Steam-electricity double-drive energy-saving system of high-power centrifugal pump

Abstract

The utility model relates to the technical field of high-power centrifugal pumps, in particular to a steam-electricity double-drive energy-saving system of a high-power centrifugal pump, which comprises a steam turbine, a centrifugal pump, a motor and a device joint debugging control cabinet, the steam turbine is connected with a speed change gear box through a first coupler, the speed change gear box is connected with a clutch, and the clutch is connected with the centrifugal pump through a second coupler. The centrifugal pump is connected with the motor through a third coupler, and the device joint debugging control cabinet is connected with the steam turbine, the clutch and the motor. According to the utility model, the problem of high energy consumption of a high-power centrifugal pump and a motor which are used for providing a large amount of circulating water for production and life is solved, and meanwhile, surplus steam in production is utilized, so that the energy-saving transformation of a water supply system of the large-scale centrifugal pump is realized, the emission of steam and tail gas in air is reduced, and the consumption of output power of the motor is reduced.

Description

Technical Field

[0001] The utility model belongs to the technical field of high-power centrifugal pumps, in particular to a steam-electric dual-drive energy-saving system for high-power centrifugal pumps. Background Technique

[0002] With the progress of reform and opening up, China's economy has grown rapidly, and great achievements have been made in the construction of all walks of life. However, it has also paid a huge price in terms of resource waste and environmental damage. The consumption of a large amount of oil, natural gas, and coal, as well as the large emissions of various greenhouse gases such as steam and tail gas, have caused global warming and attracted wide attention from the international community. Therefore, the state attaches great importance to energy conservation and emission reduction work, and has formulated a series of policies for this purpose. The "Energy Conservation Law of the People's Republic of China" states that "resource conservation is China's basic national policy", and the state implements an energy development strategy that combines conservation and development and gives priority to conservation.

[0003] In large-scale manufacturing, large water supply centrifugal pumps are the basic configuration of many production enterprises in China, especially in key industries such as petroleum, chemical industry, electric power, steel, smelting, papermaking, heating, and seawater desalination. Their production processes require a large number of high-power centrifugal pumps and motor equipment to provide a large amount of circulating water required in production and life. According to statistics of the Pump Professional Committee of the Chinese Society of Mechanical Engineering, about 19%-23% of the total annual electricity generation in China is consumed by pump products, and at the same time, a large amount of steam and tail gas are emitted, and most of them cannot be effectively treated or utilized; for example, the total installed capacity of the large water supply pumps in a light hydrocarbon comprehensive processing and utilization project of a petrochemical company is as high as 75,000 kilowatts. Calculated according to 8,000 hours of operation per year, the annual power consumption is about 420 million kilowatt-hours. Calculated at 0.65 yuan per kilowatt-hour, the electricity cost is 273 million yuan. Coupled with the environmental pollution treatment of the large amount of surplus steam and tail gas emissions, it will cost a huge price. Therefore, it is very meaningful to carry out energy-saving transformation on the pumps in the large water supply system, conduct research and development on the comprehensive utilization technology of the energy of surplus steam and tail gas, and reduce the power consumption of the motor. Even if only 10% of the system energy consumption is reduced, the enterprise can save 273 million yuan in expenditure every year. At the same time, it can also reduce the pressure on environmental pollution, bringing out the best in each other. It not only saves energy costs and creates benefits, but also contributes to the country's environmental protection cause, making the water clearer, the sky bluer, and the people happier. Summary of the Invention

[0004] In order to overcome the defects of the above-mentioned prior art, the utility model proposes a control method for a steam-electric dual-drive energy-saving system of a high-power centrifugal pump, which solves the problem of high energy consumption of high-power centrifugal pumps and motors. At the same time, it utilizes the surplus steam in production, reduces the emissions of steam and tail gas into the air, and reduces the power consumption of the motor output, achieving energy conservation and emission reduction. The technical problems to be solved by the utility model are realized through the following technical solutions:

[0005] A steam-electric dual-drive energy-saving system for a high-power centrifugal pump, comprising a steam turbine, a centrifugal pump, an electric motor, and a device joint debugging control cabinet. The steam turbine is connected to a speed-changing gearbox through a first coupling, the speed-changing gearbox is connected to a clutch, the clutch is connected to the centrifugal pump through a second coupling, the centrifugal pump is connected to the electric motor through a third coupling, and the device joint debugging control cabinet is respectively connected to the steam turbine, the clutch, and the electric motor.

[0006] Further, the clutch is a set of hydraulically coupled turbines. One turbine of the clutch is coaxially connected to the low-speed gear in the speed-changing gearbox, and the other turbine of the clutch is connected to the centrifugal pump through a second coupling.

[0007] Further, the steam turbine includes a flow regulating valve, an electromagnetic start-stop safety system, a manual emergency start-stop safety system, a bearing body, and a cooling oil tank.

[0008] Further, the centrifugal pump is a single-stage double-suction centrifugal pump, comprising a pump body, a pump shaft, an impeller, a seal, and a bearing body.

[0009] Specifically, the pump shaft has a double-shaft extension structure.

[0010] Specifically, the electric motor is a high-power and high-efficiency electric motor with a power above 1000KW.

[0011] Specifically, the device joint debugging control cabinet includes an automatic control system.

[0012] Particularly, when the centrifugal pump is under normal load, the electric motor and the steam turbine are prime movers.

[0013] Particularly, when the centrifugal pump is unloaded, the steam turbine is the prime mover, and the centrifugal pump does not include an impeller.

[0014] The utility model solves the problem of high energy consumption of high-power centrifugal pumps and electric motors that provide a large amount of circulating water required in production and life. At the same time, it utilizes the surplus steam in production, realizes the energy-saving transformation of the large centrifugal pump water supply system, reduces the emissions of steam and tail gas into the air, and reduces the consumption of the motor output power. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 is the general assembly schematic diagram of the utility model;

[0016] Figure 2 is the sectional view schematic diagram when the centrifugal pump is under load;

[0017] Figure 3 is the sectional view schematic diagram when the centrifugal pump is unloaded. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0018] Figure 1 is the general assembly schematic diagram of the utility model, as shown in Figure 1As shown in the figure, a steam-electric dual-drive energy-saving system for a high-power centrifugal pump includes a steam turbine 1, a centrifugal pump 2, an electric motor 3, and a device joint debugging control cabinet 4. The steam turbine 1 is connected to a speed-changing gearbox 6 through a first coupling 5. The speed-changing gearbox 6 is connected to a clutch 7. The clutch 7 is connected to the centrifugal pump 2 through a second coupling 8. The centrifugal pump 2 is connected to the electric motor 3 through a third coupling 9. The device joint debugging control cabinet 4 is respectively connected to the steam turbine 1, the clutch 7, and the electric motor 3. In this embodiment, the clutch 7 is a group of hydraulically coupled turbines. One turbine of the clutch 7 is coaxially connected to the low-speed gear in the speed-changing gearbox 6, and the other turbine of the clutch 7 is connected to the centrifugal pump 2 through the second coupling 8.

[0019] The steam turbine 1 includes a flow regulating valve 1.1, an electromagnetic start-stop safety system 1.2, a manual emergency start-stop safety system 1.3, a first bearing body 1.4, and a cooling oil tank 1.5. The flow regulating valve 1.1, the electromagnetic start-stop safety system 1.2, and the manual emergency start-stop safety system 1.3 are arranged at the inlet of the steam turbine 1. The first bearing body 1.4 is arranged at both ends of the steam turbine 1 to support the main shaft and rotor of the steam turbine 1. The cooling oil tank 1.5 is arranged below the first bearing body 1.4 to cool the high temperature generated during the operation of the first bearing body 1.4 and take away the heat. The flow regulating valve 1.1 can adjust the intake air volume of the steam turbine 1 as required and output the power matching the requirements of the centrifugal pump 2. The speed-changing gearbox 6 can convert the output speed of the steam turbine 1. The clutch 7 controls the opening and closing of the output power of the steam turbine 1 to the centrifugal pump 2. The flow regulating valve 1.1, the speed-changing gearbox 6, and the clutch 7 are all controlled by the device joint debugging control cabinet 4. When the steam turbine 1 encounters a fault, the electromagnetic start-stop safety system 1.2 and the manual emergency start-stop safety system 1.3 control the steam turbine 1 to stop, providing double insurance. The steam turbine 1 of the present utility model can comprehensively utilize a large amount of surplus steam generated in the production of industries such as petroleum, chemical industry, electric power, steel, smelting, and papermaking, realizing the energy-saving transformation of the water supply system of the large centrifugal pump 2, reducing the emissions of steam and tail gas, and reducing the output power of the electric motor 3.

[0020] Through a large number of tests, it is obtained that: 1. Usually, in the steam turbine and centrifugal pump hydraulic energy transmission device, the surplus steam energy recovery efficiency is about 30%-40%, and its energy conversion process is "pressure energy (steam) - mechanical energy (shaft work) - pressure energy (water)"; 2. In special cases, in the steam turbine and generator power exchange type energy recovery device, the surplus steam energy recovery efficiency is as high as 40%-55%, and its energy conversion process is "pressure energy (steam) - mechanical energy (shaft work) - electric energy".

[0021] Figure 2 It is a cross-sectional schematic diagram when the centrifugal pump is under load, as Figure 2As shown, the centrifugal pump 2 is a single-stage double-suction centrifugal pump, including a pump body 2.1, a pump shaft 2.2, an impeller 2.3, a seal 2.4 and a second bearing body 2.5. The pump shaft 2.2 passes through the pump body 2.1, the seal 2.4 and the impeller 2.3, and is supported at both ends by the second bearing body 2.5. The second bearing body 2.5 is arranged on the pump body 2.1, and the impeller 2.3 is arranged in the pump body 2.1 and in the middle of the pump shaft 2.2. The pump shaft 2.2 drives the impeller 2.3 to operate and do work on the liquid; the pump shaft 2.2 of the utility model is a double-axis extension structure design, which is convenient for connection on both sides Electric motor 3 and steam turbine 1 are bidirectionally driven. Impeller 2.3 is a double-suction impeller with staggered blades. The hydraulic performance of impeller 2.3 is highly efficient, ranging from 88% to 92%, meeting or exceeding the energy-saving evaluation value of the national energy efficiency standard for clean water centrifugal pumps GB19762-2007. The centrifugal pump has small hydraulic pulses and vibrations. At the same time, the structure well balances the radial and axial forces of the pump shaft, allowing the centrifugal pump to withstand greater shaft power when conveying large flows of liquid, thereby improving the stability and reliability of the centrifugal pump during operation and extending the service life of the pump device.

[0022] The electric motor 3 of the present invention is a high-power, high-efficiency electric motor, typically with a power of over 1000 kW and an efficiency of 94%-97%. The electric motor 3 is connected to the steam turbine 1, a speed change gearbox 6, and a clutch 7 via a device joint control cabinet 4. During operation, the electric motor 3 and the steam turbine 1 are started separately and monitored by the device joint control cabinet 4. When the output speed of the steam turbine 1 is converted by the speed change gearbox 6 to a synchronous speed with the electric motor 3, the clutch 7 closes, and the centrifugal pump 2 is dual-driven. At this time, the centrifugal pump 2 is driven by steam and electricity, and the centrifugal pump 2 is loaded to transport circulating water. The output power is P, and the output of the electric motor 3 accounts for approximately 45%-30% of P, while the output of the steam turbine 1 accounts for approximately 55%-70% of P. Compared with traditional centrifugal pumps driven by a single electric motor, the output power of the electric motor 3 of the present invention is significantly reduced, achieving high efficiency and energy saving. The device joint control cabinet 4 includes an automatic control system to ensure that the steam turbine and the electric motor output synchronous speeds after adjustment, transmitting power to the centrifugal pump.

[0023] The centrifugal pump 2 of the present utility model is the core working machine. When the centrifugal pump 2 is under normal load, the motor 3 and the steam turbine 1 are prime movers. When the output speed of the steam turbine 1 reaches the synchronous speed with the motor 3 after being transformed by the speed change gearbox 6, the clutch 7 closes, and the centrifugal pump 2 is driven by dual power. At this time, the centrifugal pump 2 realizes steam-electric dual drive, loads and transports circulating water, and provides a large amount of circulating water required in the production and life of enterprises. Compared with the traditional centrifugal pump driven by a single motor alone, the output power of the motor of the present utility model is significantly reduced, and high-efficiency energy conservation is achieved. In special cases, when the centrifugal pump 2 is unloaded, the centrifugal pump 2 does not include the impeller 2.3. The steam turbine 1 is the prime mover and transmits power to the motor 3. At this time, the motor 3 changes the circuit and generates electricity as a generator (working machine), outputs electric energy, and transports it to places where electric energy is needed for people to reuse in production and life.

[0024] The present utility model is applied to the test of a chemical industry company in Hubei. The rated flow rate of the centrifugal pump 2 is 20000 m 3 / h, the rated head is 36 m, the rated speed is 490 rpm, the output power is 2300 KW, and the power of the supporting prime mover is 2500 KW. According to the different requirements of the flow rate, head, and power of the centrifugal pump 2 at different times, through the device joint adjustment control cabinet 4 for monitoring, the flow valve 1.1 is adjusted to control the intake air volume, pressure, and temperature of the steam turbine 1, so as to adjust the output power of the steam turbine 1 and the motor 3, and achieve precise control. Among them, the output of the steam turbine 1 is about between 1200 - 1600 KW, and the output of the motor 3 is about between 1100 - 700 KW, just matching the power requirement of the centrifugal pump 2, and flexibly adjusting the water supply volume.

[0025] In special cases, when the centrifugal pump 2 is not required to transport liquid, the impeller 2.3 of the centrifugal pump 2 is removed. Of course, the impeller 2.3 of the present utility model can also not be removed. It is necessary to close the pipeline inlet and outlet valves and drain the liquid in the centrifugal pump to achieve no-load operation. However, the sealing 2.4 mating surface is easily damaged due to dry grinding. Moreover, the impeller 2.3 on the pump shaft 2.2 rotates idly for a long time, with large vibration and unstable operation. Therefore, in this embodiment, the impeller 2.3 is removed to ensure the stable and safe operation of the system; Figure 3 It is a sectional view schematic diagram when the centrifugal pump is unloaded, as Figure 3 shown. At this time, the centrifugal pump 2 does not do work on the liquid in the pump when it is unloaded, and only the pump shaft 2.2 remains to transmit the power torque of the steam turbine 1 to the motor 3. At this time, the wiring of the motor 3 is switched to other circuits through the device joint adjustment control cabinet 4 and used as a generator to generate electric energy, and the electric energy is transported to the places where the enterprise uses electricity, realizing the recycling of energy. The present utility model operates stably, is safe and reliable, has high-efficiency energy conservation, reduces the production cost of the enterprise, creates benefits for the enterprise, and contributes to the national energy conservation and emission reduction cause.

[0026] In summary, the utility model solves the problem of high energy consumption of high-power centrifugal pumps and motors that provide a large amount of circulating water required in production and life. At the same time, it utilizes the surplus steam in production, realizes the energy-saving transformation of the large centrifugal pump water supply system, reduces the emissions of steam and tail gas into the air, and reduces the consumption of the motor output power.

Claims

1. A steam-electric dual-drive energy-saving system for a high-power centrifugal pump, characterized by: The invention comprises a steam turbine, a centrifugal pump, an electric motor and a device joint control cabinet. The steam turbine is connected to a speed change gear box through a first coupling, the speed change gear box is connected to a clutch, the clutch is connected to a centrifugal pump through a second coupling, the centrifugal pump is connected to the electric motor through a third coupling, and the device joint control cabinet is connected to the steam turbine, the clutch and the electric motor respectively.

2. The steam-electric dual-drive energy-saving system for a high-power centrifugal pump according to claim 1 is characterized in that: The clutch is a set of hydraulically coupled turbines, one turbine of the clutch is coaxially connected to the low-speed gear in the speed change gear box, and the other turbine of the clutch is connected to the centrifugal pump through a second coupling.

3. The steam-electric dual-drive energy-saving system for a high-power centrifugal pump according to claim 1 is characterized in that: The steam turbine includes a flow regulating valve, an electromagnetic start-stop safety system, a manual emergency start-stop safety system, a bearing body and a cooling oil tank.

4. The steam-electric dual-drive energy-saving system for a high-power centrifugal pump according to claim 1 is characterized in that: The centrifugal pump is a single-stage double-suction centrifugal pump, comprising a pump body, a pump shaft, an impeller, a seal and a bearing body.

5. The steam-electric dual-drive energy-saving system for a high-power centrifugal pump according to claim 4 is characterized in that: The pump shaft is a double-axle extension structure.

6. The steam-electric dual-drive energy-saving system for a high-power centrifugal pump according to claim 1 is characterized in that: The motor is a high-power and high-efficiency motor with a power of more than 1000Kw.

7. The steam-electric dual-drive energy-saving system for a high-power centrifugal pump according to claim 1 is characterized in that: The device joint debugging control cabinet includes an automatic control system.

8. The steam-electric dual-drive energy-saving system for a high-power centrifugal pump according to claim 1 is characterized in that: When the centrifugal pump is under normal load, the electric motor and the steam turbine serve as prime movers.

9. The steam-electric dual-drive energy-saving system for a high-power centrifugal pump according to claim 1 is characterized in that: When the centrifugal pump is unloaded, the steam turbine serves as the prime mover and the centrifugal pump does not include an impeller.

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