A system and method for recovering waste heat from an RH vacuum refining furnace

Abstract

The application provides a RH vacuum refining furnace production waste heat recovery system and method, wherein the waste heat recovery system recovers the tail gas waste heat in the production process of the RH vacuum refining furnace through a gas extraction pipeline heat exchanger and a vacuum pump heat recovery mechanism, produces high-temperature hot water, fully recovers the production tail gas waste heat, then introduces the high-temperature hot water into an absorption refrigerating unit to produce cold water, and uses the generated cold water as cooling water in the operation process of the RH steam jet vacuum pump, thereby reducing the steam consumption and water consumption of the steam jet pump. The recovered hot water is recovered in different water pools according to different temperatures, and is used in stages, so that the recovery is more reasonable and the efficiency is higher. The recovered hot water with a lower temperature is introduced into a user heating system, the production waste heat of the RH refining furnace is fully utilized, and the energy consumption and cost of user heating are reduced; the cold water generated by the absorption refrigerating unit is collected in a cold water pool, the generated cold water is fully utilized to provide air conditioning refrigeration services, and the energy consumption of air conditioning is reduced.

Description

Technical Field

[0001] This invention belongs to the field of heat recovery technology in ladle refining of molten steel, specifically relating to a waste heat recovery system and method for RH vacuum refining furnace production. Background Technology

[0002] RH vacuum refining technology is an indispensable part of the refining process in modern steel enterprises. High-temperature flue gas is generated during the production process, and the commonly used steam jet vacuum pump generates a large amount of steam waste heat and residual steam.

[0003] Currently, the high-temperature flue gas in the system is cooled indirectly by using equipment cooling water through water-cooled pipes to lower the flue gas temperature. The flue gas then enters the vacuum system, where it is drawn into the condenser by high-speed steam. Direct cooling water then directly sprays the condenser to cool both the steam and the exhaust gas. However, due to the increased temperature, the equipment cooling water used for indirect cooling and the circulating water used for direct cooling are transported to a water treatment center, cooled by an air-cooled cooling tower, and then recycled.

[0004] It is not difficult to find in the above process that the waste heat of flue gas and steam vacuum pump generated in the RH production process is only removed by water cooling heat exchange to ensure the normal operation of the system, without further utilization. The high temperature water generated is cooled by the fan of the water treatment cooling tower, which increases the processing load of the cooling tower.

[0005] Zhou Tao et al. applied for a patent on September 7, 2023 (application number: CN202322436113.3). This patent discloses an RH smelting flue gas purification and waste heat comprehensive utilization system. The patent mainly involves using waste heat from the tail gas to generate saturated steam through a vaporization flue and a rapid cooling waste heat boiler, and then using the generated steam to generate electricity through a steam turbine unit, thereby achieving waste heat recovery. However, the operating temperature of the vaporization cooling flue generally needs to reach 800~1000℃. RH vacuum refining furnaces, due to their vacuum system, generally have long extraction pipelines, resulting in a relatively small area suitable for the operation of the vaporization cooling flue. Furthermore, the vaporization cooling flue has high requirements for cooling water quality, necessitating additional equipment and increasing costs for water quality improvement. Adding a waste heat boiler to the vacuum system pipeline can easily increase the pressure loss of the vacuum system, leading to the existing system's vacuum level failing to meet process requirements, or requiring the construction of a new vacuum system with greater vacuum capacity, which would ultimately be counterproductive.

[0006] In addition, Wang Yuzhi et al. applied for a patent on December 17, 2020 (application number: CN215908132U). This invention discloses a steam jet vacuum pump unit that utilizes process heat and exhaust waste heat. The patent mainly involves introducing hot water generated from the residual steam heat of the final stage jet pump into a refrigeration unit for cooling. The cooled water is then used to cool the vacuum pump, thereby reducing steam consumption. The main focus of this patent is the recovery of steam waste heat from the final stage pump at the final stage vacuum outlet.

[0007] During the production process of the RH refining furnace, due to the requirements of production technology and equipment operation, the latent heat generated in different parts is generated in different ways and states. In order to make full use of the waste heat in the RH refining furnace production process, it is urgent to study a device system that can make fuller and more reasonable use of the waste heat in the RH refining furnace production process, so as to further realize energy saving and consumption reduction of the RH vacuum refining device. Summary of the Invention

[0008] The purpose of this invention is to provide a waste heat recovery system for RH vacuum refining furnace production, which can make fuller and more reasonable use of waste heat from the RH refining furnace production process.

[0009] The purpose of this invention is to provide a method for recovering waste heat from RH vacuum refining furnace production. This method involves introducing hot water at a higher temperature into an absorption chiller unit to produce chilled water, which is then used as cooling water for the RH steam jet vacuum pump during operation, thereby reducing the steam and water consumption of the steam jet pump.

[0010] Therefore, the technical solution provided by the present invention is as follows: A waste heat recovery system for an RH vacuum refining furnace includes a main exhaust pipe, an exhaust pipe heat exchanger, and a filter device connected in sequence. The main exhaust pipe is connected to the exhaust port of the RH vacuum refining furnace. The hot water outlet of the exhaust pipe heat exchanger is connected to a first hot water tank. The outlet of the filter device is connected to a vacuum pump heat recovery mechanism. The vacuum pump heat recovery mechanism includes a multi-stage heat recovery device connected in sequence. The inlets of the multi-stage heat recovery devices are all connected to a fresh water distributor, a cold water distributor, and a steam distributor via pipelines. The outlets of the multi-stage heat recovery devices are connected to the first hot water tank and / or a second hot water tank via pipelines. The inlet of the cold water distributor is connected to the cold water tank via a pipeline. The inlet of the cold water tank is connected to an absorption chiller unit. The hot water inlet of the absorption chiller unit is connected to the first hot water tank. The hot water outlet of the absorption chiller unit is connected to the second hot water tank. The cold water inlet of the absorption chiller unit is connected to the new water tank. The second hot water tank and the new water tank are connected, and a second water pump, a filter, and a cooling tower are sequentially connected on the connecting pipeline between them. A first water pump is installed on the output pipeline of the new water tank. The outlet of the first water pump is connected to the first hot water tank, the absorption chiller unit, and the new water distributor via pipelines. A heating system is connected between the filter and the cooling tower via pipeline 1. Valves 1 and 2 are installed on pipeline 1, and valves 1 and 2 are respectively located at both ends of the heating system. A valve 3 is installed on the connecting pipeline between the filter and the cooling tower. The outlet of the cold water tank is connected to an air conditioning system via water pump 3 and pipeline 2. The cold water outlet of the air conditioning system is connected to the second hot water tank and is equipped with valve 4. A valve 5 is installed on pipeline 2. The vacuum pump heat recovery mechanism includes a primary heat recovery device, a secondary heat recovery device, a tertiary heat recovery device, and a final heat recovery device connected in sequence.

[0011] It also includes a PLC control system, and valves one, two, three, four, five, pump one, pump two, pump three and absorption chiller are all electrically connected to the PLC control system.

[0012] The primary heat recovery device includes, in sequence, a B1 pump heat exchanger, a B1 vacuum pump, a B1 pump heat exchanger, a B2 vacuum pump, a B2 pump heat exchanger, and a C1 condenser. The B1 vacuum pump is connected to a filtration device. The B1 pump heat exchanger, the B1 pump heat exchanger, and the B2 pump heat exchanger are all connected to a fresh water distributor. The outlet of the B1 pump heat exchanger is connected to a cold water tank. The outlets of the B1 pump heat exchanger and the B2 pump heat exchanger are connected to a first hot water tank. The outlet of the cold water tank is connected to a cold water distributor. Both vacuum pumps B1 and B2 are connected to the steam distributor, the inlet of condenser C1 is connected to the cold water distributor, and the outlet of condenser C1 is connected to the second hot water tank.

[0013] The secondary heat recovery device includes a B3 vacuum pump, a B3 pump heat exchanger, and a C2 condenser connected in sequence. The inlet of the B3 pump heat exchanger is connected to the fresh water distributor, the inlet of the C2 condenser is connected to the cold water distributor, the outlet of the B3 pump heat exchanger is connected to the first hot water tank, the inlet of the B3 vacuum pump is connected to the steam distributor, and the outlet of the C2 condenser is connected to the second hot water tank.

[0014] The three-stage heat recovery device includes an S4a vacuum pump, an S4a pump heat exchanger, an S4b vacuum pump, an S4b pump heat exchanger, and a C3 condenser. The S4a vacuum pump and the S4a pump heat exchanger are connected in sequence, and the S4b vacuum pump and the S4b pump heat exchanger are connected in sequence. The inlets of the S4a vacuum pump and the S4b vacuum pump are both connected to the C2 condenser of the two-stage heat recovery device, and the outlets of the S4a pump heat exchanger and the S4b pump heat exchanger are both connected to the C3 condenser. The inlets of the S4a and S4b pump heat exchangers are both connected to the new water distributor. The outlets of the S4a, S4b, and C3 condensers are all connected to the first hot water tank. The inlet of the C3 condenser is connected to the cold water distributor. The inlets of the S4a and S4b vacuum pumps are both connected to the steam distributor.

[0015] The final stage heat recovery device includes an S5a vacuum pump, an S5a pump heat exchanger, an S5b vacuum pump, and an S5b pump heat exchanger. The S5a vacuum pump and the S5a pump heat exchanger are connected in sequence, and the S5b vacuum pump and the S5b pump heat exchanger are also connected in sequence. The inlets of the S5a vacuum pump and the S5b vacuum pump are both connected to the C3 condenser and the steam distributor of the tertiary heat recovery device. The inlets of the S5a and S5b pump heat exchangers are both connected to the new water distributor, and the outlets of the S5a and S5b pump heat exchangers are both connected to the first hot water tank. The inlet of the C3 condenser is connected to the cold water distributor.

[0016] The filtration device includes a cooling filter and a high-efficiency filter connected in sequence. The cooling water inlet of the cooling filter is connected to a fresh water distributor, and the cooling water outlet of the cooling filter is connected to a second hot water tank.

[0017] The first hot water tank is connected to the new water tank through a pipe to adjust the temperature to between 55℃ and 100℃, and the hot water is sent to the absorption chiller unit through a water pump.

[0018] A method for recovering waste heat from RH vacuum refining furnace production involves recovering waste heat from the high-temperature exhaust gas of the RH vacuum refining furnace through a heat exchanger in the exhaust pipe. The resulting high-temperature hot water enters a first hot water tank. After heat exchange, the exhaust gas enters a cooling filter to remove dust and further recover the waste heat. The resulting hot water then enters the first hot water tank. After cooling, the exhaust gas enters a high-efficiency filter to further remove dust, reducing the amount of dust entering the vacuum pump system and thus reducing water pollution in the cooling circulating water, thereby avoiding equipment damage caused by water pollution. The exhaust gas enters the vacuum pump heat recovery mechanism, and the vacuum pump heat recovery mechanism receives external steam through the steam distributor. The high-temperature hot water generated by the steam condensation is recovered through the vacuum pump heat recovery mechanism, and the waste heat of the steam and the waste heat of the high-temperature flue gas are recovered step by step. The generated hot water enters the first hot water tank and / or the second hot water tank. The new water tank delivers new water to the first hot water tank via water pump one, adjusts the hot water temperature to between 55℃ and 100℃, and then sends the hot water to the absorption chiller unit via water pump four. The hot water outlet of the absorption chiller unit is connected to the second hot water tank to realize the circulation of the hot water system. The new water tank sends fresh water at 15℃~35℃ to the absorption chiller unit through a water pump. The absorption chiller unit produces cold water at 5℃~15℃ and collects it into the cold water tank. The cold water tank provides chilled water to the air conditioning system to provide cooling services, or provides heating services through the latent heat of hot water in the second hot water tank.

[0019] The beneficial effects of this invention are: The waste heat recovery system for RH vacuum refining furnace production provided by this invention recovers the waste heat of the tail gas during the RH vacuum refining furnace production process through a heat exchanger in the extraction pipeline and a heat recovery mechanism for the vacuum pump. It produces high-temperature hot water, fully recovers the waste heat of the production tail gas, and then introduces the high-temperature hot water into an absorption chiller unit to produce cold water. The produced cold water is then used as cooling water during the operation of the RH steam jet vacuum pump, thereby reducing the steam consumption and water consumption of the steam jet pump.

[0020] This invention recovers hot water by separating it into different pools based on its temperature, allowing for tiered and categorized use, making the recovery process more rational and efficient. The recovered, lower-temperature hot water is introduced into the user's heating system, further utilizing the waste heat from the RH refining furnace and reducing the user's heating energy consumption and costs. The chilled water produced by the absorption chiller is collected in a chilled water pool, fully utilizing the generated chilled water to provide air conditioning cooling services, thus reducing air conditioning energy consumption. Attached Figure Description

[0021] Figure 1 This is a layout diagram of one embodiment of the present invention.

[0022] In the diagram: 1. RH vacuum refining furnace; 2. Main extraction pipeline; 3. Extraction pipeline heat exchanger; 4. Cooling filter; 5. High-efficiency filter; 6. B1 vacuum pump; 7. B1 pump heat exchanger one; 8. B1 pump heat exchanger two; 9. B2 vacuum pump; 10. B2 pump heat exchanger; 11. C1 condenser; 12. B3 vacuum pump; 13. B3 pump heat exchanger; 14. C2 condenser; 15. S4a vacuum pump; 16. S4a pump heat exchanger; 17. S4b vacuum pump; 18. S4b pump heat exchanger; 19. C3 condenser; 20. S5a vacuum pump; 21. S5a pump heat exchanger; 22. S 5b vacuum pump; 23, S5b pump heat exchanger; 24, first hot water tank; 25, second hot water tank; 26, cold water tank; 27, absorption chiller unit; 28, filter; 29, cooling tower; 30, new water tank; 31, steam distributor; 32, cold water distributor; 33, new water distributor; 34, water pump one; 35, water pump two; 36, water pump three; 37, water pump four; 38, PLC control system; 39, heating system; 40, air conditioning system; 41, pipeline one; 42, valve one; 43, valve two; 44, valve three; 45, valve four; 46, valve five; 47, pipeline two. Detailed Implementation

[0023] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification.

[0024] Exemplary embodiments of the present invention will now be described with reference to the accompanying drawings. However, the present invention may be embodied in many different forms and is not limited to the embodiments described herein. These embodiments are provided to fully and completely disclose the invention and to fully convey its scope to those skilled in the art. The terminology used in the exemplary embodiments illustrated in the drawings is not intended to limit the invention. In the drawings, the same units / elements are referred to by the same reference numerals.

[0025] Unless otherwise stated, the terms used herein (including technical terms) have their common meaning as understood by one of ordinary skill in the art. Furthermore, it is understood that terms defined in commonly used dictionaries should be understood to have a meaning consistent with the context of their relevant field, and not to be interpreted as having an idealized or overly formal meaning.

[0026] Example 1 This invention provides a waste heat recovery system for RH vacuum refining furnace production, comprising a main exhaust pipe 2, an exhaust pipe heat exchanger 3, and a filter device connected in sequence. The main exhaust pipe 2 is connected to the exhaust port of the RH vacuum refining furnace 1. The hot water outlet of the exhaust pipe heat exchanger 3 is connected to a first hot water tank 24. The outlet of the filter device is connected to a vacuum pump heat recovery mechanism. The vacuum pump heat recovery mechanism includes a multi-stage heat recovery device connected in sequence. The inlets of the multi-stage heat recovery devices are all connected to a fresh water distributor 33, a cold water distributor 32, and a steam distributor 31 via pipelines. The outlets of the multi-stage heat recovery devices are connected to the first hot water tank 24 and / or a second hot water tank 25 via pipelines. The inlet of the cold water distributor 32 is connected to the cold water tank 26 via a pipeline. The inlet of the cold water tank 26 is connected to the absorption chiller unit 27. The hot water inlet of the absorption chiller unit 27 is connected to the first hot water tank 24. The hot water outlet of the absorption chiller unit 27 is connected to the second hot water tank 25. The cold water inlet of the absorption chiller unit 27 is connected to the new water tank 30. The second hot water tank 25 and the new water tank 30 are connected, and the connecting pipeline between them is connected in sequence to a second water pump 35, a filter 28, and a cooling tower 29. The output pipeline of the new water tank 30 is equipped with a first water pump 34. The outlet of the first water pump 34 is connected to the first hot water tank 24, the absorption chiller unit 27, and the new water distributor 33 via pipelines. A heating system is connected between the filter 28 and the cooling tower 29 via a pipeline 41. Valves 42 and 42 are installed on the pipeline 41, which are located at opposite ends of the heating system 39. A valve 43 is installed on the connecting pipeline between the filter 28 and the cooling tower 29. The outlet of the cold water tank 26 is connected to an air conditioning system 40 via a water pump 36 and a pipeline 47. The cold water outlet of the air conditioning system 40 is connected to the second hot water tank 25 and is equipped with a valve 44. A valve 45 is installed on the pipeline 47. In this invention, the RH vacuum refining furnace 1 is the container for the reaction of molten steel and the main source of heat and high-temperature exhaust gas generated by the system; the inlet of the steam distributor 31 is connected to an external steam source, so the external steam is another major source of heat generation in the RH refining furnace.

[0027] like Figure 1 As shown, the exhaust pipe heat exchanger 3 is installed in conjunction with the main exhaust pipe 2. Its inlet is connected to the new water distributor 33, and its outlet is connected to the first hot water tank 24. It is used to recover the waste heat of the high-temperature flue gas in the first step and to produce high-temperature hot water at the same time.

[0028] The waste heat recovery device system for RH vacuum refining furnace 1 provided by this invention recovers the waste heat of the tail gas during the production process of RH vacuum refining furnace 1 through the heat exchanger 3 of the exhaust pipe and the heat recovery mechanism of the vacuum pump, produces high-temperature hot water, fully recovers the waste heat of the production tail gas, and then introduces the high-temperature hot water into the absorption chiller unit 27 to produce cold water, and uses the generated cold water as cooling water during the operation of the RH steam jet vacuum pump, thereby reducing the steam consumption and water consumption of the steam jet pump.

[0029] This invention recovers hot water by recycling it into different pools according to its temperature, allowing for tiered and categorized use, making the recovery process more rational and efficient. The recovered, lower-temperature hot water is introduced into the user's heating system, further utilizing the waste heat from the RH refining furnace and reducing the user's heating energy consumption and costs. The cold water produced by the absorption chiller unit 27 is collected in the cold water pool 26, fully utilizing the generated cold water to provide air conditioning cooling services, thus reducing air conditioning energy consumption.

[0030] Example 2 Based on Example 1, this example provides a waste heat recovery system for RH vacuum refining furnace production, such as... Figure 1 As shown, the vacuum pump heat recovery mechanism includes a primary heat recovery device, a secondary heat recovery device, a tertiary heat recovery device, and a final heat recovery device connected in sequence.

[0031] The primary heat recovery device includes B1 pump heat exchanger 7, B1 vacuum pump 6, B1 pump heat exchanger 8, B2 vacuum pump 9, B2 pump heat exchanger 10, and C1 condenser 11 connected in sequence. B1 pump heat exchanger 7 is connected to a filter device. B1 vacuum pump 6, B1 pump heat exchanger 8, and B2 pump heat exchanger 10 are all connected to a fresh water distributor 33. The outlet of B1 pump heat exchanger 7 is connected to a cold water tank 26. The outlets of B1 pump heat exchanger 8 and B2 pump heat exchanger 10 are connected to a first hot water tank 24. The outlet of the cold water tank 26 is connected to a cold water distributor 32. The B1 vacuum pump 6 and B2 vacuum pump 9 are both connected to the steam distributor 31, the inlet of the C1 condenser 11 is connected to the cold water distributor 32, and the outlet of the C1 condenser 11 is connected to the second hot water tank 25.

[0032] like Figure 1 As shown, heat exchanger 7 of pump B1 is installed in conjunction with the inlet of vacuum pump 6 of pump B1. Its inlet is connected to the new water distributor 33, and its outlet is connected to the cold water pool 26. Vacuum pump 6 of pump B1 is used to recover the low temperature in the inlet area. Heat exchanger 8 of pump B1 is installed in conjunction with the outlet of vacuum pump 6 of pump B1. Its inlet is connected to the new water distributor 33, and its outlet is connected to the first hot water pool 24. It is used to recover the waste heat of steam and high-temperature flue gas at the end of vacuum pump 6 of pump B1.

[0033] The B2 pump heat exchanger 10 is installed in conjunction with the outlet of the B2 vacuum pump 9. Its inlet is connected to the new water distributor 33, and its outlet is connected to the first hot water tank 24. It is used to recover the waste heat of steam and high-temperature flue gas at the end of the B2 vacuum pump 9.

[0034] The inlet and outlet of condenser 11 are respectively connected to the outlet of vacuum pump 9 (B2) and the inlet of vacuum pump 12 (B3). Its cooling water inlet is connected to cold water distributor 32, and its outlet is connected to the second hot water tank 25, which is used to further cool the waste heat of steam and high-temperature flue gas in the production process.

[0035] Example 3 Based on Example 1, this example provides a waste heat recovery system for RH vacuum refining furnace production, which also includes a PLC control system. Valve 1 (42), Valve 2 (43), Valve 3 (44), Valve 4 (45), and Valve 5 (46) are all electrically connected to the PLC control system.

[0036] The PLC control system can automatically control valve 1 (42), valve 2 (43), valve 3 (44), valve 4 (45), valve 5 (46), water pump 1 (34), water pump 2 (35), water pump 3 (36), and absorption chiller unit 27, thereby completing the automatic control and operation of the system.

[0037] Example 4 Based on Example 2, this example provides a waste heat recovery system for RH vacuum refining furnace production. The secondary heat recovery device includes a B3 vacuum pump 12, a B3 pump heat exchanger 13, and a C2 condenser 14 connected in sequence. The inlet of the B3 pump heat exchanger 13 is connected to a fresh water distributor 33, the inlet of the C2 condenser 14 is connected to a cold water distributor 32, the outlet of the B3 pump heat exchanger 13 is connected to a first hot water tank 24, the inlet of the B3 vacuum pump 12 is connected to a steam distributor 31, and the outlet of the C2 condenser 14 is connected to a second hot water tank 25.

[0038] like Figure 1 As shown, the B3 pump heat exchanger 13 is installed in conjunction with the B3 vacuum pump 12. The cooling water inlet of the B3 pump heat exchanger 13 is connected to the new water distributor 33, and the outlet is connected to the first hot water pool 24, which is used to recover the waste heat of steam and high-temperature flue gas at the end of the B3 vacuum pump 12.

[0039] The inlet and outlet of the C2 condenser 14 are respectively connected to the outlet of the B3 vacuum pump 12 and the inlet of the three-stage heat recovery device. The cooling water inlet of the C2 condenser 14 is connected to the cold water distributor 32, and the outlet is connected to the second hot water pool 25, which is used to further cool the steam waste heat and high-temperature flue gas in the production process.

[0040] Example 5 Based on Example 4, this example provides a waste heat recovery system for RH vacuum refining furnace production. The three-stage heat recovery device includes an S4a vacuum pump 15, an S4a pump heat exchanger 16, an S4b vacuum pump 17, an S4b pump heat exchanger 18, and a C3 condenser 19. The S4a vacuum pump 15 and the S4a pump heat exchanger 16 are connected in sequence, and the S4b vacuum pump 17 and the S4b pump heat exchanger 18 are connected in sequence. The inlets of the S4a vacuum pump 15 and the S4b vacuum pump 17 are both connected to the C2 condenser 14 of the secondary heat recovery device, and the outlets of the S4a pump heat exchanger 16 and the S4b pump heat exchanger 18 are both connected to the C3 condenser 19. The inlets of the S4a pump heat exchanger 16 and the S4b pump heat exchanger 18 are both connected to the new water distributor 33. The outlets of the S4a pump heat exchanger 16, the S4b pump heat exchanger 18 and the C3 condenser 19 are all connected to the first hot water tank 24. The inlet of the C3 condenser 19 is connected to the cold water distributor 32. The inlets of the S4a vacuum pump 15 and the S4b vacuum pump 17 are both connected to the steam distributor 31.

[0041] like Figure 1As shown, the inlets of S4a vacuum pump 15 and S4b vacuum pump 17 are both installed to match the outlet of C2 condenser 14. S4a pump heat exchanger 16 is installed to match S4a vacuum pump 15. The cooling water inlet of S4a pump heat exchanger 16 is connected to the new water distributor 33, and the outlet is connected to the first hot water pool 24, which is used to recover the waste heat of steam and high-temperature flue gas at the end of S4a vacuum pump 15.

[0042] The S4b pump heat exchanger 18 is installed in conjunction with the S4b vacuum pump 17. The cooling water inlet of the S4b pump heat exchanger 18 is connected to the new water distributor 33, and the outlet is connected to the first hot water tank 24. It is used to recover the waste heat of steam and high-temperature flue gas at the end of the S4b vacuum pump 17.

[0043] Example 6 Based on Example 2, this example provides a waste heat recovery system for RH vacuum refining furnace production. The final stage heat recovery device includes an S5a vacuum pump 20, an S5a pump heat exchanger 21, an S5b vacuum pump 22, and an S5b pump heat exchanger 23. The S5a vacuum pump 20 and the S5a pump heat exchanger 21 are connected in sequence, and the S5b vacuum pump 22 and the S5b pump heat exchanger 23 are connected in sequence. The inlets of the S5a vacuum pump 20 and the S5b vacuum pump 22 are both connected to the C3 condenser 19 and the steam distributor 31 of the three-stage heat recovery device. The inlets of the S5a pump heat exchanger 21 and the S5b pump heat exchanger 23 are both connected to the new water distributor 33, and the outlets of the S5a pump heat exchanger 21 and the S5b pump heat exchanger 23 are both connected to the first hot water tank 24. The inlet of the C3 condenser 19 is connected to the cold water distributor 32.

[0044] like Figure 1 As shown, the outlets of vacuum pumps S4a 15 and S4b 17 are both connected to the inlet of condenser C3 19. The outlet of condenser C3 19 is installed in conjunction with the inlets of vacuum pumps S5a 20 and S5b 22, respectively. The cooling water inlet of condenser C3 19 is connected to cold water distributor 32, and the outlet is connected to the first hot water tank 24, which is used to further cool and recover the waste heat of steam and high-temperature flue gas from the production process.

[0045] The S5a pump heat exchanger 21 is installed in conjunction with the S5a vacuum pump 20. The cooling water inlet of the S5a pump heat exchanger 21 is connected to the new water distributor 33, and the outlet is connected to the first hot water tank 24. It is used to recover the waste heat of steam and high-temperature flue gas at the end of the S5a vacuum pump 20.

[0046] The inlet of the S5a vacuum pump 20 is installed in conjunction with the C3 condenser 19, and the outlet of the S5a vacuum pump 20 is connected to the first hot water tank 24, which is used to recover the waste heat of steam and high-temperature flue gas at the end of the S5a vacuum pump 20.

[0047] The S5b vacuum pump 22 inlet is installed in conjunction with the C3 condenser 19. The outlet of the S5b vacuum pump 22 is connected to the first hot water tank 24 to recover the waste heat from the steam and high-temperature flue gas at the end of the S5b vacuum pump 22.

[0048] The S5b pump heat exchanger 23 is installed in conjunction with the S5b vacuum pump 22. Its cooling water inlet is connected to the new water distributor 33, and its outlet is connected to the first hot water tank 24. It is used to recover the waste heat of steam and high-temperature flue gas at the end of the S5b vacuum pump 22.

[0049] Example 6 Based on Example 1, this example provides a waste heat recovery system for RH vacuum refining furnace production. The filtration device includes a cooling filter 4 and a high-efficiency filter 5 connected in sequence. The cooling water inlet of the cooling filter 4 is connected to the new water distributor 33, and the cooling water outlet of the cooling filter 4 is connected to the first hot water pool 24.

[0050] like Figure 1 As shown, the cooling filter 4 is installed in series with the main exhaust pipe 2 and is equipped with a cooling heat exchange device. The inlet of the cooling heat exchange device is connected to the new water distributor 33, and the outlet is connected to the first hot water tank 24. This is used to further recover the waste heat of the high-temperature flue gas and produce high-temperature hot water. At the same time, large particulate dust is filtered out while the high-temperature flue gas is cooled.

[0051] The high-efficiency filter 5 is located at the rear end of the cooling filter 4 and is installed in series with the main exhaust pipe 2. It is used to further filter the dust in the exhaust gas to ensure the cleanliness of the hot water discharged into the first hot water pool 24.

[0052] Example 7 Based on Example 1, this example provides a waste heat recovery system for RH vacuum refining furnace production. The first hot water tank 24 and the new water tank 30 are connected by a pipeline to adjust the temperature to between 55°C and 100°C, and the hot water is sent to the absorption chiller unit 27 by a water pump 37.

[0053] The first hot water tank 24 is used to collect the hot water recovered by the RH system. The first hot water tank 24 is connected to the new water tank 30 through a pipe, thereby adjusting the hot water temperature to between 55℃ and 100℃, and sending the hot water to the absorption chiller unit 27 through the water pump 37.

[0054] The hot water inlet of the absorption chiller unit 27 is connected to the first hot water pool 24, and the hot water outlet is connected to the second hot water pool 25, realizing the circulation of the hot water system. The fresh water pool 30 is connected to the cold water inlet of the absorption chiller unit 27, providing it with fresh water at 15℃~35℃. The absorption chiller unit 27 produces cold water at 5℃~15℃, which is then collected in the cold water pool 26.

[0055] The chilled water collected in the chilled water tank 26 is pumped by water pump 36 to the chilled water distributor 32, and then to condensers C1 11, C2 14, and C3 19 for cooling waste heat from steam and high-temperature flue gas. The chilled water inlet of the air conditioning system is connected to the chilled water tank 26, and the chilled water outlet is connected to the second hot water tank 25, so as to make full use of the chilled water generated by the absorption chiller unit 27 to provide air conditioning and cooling services to users.

[0056] The second hot water tank 25 is used to collect the hot water after the C1 condenser 11, C2 condenser 14 and absorption chiller 27 have been working. The hot water is then sent to the filter 28 for filtration through the second water pump 35 and pipelines. After being cooled to 15℃~35℃ by the cooling tower 29, the hot water is collected in the new water tank 30.

[0057] The heating system is installed between the filter 28 and the cooling tower 29, and a valve is installed on the connecting pipe to recover the latent heat of the hot water in the second hot water tank 25 to provide heating services to users.

[0058] Example 8 This embodiment provides a method for recovering waste heat from RH vacuum refining furnace production. The high-temperature exhaust gas from the RH vacuum refining furnace 1 is recovered through the heat exchanger 3 in the exhaust pipe. The generated high-temperature hot water enters the first hot water tank 24. After heat exchange, the exhaust gas enters the cooling filter 4, where dust is filtered out and the exhaust gas waste heat is further recovered. The generated hot water enters the first hot water tank 24. After cooling, the exhaust gas enters the high-efficiency filter 5, where dust is further filtered out, reducing the amount of dust entering the vacuum pump system, thereby reducing water pollution of the cooling circulating water and avoiding equipment damage caused by water pollution. The exhaust gas enters the vacuum pump heat recovery mechanism, and the vacuum pump heat recovery mechanism receives external steam through the steam distributor 31. The high-temperature hot water generated by the steam condensation is recovered through the vacuum pump heat recovery mechanism, and the waste heat of the steam and the waste heat of the high-temperature flue gas are recovered step by step. The generated hot water enters the first hot water pool 24 and / or the second hot water pool 25. New water tank 30 delivers new water to the first hot water tank 24 via water pump 34, adjusts the hot water temperature to between 55℃ and 100℃, and sends the hot water to the absorption chiller unit 27 via water pump 37. The hot water outlet of the absorption chiller unit 27 is connected to the second hot water tank 25 to realize the circulation of the hot water system. The new water tank 30 sends fresh water at 15℃~35℃ to the absorption chiller unit 27 via the water pump 34. The absorption chiller unit 27 produces chilled water at 5℃~15℃ and collects it in the cold water tank 26. The cold water tank 26 provides chilled water to the air conditioning system for cooling services, or the latent heat of the hot water in the second hot water tank 25 provides heating services.

[0059] According to the different parts and states of waste heat in the production process of the RH vacuum refining furnace, the present invention classifies them and adopts different recovery and treatment methods, making the waste heat recovery of the RH refining furnace more sufficient, thereby reducing the operating load of the water treatment system supporting the RH refining furnace. The higher-temperature hot water is introduced into the absorption refrigeration unit 27 to produce cold water, and the produced cold water is used as the cooling water during the operation of the RH steam jet vacuum pump, thereby reducing the steam consumption and water consumption of the steam jet pump.

[0060] The above examples are only illustrative of the present invention and do not constitute a limitation on the protection scope of the present invention. Any design identical or similar to the present invention falls within the protection scope of the present invention.

Claims

1. A waste heat recovery system for RH vacuum refining furnace production, characterized in that: The system includes a main exhaust pipe, an exhaust pipe heat exchanger, and a filter device connected in sequence. The main exhaust pipe is connected to the outlet of the RH vacuum refining furnace. The hot water outlet of the exhaust pipe heat exchanger is connected to a first hot water tank. The outlet of the filter device is connected to a vacuum pump heat recovery mechanism. The vacuum pump heat recovery mechanism includes a multi-stage heat recovery device connected in sequence. The inlets of the multi-stage heat recovery devices are all connected to a fresh water distributor, a cold water distributor, and a steam distributor via pipelines. The outlets of the multi-stage heat recovery devices are connected to the first hot water tank and / or the second hot water tank via pipelines. The inlet of the cold water distributor is connected to the cold water tank via a pipeline. The inlet of the cold water tank is connected to an absorption chiller unit. The hot water inlet of the absorption chiller unit is connected to the first hot water tank. The hot water outlet of the absorption chiller unit is connected to the second hot water tank. The cold water inlet of the absorption chiller unit is connected to the new water tank. The second hot water tank and the new water tank are connected, and a second water pump, a filter, and a cooling tower are sequentially connected on the connecting pipeline between them. A first water pump is installed on the output pipeline of the new water tank. The outlet of the first water pump is connected to the first hot water tank, the absorption chiller unit, and the new water distributor via pipelines. A heating system is connected between the filter and the cooling tower via pipeline 1. Valves 1 and 2 are installed on pipeline 1, and valves 1 and 2 are respectively located at both ends of the heating system. A valve 3 is installed on the connecting pipeline between the filter and the cooling tower. The outlet of the cold water tank is connected to an air conditioning system via water pump 3 and pipeline 2. The cold water outlet of the air conditioning system is connected to the second hot water tank and is equipped with valve 4. A valve 5 is installed on pipeline 2.

2. The RH vacuum refining furnace waste heat recovery system according to claim 1, characterized in that: The vacuum pump heat recovery mechanism includes a primary heat recovery device, a secondary heat recovery device, a tertiary heat recovery device, and a final heat recovery device connected in sequence.

3. The RH vacuum refining furnace waste heat recovery system according to claim 1, characterized in that: It also includes a PLC control system, and valves one, two, three, four, five, pump one, pump two, pump three and absorption chiller are all electrically connected to the PLC control system.

4. The RH vacuum refining furnace waste heat recovery system according to claim 2, characterized in that: The primary heat recovery device includes, in sequence, a B1 pump heat exchanger, a B1 vacuum pump, a B1 pump heat exchanger, a B2 vacuum pump, a B2 pump heat exchanger, and a C1 condenser. The B1 vacuum pump is connected to a filtration device. The B1 pump heat exchanger, the B1 pump heat exchanger, and the B2 pump heat exchanger are all connected to a fresh water distributor. The outlet of the B1 pump heat exchanger is connected to a cold water tank. The outlets of the B1 pump heat exchanger and the B2 pump heat exchanger are connected to a first hot water tank. The outlet of the cold water tank is connected to a cold water distributor. Both vacuum pumps B1 and B2 are connected to the steam distributor, the inlet of condenser C1 is connected to the cold water distributor, and the outlet of condenser C1 is connected to the second hot water tank.

5. The RH vacuum refining furnace waste heat recovery system according to claim 2, characterized in that: The secondary heat recovery device includes a B3 vacuum pump, a B3 pump heat exchanger, and a C2 condenser connected in sequence. The inlet of the B3 pump heat exchanger is connected to the fresh water distributor, the inlet of the C2 condenser is connected to the cold water distributor, the outlet of the B3 pump heat exchanger is connected to the first hot water tank, the inlet of the B3 vacuum pump is connected to the steam distributor, and the outlet of the C2 condenser is connected to the second hot water tank.

6. The RH vacuum refining furnace waste heat recovery system according to claim 2, characterized in that: The three-stage heat recovery device includes an S4a vacuum pump, an S4a pump heat exchanger, an S4b vacuum pump, an S4b pump heat exchanger, and a C3 condenser. The S4a vacuum pump and the S4a pump heat exchanger are connected in sequence, and the S4b vacuum pump and the S4b pump heat exchanger are connected in sequence. The inlets of the S4a vacuum pump and the S4b vacuum pump are both connected to the C2 condenser of the two-stage heat recovery device, and the outlets of the S4a pump heat exchanger and the S4b pump heat exchanger are both connected to the C3 condenser. The inlets of the S4a and S4b pump heat exchangers are both connected to the new water distributor. The outlets of the S4a, S4b, and C3 condensers are all connected to the first hot water tank. The inlet of the C3 condenser is connected to the cold water distributor. The inlets of the S4a and S4b vacuum pumps are both connected to the steam distributor.

7. The RH vacuum refining furnace waste heat recovery system according to claim 2, characterized in that: The final stage heat recovery device includes an S5a vacuum pump, an S5a pump heat exchanger, an S5b vacuum pump, and an S5b pump heat exchanger. The S5a vacuum pump and the S5a pump heat exchanger are connected in sequence, and the S5b vacuum pump and the S5b pump heat exchanger are also connected in sequence. The inlets of the S5a vacuum pump and the S5b vacuum pump are both connected to the C3 condenser and the steam distributor of the tertiary heat recovery device. The inlets of the S5a and S5b pump heat exchangers are both connected to the new water distributor, and the outlets of the S5a and S5b pump heat exchangers are both connected to the first hot water tank. The inlet of the C3 condenser is connected to the cold water distributor.

8. A waste heat recovery system for RH vacuum refining furnace production according to any one of claims 1-7, characterized in that: The filtration device includes a cooling filter and a high-efficiency filter connected in sequence. The cooling water inlet of the cooling filter is connected to a fresh water distributor, and the cooling water outlet of the cooling filter is connected to a first hot water pool.

9. A waste heat recovery system for RH vacuum refining furnace production according to any one of claims 1-7, characterized in that: The first hot water tank is connected to the new water tank through a pipe to adjust the temperature to between 55℃ and 100℃, and the hot water is sent to the absorption chiller unit through a water pump.

10. A method for recovering waste heat from RH vacuum refining furnace production, employing the RH vacuum refining furnace waste heat recovery system as described in claim 8, characterized in that: The high-temperature exhaust gas from the RH vacuum refining furnace undergoes waste heat recovery through a heat exchanger in the extraction pipeline. The resulting high-temperature hot water enters the first hot water tank. After heat exchange, the exhaust gas enters a cooling filter to remove dust and further recover the waste heat. The resulting hot water then enters the first hot water tank. After cooling, the exhaust gas enters a high-efficiency filter to further remove dust, reducing the amount of dust entering the vacuum pump system. This reduces water pollution in the cooling circulating water and prevents equipment damage caused by water pollution. The exhaust gas enters the vacuum pump heat recovery mechanism, and the vacuum pump heat recovery mechanism receives external steam through the steam distributor. The high-temperature hot water generated by the steam condensation is recovered through the vacuum pump heat recovery mechanism, and the waste heat of the steam and the waste heat of the high-temperature flue gas are recovered step by step. The generated hot water enters the first hot water tank and / or the second hot water tank. The new water tank delivers new water to the first hot water tank via water pump one, adjusts the hot water temperature to between 55℃ and 100℃, and then sends the hot water to the absorption chiller unit via water pump four. The hot water outlet of the absorption chiller unit is connected to the second hot water tank to realize the circulation of the hot water system. The new water tank sends fresh water at 15℃~35℃ to the absorption chiller unit through a water pump. The absorption chiller unit produces cold water at 5℃~15℃ and collects it into the cold water tank. The cold water tank provides chilled water to the air conditioning system to provide cooling services, or provides heating services through the latent heat of hot water in the second hot water tank.

Images