Heat energy utilization device for fully producing high-pressure steam in sulfuric acid production
By designing a thermal energy utilization device that increases the acid temperature of the low-temperature heat recovery system, the problem of insufficient high-pressure steam production in the existing technology is solved, the goal of producing high-pressure steam in all is achieved, the system is simplified and economic benefits are improved.
Patent Information
- Application Number
- CN202421878050.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-05
- Publication Date
- 2025-06-24
- Estimated Expiration
- 2034-08-05
AI Technical Summary
The existing thermal energy recovery system of the sulfuric acid industry cannot effectively utilize low temperature heat, resulting in insufficient high-pressure steam production and the inability to achieve full production of high-pressure steam.
Design a heat energy utilization device for fully producing high-pressure steam in sulfuric acid production. By increasing the acid temperature of the low-temperature heat recovery system and through heat transfer, the low-pressure steam system will be cancelled and all high-pressure steam will be produced.
The goal of producing high-pressure steam in all is achieved, which significantly increases the output of high-pressure steam, simplifies the system, and increases economic benefits.
Smart Images
Figure CN223016517U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of heat energy utilization, in particular to a heat energy utilization device for fully producing high-pressure steam in sulfuric acid production. Background Art
[0002] At present, the efficiency of the heat energy recovery system in the sulfuric acid industry is the top priority of the entire device. The steam production per ton of acid in the current sulfur-burning sulfuric acid plant is 1.25 - 1.32 t / t acid in high-pressure steam at 3.0 - 9.8 MPa and 400 - 540 °C. With a low-temperature heat recovery system, abbreviated as HRS (Heat Recovery Systems), it can additionally produce 0.6 - 1.0 MPa low-pressure saturated steam of about 0.45 t / t acid. The price difference between these two types of steam in the market is relatively large. Therefore, it is an urgent pursuit of the sulfuric acid industry to increase the production of high-pressure steam as much as possible to generate more economic benefits.
[0003] Chinese Patent with the application number CN2024105933155 discloses a device that, by flexibly configuring three sets of heat exchangers according to the usage scenarios and objects, tries to utilize the heat in sulfuric acid production as much as possible to increase the production of high-pressure steam. However, it is found in actual use that the acid temperature at the lower tower of the HRS tower does not exceed 230 °C, the acid temperature is not high enough, and there is not enough temperature difference to transfer all the reaction heat generated by the reaction of SO 3 in the HRS tower with water to produce sulfuric acid into the high-pressure steam system. Only secondary to that, it can produce some low-pressure steam, and it is impossible to achieve full production of high-pressure steam. Summary of the Utility Model
[0004] In order to overcome the deficiencies of the prior art, the utility model provides a heat energy utilization device for fully producing high-pressure steam in sulfuric acid production, which transfers the heat for producing low-pressure steam in the existing low-temperature heat recovery system and fully produces high-pressure steam without producing low-pressure steam, reducing the low-pressure steam system and generating more economic benefits.
[0005] To achieve the above object, a heat energy utilization device for fully producing high-pressure steam in sulfuric acid production is designed, including a low-temperature heat recovery absorption tower. The high-temperature sulfuric acid temperature at the lower tower of the low-temperature heat recovery absorption tower is 240 - 280 °C. The acid-side outlet of the low-temperature heat recovery absorption tower is divided into several paths and is respectively connected to the acid-side inlets of a high-pressure heater, a flue gas heater, and an air heater. The acid-side outlets of the high-pressure heater, the flue gas heater, and the air heater converge and are connected to the inlet of a low-temperature heat recovery absorption tower diluter. The outlet of the low-temperature heat recovery absorption tower diluter is connected to the low-temperature heat recovery absorption tower. The acid-side outlet of the flue gas heater is also connected to the acid-side inlet of a preheater. The acid-side outlet of the preheater is respectively connected to a secondary absorption unit and a drying unit.
[0006] The air temperature at the inlet of the air heater is 60~130°C, and the air temperature at the outlet of the air heater is 220~260°C; the flue gas temperature at the inlet of the flue gas heater is 70~90°C, and the flue gas temperature at the inlet of the flue gas heater is 200~250°C; the steam temperature at the inlet of the high-pressure heater is 104°C~170°C, and the steam temperature at the outlet of the high-pressure heater is 200~260°C.
[0007] The water side inlet of the preheater is connected to the high-pressure steam system. In the high-pressure steam system, the water side inlet of the preheater is connected to the desalinated water source. The water side outlet of the preheater is connected to the inlet of the deaerator. The outlet of the deaerator is respectively connected to the boiler chemical dosing device, the water side inlet of economizer 3A, the water side inlet of economizer 4A, and the dilution water pipeline of the diluter through the boiler feed pump; the water side outlets of economizer 3A and economizer 4A converge into one path and jointly connect to the water side inlet of the high-pressure heater. The water side outlet of the high-pressure heater is divided into two paths and respectively connects to the water side inlet of economizer 3B and the water side inlet of economizer 4B. The water side outlets of economizer 3B and economizer 4B converge into one path and jointly connect to the water side inlet of the waste heat boiler. The steam side inlet of the waste heat boiler, the steam side outlet of superheater 4A is connected to the steam side inlet of superheater 1B, and high-pressure steam is produced at the steam side outlet of superheater 1B.
[0008] The described drying unit includes an air filter and a drying tower. One end of the air filter is connected to an air source, and the other end is connected to the drying tower. The outlet of the drying tower is connected to the inlet of a blower, and the outlet of the blower is connected to an incineration unit through an air heater. The incineration unit includes a sulfur-burning furnace and a waste heat boiler. The outlet of the main blower and the liquid sulfur source are connected to the inlet of the sulfur-burning furnace. The outlet of the sulfur-burning furnace is connected to the flue gas side inlet of the waste heat boiler. The flue gas side outlet of the waste heat boiler is connected to a conversion unit. The conversion unit includes a converter, a heat exchanger, and a cold and heat exchanger. The flue gas side outlet of the waste heat boiler is connected to the first-stage inlet of the converter. The first-stage outlet of the converter is connected to the flue gas side inlet of superheater 1B. The flue gas side outlet of superheater 1B is connected to the second-stage inlet of the converter. The second-stage outlet of the converter is connected to the first inlet of the heat exchanger. The first outlet of the heat exchanger is connected to the third-stage inlet of the converter. The third-stage outlet of the converter is connected to the first inlet of the cold and heat exchanger. The first outlet of the cold and heat exchanger is connected to the flue gas side inlet of economizer 3B. The flue gas side inlet of economizer 3B is connected to the flue gas side inlet of economizer 3A. The flue gas side outlet of economizer 3A is connected to a primary absorption unit. The primary absorption unit includes a low-temperature heat recovery absorption tower and an acid circulation pump. The flue gas side outlet of economizer 3A is connected to the flue gas inlet of the low-temperature heat recovery absorption tower. The flue gas outlet of the low-temperature heat recovery absorption tower is connected to the flue gas inlet of a flue gas heater. The flue gas outlet of the flue gas heater is connected to the second inlet of the cold and heat exchanger. The second outlet of the cold and heat exchanger is connected to the second inlet of the heat exchanger. The second outlet of the heat exchanger is connected to the fourth-stage inlet of the converter. The fourth-stage outlet of the converter is connected to the flue gas side inlet of superheater 4A. The flue gas side outlet of superheater 4A is connected to the flue gas side inlet of economizer 4B. The flue gas side outlet of economizer 4B is connected to the flue gas side inlet of economizer 4A. The flue gas side outlet of economizer 4A is connected to a secondary absorption unit. The described secondary absorption unit includes a second absorption tower and a second absorption acid pump tank. The flue gas side outlet of economizer 4A is connected to the second absorption tower. The acid side outlet of the second absorption tower is connected to the inlet of the second absorption acid pump tank. The acid outlet of the second absorption acid pump tank is connected to the inlet of a finished acid cooler. The outlet of the finished acid cooler obtains the finished acid.
[0009] The described flue gas heater includes flue gas heater A and flue gas heater B. The acid side outlet of the low-temperature heat recovery absorption tower is divided into several paths and is respectively connected to the acid side inlets of a high-pressure heater, flue gas heater B, and air heater. The acid side outlets of the high-pressure heater, flue gas heater B, and air heater converge into two paths and are respectively connected to the inlet of the low-temperature heat recovery absorption tower diluter and the acid side inlet of flue gas heater A. The outlet of the low-temperature heat recovery absorption tower diluter is connected to the low-temperature heat recovery absorption tower. The acid side outlet of flue gas heater A is connected to the acid side inlet of a preheater. The acid side outlet of the preheater is respectively connected to the secondary absorption unit and the drying unit.
[0010] Compared with the prior art, in the existing sulfuric acid production device, the acid temperature of the low-temperature heat recovery system is increased, and through heat transfer, high-pressure steam is produced entirely, and low-pressure steam is no longer produced. The low-pressure steam system is cancelled, and the system is simplified. BRIEF DESCRIPTION OF THE DRAWINGS
[0011] Figure 1 It is a schematic diagram of the flue gas and acid system in the sulfuric acid production process of the present invention.
[0012] Figure 2 It is a schematic diagram of the water and steam system in the sulfuric acid production process of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS
[0013] The present invention will be further described below with reference to the drawings. Embodiment 1
[0014] As Figures 1 to 2 shown, in the heat energy utilization device for entirely producing high-pressure steam in the sulfuric acid production of this embodiment, the low-temperature heat recovery absorption tower 1-13 increases the temperature of the high-temperature sulfuric acid in the lower tower. The temperature of the high-temperature sulfuric acid is 240-280 °C. With sufficient temperature difference for the high-temperature sulfuric acid, it can transfer all the reaction heat of the reaction between SO 3 and water to form sulfuric acid in the low-temperature heat recovery absorption tower 1-13 into the high-pressure steam system, and all high-pressure steam is produced without producing low-pressure steam.
[0015] The high-temperature sulfuric acid in the lower tower of the low-temperature heat recovery absorption tower 1-13 serves as the direct heat source or indirect heat source of the high-pressure heater 1-24, the flue gas heater 1-14, and the air heater 1-4 respectively;
[0016] The air heater 1-4 heats the air to be incinerated. After the air is heated, it is mixed with sulfur and incinerated to provide heat for the high-pressure steam system;
[0017] The flue gas heater 1-14 heats the flue gas coming out of the low-temperature heat recovery absorption tower 1-13. After the flue gas coming out of the low-temperature heat recovery absorption tower 1-13 is heated, it enters the cold and hot heat exchanger 1-10 and exchanges heat with the flue gas on the other side of the cold and hot heat exchanger. The heat of the flue gas at the outlet on the other side of the cold and hot heat exchanger 1-10 is transferred to the high-pressure steam system through the economizer 3A1-12 and the economizer 3B1-11;
[0018] The high-pressure heaters 1-24 heat the feed water from the economizers 3A1-12 and 4A1-17 in the high-pressure steam system. The heated water then enters the economizers 3B1-11 and 4B1-16 in the high-pressure steam system for further heating. The heated water (serial number 118) also passes through the waste heat boiler 1-6, the superheater 4A1-15, and the superheater 1B1-8 to obtain high-pressure steam (serial number 121). The flue gas inlets and outlets of the waste heat boiler 1-6 are arranged between the incineration unit and the conversion unit. The superheater 4A is arranged between the conversion unit and the secondary absorption unit, and the superheater 1B is arranged within the conversion unit.
[0019] The temperature of the sulfuric acid in the lower tower of the low-temperature heat recovery absorption tower 1-13 is 240 - 280°C. The air heater 1-4 heats the air entering the incineration unit, raising the air temperature from 60 - 130°C to 220 - 260°C. The flue gas heater 1-14 heats the flue gas exiting the low-temperature heat recovery absorption tower 1-13, raising the flue gas temperature from 70 - 90°C to 200 - 250°C, and then the flue gas enters the hot and cold heat exchanger 1-10. The high-pressure heaters 1-24 heat the high-pressure feed water entering the economizers 3A1-12 and 4A1-17, raising the high-pressure feed water temperature from 104°C - 170°C to 200 - 260°C.
[0020] Temperature monitoring points and control valves are provided after the low-temperature heat recovery absorption tower 1-13, the air heater 1-4, the flue gas heater 1-14, and the high-pressure heaters 1-24. The material flow rate into the equipment is adjusted according to the set temperature parameters to control the temperature.
[0021] For the low-temperature heat recovery absorption tower 1-13, the air heater 1-4, the flue gas heater 1-14, and the high-pressure heaters 1-24, acid-resistant stainless steel is selected for the materials in contact with high-temperature sulfuric acid, and carbon steel is selected for the materials in contact with hot water and steam.
[0022] The sulfuric acid production process includes, but is not limited to, sulfur-based acid production, pyrite-based acid production, and smelting flue gas-based acid production.
[0023] In sulfuric acid production, air is filtered through the air filter 1-1, and the filtered air enters the drying tower 1-2 for drying. Then, the dried air is pressurized by the fan 1-3 and heated by the air heater 1-4, and enters the sulfur-burning furnace 1-5, where it burns and reacts with liquid sulfur to produce high-temperature SO₂-containing flue gas. The SO₂-containing flue gas enters the waste heat boiler 1-6, where the high-temperature heat in the flue gas is transferred to the high-pressure steam system. Through the high-pressure feed water in the waste heat boiler 1-6, high-pressure steam is generated. After the SO₂-containing flue gas comes out of the waste heat boiler 1-6, it enters the converter 1-7 for catalytic oxidation. The flue gas after the first catalytic oxidation comes out of the first stage of the converter and enters the superheater 1B 1-8, where the heat is transferred to the high-pressure steam in the superheater 1B. After the flue gas cools down, it enters the second stage of the converter 1-7 for secondary catalytic oxidation. The flue gas coming out of the second stage of the converter enters the heat exchanger 1-9, where the heat is transferred to the flue gas on the other side of the heat exchanger 1-9. The cooled flue gas enters the converter 1-7 for the third catalytic oxidation for the third time. After the flue gas comes out of the outlet of the third stage of the converter 1-7, it passes through the cold and hot heat exchanger 1-10, economizer 3A, and economizer 3B. The heat in the flue gas is transferred to the high-pressure feed water passing through the economizer 3A and economizer 3B. After the flue gas cools down, it enters the low-temperature heat recovery absorption tower 1-13 for SO₃ absorption. The flue gas coming out of the low-temperature heat recovery absorption tower 1-13 passes through the flue gas heater 1-14, cold and hot heat exchanger 1-10, and heat exchanger 1-9, and then enters the fourth stage of the converter 1-7 for the fourth catalytic oxidation. The flue gas at the outlet of the fourth stage of the converter 1-7 passes through the superheater 4A, economizer 4B, and economizer 4A, and the high-temperature heat in the flue gas is transferred to the high-pressure steam and feed water passing through the superheater 4A, economizer 4B, and economizer 4A. After the cooled flue gas enters the second absorption tower 1-18 for secondary absorption of SO₃.
[0024] The high-temperature sulfuric acid coming out of the low-temperature heat recovery absorption tower 1-13 is respectively passed through the air heater 1-4, flue gas heater 1-14, and high-pressure heater 1-24, and then converges and is divided into two paths. One path enters the preheater and then enters the second absorption acid pump tank 1-19, and then passes through the finished acid cooler 1-21 to obtain the finished acid 1-22. The other path of high-temperature sulfuric acid passes through the low-temperature heat recovery absorption tower diluter 1-25, is diluted with water and circulated acid, and then returns to the low-temperature heat recovery absorption tower 1-13 to repeat the absorption process.
[0025] The acid side outlet of the low-temperature heat recovery absorption tower 1-13 is respectively connected to the acid side inlets of the high-pressure heater 1-24, the flue gas heater 1-14, and the air heater 1-4 through the acid circulation pump 1-23; the acid side outlets of the high-pressure heater 1-24, the flue gas heater 1-14, and the air heater 1-4 converge and are connected to the inlet of the low-temperature heat recovery absorption tower diluter 1-25, and the outlet of the low-temperature heat recovery absorption tower diluter 1-25 is connected to the low-temperature heat recovery absorption tower 1-13. The acid side outlet of the flue gas heater 1-14 is connected to the acid side inlet of the preheater 1-26, and the acid side outlet of the preheater 1-26 is respectively connected to the secondary absorption unit and the drying unit.
[0026] The drying unit includes, but is not limited to, an air filter 1-1 and a drying tower 1-2. One end of the air filter 1-1 is connected to an air source, and the other end of the air filter 1-1 is connected to the drying tower 1-2. The outlet of the drying tower 1-2 is connected to the inlet of a blower 1-3, and the outlet of the blower 1-3 is connected to the incineration unit through an air heater 1-4. The incineration unit includes, but is not limited to, a sulfur-burning furnace 1-5 and a waste heat boiler 1-6. The outlet of the main blower 1-3 and a liquid sulfur source are connected to the inlet of the sulfur-burning furnace 1-5. The outlet of the sulfur-burning furnace 1-5 is connected to the flue gas side inlet of the waste heat boiler 1-6. The flue gas side outlet of the waste heat boiler 1-6 is connected to the conversion unit. The conversion unit includes, but is not limited to, a converter 1-7, a heat exchanger 1-9, and a cold and heat exchanger 1-10. The flue gas side outlet of the waste heat boiler 1-6 is connected to the first-stage inlet of the converter 1-7. The first-stage outlet of the converter 1-7 is connected to the flue gas side inlet of a superheater 1B1-8. The flue gas side outlet of the superheater 1B is connected to the second-stage inlet of the converter 1-7. The second-stage outlet of the converter 1-7 is connected to the first inlet of the heat exchanger 1-9. The first outlet of the heat exchanger 1-9 is connected to the third-stage inlet of the converter 1-7. The third-stage outlet of the converter 1-7 is connected to the first inlet of the cold and heat exchanger 1-10. The first outlet of the cold and heat exchanger 1-10 is connected to the flue gas side inlet of an economizer 3B. The flue gas side inlet of the economizer 3B is connected to the flue gas side inlet of an economizer 3A. The flue gas side outlet of the economizer 3A is connected to the primary absorption unit. The primary absorption unit includes, but is not limited to, a low-temperature heat recovery absorption tower 1-13 and an acid circulation pump 1-23. The flue gas side outlet of the economizer 3A is connected to the flue gas inlet of the low-temperature heat recovery absorption tower 1-13. The flue gas outlet of the low-temperature heat recovery absorption tower 1-13 is connected to the flue gas inlet of a flue gas heater 1-14. The flue gas outlet of the flue gas heater 1-14 is connected to the second inlet of the cold and heat exchanger 1-10. The second outlet of the cold and heat exchanger 1-10 is connected to the second inlet of the heat exchanger 1-9. The second outlet of the heat exchanger 1-9 is connected to the fourth-stage inlet of the converter 1-7. The fourth-stage outlet of the converter 1-7 is connected to the flue gas side inlet of a superheater 4A. The flue gas side outlet of the superheater 4A is connected to the flue gas side inlet of an economizer 4B. The flue gas side outlet of the economizer 4B is connected to the flue gas side inlet of the economizer 4A. The flue gas side outlet of the economizer 4A is connected to the secondary absorption unit. The secondary absorption unit includes, but is not limited to, a second absorption tower 1-18 and a second absorption acid pump tank 1-19. The flue gas side outlet of the economizer 4A is connected to the second absorption tower 1-18. The acid side outlet of the second absorption tower 1-18 is connected to the inlet of the second absorption acid pump tank 1-19. The acid outlet of the second absorption acid pump tank 1-19 is connected to the inlet of a finished acid cooler 1-21. The outlet of the finished acid cooler 1-21 obtains the finished acid.
[0027] In the high-pressure steam system, the water-side inlet of the preheater 1-26 is connected to the desalinated water source, and the water-side outlet of the preheater 1-26 is connected to the inlet of the deaerator 1-30. The outlet of the deaerator 1-30 is respectively connected to the boiler chemical dosing device 1-38, the water-side inlet of the economizer 3A, the water-side inlet of the economizer 4A, and the dilution water pipeline 1-32 of the diluter through the boiler feed water pump 1-37. The water-side outlets of the economizer 3A and the economizer 4A converge into one path and jointly connect to the water-side inlet of the high-pressure heater 1-24. The water-side outlet of the high-pressure heater 1-24 is divided into two paths and respectively connected to the water-side inlet of the economizer 3B and the water-side inlet of the economizer 4B. The water-side outlets of the economizer 3B and the economizer 4B converge into one path and jointly connect to the water-side inlet of the waste heat boiler 1-6. The steam-side outlet of the waste heat boiler 1-6 is connected to the steam-side inlet of the superheater 4A, the steam-side outlet of the superheater 4A is connected to the steam-side inlet of the superheater 1B, and the steam-side outlet of the superheater 1B produces high-pressure steam 121.
[0028] The acid-side outlet of the preheater 1-26 is respectively connected to the inlets of the dry acid pump tank 1-27 and the secondary absorption acid pump tank 1-19. The outlet of the dry acid pump tank 1-27 is respectively connected to the inlet of the secondary absorption acid pump tank 1-19 and the inlet of the low-temperature heat recovery absorption tower diluter 1-25. The outlet of the secondary absorption acid pump tank 1-19 is connected to the inlet of the secondary absorption acid cooler 1-20. The outlet of the secondary absorption acid cooler 1-20 is respectively connected to the inlets of the low-temperature heat recovery absorption tower 1-13 and the secondary absorption tower 1-18.
[0029] The outlet of the dry acid pump tank 1-27 is also connected to the inlet of the dry acid cooler 1-28. The outlet of the dry acid cooler 1-28 is connected to the acid inlet of the drying tower 1-2. The acid outlet of the drying tower 1-2 is connected to the dry acid pump tank 1-27.
[0030] In this embodiment, the low-temperature heat recovery absorption tower 1-13 is increased from about 200 °C in the traditional low-temperature heat recovery system to 220 - 260 °C through high-temperature acid circulation (serial number 72). The sulfuric acid temperature in the lower tower (serial number 63) has changed from less than 230 °C in the traditional process to 240 - 280 °C.
[0031] The air heater 1-4 heats the air entering the sulfur-burning furnace 1-5 from 60 - 130 °C to 220 - 260 °C. The heated air enters the sulfur-burning furnace 1-5. The flue gas after the combustion reaction enters the waste heat boiler 1-6, and transfers the high-temperature heat in the flue gas to the high-pressure steam system in the water vapor of the waste heat boiler 1-6 (i.e., Figure 2 serial number 118 in it), generating more high-pressure steam.
[0032] The flue gas heater 1-14 heats the flue gas (serial number 18) coming out of the low-temperature heat recovery absorption tower 1-13 from 70-90°C to 200-250°C. The heated flue gas (serial number 20) enters the cold and hot heat exchanger 1-10 to exchange heat with the flue gas (serial number 14) coming from the third-stage outlet of the converter 1-7 and is further heated to about 330°C (serial number 21), and then enters the heat exchanger 1-9 for heat exchange. The flue gas (serial number 22) meeting the process requirements enters the fourth stage of the converter. The flue gas (serial number 14) coming from the third-stage outlet of the converter 1-7 has a temperature of 450-470°C. The temperature of the flue gas (serial number 15) after heat exchange in the cold and hot heat exchanger 1-10 is about 310-350°C. In the traditional process, the temperature here is usually about 250-280°C, which is 60-100°C higher. The heat of the flue gas (serial number 20) heated by the flue gas heater reduces the heat consumed by another flue gas (serial number 15) coming out of the cold and hot heat exchanger, and heats the high-pressure hot water through the economizer 3A and the economizer 3B. After the improvement of the present utility model, the heat of the part higher than the temperature in the traditional method is the heat transferred and utilized from the low-temperature heat source. This part of the heat is absorbed and utilized by the economizer 3A and the economizer 3B to generate more high-pressure steam.
[0033] During specific use, the heating medium source in the air heater and the flue gas heater is one or more of high-temperature sulfuric acid, high-pressure hot water, high-pressure steam, and external heat sources generated in the sulfuric acid production process.
[0034] The heat source of the high-pressure heater comes from the high-temperature sulfuric acid generated by the low-temperature heat recovery absorption tower. The high-temperature sulfuric acid enters the heat source medium inlet of the high-pressure heater to exchange heat with the boiler feed water and then flows out from the heat source medium outlet of the high-pressure heater.
[0035] The high-pressure heater 1-24 heats the boiler feed water (serial number 112) coming from the economizer 3A and the economizer 4A from 104°C - 170°C to 200-260°C and then enters the economizer 3B and the economizer 4B, or enters the economizer 3B and the economizer 4B after serving as the heat source of the air heater and the flue gas heater. It improves the temperature and heat of the boiler feed water to the economizer, and finally increases the high-pressure steam output. Embodiment 2
[0036] This embodiment only illustrates the differences from Embodiment 1, and the same parts will not be repeated. In this embodiment, the flue gas heater 1-14 includes a flue gas heater A and a flue gas heater B. The high-temperature sulfuric acid in the lower tower of the low-temperature heat recovery absorption tower 1-13 enters the high-pressure heater 1-24, the flue gas heater B, and the air heater 1-4 respectively. The temperature of the sulfuric acid coming out of the high-pressure heater 1-24, the flue gas heater B, and the air heater 1-4 decreases, and then enters the flue gas heater A to provide heat. The flue gas heater A and the flue gas heater B heat the flue gas coming out of the low-temperature heat recovery absorption tower 1-13 in two stages.
[0037] The flue gas discharged from the low-temperature heat recovery absorption tower 1-13 is first heated by the flue gas heater A, heating the flue gas from 70 to 90 °C to 150 ± 10 °C, and then the flue gas is heated for the second time by the flue gas heater B, heating the flue gas to 200 to 250 °C, and then entering the cold and heat exchanger 1-10.
[0038] The acid side outlet of the low-temperature heat recovery absorption tower 1-13 is divided into several paths, which are respectively connected to the acid side inlets of the high-pressure heater 1-24, the flue gas heater B, and the air heater 1-4. The acid side outlets of the high-pressure heater 1-24, the flue gas heater B, and the air heater 1-4 converge into two paths, which are respectively connected to the inlets of the low-temperature heat recovery absorption tower diluter 1-25 and the acid side inlet of the flue gas heater A. The outlet of the low-temperature heat recovery absorption tower diluter 1-25 is connected to the low-temperature heat recovery absorption tower 1-13, and the acid side outlet of the flue gas heater A is connected to the acid side inlet of the preheater 1-26. The acid side outlet of the preheater 1-26 is respectively connected to the secondary absorption unit and the drying unit.
[0039] The utility model increases the acid temperature in the lower tower of the low-temperature heat recovery absorption tower from not exceeding 230 °C to 240 to 280 °C. And through the air heater, the flue gas heater, and the high-pressure heater, the heat in the high-temperature acid is transferred to the high-pressure steam system, canceling the low-pressure steam part in the traditional low-temperature heat recovery system, achieving the purpose of fully producing high-pressure steam, significantly increasing the output of high-pressure steam, and maximizing the economic benefits.
Claims
1. A thermal energy utilization device for producing high-pressure steam in sulfuric acid production, comprising a low-temperature heat recovery absorption tower, characterized in that: The temperature of the high-temperature sulfuric acid in the lower tower of the low-temperature heat recovery absorption tower (1-13) is 240-280°C. The acid side outlet of the low-temperature heat recovery absorption tower (1-13) is divided into several paths, which are respectively connected to the acid side inlets of the high-pressure heater (1-24), the flue gas heater (1-14), and the air heater (1-4); the acid side outlets of the high-pressure heater (1-24), the flue gas heater (1-14), and the air heater (1-4) are connected to the inlet of the low-temperature heat recovery absorption tower diluter (1-25) after being converged, the outlet of the low-temperature heat recovery absorption tower diluter (1-25) is connected to the low-temperature heat recovery absorption tower (1-13), the acid side outlet of the flue gas heater (1-14) is also connected to the acid side inlet of the preheater (1-26), and the acid side outlet of the preheater (1-26) is respectively connected to the secondary absorption unit and the drying unit.
2. The thermal energy utilization device for producing high-pressure steam in sulfuric acid production according to claim 1, characterized in that: The air temperature at the inlet of the air heater (1-4) is 60-130°C, and the air temperature at the outlet of the air heater (1-4) is 220-260°C; the flue gas temperature at the inlet of the flue gas heater (1-14) is 70-90°C, and the flue gas temperature at the inlet of the flue gas heater (1-14) is 200-250°C; the steam temperature at the inlet of the high-pressure heater (1-24) is 104-170°C, and the steam temperature at the outlet of the high-pressure heater (1-24) is 200-260°C.
3. The thermal energy utilization device for producing high-pressure steam in sulfuric acid production according to claim 1, characterized in that: The water side inlet of the preheater (1-26) is connected to a high-pressure steam system. In the high-pressure steam system, the water side inlet of the preheater (1-26) is connected to a desalted water source. The water side outlet of the preheater (1-26) is connected to an inlet of a deaerator (1-30). The outlet of the deaerator (1-30) is respectively connected to a boiler dosing device (1-38), a water side inlet of an economizer 3A (1-12), a water side inlet of an economizer 4A (1-17), and a dilution water pipeline (1-32) of a diluter through a boiler feed water pump (1-37). The water side outlet of the economizer 3A (1-12) and the water side outlet of the economizer 4A (1-17) are combined into one path and connected to the high-pressure steam system. The water side inlet of the high-pressure heater (1-24) is connected to the water side inlet of the economizer (1-24), and the water side outlet of the high-pressure heater (1-24) is divided into two paths, which are respectively connected to the water side inlet of the economizer 3B (1-11) and the water side inlet of the economizer 4B (1-16). The water side outlet of the economizer 3B (1-11) and the water side outlet of the economizer 4B (1-16) converge into one path and are connected to the water side inlet of the waste heat boiler (1-6). The steam side outlet of the waste heat boiler (1-6) is connected to the steam side inlet of the superheater 4A (1-15), and the steam side outlet of the superheater 4A (1-15) is connected to the steam side inlet of the superheater 1B (1-8). The steam side outlet of the superheater 1B (1-8) produces high-pressure steam (121).
4. The thermal energy utilization device for producing high-pressure steam in sulfuric acid production according to claim 1, characterized in that: The drying unit comprises an air filter (1-1) and a drying tower (1-2); one end of the air filter (1-1) is connected to an air source, and the other end of the air filter (1-1) is connected to the drying tower (1-2); the outlet of the drying tower (1-2) is connected to the inlet of a fan (1-3); and the outlet of the fan (1-3) is connected to the incineration unit via an air heater (1-4);The incineration unit comprises a sulfur incinerator (1-5) and a waste heat boiler (1-6); the outlet of the main fan (1-3) and the liquid sulfur source are connected to the inlet of the sulfur incinerator (1-5); the outlet of the sulfur incinerator (1-5) is connected to the flue gas side inlet of the waste heat boiler (1-6); the flue gas side outlet of the waste heat boiler (1-6) is connected to the conversion unit; the conversion unit comprises a converter (1-7), a heat exchanger (1-9), and a cold heat exchanger (1-10); the flue gas side outlet of the waste heat boiler (1-6) is connected to the first stage inlet of the converter (1-7); the first stage outlet of the converter (1-7) is connected to the flue gas side inlet of the superheater 1B (1-8); the flue gas side outlet of the superheater 1B (1-8) is connected to the converter (1-7); -7) second stage inlet, the second stage outlet of the converter (1-7) is connected to the first inlet of the heat exchanger (1-9), the first outlet of the heat exchanger (1-9) is connected to the third stage inlet of the converter (1-7), the third stage outlet of the converter (1-7) is connected to the first inlet of the cold heat exchanger (1-10), the first outlet of the cold heat exchanger (1-10) is connected to the flue gas side inlet of the economizer 3B (1-11), the flue gas side inlet of the economizer 3B (1-11) is connected to the flue gas side inlet of the economizer 3A (1-12), the flue gas side outlet of the economizer 3A (1-12) is connected to the primary absorption unit, the primary absorption unit includes a low temperature heat recovery absorption tower (1-13), an acid circulation pump (1-23 ), the flue gas side outlet of the economizer 3A (1-12) is connected to the flue gas inlet of the low-temperature heat recovery absorption tower (1-13), the flue gas outlet of the low-temperature heat recovery absorption tower (1-13) is connected to the flue gas inlet of the flue gas heater (1-14), the flue gas outlet of the flue gas heater (1-14) is connected to the second inlet of the cold-hot heat exchanger (1-10), the second outlet of the cold-hot heat exchanger (1-10) is connected to the second inlet of the heat exchanger (1-9), the second outlet of the heat exchanger (1-9) is connected to the fourth-stage inlet of the converter (1-7), the fourth-stage outlet of the converter (1-7) is connected to the flue gas side inlet of the superheater 4A (1-15), and the flue gas side outlet of the superheater 4A (1-15) is connected The flue gas side inlet of the economizer 4B (1-16) is connected, the flue gas side outlet of the economizer 4B (1-16) is connected to the flue gas side inlet of the economizer 4A (1-17), the flue gas side outlet of the economizer 4A (1-17) is connected to the secondary absorption unit, the secondary absorption unit comprises a secondary absorption tower (1-18) and a secondary absorption acid pump tank (1-19), the flue gas side outlet of the economizer 4A (1-17) is connected to the secondary absorption tower (1-18), the acid side outlet of the secondary absorption tower (1-18) is connected to the inlet of the secondary absorption acid pump tank (1-19), the acid outlet of the secondary absorption acid pump tank (1-19) is connected to the inlet of the finished acid cooler (1-21), and the finished acid is obtained at the outlet of the finished acid cooler (1-21). ; 5. The thermal energy utilization device for producing high-pressure steam in sulfuric acid production according to claim 1, characterized in that: The flue gas heater (1-14) comprises a flue gas heater A (1-14-1) and a flue gas heater B (1-14-2). The acid side outlet of the low-temperature heat recovery absorption tower (1-13) is divided into several paths, which are respectively connected to the acid side inlets of the high-pressure heater (1-24), the flue gas heater B (1-14-2) and the air heater (1-4). The acid side outlets of the high-pressure heater (1-24), the flue gas heater B (1-14-2) and the air heater (1-4) are converged into two paths, which are respectively connected to the inlet of the low-temperature heat recovery absorption tower diluter (1-25) and the acid side inlet of the flue gas heater A (1-14-1). The outlet of the low-temperature heat recovery absorption tower diluter (1-25) is connected to the low-temperature heat recovery absorption tower (1-13). The acid side outlet of the flue gas heater A (1-14-1) is connected to the acid side inlet of the preheater (1-26). The acid side outlet of the preheater (1-26) is respectively connected to the secondary absorption unit and the drying unit.