-and-tube heat exchanger, with the tube bundle made of 304 stainless steel, and the heat exchange area is matched according to the unit capacity.

[0009] Furthermore, the condenser makeup water temperature of the cooling medium supply unit is ≤32℃ in summer, and the flow rate is controlled at 5-8m³ / h. 3 / h; A Y-type filter with a filtration accuracy of ≤100μm is installed at the inlet of the condenser water supply pipeline.

[0010] Furthermore, the first electric regulating valve is interlocked with the unit's DCS system. When the temperature of the mixed gas at the vacuum pump inlet is ≥40℃, the first electric regulating valve automatically opens to increase the cooling water volume; when the temperature of the mixed gas at the vacuum pump inlet is ≤25℃, the first electric regulating valve closes to save energy. The regulating accuracy of the first electric regulating valve is ≤5% for flow deviation and ≥1.6MPa for nominal pressure.

[0011] Furthermore, the nominal pressure of the second electric regulating valve is ≥1.6MPa, and the connection method is flange connection; the bypass pipeline is also equipped with a manual regulating valve, which is connected in parallel with the second electric regulating valve to form a double backup.

[0012] Furthermore, the liquid level sensor has a measurement range of 0-500mm and an accuracy of ±1mm; the automatic steam trap has a nominal pressure ≥1.6MPa and a drainage capacity ≥0.5m. 3 / h, when the liquid level sensor detects that the liquid level in the surface heat exchanger is ≥300mm, the automatic drain valve opens; when the liquid level is ≤100mm, the automatic drain valve closes.

[0013] Furthermore, the interface between the extraction piping system and the surface heat exchanger is welded using argon arc welding, resulting in a low leakage rate. The slope of the condenser water supply pipeline is ≥0.3% to avoid air blockage or water accumulation.

[0014] The present invention also provides a vacuum cooling method using the aforementioned device, comprising: During periods of high summer temperatures, the high-temperature mixed gas extracted from the condenser first enters a surface heat exchanger connected in series in the extraction piping system. Simultaneously, the low-temperature condenser makeup water in the condensate water tank is pressurized by the condensate transfer pump and enters the cooling side of the surface heat exchanger through the condenser makeup water pipeline. Inside the surface heat exchanger, the high-temperature mixed gas and the low-temperature condenser makeup water undergo thorough heat exchange, reducing the temperature of the mixed gas to 20-30°C, after which it enters the vacuum pump. The condenser makeup water, having completed heat exchange, enters the condenser through the first electric regulating valve, achieving recycling. When the temperature of the mixed gas at the vacuum pump inlet exceeds 40°C, the first electric regulating valve of the cooling medium supply unit is opened wider by the DCS system to increase the cooling water volume and enhance the heat exchange effect. If the surface heat exchanger malfunctions and needs maintenance, the second electric regulating valve of the bypass pipeline is opened to allow the mixed gas to directly enter the vacuum pump to ensure the normal operation of the unit. The condensate draining unit, through the cooperation of the liquid level sensor and the automatic condensate draining valve, discharges the condensate in the surface heat exchanger in real time to avoid water accumulation affecting the heat exchange efficiency.

[0015] The present invention also provides a condensing steam turbine unit, including the aforementioned vacuum pump efficiency improvement and vacuum cooling device.

[0016] By employing the above-mentioned scheme, the vacuum pump-based vacuum cooling device, method, and condensing steam turbine unit achieve the following technical effects: 1) Significantly improves vacuum efficiency: By combining the surface heat exchanger with condenser water supply, the inlet gas temperature of the vacuum pump is effectively reduced (by 15-25℃), greatly alleviating the problem of decreased vacuum pump efficiency during high-temperature seasons. Under the same external high-temperature conditions, the vacuum pump efficiency increases by ≥15% after applying this device, and the effective pumping capacity is significantly enhanced.

[0017] 2) Improve the unit vacuum and economy: The improved efficiency of the vacuum pump is directly translated into the improvement of the condenser vacuum (the vacuum improvement ≥ 0.5 kPa). A higher vacuum can reduce the heat consumption of the unit for power generation (the heat consumption is reduced ). Taking a 300 MW unit as an example, about 500 tons of standard coal can be saved annually, significantly improving the economic benefits of the unit operation.

[0018] 3) Enhance the operation safety: A stable vacuum level can effectively prevent the deformation of the low-pressure cylinder of the steam turbine and reduce safety risks such as vibration. At the same time, the setting of the bypass regulating mechanism avoids the impact of a single equipment failure on the unit operation, and the drainage unit ensures the stable operation of the heat exchanger, ensuring the safe and stable operation of the unit in a high-temperature environment in multiple aspects.

[0019] 4) Have cost and energy consumption advantages: Using the condensate water replenishment of the condenser as the cooling medium, there is no need to newly add an additional cooling source, reducing the equipment procurement cost; there is no additional energy consumption during the operation of the device (only a small amount of electric energy is consumed by the condensate water transfer pump, and the energy consumption can be dynamically adjusted by the DCS system to control the flow rate), and only regular cleaning of the tube bundle and inspection of the valves are required for later maintenance, with low maintenance costs.

[0020] The above description is only an overview of the technical solution of the present invention. In order to be able to understand the technical means of the present invention more clearly and implement it in accordance with the content of the description, the following will be described in detail with reference to the preferred embodiments of the present invention and the accompanying drawings. Brief Description of the Drawings

[0021] Figure 1 It is a schematic connection diagram of the vacuum pump efficiency improvement vacuum extraction cooling device and the condensing steam turbine unit of the present invention.

[0022] The reference numerals in the figure: 1 - Condenser; 2 - Air extraction pipe; 3 - Surface heat exchanger; 4 - Manual valve for cooler drainage; 5 - Vacuum pump; 6 - Cooling water for surface heat exchanger; 7 - Condensate replenishment tank; 8 - Condensate water transfer pump; 9 - Cooling tube bundle of surface heat exchanger; 10 - Condenser water replenishment pipeline; 11 - Bypass pipeline; 12 - First electric regulating valve; 13 - Y-type filter; 14 - Second electric regulating valve; 15 - Manual regulating valve. Detailed Embodiments <​​​​​​​ The extraction piping system is connected at both ends to the condenser 1 and vacuum pump 5 of the condensing steam turbine unit, respectively, to provide a transport channel for the high-temperature mixed gas extracted from the condenser 1. Cuttings are made at the heat exchanger installation location to reserve interfaces. The interface between the extraction piping system and the surface heat exchanger is welded using argon arc welding to ensure airtightness and minimize leakage. The slope of the condenser water supply pipeline should be ≥0.3% to avoid air blockage or water accumulation.

[0025] The surface heat exchanger 3 is connected in series in the extraction pipeline system, located between the condenser extraction air pipe 2 and the inlet of the vacuum pump 5, at a distance of ≥1.5m from the inlet of the vacuum pump 5. This prevents the gas from heating up again after cooling. It is used to achieve heat exchange between the high-temperature mixed gas and the condenser makeup water, thereby reducing the temperature of the mixed gas. In this embodiment, the surface heat exchanger 3 is a shell-and-tube heat exchanger, with the tube bundle material being 304 stainless steel (suitable for demineralized water corrosion protection). The heat exchange area is matched according to the unit capacity; for example, a 300MW unit requires ≥20㎡, and a 600MW unit requires ≥35㎡, ensuring sufficient heat exchange between the mixed gas and the cooling medium.

[0026] The cooling medium supply unit includes a condensate tank 7, a condensate transfer pump 8, a condenser makeup water pipeline 10, and a first electric regulating valve 12. One end of the condenser makeup water pipeline 10 is connected to the condensate tank 7, and the other end is connected to the cooling side inlet of the surface heat exchanger 3 via the condensate transfer pump 8. The cooling side outlet of the surface heat exchanger 3 is connected to the condenser 1 via the first electric regulating valve 12. The cooling medium is condenser makeup water (demineralized water). The condenser makeup water temperature of the cooling medium supply unit is ≤32℃ in summer, and the flow rate is controlled at 5-8 m³ / h. 3 The cooling water flow rate can be dynamically adjusted via the first electric regulating valve. A Y-type filter 13 is installed at the inlet of the condenser makeup water line to filter impurities in the cooling water and prevent them from entering the heat exchanger and clogging the tube bundle. The filtration accuracy is ≤100μm, and the nominal pressure is ≥1.6MPa. The first electric regulating valve 12 is interlocked with the unit's DCS system for automatic control. When the mixed gas temperature at the vacuum pump inlet is ≥40℃, the first electric regulating valve 12 automatically opens to increase the cooling water flow rate; when the mixed gas temperature at the vacuum pump inlet is ≤25℃, the first electric regulating valve 12 appropriately closes to save energy. The adjustment accuracy of the first electric regulating valve 12 is ≤5% for flow deviation and ≥1.6MPa for nominal pressure.

[0027] A bypass regulating mechanism is connected in parallel across both ends of the surface heat exchanger 3, including a bypass pipe 11 and a second electrically operated regulating valve 14 installed on the bypass pipe 11. The second electrically operated regulating valve 14 has a nominal pressure ≥1.6MPa and is connected by a flange, used to regulate the bypass flow of the mixed gas. A manual regulating valve 15 can also be installed on the bypass pipe 11, forming a double backup in parallel with the second electrically operated regulating valve 14. When the surface heat exchanger malfunctions and requires maintenance or the cooling water volume is insufficient, the bypass regulating mechanism can be opened to ensure normal gas intake of the vacuum pump and avoid affecting the operation of the unit.

[0028] The condensate drain unit includes a level sensor, an automatic drain valve, and a manual drain door 4 for the cooler. One end of the drain unit is connected to the bottom of the surface heat exchanger 3, and the other end is connected to the condenser hot water well to drain the condensate inside the surface heat exchanger 3. The level sensor monitors the condensate level inside the heat exchanger in real time, providing a control signal to the automatic drain valve. When the level reaches the set value, the automatic drain valve opens to drain the condensate, preventing water accumulation from affecting heat exchange efficiency and simultaneously enabling condensate recycling. The level sensor has a measurement range of 0-500mm and an accuracy of ±1mm; the automatic drain valve has a nominal pressure ≥1.6MPa and a drainage capacity ≥0.5m³. 3 The system opens or closes per hour based on the liquid level sensor signal to drain condensate from the heat exchanger. The cooler drain valve has four manual valves with a nominal pressure of ≥1.6MPa and a flange connection. When the liquid level sensor detects a liquid level ≥300mm in the surface heat exchanger 3, the automatic drain valve opens; when the liquid level ≤100mm, the automatic drain valve closes.

[0029] Figure 1 The mixed gas in the intermediate condenser 1 enters the surface heat exchanger 3 through the air extraction pipe 2, where it exchanges heat with the condenser makeup water in the cooling tube bundle 9 of the surface heat exchanger. The makeup water in the condensate water tank 7 is pressurized by the condensate transfer pump 8, filtered by the Y-type filter 13, and then enters the cooling tube bundle 9 of the surface heat exchanger through the condenser makeup water pipeline 10 (including the electric regulating valve). After completing the heat exchange, it returns to the condenser 1. The condensate in the surface heat exchanger 3 is discharged through the level sensor, automatic drain valve, or cooler drain manual valve 4, and finally connects to the condenser 1. The bypass regulating mechanism is connected in parallel to both ends of the surface heat exchanger 3. When the surface heat exchanger fails, the second electric regulating valve 14 of the bypass pipeline 11 is opened, and the mixed gas directly enters the vacuum pump 5 through the bypass pipeline 11 to ensure the normal operation of the vacuum pump 5. The vacuum pump 5 achieves self-cooling through the surface heat exchanger cooling water 6 and finally discharges the treated gas into the atmosphere.

[0030] During the high temperatures of summer, the high-temperature mixed gas (original temperature usually 40-50℃) extracted from condenser 1 first enters the surface heat exchanger 3 connected in series in the extraction pipeline system; at the same time, the low-temperature condenser makeup water (temperature ≤32℃) in the condensate makeup water tank 7 is pressurized by the condensate transfer pump 8 and enters the cooling side of the surface heat exchanger 3 through the condenser makeup water pipeline 10; in the surface heat exchanger 3, the high-temperature mixed gas and the low-temperature condenser makeup water undergo sufficient heat exchange, and the temperature of the mixed gas drops to 20-30℃ (15-25℃ lower than the original temperature), and then enters the vacuum pump 5; the condenser makeup water after heat exchange enters condenser 1 through the first electric regulating valve 12, realizing recycling; When the temperature of the mixed gas at the inlet of vacuum pump 5 exceeds 40°C, the first electric regulating valve 12 of the cooling medium supply unit is opened by the DCS system to increase the cooling water volume and enhance the heat exchange effect. If the surface heat exchanger 3 malfunctions and needs to be repaired, the second electric regulating valve 14 of the bypass pipe 11 is opened to allow the mixed gas to directly enter the vacuum pump 5 to ensure the normal operation of the unit. The condensate draining unit, through the cooperation of the liquid level sensor and the automatic condensate draining valve, discharges the condensate in the surface heat exchanger 3 in real time to avoid water accumulation affecting the heat exchange efficiency.

[0031] This embodiment also provides a condensing steam turbine unit, including the aforementioned vacuum pump efficiency improvement and vacuum cooling device.

[0032] The installation and commissioning steps for the vacuum pump efficiency improvement and cooling device are as follows: Pipeline pretreatment: The original extraction pipeline (connecting the condenser and vacuum pump) is cut, and a surface heat exchanger interface is pre-installed between the condenser extraction pipe and the vacuum pump inlet. The interface dimensions match the heat exchanger inlet and outlet. Argon arc welding is used at the interface, and an airtightness test is performed after welding to ensure a low leakage rate. .

[0033] Heat exchanger installation: Hoist the surface heat exchanger to the designated location (ensuring a distance of ≥1.5m from the vacuum pump inlet), connect it to the existing exhaust pipe via a flange, and tighten the bolts evenly to prevent leakage. Simultaneously, install a Y-type filter on the inlet pipe on the cooling side of the heat exchanger and an electric regulating valve on the outlet pipe.

[0034] Cooling medium supply unit installation: Connect one end of the condenser makeup water pipeline to the condensate makeup water tank outlet, and the other end to the heat exchanger cooling side inlet after passing through the condensate transfer pump and Y-type filter; the heat exchanger cooling side outlet is connected to the condenser via an electric regulating valve. During pipeline installation, ensure a reasonable pipeline slope (slope ≥ 0.3%) to avoid air blockage or water accumulation.

[0035] Bypass regulating mechanism installation: Connect both ends of the bypass pipe to the original exhaust pipes before and after the heat exchanger, and install an electric regulating valve on the bypass pipe (if a manual + electric dual backup is used, an additional manual valve needs to be installed) to ensure that the bypass pipe is tightly connected to the original exhaust pipe without leakage.

[0036] Drainage unit installation: Install a liquid level sensor at the bottom of the surface heat exchanger, and connect the automatic drain valve and the cooler drain manual valve (the two are connected in parallel). The outlet pipe of the drainage unit is connected to the condenser hot water well to ensure that the condensate can be recovered smoothly.

[0037] Control system integration: Connect the control signals of equipment such as electric regulating valves, liquid level sensors, and condensate transfer pumps to the unit's DCS system and set interlock logic: When the mixed gas temperature at the vacuum pump inlet is ≥40℃, automatically open the electric regulating valve of the cooling medium supply unit to increase the cooling water volume; when the temperature is ≤25℃, appropriately close the electric regulating valve; when the liquid level sensor detects that the liquid level in the heat exchanger is ≥300mm, automatically open the automatic drain valve, and when the liquid level is ≤100mm, close the automatic drain valve.

[0038] Commissioning: No-load commissioning: Close the vacuum pump inlet valve, turn on the condensate delivery pump, and adjust the cooling water flow rate to 5-8 m³ / h using the electric regulating valve of the cooling medium supply unit controlled by the DCS system. 3 Within the range of / h, check whether the pipes and valves are leaking, and whether the heat exchanger and water pump are operating normally, without abnormal noise or vibration.

[0039] Load testing: Open the vacuum pump inlet valve to allow the mixed gas to enter the heat exchanger, and monitor the vacuum pump inlet gas temperature in real time. Initially, open the electric regulating valve of the bypass mechanism to allow some of the mixed gas to enter the vacuum pump via the bypass. Gradually close the bypass valve and observe the cooling effect of the mixed gas. If the vacuum pump inlet gas temperature does not drop to 20-30℃ within 30 minutes, appropriately increase the opening of the electric regulating valve of the cooling medium supply unit to increase the cooling water flow until the temperature reaches the target range.

[0040] Interlock Testing: Simulate a rise in the inlet gas temperature of the vacuum pump (simulated via temperature sensor signal). When the temperature reaches 40℃, check if the DCS system automatically opens the electric regulating valve for the cooling medium; simulate a drop in temperature below 25℃, and check if the electric regulating valve automatically closes. Simultaneously, simulate a rise in the liquid level inside the heat exchanger (simulated via liquid level sensor signal), and check if the automatic drain valve opens when the liquid level is ≥300mm and closes when the liquid level is ≤100mm, ensuring the interlock function is normal.

[0041] Maintenance: Clean the cooling tube bundle regularly (using high-pressure water flushing, pressure ≤0.8MPa); check the condition of the drain valve monthly to prevent jamming and water accumulation; test the airtightness of the heat exchanger annually to ensure there are no leaks.

[0042] This invention adds a surface heat exchanger to the original extraction pipeline. The extracted mixed gas is cooled by the heat exchanger (the cooling medium is condenser makeup water) before entering the vacuum pump. Because the temperature of the mixed gas entering the vacuum pump is significantly lower than the original extraction temperature, the vacuum pump's efficiency is effectively improved, thereby improving the unit's economics and ensuring stable operation of the condensing steam turbine unit under high-temperature conditions. Applying this device can reduce the vacuum pump inlet gas temperature by 15-25°C, increase the condenser vacuum by ≥0.5 kPa, and reduce the unit's heat consumption. It combines economy and safety, and is suitable for vacuum pump efficiency improvement retrofitting of various condensing steam turbine units.

[0043] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A vacuum pump efficiency boosting vacuum cooling apparatus, characterized by, The application relates to a surface heat exchanger and a cooling medium supply unit, a bypass regulating mechanism and a drainage unit. The surface heat exchanger is connected with a condenser and a vacuum pump of a condensing steam turbine unit, and is used for providing a conveying channel for high-temperature mixed gas drawn from the condenser. The surface heat exchanger is connected with a condenser and a vacuum pump of a condensing steam turbine unit, and is used for providing a conveying channel for high-temperature mixed gas drawn from the condenser. The cooling medium supply unit comprises a condenser makeup water tank, a condensate water conveying pump, a condenser makeup water pipeline and a first electric regulating door. The bypass regulating mechanism is connected with the surface heat exchanger in parallel, and comprises a bypass pipeline and a second electric regulating door arranged on the bypass pipeline. The drainage unit comprises a liquid level sensor, an automatic drainage valve and a cooler drainage manual door.

2. The vacuum pump efficiency boosting vacuum cooling apparatus according to claim 1, characterized in that, The first electric regulating door is interlocked with a DCS system of the unit.

3. The vacuum pump efficiency boosting vacuum cooling apparatus according to claim 1, characterized in that, The condenser water supply temperature of the cooling medium supply unit is ≤32℃ in summer, and the flow rate is controlled at 5-8 m 3 / h; a Y-type filter is installed at the inlet of the condenser water supply pipeline, with a filtering accuracy of ≤100 μm.

4. The vacuum pump efficiency boosting vacuum cooling apparatus according to claim 3, characterized in that, The second electric regulating door has a nominal pressure of greater than or equal to 1.6 MPa, and is connected in a flange connection mode.

5. The vacuum pump efficiency boosting vacuum cooling apparatus according to claim 1, characterized by, The bypass pipeline is also provided with a manual regulating door, and the second electric regulating door and the manual regulating door are connected in parallel to form a double backup.

6. The vacuum pump assisted flash vacuum cooling apparatus of claim 1, wherein, The liquid level sensor has a measuring range of 0-500mm and an accuracy of ±1mm; the automatic drain valve has a nominal pressure of ≥1.6MPa and a drainage capacity of ≥0.5m 3 When the liquid level sensor detects that the liquid level in the surface heat exchanger is ≥300mm, the automatic drain valve is opened, and when the liquid level is ≤100mm, the automatic drain valve is closed.

7. The vacuum pump assisted flash vacuum cooling apparatus of claim 1, wherein, The argon arc welding is used in the interface between the air extraction pipeline system and the surface heat exchanger, and the leakage rate is The slope of the condenser water supply pipeline is greater than or equal to 0.3% to avoid air blockage or water accumulation.

8. A vacuum cooling method using the apparatus according to any one of claims 1 to 7, characterized by, The application has the advantages that when the temperature of the mixed gas drawn from the condenser is high in summer, the mixed gas is first introduced into the surface heat exchanger connected in the air exhaust pipeline system. When the temperature of the mixed gas at the inlet of the vacuum pump is higher than 40 DEG C, the first electric regulating door of the cooling medium supply unit is controlled to be opened by the DCS system, so that the cooling water amount is increased, and the heat exchange effect is strengthened. If the surface heat exchanger is damaged and needs to be repaired, the second electric regulating door of the bypass pipeline is opened, so that the mixed gas is directly introduced into the vacuum pump, and the normal operation of the unit is ensured. The liquid level sensor and the automatic drainage valve are matched, and the condensate water in the surface heat exchanger is discharged in real time, so that the influence of water accumulation on the heat exchange efficiency is avoided.

9. A condensing steam turbine unit characterized by The vacuum pump efficiency improving and vacuum cooling device of any one of claims 1 to 7 is included.

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