Comprehensive utilization system for surplus low-pressure steam heat energy
By utilizing surplus low-pressure steam to drive a low-grade thermal refrigerator, the problems of steam waste and high energy consumption in polysilicon production are solved, the recovery of steam waste heat, energy conservation and consumption reduction are achieved, and production costs are reduced.
Patent Information
- Application Number
- CN202422110855.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-29
- Publication Date
- 2025-10-03
- Estimated Expiration
- 2034-08-29
AI Technical Summary
The existing reduction furnace steam utilization system has problems of steam waste and high energy consumption. Especially in polysilicon production, the surplus low-pressure saturated steam is not reasonably utilized, resulting in increased production costs and energy consumption.
Surplus low-pressure steam is used as the driving force, and low-grade heat refrigeration is used to cool the process, replacing the electric-driven screw refrigeration unit to achieve low-grade steam waste heat recovery and energy saving and consumption reduction.
It realizes the recovery of low-grade steam waste heat, reduces production costs and energy consumption, and has a significant energy-saving and emission-reduction effect.
Smart Images
Figure CN223412280U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the field of steam utilization in a reduction furnace, in particular to a comprehensive utilization system of surplus low-pressure steam heat energy. Background Art
[0002] The steam thermal energy comprehensive utilization system is a supporting equipment for utilizing steam from the reduction furnace. The reduction furnace is a key equipment in the polysilicon production process. Currently, the reduction furnace produces 0.4 MPa (G) saturated steam as a by-product. The above steam is mainly used for production needs. After the steam production of the entire process is balanced, there is still a surplus of 40t / h of saturated steam that has not been reasonably utilized. With the continuous development of science and technology, people have higher and higher requirements for the manufacturing process of the steam thermal energy comprehensive utilization system.
[0003] The existing reduction furnace steam utilization system has certain drawbacks. Currently, the steam is condensed into condensate using venting or air cooling, which is then used for reduction. This increases polysilicon production costs and energy consumption, wasting electricity. Furthermore, the exhaust gas recovery unit 223A is equipped with four electrically driven R507A refrigeration units with a cooling capacity of 3700 kW and an electrical power of 2240 kW. The refrigerant, ethylene glycol, is used at a -20°C output temperature to cool the process medium, thereby condensing the chlorosilane. This refrigeration and cooling process consumes a significant amount of electricity, which has a certain negative impact on actual use. Therefore, we propose a system for the comprehensive utilization of excess low-pressure steam thermal energy. Utility Model Content
[0004] Technical problem solved: In response to the shortcomings of the existing technology, the utility model provides a comprehensive utilization system of surplus low-pressure steam thermal energy, which uses the surplus low-pressure saturated steam heat source in production as the driving force, adopts a low-grade heat refrigerator, and provides it for process cooling after refrigeration, thereby realizing the recovery of low-grade steam waste heat and replacing the electric-driven screw refrigeration unit, thereby achieving the purpose of energy saving and consumption reduction, which is of great significance to reducing production costs and energy conservation and emission reduction, and can effectively solve the problems in the background technology.
[0005] Technical solution: In order to achieve the above-mentioned purpose, the technical solution adopted by the present invention is: a comprehensive utilization system of surplus low-pressure steam heat energy, including a waste heat refrigerator, the waste heat refrigerator is connected to a saturated steam box and a liquid ammonia tank, the liquid ammonia tank is connected to a first evaporator, the first evaporator is connected to an ethylene glycol solution tank, the ethylene glycol solution tank is connected to a heat exchanger, the heat exchanger is connected to a second evaporator, the second evaporator is connected to a gas ammonia box, the gas ammonia box is connected to a flow monitor, a temperature monitor is connected between the first evaporator and the ethylene glycol solution tank, and a flow monitor is connected between the gas ammonia box and the waste heat refrigerator.
[0006] Preferably, the temperature monitor is internally provided with a temperature sensor, a data collector, a central processing unit, a switch controller and a temperature display, the temperature sensor is connected to the data collector, the data collector is connected to the central processing unit, and the central processing unit is connected to the switch controller and the temperature display.
[0007] Preferably, a flow sensor, a PLC single chip microcomputer, a flow controller and a flow display are provided inside the flow monitor, the flow sensor is connected to the PLC single chip microcomputer, and the PLC single chip microcomputer is connected to the flow display and the flow controller.
[0008] Preferably, the output end of the temperature sensor is electrically connected to the input end of the central processing unit through a data collector, and the output end of the central processing unit is electrically connected to the input ends of the switch controller and the temperature display.
[0009] Preferably, the output end of the flow sensor is electrically connected to the input end of the PLC single chip microcomputer, and the output end of the PLC single chip microcomputer is electrically connected to the input end of the flow display and the flow controller.
[0010] Preferably, the waste heat refrigerator, the liquid ammonia tank, the first evaporator, the ethylene glycol solution tank, the heat exchanger, the second evaporator and the gaseous ammonia tank are circulated among each other.
[0011] Beneficial effects: Compared with the prior art, the present invention provides a system for comprehensive utilization of surplus low-pressure steam heat energy, which has the following beneficial effects: the system utilizes surplus low-pressure saturated steam heat source in production as a driving force, adopts a low-grade heat refrigerator, and provides the heat for process cooling after refrigeration, thereby realizing the recovery of low-grade steam waste heat and replacing the electric-driven screw refrigeration unit, thereby achieving the purpose of energy saving and consumption reduction, which is of great significance to reducing production costs and energy conservation and emission reduction;
[0012] This system utilizes low-grade waste heat refrigeration, utilizing surplus 0.4 MPa (G) saturated steam at 152°C as the driving force. Liquid ammonia at approximately 1.2 MPa (G) is generated through a heat and cold energy converter. This liquid ammonia then evaporates at -23°C in an evaporator, absorbing heat and producing a -20°C ethylene glycol solution. The -20°C ethylene glycol solution then enters a heat exchanger to cool the process material. After evaporation, the remaining 0.066 MPa (G) ammonia gas enters a low-grade waste heat refrigeration system for recycling. This system replaces existing screw refrigeration systems for production, replacing -25°C screw chillers and reducing refrigeration electricity consumption. The entire steam heat energy comprehensive utilization system is simple in structure, easy to operate, and offers superior performance compared to traditional methods. BRIEF DESCRIPTION OF THE DRAWINGS
[0013] Figure 1This is a schematic diagram of the overall structure of a comprehensive utilization system of surplus low-pressure steam thermal energy in the utility model.
[0014] Figure 2 This is a structural schematic diagram of a temperature monitor in a system for comprehensive utilization of surplus low-pressure steam thermal energy according to the present invention.
[0015] Figure 3 This is a structural schematic diagram of a flow monitor in a system for comprehensive utilization of surplus low-pressure steam thermal energy according to the present invention.
[0016] Figure 4 This is a comparison diagram of the heat energy utilization process in a comprehensive utilization system of surplus low-pressure steam heat energy in the utility model.
[0017] In the figure: 1. Waste heat refrigerator; 2. Saturated steam box; 3. Liquid ammonia tank; 4. First evaporator; 5. Temperature monitor; 6. Ethylene glycol solution tank; 7. Heat exchanger; 8. Second evaporator; 9. Gas ammonia tank; 10. Flow monitor; 11. Flow display; 12. Temperature sensor; 13. Data acquisition unit; 14. Central processing unit; 15. Switch controller; 16. Temperature display; 17. Flow sensor; 18. PLC microcontroller; 19. Flow controller. DETAILED DESCRIPTION
[0018] The technical solution of the present invention will be clearly and completely described below in conjunction with the accompanying drawings and specific embodiments, but those skilled in the art will understand that the embodiments described below are part of the embodiments of the present invention, rather than all of the embodiments, and are only used to illustrate the present invention, and should not be regarded as limiting the scope of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative work are within the scope of protection of the present invention. If specific conditions are not specified in the embodiments, they are carried out according to conventional conditions or the conditions recommended by the manufacturer. If the manufacturer is not specified for the reagents or instruments used, they are all conventional products that can be purchased commercially.
[0019] In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating positions or relationships, are based on the positions or relationships shown in the accompanying drawings and are intended solely to facilitate the description of this utility model and simplify the description. They do not indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on this utility model. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.
[0020] In the description of this utility model, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; mechanical connections, electrical connections; direct connections, indirect connections through an intermediate medium, and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in this utility model based on the specific circumstances.
[0021] like Figure 1-4 As shown, a system for comprehensive utilization of surplus low-pressure steam heat energy includes a waste heat refrigerator 1, the waste heat refrigerator 1 is connected to a saturated steam box 2 and a liquid ammonia box 3, the liquid ammonia box 3 is connected to a first evaporator 4, the first evaporator 4 is connected to an ethylene glycol solution box 6, the ethylene glycol solution box 6 is connected to a heat exchanger 7, the heat exchanger 7 is connected to a second evaporator 8, the second evaporator 8 is connected to an ammonia gas box 9, the ammonia gas box 9 is connected to a flow monitor 10, a temperature monitor 5 is connected between the first evaporator 4 and the ethylene glycol solution box 6, and a flow monitor 10 is connected between the ammonia gas box 9 and the waste heat refrigerator 1. The surplus low-pressure saturated steam heat source in the production is used as the driving force, and a low-grade heat refrigerator is used to cool the process after refrigeration, thereby realizing the recovery of low-grade steam waste heat and replacing the electric-driven screw refrigeration unit, thereby achieving the purpose of energy saving and consumption reduction, which is of great significance to reducing production costs and energy conservation and emission reduction.
[0022] Furthermore, the temperature monitor 5 is internally provided with a temperature sensor 12, a data collector 13, a central processing unit 14, a switch controller 15 and a temperature display 16. The temperature sensor 12 is connected to the data collector 13, the data collector 13 is connected to the central processing unit 14, and the central processing unit 14 is connected to the switch controller 15 and the temperature display 16.
[0023] Furthermore, the flow monitor 10 is internally provided with a flow sensor 17 , a PLC single chip computer 18 , a flow controller 19 and a flow display 11 . The flow sensor 17 is connected to the PLC single chip computer 18 , and the PLC single chip computer 18 is connected to the flow display 11 and the flow controller 19 .
[0024] Furthermore, the output end of the temperature sensor 12 is electrically connected to the input end of the central processing unit 14 through the data collector 13 , and the output end of the central processing unit 14 is electrically connected to the input ends of the switch controller 15 and the temperature display 16 .
[0025] Furthermore, the output end of the flow sensor 17 is electrically connected to the input end of the PLC microcontroller 18 , and the output end of the PLC microcontroller 18 is electrically connected to the input ends of the flow display 11 and the flow controller 19 .
[0026] Furthermore, the waste heat refrigerator 1 , the liquid ammonia tank 3 , the first evaporator 4 , the ethylene glycol solution tank 6 , the heat exchanger 7 , the second evaporator 8 and the gaseous ammonia tank 9 circulate among each other.
[0027] Example:
[0028] 1. Energy consumption of low-grade waste heat refrigeration machine
[0029] (1) Electricity
[0030] The waste heat unit has a cooling capacity of 11,100 kW, and its calculated electricity consumption is 107.8 × 2 kW. The annual electricity consumption is: 107.8 × 2 × 8,000 = 1,724,800 kW-h. The annual electricity cost is: 1,724,800 × 0.35 = 603,680 yuan (the electricity price is 0.35 yuan / kWh provided by the owner).
[0031] (2) Water use
[0032] Two waste heat chillers with a cooling capacity of 11,100 kW each use 4,200 t / h of circulating water. The circulating water cost is temporarily calculated at 0.15 yuan / ton. The annual water cost is: 4,200 x 8,000 x 0.15 = 5,040,000 yuan.
[0033] 2. Energy consumption of alternative screw electric refrigeration compressors
[0034] (1) Electricity
[0035] This system replaces three existing electric-driven R507A compressors, each with a 2,240 kW compressor and a 15 kW oil pump, for a total of 2,255 kW. The three units generate a total of 6,765 kW. Each electric chiller has a cooling capacity of 3,700 kW and an electrical power of 2,240 kW. Using evaporative cooling to transfer heat, each 3,700 kW electric chiller is equipped with two evaporative cooling units, three chiller units, and six units. These units include 2 x 3 x 4 x 11 kW evaporative cooling fans and 2 x 3 x 4 x 15 kW spray pumps, for a total evaporative cooling power of 624 kW. The combined power consumption of the compressors and evaporative cooling units is 7,344 kW.
[0036] The selection parameters for a single-unit evaporative cooling system are as follows: Annual electricity consumption: 7,344 × 8,000 = 58,752,000 kW.h;
[0037] The annual electricity cost is: 58,752,000×0.35 = 20,563,200 yuan (the electricity price is 0.35 yuan / kWh provided by the owner).
[0038] (2) Water use
[0039] The water consumption of a single electric refrigeration unit using evaporative cooling is calculated as 3.2×4 t / h. The total water consumption is: 3.2×4×6 = 76.8 t / h. The annual water consumption fee is: 76.8×8,000×7.5 = 4,608,000 yuan (the water consumption price is calculated at 7.5 yuan / ton).
[0040] 3. Annual total energy saving cost
[0041]
[0042] Working principle: The utility model includes a waste heat refrigerator 1, a saturated steam box 2, a liquid ammonia box 3, a first evaporator 4, a temperature monitor 5, an ethylene glycol solution box 6, a heat exchanger 7, a second evaporator 8, a gas ammonia box 9, a flow monitor 10, a flow display 11, a temperature sensor 12, a data collector 13, a central processing unit 14, a switch controller 15, a temperature display 16, and a flow sensor 17. It utilizes a low-pressure saturated steam heat source with a surplus of 0.4 MPa (G), 152°C, and a flow rate of 40 t / h in production as a driving force, and adopts a low-grade heat refrigerator to provide process cooling after refrigeration, thereby realizing the recovery of low-grade steam waste heat and replacing the electric-driven screw refrigeration unit, thereby achieving the purpose of energy saving and consumption reduction, which is of great significance to reducing production costs and energy conservation and emission reduction.
[0043] Waste heat refrigeration utilizes a low-grade heat source, requiring only a small amount of electricity to power the working fluid shield turbine. The waste heat refrigeration unit replaces the existing three electrically driven R507A screw refrigeration units, recycling the existing excess saturated steam at 0.4 MPa (G), 152°C, and 40 t / h. Depending on the heat source, the waste heat refrigeration unit can output a 20-mg ethylene glycol solution with a cooling capacity of 11,100 kW, thus addressing the high power consumption of electrically driven refrigeration units.
[0044] The renovation plan utilizes low-grade waste heat refrigeration, utilizing surplus 0.4 MPa (G) saturated steam at 152°C as the driving force. Liquid ammonia at approximately 1.2 MPa (G) is generated through a heat and cold energy converter. This liquid ammonia then evaporates at -23°C in an evaporator, absorbing heat and producing a -20°C ethylene glycol solution. The -20°C ethylene glycol solution then enters a heat exchanger to cool the process material. After evaporation, the 0.066 MPa (G) ammonia vapor enters a low-grade waste heat refrigeration unit for recycling. This replaces the existing screw refrigeration system for production use, replacing the -25°C screw chiller and reducing refrigeration electricity consumption.
[0045] The waste heat is used to cool the output of -20℃ refrigerant ethylene glycol, with a total cooling capacity of 5,550×2kW. The annual operating time is 8,000 hours, and the energy saving benefits are estimated based on this operating condition.
[0046] It should be noted that, in this document, relational terms such as first and second (number one, number two), etc., are used solely to distinguish one entity or operation from another, and do not necessarily require or imply any actual relationship or order between these entities or operations. Furthermore, the terms "include," "comprise," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, article, or apparatus that includes a series of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus. In the absence of further limitations, an element defined by the phrase "includes a..." does not preclude the presence of additional identical elements in the process, method, article, or apparatus that includes the element.
[0047] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments. The above embodiments and descriptions are merely illustrative of the principles of the present invention. Various changes and improvements may be made to the present invention without departing from the spirit and scope of the present invention, and such changes and improvements shall fall within the scope of the present invention as claimed.
Claims
1. A system for comprehensive utilization of surplus low-pressure steam heat energy, comprising a waste heat refrigerator (1), characterized in that: The waste heat refrigerator (1) is connected to a saturated steam tank (2) and a liquid ammonia tank (3), the liquid ammonia tank (3) is connected to a first evaporator (4), the first evaporator (4) is connected to an ethylene glycol solution tank (6), the ethylene glycol solution tank (6) is connected to a heat exchanger (7), the heat exchanger (7) is connected to a second evaporator (8), the second evaporator (8) is connected to an ammonia gas tank (9), the ammonia gas tank (9) is connected to a flow monitor (10), a temperature monitor (5) is connected between the first evaporator (4) and the ethylene glycol solution tank (6), and a flow monitor (10) is connected between the ammonia gas tank (9) and the waste heat refrigerator (1).
2. The system for comprehensive utilization of surplus low-pressure steam thermal energy according to claim 1, characterized in that: The temperature monitor (5) is internally provided with a temperature sensor (12), a data collector (13), a central processing unit (14), a switch controller (15) and a temperature display (16); the temperature sensor (12) is connected to the data collector (13); the data collector (13) is connected to the central processing unit (14); and the central processing unit (14) is connected to the switch controller (15) and the temperature display (16).
3. The system for comprehensive utilization of surplus low-pressure steam thermal energy according to claim 1, characterized in that: The flow monitor (10) is internally provided with a flow sensor (17), a PLC single-chip computer (18), a flow controller (19) and a flow display (11); the flow sensor (17) is connected to the PLC single-chip computer (18); and the PLC single-chip computer (18) is connected to the flow display (11) and the flow controller (19).
4. The system for comprehensive utilization of surplus low-pressure steam thermal energy according to claim 2, characterized in that: The output end of the temperature sensor (12) is electrically connected to the input end of the central processing unit (14) through the data acquisition unit (13), and the output end of the central processing unit (14) is electrically connected to the input ends of the switch controller (15) and the temperature display (16).
5. The system for comprehensive utilization of surplus low-pressure steam thermal energy according to claim 3, characterized in that: The output end of the flow sensor (17) is electrically connected to the input end of the PLC single chip microcomputer (18), and the output end of the PLC single chip microcomputer (18) is electrically connected to the input ends of the flow display (11) and the flow controller (19).
6. The system for comprehensive utilization of surplus low-pressure steam thermal energy according to claim 1, characterized in that: The waste heat refrigeration machine (1), the liquid ammonia tank (3), the first evaporator (4), the ethylene glycol solution tank (6), the heat exchanger (7), the second evaporator (8) and the gas ammonia tank (9) are circulated among each other.