Power generation system utilizing negative pressure steam

Abstract

The utility model relates to a power generation system utilizing negative pressure steam, which comprises a steam compressor system, the steam compressor system comprises a steam inlet pipeline, a steam compression assembly and a steam outlet pipeline, an inlet of the steam compression assembly is communicated with an outlet of the steam inlet pipeline, and an outlet of the steam compression assembly is communicated with an inlet of the steam outlet pipeline; the steam compression assembly is used for pressurizing the negative pressure steam, the ORC unit receives the steam pressurized by the steam compression assembly for power generation, by means of the scheme, the industrially produced negative pressure steam can enter the ORC unit after being pressurized by the steam compression assembly, and power generation is achieved through heat exchange of the ORC unit. And the generated electric energy is used for supplementing the steam compressor system and the steam compressor system, so that the by-product negative pressure steam generated in industrial production is efficiently utilized.

Description

Technical Field

[0001] The present application relates to the technical field of negative pressure steam waste heat recovery, and in particular to a power generation system utilizing negative pressure steam. Background Art

[0002] Low-temperature heat sources refer to relatively low-grade heat energy sources, generally with temperatures between 80 and 200°C, including renewable energy sources such as air, surface water, groundwater, soil, solar thermal energy, various industrial waste heat, geothermal energy, and ocean temperature differences.

[0003] At present, most thermal power generation technologies use the Rankine cycle or its improved version. Although the technology is mature, it requires a higher heat source temperature and has low efficiency in utilizing low-grade thermal energy.

[0004] Especially in the food processing, chemical and other industries, there is a large amount of by-product steam. This steam is low-temperature negative pressure steam. Under current technical means, it cannot be efficiently utilized and can only be dissipated into the atmosphere in large quantities, which not only causes energy waste, but also increases production costs. Utility Model Content

[0005] The present application provides a power generation system utilizing negative pressure steam, which can solve the problem that the negative pressure steam generated by the existing industry is not efficiently utilized, resulting in a large amount of steam being emitted and wasting energy.

[0006] The technical solution of this application is as follows:

[0007] A power generation system utilizing negative pressure steam, comprising:

[0008] A steam compressor system, comprising a steam inlet pipeline, a steam compression assembly, and a steam outlet pipeline, wherein the inlet of the steam compression assembly is connected to the outlet of the steam inlet pipeline, and the outlet of the steam compression assembly is connected to the inlet of the steam outlet pipeline, and the steam compression assembly is used to pressurize negative pressure steam;

[0009] The ORC unit receives steam that has been pressurized by the steam compression component to generate electricity.

[0010] By adopting the above solution, the negative-pressure steam produced by industrial production can enter the ORC unit after being pressurized by the steam compression component, generate electricity through heat exchange by the ORC unit itself, and use the generated electricity to supplement itself and the steam compressor system, so that the negative-pressure steam produced as a by-product in industrial production can be efficiently utilized.

[0011] In one embodiment of the present application, the steam compression assembly includes a steam compressor, an electric motor and a transmission assembly, and the electric motor is connected to the steam compressor through the transmission assembly.

[0012] By adopting the above solution, the steam compressor can pressurize the negative-pressure steam produced as a by-product of industrial output so that it can meet the power generation needs of the ORC unit, thereby making efficient use of the negative-pressure steam produced as a by-product of industrial output and improving energy utilization.

[0013] In one embodiment of the present application, the steam compressor is a centrifugal steam compressor or an axial flow steam compressor.

[0014] In one embodiment of the present application, the transmission assembly is a gear box, the drive shaft of the motor is connected and assembled with the input shaft of the gear box, and the output shaft of the gear box is connected and assembled with the steam compressor.

[0015] By adopting the above solution, the motor drives the steam compressor to rotate through the transmission of the gear box, and the output power of the steam compressor can be adjusted by adjusting the output power of the motor, thereby improving the convenience of steam pressure regulation.

[0016] In one embodiment of the present application, a drain valve and a steam compressor steam inlet valve are sequentially provided on the steam inlet pipeline along the steam inlet direction.

[0017] By adopting the above solution, when a fault occurs inside the steam compressor system, the drain valve opens and the steam compressor steam inlet valve closes, so that the negative pressure steam can be discharged into the atmosphere without affecting the normal operation of other processes in industrial production.

[0018] In one embodiment of the present application, a flow meter, a safety valve, a stop valve and a check valve are sequentially provided on the steam outlet pipeline along the steam outlet direction.

[0019] By adopting the above solution, the stop valve is used to control the circulation of steam inside the steam outlet pipeline, the flow meter can measure the steam flow passing through, the safety valve can ensure that the pressure of the pressurized steam entering the ORC unit is not too high, preventing system overpressure, and the check valve can prevent steam backflow when the steam compressor stops or fails, causing overspeed and damage to the steam compressor, thereby improving the safety of the entire system.

[0020] In one embodiment of the present application, the ORC unit includes an evaporator, an expander power generation component and a condensing component. The evaporator is provided with inlet one, inlet two, outlet one and outlet two. The evaporator is connected to the outlet of the steam outlet pipeline through inlet one, the evaporator is connected to the inlet of the expander power generation component through outlet one, the outlet of the expander power generation component is connected to the inlet of the condensing component, the evaporator is connected to the outlet of the condensing component through inlet two, and the outlet two is used to discharge the condensed water formed after steam heat exchange. The expander power generation component is electrically connected to the steam compression component.

[0021] In one embodiment of the present application, the condensation component includes a condenser, a cooling tower, a working fluid pump and a circulating water pump. The condenser is also provided with a cooling water inlet and a cooling water outlet. The cooling water inlet of the condenser is connected to the outlet of the circulating water pump, and the cooling water outlet of the condenser is connected to the inlet of the cooling tower. The working fluid pump is arranged between the evaporator through inlet 2 and the outlet of the condenser, and is connected to both through pipes.

[0022] In one embodiment of the present application, the expander power generation assembly includes an expander and a generator, and the output shaft of the expander is connected and assembled with the generator to drive the generator to generate electricity.

[0023] By adopting the above scheme, the pressurized steam enters the evaporator, and the high-temperature and high-pressure steam undergoes heat exchange in the evaporator, and its heat is transferred to the low-boiling-point working fluid in the evaporator, forming high-temperature and high-pressure organic working fluid vapor, which is then used to enter the expander so that it can continuously work on the generator, realizing the conversion of thermal energy into electrical energy. The organic working fluid vapor then enters the condenser and is re-condensed back into liquid working fluid. Under the action of the working fluid pump, it is pumped back into the evaporator, realizing the recycling of the organic working fluid.

[0024] In one embodiment of the present application, the expander power generation assembly further includes an expander intake valve and a bypass valve, a connecting pipe communicating with the expander inlet is provided between the outlet 1 and the expander inlet, the expander intake valve is provided on the connecting pipe, a bypass pipe communicating with the expander outlet is provided between the outlet 1 and the expander outlet, and the bypass valve is provided on the bypass pipe.

[0025] By adopting the above solution, bypass pipes and bypass valves are set at the inlet and outlet of the expander. When the expander is started, stopped or fails, the bypass valve opens to prevent the organic working fluid steam from being congested in the ORC unit and causing excessive pressure on the entire system.

[0026] In summary, this application includes at least one of the following beneficial technical effects:

[0027] 1. By setting up a steam compressor system and ORC unit in conjunction, the negative pressure steam generated as a by-product of industrial production is pressurized and improved to meet the pressure requirements of the ORC unit for recycling and utilization, and the heat energy therein is converted into electrical energy for reuse by the entire system. The remaining electrical energy is supplemented to industrial production, thereby greatly improving the utilization rate of the negative pressure steam by-product generated in industrial production, reducing carbon emissions, saving energy, and improving economic benefits.

[0028] 2. By installing a drain valve and a steam compressor steam inlet valve on the steam inlet pipe, and installing a safety valve and a check valve on the steam outlet pipe, and utilizing the performance of each valve and selecting the assembly position and assembly method of the above-mentioned valve bodies, the ability of the entire device to cope with emergencies during operation is greatly improved, thereby improving the safety of the entire system.

[0029] 3. By installing an ORC unit and electrically connecting its internal motor to the steam compression component, the entire system converts industrial waste heat into electricity while redistributing the generated electricity to power electrical equipment within the system, including but not limited to: drive motors, working fluid pumps, circulating water pumps, and cooling towers. The remaining electricity is supplemented by industrial production, thereby improving the energy utilization rate of the entire system and enhancing the economic benefits of the industrial production line. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is a schematic diagram of a power generation system utilizing negative pressure steam provided in an embodiment of the present application.

[0031] Explanation of the accompanying symbols: 1. Steam compressor system; 1a. Steam outlet pipeline; 1b. Steam compression component; 1c. Steam inlet pipeline; 11. Exhaust valve; 12. Steam compressor steam inlet valve; 13. Steam compressor; 14. Transmission component; 15. Electric motor; 16. Flow meter; 17. Safety valve; 18. Stop valve; 19. Check valve; 2. ORC unit; 2a. Expander power generation component; 2b. Condensation component; 21. Expander air inlet valve; 22. Bypass valve; 23. Expander; 24. Generator; 25. Condenser; 26. Working fluid pump; 27. Evaporator; 27a. Inlet 1; 27b. Inlet 2; 27c. Outlet 1; 27d. Outlet 2; 28. Circulating water pump; 29. Cooling tower DETAILED DESCRIPTION

[0032] The following is combined with Figure 1 The power generation system using negative pressure steam provided in this application is further described in detail.

[0033] See also Figure 1 , is a power generation system using negative pressure steam provided in an embodiment of the present application, including a steam compressor system 1 and an ORC unit 2.

[0034] The steam compressor system 1 includes a steam inlet pipeline 1c, a steam compression assembly 1b and a steam outlet pipeline 1a. The inlet of the steam compression assembly 1b is connected to the outlet of the steam inlet pipeline 1c, and the outlet of the steam compression assembly 1b is connected to the inlet of the steam outlet pipeline 1a. The steam compression assembly 1b is used to increase the pressure and improve the quality of negative pressure steam.

[0035] In ORC unit 2, the negative-pressure steam generated as an industrial byproduct passes through the steam inlet line 1c and reaches the steam compression component 1b. The steam compression component 1b then increases the pressure of the negative-pressure steam to a level sufficient to meet the power generation needs of ORC unit 2. ORC unit 2 generates electricity using the steam pressurized by the steam compression component 1b. The generated electricity provides energy support for ORC unit 2 itself and the steam compression component 1b, thereby achieving energy recycling. The remaining electricity is then used to supplement industrial production. Among them, ORC unit 2 (organic Rankine cycle power generation system) is a system that utilizes the difference in boiling points of organic working fluids at different pressures to convert thermal energy into mechanical energy.

[0036] In this embodiment, a control system and an electrical system used in existing conventional technical equipment are also included. The control system and the electrical system are electrically connected to the steam compressor system 1 and the ORC unit 2. The specific connection method is a conventional connection method in the prior art, so it will not be repeated here. The control system links the steam compressor system 1, the ORC unit 2 and the external production line equipment as a whole. Under the premise of not affecting the normal operation of the external production line equipment, the steam compressor system 1 and the ORC unit 2 are coordinated and controlled to recover as much waste heat as possible. The external production line equipment is the main production equipment for industrial production such as food and chemical industry, and a large amount of negative pressure by-product steam is generated in industrial production;

[0037] The electrical system links the steam compressor system 1 and ORC unit 2 into a whole, monitoring and balancing their power usage in real time. It is also connected to the power supply system of external production line equipment to ensure stable power consumption of each component during system startup, shutdown, and failure. Furthermore, the electrical system can also output the surplus power of the ORC unit 2 to the power supply system of external production line equipment, reducing the electricity cost of the external production line equipment.

[0038] The steam compression component 1b includes a steam compressor 13, an electric motor 15 and a transmission component 14. The electric motor 15 is connected and assembled with the steam compressor 13 through the transmission component 14. The transmission component 14 can be a gear box. Different types of gear boxes are selected according to actual working conditions, and the drive shaft of the electric motor 15 is connected and assembled with the input shaft of the gear box, and the output shaft of the gear box is connected and assembled with the steam compressor to increase the rotation speed and improve the working efficiency of the steam compressor 13.

[0039] The steam compressor 13 is a centrifugal steam compressor or an axial flow steam compressor. The steam flow rate and pressure at the outlet of the device can be adjusted by adjusting the rotation speed of the steam compressor 13 .

[0040] In this embodiment, the steam flow rate is adjusted within a range of 50% to 100%; the compressor pressure ratio is 1 to 2; and the compression isentropic efficiency is 80% to 85%.

[0041] Take the negative pressure saturated steam with parameters of pressure 80KPa.a, temperature 93.5℃ and flow rate 10t / h as an example:

[0042] Calculations show that by controlling the motor frequency, the steam compressor system consumes approximately 200 kW of electricity, which can boost the negative pressure steam to meet the parameters required by the organic Rankine cycle power generation system. That is, the parameters of the boosted saturated steam are: pressure 110 kPa.a, temperature 130°C, and pressure ratio 1.38. The steam then enters the organic Rankine cycle power generation system 2 for power generation. Calculations show that steam with a pressure of 110 kPa.a, a temperature of 130°C, and a flow rate of 10 t / h can generate approximately 640 kW of electricity, excluding the combined self-consumption of the steam compressor system 1 and the organic Rankine cycle power generation system 2, which is approximately 300 kW.

[0043] It can be seen from the above embodiment that after deducting the self-consumption electricity, there is still about 340KW of net power generation available to the grid, which has considerable economic benefits.

[0044] The motor 15 adopts variable frequency control so that it can operate stably under wide voltage fluctuations.

[0045] In other embodiments, according to the requirements of actual working conditions, for example, when the steam compressor 13 itself meets the requirement of increasing the steam pressure, the output shaft of the motor 15 can be directly connected to the steam compressor 13 for assembly to save assembly steps.

[0046] An exhaust valve 11 and a steam compressor steam inlet valve 12 are sequentially arranged on the steam inlet pipeline 1c along the steam inlet direction. When the steam compressor system 1 fails and cannot pressurize the negative pressure steam in real time, the exhaust valve 11 is opened and the steam compressor steam inlet valve 12 is closed through the control system interlock. After the outlet of the steam inlet pipeline 1c is sealed, the negative pressure steam is automatically discharged into the atmosphere through the exhaust valve 11 without affecting the normal operation of the main production process.

[0047] A flow meter 16, a safety valve 17, a stop valve 18, and a check valve 19 are sequentially provided on the steam outlet pipeline 1a along the steam outlet direction. The safety valve 17 can ensure that the pressure of the pressurized steam entering the ORC unit 2 is not too high, and plays a role in limiting the pressure in the system. The check valve 19 can prevent steam backflow when the steam compressor 13 stops or fails, causing overspeed and damage to the steam compressor 13, thereby improving the safety of the entire system.

[0048] The ORC unit 2 includes an evaporator 27, an expander power generation component 2a and a condensing component 2b. The evaporator 27 is provided with an inlet 1 27a, an inlet 27b, an outlet 1 27c and an outlet 27d. The evaporator 27 is connected to the outlet of the steam outlet pipeline 1a through the inlet 1 27a, the evaporator 27 is connected to the inlet of the expander power generation component 2a through the outlet 1 27c, the outlet of the expander power generation component 2a is connected to the inlet of the condensing component 2b, the evaporator 27 is connected to the outlet of the condenser 25 through the inlet 27b, and the outlet 27d is used to discharge steam for heat exchange. The condensed water is then formed, and the expander power generation component 2a is electrically connected to the steam compression component 1b. When the pressurized steam enters the evaporator 27, a low-boiling-point organic working fluid is provided inside the evaporator 27, wherein the organic working fluid can be pentafluoropropane liquid. The high-temperature and high-pressure steam exchanges heat with the organic working fluid, and the organic working fluid evaporates to form high-temperature and high-pressure working fluid steam. The working fluid steam enters the expander power generation component 2a to generate electricity, and is re-condensed into a liquid organic working fluid by the condensation component 2b through indirect heat exchange, and is transported to the evaporator 27, and the cycle is repeated.

[0049] In this embodiment, the condensed water in the second outlet 27d can also be recycled to the main production process through a recycling device, thereby reducing production costs. The recycling device can be a water pump or a water pipe.

[0050] The condensation component 2b includes a condenser 25, a cooling tower 29, a working fluid pump 26 and a circulating water pump 28. The condenser 25 is also provided with a cooling water inlet and a cooling water outlet. The cooling water inlet of the condenser 25 is connected to the outlet of the circulating water pump 28, and the cooling water outlet of the condenser 25 is connected to the inlet of the cooling tower 29. The working fluid pump 26 is arranged between the evaporator 27 through the second inlet 27b and the outlet of the condenser 25, and is connected to the two through pipelines. The working fluid vapor discharged from the expander power generation component 2a enters the condenser 25 and undergoes secondary heat exchange with the cooling water in the condenser. The low-pressure working fluid vapor is re-condensed to a liquid state and pumped into the evaporator 27 by the working fluid pump 26, thereby realizing the recycling of the working fluid liquid.

[0051] The expander power generation assembly 2a includes an expander 23 and a generator 24. The output shaft of the expander 23 is connected and assembled with the generator 24 to drive the generator 24 to generate electricity. After the high-temperature and high-pressure working fluid steam enters the expander 23, it drives the expander 23 to do work and drives the generator directly connected to it to generate electricity, thereby saving energy and improving economic benefits.

[0052] The expander power generation component 2a also includes an expander air inlet valve 21 and a bypass valve 22. A connecting pipe connecting the outlet 27c and the inlet of the expander 23 is provided between the two. The expander air inlet valve 21 is provided on the connecting pipe. A bypass pipe connecting the outlet 27c and the outlet of the expander 23 is provided between the two. The bypass valve 22 is provided on the bypass pipe.

[0053] The above are all preferred embodiments of the present application, and are not intended to limit the scope of protection of the present application. Therefore, any equivalent changes made based on the structure, shape, and principle of the present application should be included in the scope of protection of the present application.

Claims

1. A power generation system using negative pressure steam, characterized in that: include: A steam compressor system (1), the steam compressor system (1) comprising a steam inlet pipeline (1c), a steam compression component (1b) and a steam outlet pipeline (1a), the inlet of the steam compression component (1b) being in communication with the outlet of the steam inlet pipeline (1c), the outlet of the steam compression component (1b) being in communication with the inlet of the steam outlet pipeline (1a), and the steam compression component (1b) being used to pressurize negative pressure steam; The ORC unit (2) receives steam pressurized by the steam compression component (1b) to generate electricity.

2. The power generation system using negative pressure steam according to claim 1, characterized in that: The steam compression assembly (1b) comprises a steam compressor (13), an electric motor (15) and a transmission assembly (14), wherein the electric motor (15) is connected to the steam compressor (13) via the transmission assembly (14).

3. The power generation system using negative pressure steam according to claim 2, characterized in that: The steam compressor (13) is a centrifugal steam compressor or an axial flow steam compressor.

4. The power generation system using negative pressure steam according to claim 2, characterized in that: The transmission assembly (14) is a gear box, the drive shaft of the motor (15) is connected and assembled with the input shaft of the gear box, and the output shaft of the gear box is connected and assembled with the steam compressor.

5. The power generation system using negative pressure steam according to claim 1, characterized in that: The steam inlet pipeline (1c) is provided with an exhaust valve (11) and a steam compressor steam inlet valve (12) in sequence along the steam inlet direction.

6. The power generation system using negative pressure steam according to claim 1, characterized in that: A flow meter (16), a safety valve (17), a stop valve (18), and a check valve (19) are sequentially arranged on the steam outlet pipeline (1a) along the steam outlet direction.

7. The power generation system using negative pressure steam according to claim 1, characterized in that: The ORC unit (2) includes an evaporator (27), an expander power generation component (2a) and a condensing component (2b). The evaporator (27) is provided with an inlet 1 (27a), an inlet 2 (27b), an outlet 1 (27c) and an outlet 2 (27d). The evaporator (27) is connected to the outlet of the steam outlet pipeline (1a) through the inlet 1 (27a), the evaporator (27) is connected to the inlet of the expander power generation component (2a) through the outlet 1 (27c), the outlet of the expander power generation component (2a) is connected to the inlet of the condensing component (2b), the evaporator (27) is connected to the outlet of the condensing component (2b) through the inlet 2 (27b), the outlet 2 (27d) is used to discharge condensed water formed after steam heat exchange, and the expander power generation component (2a) is electrically connected to the steam compression component (1b).

8. The power generation system using negative pressure steam according to claim 7, characterized in that: The condensation component (2b) includes a condenser (25), a cooling tower (29), a working fluid pump (26) and a circulating water pump (28). The condenser (25) is also provided with a cooling water inlet and a cooling water outlet. The cooling water inlet of the condenser (25) is connected to the outlet of the circulating water pump (28), and the cooling water outlet of the condenser (25) is connected to the inlet of the cooling tower (29). The working fluid pump (26) is arranged between the evaporator (27) and the outlet of the condenser (25) through the second inlet (27b), and is connected to both through pipelines.

9. The power generation system using negative pressure steam according to claim 7, characterized in that: The expander power generation assembly (2a) comprises an expander (23) and a generator (24), wherein an output shaft of the expander (23) is connected and assembled with the generator (24) for driving the generator (24) to generate electricity.

10. The power generation system using negative pressure steam according to claim 9, characterized in that: The expander power generation assembly (2a) further includes an expander air inlet valve (21) and a bypass valve (22); a connecting pipe communicating with the first outlet (27c) and the inlet of the expander (23) is provided between the first outlet (27c) and the outlet of the expander (23); the expander air inlet valve (21) is provided on the connecting pipe; a bypass pipe communicating with the first outlet (27c) and the outlet of the expander (23) is provided between the first outlet (27c) and the outlet of the expander (23); and the bypass valve (22) is provided on the bypass pipe.

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