Low-grade steam condensate heat cascade recovery and reuse device

Abstract

The utility model relates to hollow division technical field in coal chemical industry, it is a kind of low-grade steam condensate heat ladder recycling device, including condensate recovery device, air separation lithium bromide unit, heating unit, raw water heater, condensate treatment device, condensate recovery device, air separation lithium bromide unit, heating unit, raw water heater, condensate treatment device are fixedly connected in turn intercommunication, and condensate recovery pipeline is fixedly connected in condensate recovery device import intercommunication, and desalted water export pipeline is fixedly connected in condensate treatment device outlet intercommunication.The utility model is reasonable and compact in structure, convenient to use, its setting different grades low-grade heat utilization device, realize the ladder full use to steam condensate such low-grade heat source, not only reduce the waste of heat, also greatly reduce the use of cooling circulating water, reduce the scale of circulating water, thereby reduce the production cost investment of enterprise, with safe, energy-saving, simple, efficient characteristics.

Description

Technical Field

[0001] This utility model relates to the field of air separation technology in coal chemical industry, and is a device for the step-by-step recovery and reuse of heat from low-grade steam condensate. Background Technology

[0002] In chemical production processes, steam plays a crucial supporting role. Substances require heating to produce physicochemical reactions and complete processing; high temperature and stable heating are key indicators. Industries use steam to achieve homogeneous heating in 20,000-ton reaction tanks or to maintain constant temperature sterilization in 0.5-micron filter membrane systems. Steam can be involved in every pipeline and every decomposition step to drive the production process.

[0003] In the operation of coal chemical plants, a large amount of steam is required as a heat source, resulting in the generation of substantial amounts of condensate. This condensate, due to its relatively low temperature and low-grade heat, is difficult to reuse, posing a significant challenge to the industry. Therefore, the recovery and utilization of steam condensate in coal chemical production has significant economic and environmental benefits, mainly reflected in the following aspects: (1) Energy saving and consumption reduction: Recovering steam condensate can significantly increase the boiler feedwater temperature. For every 6°C increase in water temperature, fuel consumption can be reduced by about 1%. If the boiler feedwater temperature is increased from 20°C to 80°C, fuel consumption can be reduced by more than 10%. At the same time, condensate reuse can reduce boiler blowdown and reduce the waste of heat energy and water resources.

[0004] (2) Economic benefits: Recycling condensate can reduce the cost of preparing softened water or demineralized water. It can save 0.55 kg of industrial salt per ton of softened water. If a reverse osmosis water treatment system is used, the cost savings are even more significant. In addition, condensate reuse can also reduce wastewater discharge and treatment costs.

[0005] (3) Environmental value: If untreated condensate is discharged directly, it may pollute the environment and increase wastewater treatment costs. Recycling can prevent pollutants from entering the public drainage system and reduce the environmental pressure on enterprises.

[0006] (4) Process optimization: Condensate recycling can keep the boiler evaporation rate within the rated range (80% to 100%) and avoid a decrease in thermal efficiency. At the same time, the low oxygen content of the condensate can reduce the risk of corrosion of boiler equipment and pipelines.

[0007] Currently, in the air separation sector of coal chemical production, most enterprises use circulating water to cool the steam condensate to room temperature before sending it to the demineralized water treatment station for further processing and purification, and then recirculating it. This results in a significant waste of heat and increases the energy consumption of the unit. Furthermore, the need for circulating water for condensate cooling also increases the scale of circulating water system construction, thereby increasing production costs.

[0008] Therefore, it is necessary to develop a steam condensate recovery device to solve the above problems. Summary of the Invention

[0009] This invention provides a low-grade steam condensate heat recovery and reuse device, which overcomes the shortcomings of the prior art and can effectively solve the problem of high production costs caused by the inability to fully utilize the heat of low-grade steam condensate in the air separation process of existing coal chemical industry.

[0010] The technical solution of this utility model is achieved through the following measures: a low-grade steam condensate heat recovery and reuse device, including a condensate recovery device, an air separation lithium bromide unit, a heating unit, a raw water heater, and a condensate treatment device. The condensate recovery device, the air separation lithium bromide unit, the heating unit, the raw water heater, and the condensate treatment device are sequentially and fixedly connected. The inlet of the condensate recovery device is fixedly connected to a condensate recovery pipeline, and the outlet of the condensate treatment device is fixedly connected to a demineralized water delivery pipeline.

[0011] The following are further optimizations and / or improvements to the above-mentioned utility model technical solution: The above also includes an air separation and air-cooling tower, with the first inlet of the air separation and air-cooling tower fixedly connected to an air separation air intake pipeline, the outlet of the air separation and air-cooling tower fixedly connected to a molecular sieve removal pipeline, the second inlet of the air separation and air-cooling tower and the first outlet of the air separation lithium bromide unit fixedly connected to a 7°C cooling water inlet pipeline, and the first inlet of the air separation lithium bromide unit fixedly connected to a 14°C cooling water inlet pipeline.

[0012] The aforementioned condensate recovery pipelines include a first condensate recovery pipeline, a second condensate recovery pipeline, a third condensate recovery pipeline, a fourth condensate recovery pipeline, a fifth condensate recovery pipeline, and a sixth condensate recovery pipeline. The first and second condensate recovery pipelines are both fixedly connected to the inlet of the condensate recovery device. The outlet of the condensate recovery device is fixedly connected to the second inlet of the lithium bromide air separation unit via a third condensate recovery pipeline. The second outlet of the lithium bromide air separation unit is fixedly connected to the first inlet of the heating unit via a fourth condensate recovery pipeline. The first outlet of the heating unit is fixedly connected to the first inlet of the raw water heater via a fifth condensate recovery pipeline. The first outlet of the raw water heater is fixedly connected to the inlet of the condensate recovery device via a sixth condensate recovery pipeline.

[0013] The second inlet of the aforementioned heating unit is fixedly connected to a heating and ventilation return water pipeline, and the second outlet of the heating unit is fixedly connected to a heating and ventilation supply water pipeline.

[0014] The second inlet of the aforementioned raw water heater is fixedly connected to a raw water inlet pipeline, and the second outlet of the raw water heater is fixedly connected to a raw water outlet pipeline.

[0015] The above-mentioned condensate recovery device, air separation lithium bromide unit, heating unit, raw water heater, condensate treatment device, condensate recovery device, air separation lithium bromide unit, heating unit, raw water heater, condensate treatment device and air separation air-cooling tower are all equipped with thermometers.

[0016] Regulating valves are fixedly installed on the aforementioned first condensate recovery pipeline, second condensate recovery pipeline, third condensate recovery pipeline, fourth condensate recovery pipeline, fifth condensate recovery pipeline, sixth condensate recovery pipeline, air separation air inlet pipeline, molecular sieve removal pipeline, 7℃ cooling water inlet pipeline, 14℃ cooling water inlet pipeline, HVAC return water pipeline, HVAC water supply pipeline, raw water inlet pipeline, and raw water outlet pipeline.

[0017] An interlock is provided between the thermometer and the regulating valve.

[0018] This utility model has a reasonable and compact structure and is easy to use. It is equipped with low-grade heat utilization devices of different levels to achieve full utilization of low-grade heat sources such as steam condensate. This not only reduces heat waste, but also greatly reduces the use of cooling circulating water and reduces the scale of circulating water, thereby reducing the production cost investment of enterprises. It has the characteristics of safety, energy saving, simplicity and high efficiency. Attached Figure Description

[0019] Appendix Figure 1 This is a schematic diagram of the process flow of this utility model.

[0020] Appendix Figure 1 The codes in the diagram are as follows: 1 for condensate recovery unit, 2 for air separation lithium bromide unit, 3 for heating unit, 4 for raw water heater, 5 for condensate treatment unit, 6 for air separation air-cooled tower, 7 for demineralized water delivery pipeline, 8 for first condensate recovery pipeline, 9 for second condensate recovery pipeline, 10 for third condensate recovery pipeline, 11 for fourth condensate recovery pipeline, 12 for fifth condensate recovery pipeline, 13 for sixth condensate recovery pipeline, 14 for air separation air intake pipeline, 15 for molecular sieve removal pipeline, 16 for 7℃ cooling water inlet pipeline, 17 for 14℃ cooling water inlet pipeline, 18 for HVAC return water pipeline, 19 for HVAC supply water pipeline, 20 for raw water inlet pipeline, and 21 for raw water outlet pipeline. Detailed Implementation

[0021] This utility model is not limited to the following embodiments, and the specific implementation method can be determined according to the technical solution of this utility model and the actual situation.

[0022] Unless otherwise specified, all equipment and devices used in this invention are existing, publicly known, and commonly used equipment and devices in the field. For example, the condensate recovery device 1, the lithium air separation unit 2, the heating unit 3, the raw water heater 4, and the condensate treatment device 5 are all existing, publicly known, and commonly used equipment.

[0023] In this utility model, for ease of description, the description of the relative positions of the components is based on the appendix to the specification. Figure 1 The layout is described using a diagrammatic method, such as the positional relationships of front, back, top, bottom, left, and right, which are based on the instructions attached. Figure 1 The orientation of the layout is determined by the direction of the map.

[0024] The present invention will be further described below with reference to the embodiments and accompanying drawings: Example 1: As shown in the attached document Figure 1 As shown, the low-grade steam condensate heat recovery and reuse device includes a condensate recovery device 1, an air separation lithium bromide unit 2, a heating unit 3, a raw water heater 4, and a condensate treatment device 5. The condensate recovery device 1, the air separation lithium bromide unit 2, the heating unit 3, the raw water heater 4, and the condensate treatment device 5 are sequentially and fixedly connected. The inlet of the condensate recovery device 1 is fixedly connected to a condensate recovery pipeline, and the outlet of the condensate treatment device 5 is fixedly connected to a demineralized water delivery pipeline 7.

[0025] This invention utilizes a condensate recovery device 1 to recover steam condensate from a coal chemical plant, obtaining steam condensate with a temperature of 100℃ to 120℃. The condensate is then pressurized and sent to a lithium bromide air separation unit 2 as its heat source. After being processed by the lithium bromide air separation unit 2, the condensate is sent to a heating unit 3 to heat the heating water, further reducing its temperature. Finally, it is sent to a condensate treatment device 5 to exchange heat with the raw water, lowering the condensate temperature to ambient temperature. This process fully utilizes the heat in the condensate before it is purified in the condensate treatment device 5, yielding demineralized water for reuse in the coal chemical plant. By employing cold sources of different temperatures, this invention utilizes the low-grade heat source, steam condensate, in a tiered manner, fully leveraging the heat from each stage of the condensate and significantly reducing the plant's operating energy consumption.

[0026] The above-mentioned low-grade steam condensate heat recovery and reuse device can be further optimized and / or improved according to actual needs: Example 2: Its difference from Example 1 is as follows: (See attached) Figure 1As shown, it also includes an air separation and air-cooling tower 6, with an air separation air inlet pipeline 14 fixedly connected to the first inlet of the air separation and air-cooling tower 6, a molecular sieve-to-airway pipeline 15 fixedly connected to the outlet of the air separation and air-cooling tower 6, a 7°C cooling water inlet pipeline 16 fixedly connected between the second inlet of the air separation and air-cooling tower 6 and the first outlet of the air separation lithium bromide unit 2, and a 14°C cooling water inlet pipeline 17 fixedly connected to the first inlet of the air separation lithium bromide unit 2.

[0027] Cooling water at 7°C enters the air separation air-cooling tower 6, reducing the outlet temperature of the air in the air separation air-cooling tower 6 to about 14°C. The resulting air at about 14°C is sent to the downstream air separation molecular sieve, which not only enhances the adsorption performance of the air separation molecular sieve and improves the safety of its operation, but also reduces the operating energy consumption of the air separation molecular sieve due to the lower air temperature.

[0028] Example 3: Its difference from Examples 1 to 2 is as follows: (See attached) Figure 1 As shown, the condensate recovery pipeline includes a first condensate recovery pipeline 8, a second condensate recovery pipeline 9, a third condensate recovery pipeline 10, a fourth condensate recovery pipeline 11, a fifth condensate recovery pipeline 12, and a sixth condensate recovery pipeline 13. The first condensate recovery pipeline 8 and the second condensate recovery pipeline are both fixedly connected to the inlet of the condensate recovery device 1. The outlet of the condensate recovery device 1 is fixedly connected to the second inlet of the air separation lithium bromide unit 2 via the third condensate recovery pipeline 10. The second outlet of the air separation lithium bromide unit 2 is fixedly connected to the first inlet of the heating unit 3 via the fourth condensate recovery pipeline 11. The first outlet of the heating unit 3 is fixedly connected to the first inlet of the raw water heater 4 via the fifth condensate recovery pipeline 12. The first outlet of the raw water heater 4 is fixedly connected to the inlet of the condensate recovery device 1 via the sixth condensate recovery pipeline 13.

[0029] Example 4: Its difference from Examples 1 to 3 is as follows: (See attached) Figure 1 As shown, the second inlet of the heating unit 3 is fixedly connected to the HVAC return water pipeline 18, and the second outlet of the heating unit 3 is fixedly connected to the HVAC supply water pipeline 19.

[0030] As needed, the condensate steam at around 75°C heats the heating water at 45°C to 55°C, while the temperature of the condensate steam drops to 55°C at the same time.

[0031] Example 5: It differs from Examples 1 to 4 in that, as shown in the appendix... Figure 1 As shown, the second inlet of the raw water heater 4 is fixedly connected to the raw water inlet pipeline 20, and the second outlet of the raw water heater 4 is fixedly connected to the raw water outlet pipeline 21.

[0032] Example 6: Its difference from Examples 1 to 5 is as follows: (See attached) Figure 1As shown, thermometers are installed on the condensate recovery unit 1, the air separation lithium bromide unit 2, the heating unit 3, the raw water heater 4, the condensate treatment unit 5, and the air separation air-cooling tower 6.

[0033] Example 7: Its difference from Examples 1 to 6 is as follows: (See attached) Figure 1 As shown, regulating valves are fixedly installed on the first condensate recovery pipeline 8, the second condensate recovery pipeline 9, the third condensate recovery pipeline 10, the fourth condensate recovery pipeline 11, the fifth condensate recovery pipeline 12, the sixth condensate recovery pipeline 13, the air separation air inlet pipeline 14, the molecular sieve removal pipeline 15, the 7℃ cooling water inlet pipeline 16, the 14℃ cooling water inlet pipeline 17, the HVAC return water pipeline 18, the HVAC supply water pipeline 19, the raw water inlet pipeline 20, and the raw water outlet pipeline 21.

[0034] Example 8: It differs from Examples 1 to 7 in that: as shown in the appendix Figure 1 As shown, an interlock is installed between the thermometer and the regulating valve.

[0035] Through the interlock between the thermometers and the regulating valves, the opening degree of each regulating valve can be adjusted in real time according to the temperature monitored by the thermometers of the condensate recovery unit 1, the air separation lithium bromide unit 2, the heating unit 3, the raw water heater 4, the condensate treatment unit 5, the condensate recovery unit 1, the air separation lithium bromide unit 2, the heating unit 3, the raw water heater 4, the condensate treatment unit 5, and the air separation air-cooling tower 6, so as to ensure the stable operation of each unit.

[0036] Depending on the needs, the pipelines and equipment of this low-grade steam condensate heat recovery and reuse device may also be equipped with conventional valves and pressure gauges known and commonly used in the field, according to production requirements.

[0037] The above technical features constitute the embodiments of this utility model, which have strong adaptability and implementation effect. Unnecessary technical features can be added or removed according to actual needs to meet the needs of different situations.

[0038] The process of using this utility model: In the first step, the steam condensate (including process steam condensate, heat tracing condensate, etc.) from various units of the coal chemical project is collected into the condensate recovery unit 1 through the first condensate recovery pipeline 8 and the second condensate recovery pipeline 9 to obtain steam condensate at about 100°C to 120°C. In the second step, the 14°C cooling water in the air separation boundary zone is transported to the air separation lithium bromide unit 2 via the 14°C cooling water inlet pipeline 17. The steam condensate at about 100°C to 120°C in the condensate recovery device 1 is transported to the air separation lithium bromide unit 2 via the third condensate recovery pipeline 10. It is used as a heat source for the air separation lithium bromide unit 2 to utilize heat and output cooling capacity, thereby cooling down the 14°C cooling water in the air separation boundary zone to obtain 7°C cooling water and about 75°C steam condensate. The third step involves 7°C cooling water entering pipeline 16 and being transported to the air separation air-cooling tower 6 to cool the 90°C hot air transported by the air separation air inlet pipeline 14, thereby reducing the air outlet temperature of the air separation air-cooling tower 6 and obtaining air separation air at around 14°C, which is then sent to the downstream air separation molecular sieve. In the fourth step, the condensate at around 75°C is transported to the heating unit 3 via the fourth condensate recovery pipeline 11, where it heats the 45°C heating water supplied by the HVAC return water pipeline 18. The resulting 55°C heating water is output through the HVAC supply water pipeline 19, thus realizing the secondary utilization of the heat of the condensate after the air separation lithium bromide unit 2, and obtaining condensate at around 55°C. In the fifth step, the steam condensate at about 55°C is transported to the raw water heater 4 through the fifth condensate recovery pipeline 12, where it exchanges heat with the low-temperature raw water transported by the raw water inlet pipeline 20. The raw water at about 15°C is heated to about 23°C and then output through the raw water outlet pipeline 21, while steam condensate at about 25°C is obtained at the same time. In the sixth step, the steam condensate at around 25°C is transported to the condensate treatment device 5 via the sixth condensate recovery pipeline 13. After purification, demineralized water is obtained and output via the demineralized water delivery pipeline 7 for reuse, thereby realizing the full recycling of the waste heat of the steam condensate.

Claims

1. A device for the step-by-step recovery and reuse of heat from low-grade steam condensate, characterized in that... It includes a condensate recovery unit, an air separation lithium bromide unit, a heating unit, a raw water heater, and a condensate treatment unit. The condensate recovery unit, the air separation lithium bromide unit, the heating unit, the raw water heater, and the condensate treatment unit are sequentially and fixedly connected. The inlet of the condensate recovery unit is fixedly connected to a condensate recovery pipeline, and the outlet of the condensate treatment unit is fixedly connected to a demineralized water delivery pipeline.

2. The low-grade steam condensate heat recovery and reuse device according to claim 1, characterized in that... It also includes an air separation and air-cooling tower, with the first inlet of the air separation and air-cooling tower fixedly connected to an air separation air intake pipeline, the outlet of the air separation and air-cooling tower fixedly connected to a molecular sieve pipeline, the second inlet of the air separation and air-cooling tower and the first outlet of the air separation lithium bromide unit fixedly connected to a 7°C cooling water inlet pipeline, and the first inlet of the air separation lithium bromide unit fixedly connected to a 14°C cooling water inlet pipeline.

3. The low-grade steam condensate heat recovery and reuse device according to claim 1 or 2, characterized in that... The condensate recovery pipeline includes a first condensate recovery pipeline, a second condensate recovery pipeline, a third condensate recovery pipeline, a fourth condensate recovery pipeline, a fifth condensate recovery pipeline, and a sixth condensate recovery pipeline. The first and second condensate recovery pipelines are both fixedly connected to the inlet of the condensate recovery device. The outlet of the condensate recovery device is fixedly connected to the second inlet of the lithium bromide air separation unit via a third condensate recovery pipeline. The second outlet of the lithium bromide air separation unit is fixedly connected to the first inlet of the heating unit via a fourth condensate recovery pipeline. The first outlet of the heating unit is fixedly connected to the first inlet of the raw water heater via a fifth condensate recovery pipeline. The first outlet of the raw water heater is fixedly connected to the inlet of the condensate recovery device via a sixth condensate recovery pipeline.

4. The low-grade steam condensate heat recovery and reuse device according to claim 1 or 2, characterized in that... The second inlet of the heating unit is fixedly connected to the HVAC return water pipeline, and the second outlet of the heating unit is fixedly connected to the HVAC supply water pipeline.

5. The low-grade steam condensate heat recovery and reuse device according to claim 3, characterized in that... The second inlet of the heating unit is fixedly connected to the HVAC return water pipeline, and the second outlet of the heating unit is fixedly connected to the HVAC supply water pipeline.

6. The low-grade steam condensate heat recovery and reuse device according to claim 1, 2, or 5, characterized in that... The second inlet of the raw water heater is fixedly connected to a raw water inlet pipeline, and the second outlet of the raw water heater is fixedly connected to a raw water outlet pipeline.

7. The low-grade steam condensate heat recovery and reuse device according to claim 6, characterized in that... Thermometers are installed on the condensate recovery unit, the air separation lithium bromide unit, the heating unit, the raw water heater, the condensate treatment unit, and the air separation air-cooling tower.

8. The low-grade steam condensate heat recovery and reuse device according to claim 6, characterized in that... Regulating valves are fixedly installed on the first condensate recovery pipeline, the second condensate recovery pipeline, the third condensate recovery pipeline, the fourth condensate recovery pipeline, the fifth condensate recovery pipeline, the sixth condensate recovery pipeline, the air separation air inlet pipeline, the molecular sieve depot pipeline, the 7℃ cooling water inlet pipeline, the 14℃ cooling water inlet pipeline, the HVAC return water pipeline, the HVAC water supply pipeline, the raw water inlet pipeline, and the raw water outlet pipeline.

9. The low-grade steam condensate heat recovery and reuse device according to claim 7, characterized in that... Regulating valves are fixedly installed on the first condensate recovery pipeline, the second condensate recovery pipeline, the third condensate recovery pipeline, the fourth condensate recovery pipeline, the fifth condensate recovery pipeline, the sixth condensate recovery pipeline, the air separation air inlet pipeline, the molecular sieve depot pipeline, the 7℃ cooling water inlet pipeline, the 14℃ cooling water inlet pipeline, the HVAC return water pipeline, the HVAC water supply pipeline, the raw water inlet pipeline, and the raw water outlet pipeline.

10. The low-grade steam condensate heat recovery and reuse device according to claim 8 or 9, characterized in that... An interlock is installed between the thermometer and the regulating valve.

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