System for dynamically converting polluted steam into fresh steam and control method thereof

Abstract

The invention relates to a system for dynamically converting polluted steam into fresh steam and a control method of the system, and belongs to the technical field of polluted steam treatment and heat energy recovery equipment.The system comprises a first-stage evaporation indirect heat exchanger, and a polluted steam supply pipe is arranged on the first-stage evaporation indirect heat exchanger; a steam generator and a softened water tank which are communicated with the primary evaporation indirect heat exchanger through pipelines are arranged on the side edge of the primary evaporation indirect heat exchanger, a make-up pump communicated with the lower end of the softened water tank through pipelines is arranged between the middle of the steam generator and the lower end of the softened water tank, a softened water supply pipe communicated with the softened water tank is arranged on the upper portion of the softened water tank, and a new steam discharge pipe is arranged at the upper end of the steam generator. An evaporation circulating pump communicated with the first-stage evaporation indirect heat exchanger through a pipeline is arranged between the lower portion of the steam generator and the first-stage evaporation indirect heat exchanger, and the middle of the steam generator is communicated with the first-stage evaporation indirect heat exchanger through a pipeline. Polluted steam is rapidly and dynamically converted into new steam, heat energy of low-pressure polluted steam is fully utilized, emission of the low-pressure polluted steam is reduced or completely eradicated, and meanwhile pollution to the environment is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of polluted steam treatment and heat recovery equipment, and in particular to a system for dynamically converting polluted steam into new steam and a control method thereof. Background Art

[0002] Aluminum powder is added to the alkaline aerated concrete slurry, and the aluminum powder reacts with water to generate hydrogen. The hydrogen forms bubbles in the concrete slurry, and forms an aerated concrete body after initial setting. The body is heated by direct contact with steam in the autoclave, and the aerated concrete product is formed by steam curing for a certain period of time at 0.8-1.4Mpa. During the curing process, the autoclave first uses steam to exhaust the air in the autoclave or evacuates the air, but there is always some air remaining in the autoclave. Then, steam is introduced into the autoclave to gradually increase the temperature to the curing pressure. During the heating and curing process, the hydrogen bubbles in the body are heated and expanded and released into the steam space. The body generates odorous gas during the hydration reaction at high temperature, and the air, hydrogen and odorous gas are partially mixed in the curing steam.

[0003] After the curing of aerated concrete is completed, the curing steam is first poured into the autoclave of the newly added green body to increase the temperature, and is also used for other heat-using processes. In this way, the curing steam can be recycled and reused to heat the green body, and the unused curing steam is discharged into the environment. After the steam is exhausted, the pressure of the autoclave is reduced to 0 pressure and the aerated concrete products are taken out of the autoclave. With the repeated use of curing steam, air, hydrogen and odorous gases are gradually enriched. Since air and hydrogen are non-condensable gases, the heat transfer coefficient of steam decreases after enrichment, and the heat transfer capacity decreases. The aerated concrete green body cannot be quickly and effectively heated to the reaction temperature, which will affect the curing effect of the green body, and then cause product defects, and in severe cases, damage the product. The odorous gas is discharged into the environment, which also causes environmental pollution.

[0004] Theoretically, air and hydrogen are non-condensable gases, and odorous gases are condensable gases, which can be condensed at low temperatures and dissolved in water, but cannot be completely condensed and can only partially form gases. Since steam contains air, hydrogen and odorous gases, it is contaminated steam containing non-condensable gases, so it is hereinafter referred to as contaminated steam.

[0005] In order to reduce the energy consumption in the production process, reduce the environmental impact of polluted steam emissions, and balance the imbalance in the production process, in the existing technology, except for using reverse steam, polluted steam is directly or indirectly used for heat exchange to heat water into high-temperature and high-pressure water, and the high-temperature water is stored by heat storage. When needed, the pressure is reduced and flashed to release the flash steam for reuse. Due to the large water volume (20 - 200 m³) and large heat storage capacity of the heat accumulator, it can better balance production. When polluted steam directly heats the heat-stored high-temperature water in the heat accumulator, air and hydrogen are mainly mixed in the steam space at the upper part of the heat accumulator, the odor gas is mainly dissolved in the high-temperature water, and part of the hydrogen is also dissolved in the heat-stored water. When supplying steam externally, the odor and non-condensable gases are released again and mixed with water vapor to form polluted steam and are discharged from the heat accumulator. Therefore, the directly heated heat accumulator can only store heat periodically, but cannot completely remove non-condensable gases and pollutants. The indirectly heated heat accumulator heats water through indirect heat exchange, and the odor gas and water vapor are condensed into condensed water, which has a certain effect of removing pollutants. However, due to the large heat exchange amount required and long cycle, the steaming and curing steam cannot be utilized quickly and in a timely manner.

[0006] Due to the large water volume of the heat exchange system, large heat storage capacity, and long heating time required, the steam pressure loss is very large and the temperature difference is also very large during heat storage. However, the pressure changes greatly during steam exhaust, the high-pressure steam exhaust period is not long, and the temperature and pressure inside the heat accumulator are always relatively low. When the exhaust pressure and the heat storage pressure of the heat accumulator are balanced or the pressure difference is very small, heat storage can no longer be carried out and forced discharge has to be carried out. Although multi-stage heat storage can be used to recover part of the low-pressure steam, it takes a long time. Therefore, when using the method of heat storage to utilize the steaming and curing steam to recover the heat energy of the steaming and curing steam, the external supply steam pressure is not high, it is also very difficult to quickly remove the pollutants in the steaming and curing steam, and it is also difficult to utilize the low-pressure polluted steam. In order to improve production efficiency, the low-pressure steam can only be discharged into the environment, resulting in large heat energy loss and serious pollution. Due to the large water volume of the equipment, the corresponding equipment is very large, the equipment quality is large, and the cost is very high. Summary of the Invention

[0007] The present invention mainly solves the deficiencies existing in the prior art, and provides a system for dynamically converting polluted steam into new steam and its control method, which can quickly remove non-condensable gases and odor gases in polluted steam within a short time, quickly and dynamically convert polluted steam into new steam, use the new steam to heat and cure other autoclaves, reduce the steam conversion pressure difference at the same time, effectively utilize low-pressure polluted steam, thereby improving production efficiency, improving product quality, fully utilizing the heat energy of low-pressure polluted steam, reducing or eliminating the discharge of low-pressure polluted steam, saving a large amount of energy, and reducing environmental pollution at the same time.

[0008] The above technical problems of the present invention are mainly solved by the following technical solutions: In order to prevent polluted steam from polluting new steam, the evaporation heat exchanger can only use an indirect surface heat exchanger, and polluted steam can be effectively converted into new steam through indirect heat exchange.

[0009] According to the basic principle of heat transfer, the amount of heat transferred is equal to the product of the heat transfer coefficient K, the temperature difference T, and the heat transfer area F, i.e., Q = K * T * F. The total amount of heat transfer is equal to the sum of the heat supplied to the steam and the heat capacity of the heat exchange system. To achieve rapid dynamic steam supply, it is necessary to reduce the heat capacity of the heat exchange system. The heat capacity of the heat exchange system is equal to the product of the temperature difference, the specific heat capacity of water, and the water volume.

[0010] Therefore, to achieve the object of the present invention, it is necessary to reduce the total amount of heat transfer in the heat exchange system, and thus it is also necessary to reduce the water volume in the heat exchange system; reducing the temperature difference is to reduce the pressure difference of steam heat exchange, so that low-pressure steam can be effectively utilized; after the temperature difference is reduced, according to the basic principle of heat transfer, it is necessary to increase the heat transfer area and improve the heat transfer coefficient.

[0011] To reduce the water volume of the system, it is necessary to separate the indirect heat exchange system and the new steam generation system. After separation, the water volume of the system will be greatly reduced. In this way, the contaminated steam can quickly and dynamically heat the clean water in the system into a steam-water mixture, and then after steam-water separation in the steam generator, new steam is formed for dynamic process use.

[0012] During the heat exchange process, non-condensable gases in the contaminated steam are dynamically discharged in a timely manner. This can not only reduce the thermal resistance, but also make the steam flow and be disturbed. The steam can increase the heat transfer coefficient during the flow process, and the heat exchange efficiency is improved.

[0013] Therefore, through the above methods, non-condensable gases and odor gases in the contaminated steam can be quickly removed within a short time, and the contaminated steam can be quickly and dynamically converted into new steam.

[0014] Since the odor gas is a condensable gas with a low condensation temperature and high solubility in water, heat exchange condensation cooling of the contaminated steam can remove the odor gas. The condensed odor substances are dissolved in the condensed water, and the condensed water is mixed in the process water or directly used as process water for production circulation.

[0015] Generally speaking, the method is that the contaminated steam heats the clean water through indirect heat exchange, quickly forms a steam-water mixture, and at the same time separates the steam generation part and the heat exchange system, so that the water volume of the system is reduced. After the water volume is reduced, the contaminated steam heats the clean water into a steam-water mixture through an indirect heat exchanger, and the steam-water mixture forms new steam after steam-water separation in the steam generator. During the heat exchange process, non-condensable gases in the contaminated steam are dynamically discharged in a timely manner, making the steam flow and be disturbed, reducing the thermal resistance, and the steam increases the heat transfer coefficient during the flow process, so the heat transfer efficiency is improved, and thus the contaminated steam is quickly and dynamically converted into new steam.

[0016] The clean water can be water sources such as softened water and pure water. In this description, softened water is taken as an example for illustration.

[0017] A system for dynamically converting contaminated steam into new steam, including a primary evaporation indirect heat exchanger, a contaminated steam supply pipe is provided on the primary evaporation indirect heat exchanger, a steam generator and a soft water tank in pipeline connection with the primary evaporation indirect heat exchanger are arranged on the side of the primary evaporation indirect heat exchanger, a make-up water pump in pipeline connection is arranged between the middle of the steam generator and the lower end of the soft water tank, a soft water supply pipe communicated with the soft water tank is arranged on the upper part of the soft water tank, a new steam discharge pipe is arranged at the upper end of the steam generator, an evaporation circulation pump in pipeline connection is arranged between the lower part of the steam generator and the primary evaporation indirect heat exchanger, the middle of the steam generator is in pipeline connection with the primary evaporation indirect heat exchanger, a regulating valve and a primary steam trap in parallel pipeline connection are arranged at the lower part of the primary evaporation indirect heat exchanger, and the regulating valve is used for regulating drainage or exhaust steam.

[0018] Preferably, a waste heat recovery component is arranged between the soft water tank and the primary evaporation indirect heat exchanger, the upper end of the waste heat recovery component is in pipeline connection with the upper end of the soft water tank, a regulating valve and a primary steam trap in parallel pipeline connection are arranged between the waste heat recovery component and the primary evaporation indirect heat exchanger, and a process water tank or a process device is arranged at the outlet of the primary steam trap.

[0019] Preferably, the waste heat recovery component includes a secondary waste heat exchanger, the secondary waste heat exchanger is a direct or indirect heat exchanger, and is configured in parallel or in series according to actual needs, the secondary waste heat exchanger is provided with a hydrogen and air discharge pipe, the upper end of the secondary waste heat exchanger is in pipeline connection with the upper end of the soft water tank, a heat energy recovery circulation pump I is arranged between the secondary waste heat exchanger and the soft water tank and between the secondary waste heat exchanger and the make-up water pump, and a secondary steam trap is arranged between the secondary waste heat exchanger and the process water tank or the process device.

[0020] Preferably, the waste heat recovery component includes a secondary waste heat direct mixing heat exchanger, the secondary waste heat direct mixing heat exchanger is in pipeline connection with the process water tank or the process device, a hydrogen and air discharge pipe is arranged at the upper end of the secondary waste heat direct mixing heat exchanger, a circulating water heat exchanger is arranged between the secondary waste heat direct mixing heat exchanger and the soft water tank, and a heat exchange circulation pump is arranged between the circulating water heat exchanger and the lower end of the secondary waste heat direct mixing heat exchanger.

[0021] Preferably, the waste heat recovery assembly includes a secondary waste heat exchanger and a secondary waste heat direct mixing heat exchanger connected in series in the pipeline between the regulating valve and the soft water tank. The secondary waste heat direct mixing heat exchanger is connected to the process water tank or process equipment through a pipeline. A heat energy recovery circulation pump I is provided between the secondary waste heat exchanger and the soft water tank and between the secondary waste heat exchanger and the makeup water pump. A hydrogen and air discharge pipe is provided at the upper end of the secondary waste heat direct mixing heat exchanger. A circulating water heat exchanger is provided between the secondary waste heat direct mixing heat exchanger and the soft water tank. A heat energy recovery circulation pump II is provided between the circulating water heat exchanger and the lower end of the soft water tank. A heat exchange circulation pump is provided between the circulating water heat exchanger and the lower end of the secondary waste heat direct mixing heat exchanger.

[0022] A control method for a system that dynamically converts contaminated steam into new steam. The contaminated steam indirectly heats clean water, and after heating, a steam-water mixture is rapidly formed. At the same time, the steam generation part and the heat exchange system are separated, which reduces the water volume of the heat exchange system. After the water volume is reduced, the contaminated steam rapidly heats the clean water into a steam-water mixture through an indirect heat exchanger. The steam-water mixture is separated into new steam in the steam generator. At the same time, during the heat exchange process, the non-condensable gases in the contaminated steam are dynamically discharged in a timely manner to reduce the thermal resistance, and the steam is allowed to flow and be disturbed to reduce the thermal resistance. The heat transfer coefficient is increased during the flow of the steam, so the heat transfer efficiency is improved. In this way, the contaminated steam is rapidly and dynamically converted into new steam.

[0023] A control method for a system that dynamically converts contaminated steam into new steam, including the following operating steps: First step: Indirect heat exchange between the contaminated steam and the clean water.

[0024] Second step: Steam generation.

[0025] Third step: Discharge condensate water and contaminated steam rich in non-condensable gases during the heat exchange process.

[0026] Fourth step: Recover the heat energy of the discharged contaminated steam rich in non-condensable gases for preheating makeup water.

[0027] Fifth step: Supply water to the steam generator.

[0028] A control method for a system that dynamically converts contaminated steam into new steam, including the following operating steps: The first step: Softened water is added to the soft water tank through the softened water supply pipe. After adding the softened water, start the makeup water pump to supply water to the steam generator. After the steam generator is filled with water, first introduce contaminated steam into the first-stage evaporation indirect heat exchanger through the contaminated steam supply pipe, and circulate and heat through the steam generator and the evaporation circulation pump. The contaminated steam exchanges heat indirectly in the first-stage evaporation indirect heat exchanger. Since the system water capacity is very small, the low-pressure contaminated steam quickly heats the softened water in the evaporation system into a steam-water mixture. The steam-water mixture enters the steam generator and then undergoes steam-water separation. The separated steam forms new steam, and the new steam can be dynamically supplied to the autoclave or other processes that require clean steam through the new steam discharge pipe. The water then flows into the lower part of the steam generator and is circulated and heated by the evaporation circulation pump to achieve dynamic steam supply. As the softened water continuously evaporates, the water level gradually decreases. When it reaches the lower limit water level, start the makeup water pump to supply water to the steam generator to the control water level.

[0029] The second step: During the heat exchange process of the contaminated steam in the first-stage evaporation indirect heat exchanger, water vapor and odor gases continuously condense into condensed water. Except for part of the air, hydrogen, and odor gases in the contaminated steam that dissolve into the condensed water, most of the air, hydrogen, and odor gases are gradually enriched to form non-condensable gas-enriched contaminated steam with a relatively high concentration. The enriched contaminated steam is continuously transported into the second-stage waste heat exchanger through the regulating valve for adjustment.

[0030] The third step: The softened water then enters the second-stage waste heat exchanger, and through heat exchange, water vapor and odor gases are condensed into supercooled condensed water, and the odor gases also dissolve into the condensed water. After cooling, the condensed water enters the process water tank for process circulation use.

[0031] The fourth step: The softened water that has been reheated in the second-stage waste heat exchanger returns to the soft water tank and is used to supply water to the steam generator through the makeup water pump.

[0032] A control method for a system that dynamically converts contaminated steam into new steam, including the following operating steps: The first step: Softened water is added to the soft water tank through the softened water supply pipe. After adding the softened water, start the makeup water pump to supply water to the steam generator. After the steam generator is filled with water, first introduce contaminated steam into the first-stage evaporation indirect heat exchanger through the contaminated steam supply pipe, and circulate and heat through the steam generator and the evaporation circulation pump. The contaminated steam exchanges heat indirectly in the first-stage evaporation indirect heat exchanger. Since the system water capacity is very small, the low-pressure contaminated steam quickly heats the softened water in the evaporation system into a steam-water mixture. The steam-water mixture enters the steam generator and then undergoes steam-water separation. The separated steam forms new steam, and the new steam can be dynamically supplied to the autoclave or other processes that require clean steam through the new steam discharge pipe. The water flows into the lower part of the steam generator and is circulated and heated by the evaporation circulation pump to achieve dynamic steam supply. As the softened water continuously evaporates, the water level gradually decreases. When it reaches the lower limit water level, start the makeup water pump to supply water to the steam generator to the control water level.

[0033] Step 2: While admitting steam into the primary evaporation indirect heat exchanger, start the heat energy recovery circulation pump and the heat exchange circulation pump. The water vapor and odor gas are continuously condensed into condensate. Besides partial dissolution into the condensate, most of the air, hydrogen, and odor gas in the contaminated steam are gradually enriched, forming an enriched contaminated steam containing a relatively high concentration of non-condensable gas. The enriched contaminated steam is continuously transported into the secondary waste heat direct mixing heat exchanger through regulation by a control valve. The contaminated steam enriched with non-condensable gas can also directly enter the secondary waste heat direct mixing heat exchanger to recover heat energy, or can be directly used in production processes with relatively low requirements for steam quality.

[0034] Step 3: In the secondary waste heat direct mixing heat exchanger, the enriched contaminated steam and water are directly mixed to cool and condense. The water vapor is continuously condensed into water, the water volume continuously increases, and the water level gradually rises. When the water level rises to the drain outlet, the water is discharged into the process water tank through an overflow pipe for recycling and process utilization.

[0035] Step 4: The softened water reheated in the secondary waste heat direct mixing heat exchanger returns to the soft water tank and is replenished into the steam generator through a make-up water pump.

[0036] A control method for a system that dynamically converts contaminated steam into new steam includes the following operating steps: Step 1: Softened water is added to the soft water tank through a softened water supply pipe. After adding the softened water, start the make-up water pump to replenish water into the steam generator. After the steam generator is filled with water, first introduce contaminated steam through a contaminated steam supply pipe into the primary evaporation indirect heat exchanger, and circulate and heat through the steam generator and the evaporation circulation pump. The contaminated steam exchanges heat indirectly in the primary evaporation indirect heat exchanger. Due to the very small water capacity of the system, the low-pressure contaminated steam quickly heats the softened water in the evaporation system into a steam-water mixture. The steam-water mixture enters the steam generator for steam-water separation. The steam after steam-water separation forms new steam, and the new steam can be dynamically supplied to an autoclave or other processes that require clean steam through a new steam discharge pipe. The water flows into the lower part of the steam generator and is circulated and heated by the evaporation circulation pump to achieve dynamic steam supply. As the softened water continuously evaporates, the water level gradually decreases. When it reaches the lower limit water level, start the make-up water pump to replenish water into the steam generator to the control water level.

[0037] Step 2: During the heat exchange process of the contaminated steam in the primary evaporation indirect heat exchanger, water vapor and odor gases are continuously condensed into condensate. In addition to partial dissolution into the condensate, most of the air, hydrogen, and odor gases in the contaminated steam are gradually enriched, forming a non-condensable gas-enriched contaminated steam with a relatively high concentration. The enriched contaminated steam is continuously transported into the secondary waste heat exchanger and the secondary waste heat direct mixing heat exchanger through regulation by a control valve. The contaminated steam enriched with non-condensable gases can also directly enter the secondary waste heat direct mixing heat exchanger to recover heat energy, or can be directly used in production processes with low requirements for steam quality.

[0038] Step 3: When the high-temperature condensate enters the steam inlet of the primary evaporation indirect heat exchanger, the heat energy recovery circulation pump is started. After startup, the condensate with a low temperature is discharged into the process water tank for process circulation use. At the same time, in the secondary waste heat direct mixing heat exchanger, the enriched contaminated steam and water are directly mixed and cooled for condensation. The water vapor is continuously condensed into water, and the water volume continuously increases, and the water level gradually rises. When the water level rises to the drainage outlet, the water is discharged into the process water tank through the overflow pipe for process circulation utilization again.

[0039] Step 4: The softened water heated and raised in temperature after heat exchange through the secondary waste heat exchanger and the secondary waste heat direct mixing heat exchanger returns to the soft water tank as makeup water for the steam generator.

[0040] The present invention can achieve the following effects: The present invention provides a system for dynamically converting contaminated steam into new steam and its control method. Compared with the prior art, it can rapidly remove non-condensable gases and odor gases in the contaminated steam within a short time, quickly and dynamically convert the contaminated steam into new steam, use the new steam to heat and cure other autoclaves, reduce the steam conversion pressure difference, effectively utilize low-pressure contaminated steam, thereby improving production efficiency, improving product quality, fully utilizing the heat energy of low-pressure contaminated steam, reducing or eliminating the emission of low-pressure steam, achieving significant energy conservation, and at the same time reducing environmental pollution.

[0041] The contaminated steam containing non-condensable gases heats softened water through indirect heat exchange to form a steam-water mixture. After the steam-water separation in a steam generator separated from the heat exchanger, new steam is formed. Discharging a small amount of enriched contaminated steam in front of the steam trap in the indirect heat exchange system can improve the heat transfer efficiency, and further recover the heat energy of the discharged enriched contaminated steam with a heat exchanger. The condensate is recycled for process water circulation. It realizes the efficient and dynamic clean utilization of the energy of contaminated steam. Brief Description of the Drawings

[0042] Figure 1 is a schematic structural diagram of the present invention.

[0043] Figure 2 is a schematic structural diagram of the present invention adopting a secondary waste heat exchanger.

[0044] Figure 3 It is a schematic structural diagram of the secondary waste heat direct mixing heat exchanger adopted by the present invention.

[0045] Figure 4 It is a schematic structural diagram of the secondary waste heat exchanger and the secondary waste heat direct mixing heat exchanger adopted by the present invention.

[0046] In the figure: new steam discharge pipe 1, steam generator 2, contaminated steam supply pipe 3, regulating valve 4, waste heat recovery assembly 5, soft water tank 6, soft water supply pipe 7, heat energy recovery circulation pump I 8, make-up water pump 9, primary steam trap 10, primary evaporation indirect heat exchanger 11, evaporation circulation pump 12, secondary waste heat exchanger 13, hydrogen and air discharge pipe 14, secondary steam trap 15, process water tank 16, secondary waste heat direct mixing heat exchanger 17, circulating water heat exchanger 18, heat exchange circulation pump 19, heat energy recovery circulation pump II 20. Specific implementation mode

[0047] The technical solution of the invention will be further specifically described below through embodiments in conjunction with the drawings.

[0048] Embodiment 1: As Figure 1 and Figure 2 shown, a system for dynamically converting contaminated steam into new steam includes a primary evaporation indirect heat exchanger 11. A contaminated steam supply pipe 3 is provided on the primary evaporation indirect heat exchanger 11. A steam generator 2 and a soft water tank 6 which are in pipeline connection with the primary evaporation indirect heat exchanger 11 are arranged on the side of the primary evaporation indirect heat exchanger 11. A make-up water pump 9 which is in pipeline connection is arranged between the middle of the steam generator 2 and the lower end of the soft water tank 6. A soft water supply pipe 7 which is connected to the soft water tank 6 is provided on the upper part of the soft water tank 6. A new steam discharge pipe 1 is provided at the upper end of the steam generator 2. An evaporation circulation pump 12 which is in pipeline connection is arranged between the lower part of the steam generator 2 and the primary evaporation indirect heat exchanger 11. The middle of the steam generator 2 is in pipeline connection with the primary evaporation indirect heat exchanger 11. A regulating valve 4 and a primary steam trap 10 which are in parallel pipeline connection are arranged at the lower part of the primary evaporation indirect heat exchanger 11. The regulating valve 4 is used for regulating drainage or exhaust steam. A waste heat recovery assembly 5 is arranged between the soft water tank 6 and the primary evaporation indirect heat exchanger 11. The upper end of the waste heat recovery assembly 5 is in pipeline connection with the upper end of the soft water tank 6. A regulating valve 4 and a primary steam trap 10 which are in parallel pipeline connection are arranged between the waste heat recovery assembly 5 and the primary evaporation indirect heat exchanger 11. The outlet of the primary steam trap 10 is provided with a process water tank 16.

[0049] The waste heat recovery component 5 includes a secondary waste heat exchanger 13, which is a direct or indirect heat exchanger and is configured in parallel or series according to actual needs. The secondary waste heat exchanger 13 is provided with a hydrogen and air discharge pipe 14. The upper end of the secondary waste heat exchanger 13 is connected to the upper end of the soft water tank 6 through a pipeline. A heat energy recovery circulation pump I 8 is provided between the secondary waste heat exchanger 13 and the soft water tank 6 and between the secondary waste heat exchanger 13 and the makeup water pump 9. A secondary steam trap 15 is provided between the secondary waste heat exchanger 13 and the process water tank 16.

[0050] A control method for a system that dynamically converts contaminated steam into new steam includes the following operating steps: First step: Softened water is added to the soft water tank 6 through the softened water supply pipe 7. After adding the softened water, the makeup water pump 9 is started to supply water to the steam generator 2. After the steam generator 2 is filled with water, contaminated steam is first introduced into the primary evaporation indirect heat exchanger 11 through the contaminated steam supply pipe 3. Through the circulation heating of the steam generator 2 and the evaporation circulation pump 12, the contaminated steam exchanges heat indirectly in the primary evaporation indirect heat exchanger 11. Since the water capacity of the system is very small, the low-pressure contaminated steam quickly heats the softened water in the evaporation system into a steam-water mixture. The steam-water mixture enters the steam generator 2 for steam-water separation. The steam after steam-water separation forms new steam, and the new steam can be dynamically supplied to the autoclave or other processes that require clean steam through the new steam discharge pipe 1. The water then flows into the lower part of the steam generator 2 and is circulated and heated by the evaporation circulation pump 12 to achieve dynamic steam supply. As the softened water continuously evaporates, the water level gradually decreases. When it reaches the lower limit water level, the makeup water pump 9 is started to supply water to the steam generator 2 to the control water level.

[0051] Second step: During the heat exchange process of the contaminated steam in the primary evaporation indirect heat exchanger 11, water vapor and odor gases are continuously condensed into condensed water. Most of the air, hydrogen, and odor gases in the contaminated steam are gradually enriched in addition to some being dissolved in the condensed water, forming an enriched contaminated steam containing a relatively high concentration of non-condensable gases. The enriched contaminated steam is continuously transported into the secondary waste heat indirect heat exchanger 13 through the adjustment of the regulating valve 4.

[0052] Third step: The high-temperature condensed water flowing out of the primary evaporation indirect heat exchanger 11 is discharged to the process water tank 16 through the primary steam trap 10. Since the primary steam trap 10 itself has a certain small ability to discharge non-condensable gases, the condensed water still contains some air, hydrogen, and odor gases; the air, hydrogen, and odor gases in the flash steam and condensed water are collected in the secondary waste heat exchanger 13 through the steam pipeline and exchange heat in the secondary waste heat exchanger 13. The remaining air and hydrogen after the flash steam and odor gases are condensed are discharged through the hydrogen and air discharge pipe 14.

[0053] Fourth step: Start the heat energy recovery circulation pump 8 while the primary evaporation indirect heat exchanger 11 admits steam.

[0054] Step 5: The softened water then enters the secondary waste heat exchanger 13, where through heat exchange, the water vapor and odor gas are condensed into supercooled condensate water, and the odor gas also dissolves in the condensate water. After cooling, the condensate water enters the process water tank 16 for process circulation use.

[0055] Step 6: The softened water reheated in the secondary waste heat exchanger 13 returns to the soft water tank 6, and makeup water pump 9 is used to supply water to the steam generator 2.

[0056] Example 2: As Figure 1 and Figure 3 shown, a system for dynamically converting contaminated steam into new steam includes a primary evaporation indirect heat exchanger 11, on which there is a contaminated steam supply pipe 3. On the side of the primary evaporation indirect heat exchanger 11, there are a steam generator 2 and a soft water tank 6 that are connected by pipelines. Between the middle of the steam generator 2 and the lower end of the soft water tank 6, there is a makeup water pump 9 connected by a pipeline. At the upper part of the soft water tank 6, there is a softened water supply pipe 7 connected to the soft water tank 6. At the upper end of the steam generator 2, there is a new steam discharge pipe 1. Between the lower part of the steam generator 2 and the primary evaporation indirect heat exchanger 11, there is an evaporation circulation pump 12 connected by a pipeline. Between the middle of the steam generator 2 and the primary evaporation indirect heat exchanger 11, there is a pipeline connection. At the lower part of the primary evaporation indirect heat exchanger 11, there are a regulating valve 4 and a primary steam trap 10 connected in a parallel pipeline. The regulating valve 4 is used to regulate drainage or steam exhaust. Between the soft water tank 6 and the primary evaporation indirect heat exchanger 11, there is a waste heat recovery component 5. The upper end of the waste heat recovery component 5 is connected to the upper end of the soft water tank 6 by a pipeline. Between the waste heat recovery component 5 and the primary evaporation indirect heat exchanger 11, there are a regulating valve 4 and a primary steam trap 10 connected in a parallel pipeline. The outlet of the primary steam trap 10 is provided with a process water tank 16 or process equipment.

[0057] The waste heat recovery component 5 includes a secondary waste heat direct mixing heat exchanger 17, which is connected to the process water tank 16 by a pipeline. At the upper end of the secondary waste heat direct mixing heat exchanger 17, there is a hydrogen and air discharge pipe 14. Between the secondary waste heat direct mixing heat exchanger 17 and the soft water tank 6, there is a circulating water heat exchanger 18. Between the lower end of the circulating water heat exchanger 18 and the secondary waste heat direct mixing heat exchanger 17, there is a heat exchange circulation pump 19.

[0058] A control method for a system for dynamically converting contaminated steam into new steam includes the following operating steps: Step 1: Softened water is added to the soft water tank 6 through the softened water supply pipe 7. After adding the softened water, start the make-up water pump 9 to supply water to the steam generator 2. After the steam generator 2 is filled with water, first introduce contaminated steam into the primary evaporation indirect heat exchanger 11 through the contaminated steam supply pipe 3, and circulate and heat through the steam generator 2 and the evaporation circulation pump 12. The contaminated steam exchanges heat indirectly in the primary evaporation indirect heat exchanger 11. Since the system water capacity is very small, the low-pressure contaminated steam quickly heats the softened water in the evaporation system into a steam-water mixture. The steam-water mixture enters the steam generator 2 for steam-water separation. The steam after steam-water separation forms new steam, and the new steam can be dynamically supplied to the autoclave or other processes that require clean steam through the new steam discharge pipe 1. The water then flows into the lower part of the steam generator 2 and is circulated and heated by the evaporation circulation pump 12 to achieve dynamic steam supply. As the softened water continuously evaporates, the water level gradually decreases. When it reaches the lower limit water level, start the make-up water pump 9 to supply water to the steam generator 2 to the control water level.

[0059] Step 2: Start the heat recovery circulation pump 9 and the heat exchange circulation pump 19 while the primary evaporation indirect heat exchanger 11 admits steam. The water vapor and odor gas are continuously condensed into condensate. Except for part of the air, hydrogen, and odor gas dissolved in the condensate, most of the air, hydrogen, and odor gas are gradually enriched to form a non-condensable gas-enriched contaminated steam with a relatively high concentration. The enriched contaminated steam is continuously transported into the secondary waste heat direct mixing heat exchanger 17 through the regulating valve 4 for adjustment.

[0060] Step 3: The high-temperature condensate flowing out of the primary evaporation indirect heat exchanger 11 is discharged to the process water tank 16 through the primary steam trap 10. Since the primary steam trap 10 itself has a certain small function of discharging non-condensable gases, the condensate still contains some air, hydrogen, and odor gas; the air, hydrogen, and odor gas in the flash steam and condensate are collected in the steam pipeline and sent to the secondary waste heat direct mixing heat exchanger 17 for heat exchange. The remaining air and hydrogen after the flash steam and odor gas are condensed are discharged through the hydrogen and air discharge pipe 14.

[0061] Step 4: The heated circulating water enters the circulating water heat exchanger 18 through the hot circulation pump 19. After being cooled, the circulating water enters the secondary waste heat direct mixing heat exchanger 17 to directly mix and recycle with the enriched contaminated steam, and the softened water is reheated and then returned to the soft water tank 6.

[0062] Step 5: In the secondary waste heat direct mixing heat exchanger 17, the enriched contaminated steam and water are directly mixed and cooled and condensed. The water vapor is continuously condensed into water, and the water volume continuously increases, and the water level gradually rises. When the water level rises to the drain outlet, the water flows through the overflow pipe into the process water tank 16 for reuse in the process cycle.

[0063] Step 6: The softened water after the circulating water heat exchanger 18 is heated again returns to the soft water tank 6, and the make-up water pump 9 is used to supply water to the steam generator 2.

[0064] Embodiment 3: As Figure 1 and Figure 4 shown, a system for dynamically converting contaminated steam into new steam includes a primary evaporation indirect heat exchanger 11. A contaminated steam supply pipe 3 is provided on the primary evaporation indirect heat exchanger 11. A steam generator 2 and a soft water tank 6 that are connected to the primary evaporation indirect heat exchanger 11 through pipelines are provided on the side of the primary evaporation indirect heat exchanger 11. A make-up water pump 9 that is connected by a pipeline is provided between the middle of the steam generator 2 and the lower end of the soft water tank 6. A soft water supply pipe 7 that is connected to the soft water tank 6 is provided at the upper part of the soft water tank 6. A new steam discharge pipe 1 is provided at the upper end of the steam generator 2. An evaporation circulation pump 12 that is connected by a pipeline is provided between the lower part of the steam generator 2 and the primary evaporation indirect heat exchanger 11. The middle of the steam generator 2 is connected to the primary evaporation indirect heat exchanger 11 through a pipeline. A regulating valve 4 and a primary steam trap 10 that are connected in a parallel pipeline are provided at the lower part of the primary evaporation indirect heat exchanger 11. The regulating valve 4 is used to regulate drainage or steam exhaust. A waste heat recovery component 5 is provided between the soft water tank 6 and the primary evaporation indirect heat exchanger 11. The upper end of the waste heat recovery component 5 is connected to the upper end of the soft water tank 6 through a pipeline. A regulating valve 4 and a primary steam trap 10 that are connected in a parallel pipeline are provided between the waste heat recovery component 5 and the primary evaporation indirect heat exchanger 11. The outlet of the primary steam trap 10 is provided with a process water tank 16 or process equipment.

[0065] The waste heat recovery component 5 includes a secondary waste heat exchanger 13 and a secondary waste heat direct mixing heat exchanger 17 that are connected in series through pipelines between the regulating valve 4 and the soft water tank 6. The secondary waste heat direct mixing heat exchanger 17 is connected to the process water tank 16 through a pipeline. A heat energy recovery circulation pump I 8 is provided between the secondary waste heat exchanger 13 and the soft water tank 6 and between the secondary waste heat exchanger 13 and the make-up water pump 9. A hydrogen and air discharge pipe 14 is provided at the upper end of the secondary waste heat direct mixing heat exchanger 17. A circulating water heat exchanger 18 is provided between the secondary waste heat direct mixing heat exchanger 17 and the soft water tank 6. A heat energy recovery circulation pump II 20 is provided between the circulating water heat exchanger 18 and the lower end of the soft water tank 6. A heat exchange circulation pump 19 is provided between the circulating water heat exchanger 18 and the lower end of the secondary waste heat direct mixing heat exchanger 17.

[0066] A control method for a system for dynamically converting contaminated steam into new steam includes the following operating steps: Step 1: Softened water is added to the soft water tank 6 through the softened water supply pipe 7. After adding the softened water, the makeup water pump 9 is started to supply water to the steam generator 2. After the steam generator 2 is filled with water, contaminated steam is first introduced into the primary evaporation indirect heat exchanger 11 through the contaminated steam supply pipe 3 and circulated and heated by the steam generator 2 and the evaporation circulation pump 12. The contaminated steam exchanges heat indirectly in the primary evaporation indirect heat exchanger 11. Since the system water capacity is very small, the low-pressure contaminated steam quickly heats the softened water in the evaporation system into a steam-water mixture. The steam-water mixture enters the steam generator 2 for steam-water separation. The separated steam forms new steam, and the new steam can be dynamically supplied to the autoclave or other processes that require clean steam through the new steam discharge pipe 1. The water then flows back to the lower part of the steam generator 2 and is circulated and heated by the evaporation circulation pump 12 to achieve dynamic steam supply. As the softened water continuously evaporates, the water level gradually decreases. When it reaches the lower limit water level, the makeup water pump 9 is started to supply water to the steam generator 2 to the control water level.

[0067] Step 2: During the heat exchange process of the contaminated steam in the primary evaporation indirect heat exchanger 11, water vapor and odor gases are continuously condensed into condensate. Most of the air, hydrogen, and odor gases in the contaminated steam, except for a part dissolved in the condensate, are gradually enriched to form non-condensable gas-enriched contaminated steam with a relatively high concentration. The enriched contaminated steam is continuously transported into the secondary waste heat indirect heat exchanger 13 and the secondary waste heat direct mixing heat exchanger 17 through the regulating valve 4. The remaining air and hydrogen after the flash steam and odor gases are condensed are discharged through the hydrogen and air discharge pipe 14.

[0068] Step 3: In the secondary waste heat direct mixing heat exchanger 17, the circulating water that has been heated enters the circulating water heat exchanger 18 through the hot circulation pump 19 for heat exchange and cooling of the softened water. The cooled circulating water then enters the secondary waste heat direct mixing heat exchanger 17 again to be directly mixed and recycled with the enriched contaminated steam, and the softened water is reheated and then returns to the soft water tank 6.

[0069] Step 4: The heat energy recovery circulation pump 8 is started simultaneously when the steam is introduced into the primary evaporation indirect heat exchanger 11.

[0070] At the same time, in the secondary waste heat direct mixing heat exchanger 17, the enriched contaminated steam and water are directly mixed and cooled and condensed. The water vapor is continuously condensed into water, and the water volume continuously increases, and the water level gradually rises. When the water level rises to the drain outlet, the water is discharged to the process water tank 16 through the overflow pipe for reuse in the process circulation.

[0071] Step 5: The softened water that has been heated after heat exchange in the secondary waste heat indirect heat exchanger 13 and the secondary waste heat direct mixing heat exchanger 19 returns to the soft water tank 6 as the makeup water for the steam generator 2. At the same time, the softened water in the soft water tank 6 is transported to the circulating water heat exchanger 18 for circulating heat exchange through the heat energy recovery circulation pump II 20.

[0072] In summary, the system for dynamically converting contaminated steam into new steam and its control method can rapidly remove non-condensable gases and odor gases in the contaminated steam within a short time, quickly and dynamically convert the contaminated steam into new steam, use the new steam to heat and cure other autoclaves, reduce the steam conversion pressure difference, effectively utilize low-pressure contaminated steam, thereby improving production efficiency, enhancing product quality, fully utilizing the heat energy of low-pressure contaminated steam, reducing or eliminating the emission of low-pressure steam, achieving significant energy conservation, and simultaneously reducing environmental pollution.

[0073] The above are only specific embodiments of the present invention, but the structural features of the present invention are not limited thereto. Any changes or modifications made by those skilled in the art within the scope of the present invention are covered by the patent scope of the present invention.

Claims

1. A system for dynamically converting contaminated steam into new steam, characterized in that: It includes a primary evaporation indirect heat exchanger (11). A contaminated steam supply pipe (3) is provided on the primary evaporation indirect heat exchanger (11). A steam generator (2) and a soft water tank (6) which are in pipeline communication with the primary evaporation indirect heat exchanger (11) are provided on the side of the primary evaporation indirect heat exchanger (11). A makeup water pump (9) in pipeline communication is provided between the middle of the steam generator (2) and the lower end of the soft water tank (6). A soft water supply pipe (7) connected to the soft water tank (6) is provided at the upper part of the soft water tank (6). A new steam discharge pipe (1) is provided at the upper end of the steam generator (2). An evaporation circulation pump (12) in pipeline communication is provided between the lower part of the steam generator (2) and the primary evaporation indirect heat exchanger (11). The middle of the steam generator (2) is in pipeline communication with the primary evaporation indirect heat exchanger (11). A regulating valve (4) and a primary steam trap (10) in parallel pipeline communication are provided at the lower part of the primary evaporation indirect heat exchanger (11). The regulating valve (4) is used to regulate drainage or exhaust steam.

2. The system for dynamically converting contaminated steam into new steam according to claim 1, characterized in that: A waste heat recovery component (5) is provided between the soft water tank (6) and the primary evaporation indirect heat exchanger (11). The upper end of the waste heat recovery component (5) is in pipeline communication with the upper end of the soft water tank (6). A regulating valve (4) and a primary steam trap (10) in parallel pipeline communication are provided between the waste heat recovery component (5) and the primary evaporation indirect heat exchanger (11). A process water tank (16) is provided between the outlets of the primary steam traps (10).

3. The system for dynamically converting contaminated steam into fresh steam according to claim 2, wherein: The waste heat recovery component (5) includes a secondary waste heat exchanger (13). The secondary waste heat exchanger (13) is a direct or indirect heat exchanger, configured in parallel or in series according to actual needs. A hydrogen and air discharge pipe (14) is provided on the secondary waste heat exchanger (13). The upper end of the secondary waste heat exchanger (13) is in pipeline communication with the upper end of the soft water tank (6). A heat energy recovery circulation pump I (8) is provided between the secondary waste heat exchanger (13) and the soft water tank (6) and between the secondary waste heat exchanger (13) and the makeup water pump (9). A secondary steam trap (15) is provided between the secondary waste heat exchanger (13) and the process water tank (16).

4. The system for dynamically converting contaminated steam into new steam according to claim 2, wherein: The waste heat recovery component (5) includes a secondary waste heat direct mixing heat exchanger (17). The secondary waste heat direct mixing heat exchanger (17) is in pipeline communication with the process water tank (16). A hydrogen and air discharge pipe (14) is provided at the upper end of the secondary waste heat direct mixing heat exchanger (17). A circulating water heat exchanger (18) is provided between the secondary waste heat direct mixing heat exchanger (17) and the soft water tank (6). A heat exchange circulation pump (19) is provided between the circulating water heat exchanger (18) and the lower end of the secondary waste heat direct mixing heat exchanger (17).

5. The system for dynamically converting contaminated steam into fresh steam according to claim 2, wherein: The described waste heat recovery component (5) includes a secondary waste heat exchanger (13) and a secondary waste heat direct mixing heat exchanger (17) connected in series in the pipeline between the regulating valve (4) and the soft water tank (6). The secondary waste heat direct mixing heat exchanger (17) is connected to the process water tank (16) through a pipeline. A secondary steam trap (15) is provided between the secondary waste heat exchanger (13) and the process water tank (16). A heat energy recovery circulation pump I (8) is provided between the secondary waste heat exchanger (13) and the soft water tank (6), and between the secondary waste heat exchanger (13) and the make-up water pump (9). A hydrogen and air discharge pipe (14) is provided at the upper end of the secondary waste heat direct mixing heat exchanger (17). A circulating water heat exchanger (18) is provided between the secondary waste heat direct mixing heat exchanger (17) and the soft water tank (6). A heat energy recovery circulation pump II (20) is provided between the circulating water heat exchanger (18) and the lower end of the soft water tank (6). A heat exchange circulation pump (19) is provided between the circulating water heat exchanger (18) and the lower end of the secondary waste heat direct mixing heat exchanger (17).

6. A control method for a system that dynamically converts contaminated steam into new steam according to claim 3 or claim 4 or claim 5, characterized in that: The contaminated steam heats the clean water through indirect heat exchange, and quickly forms a steam-water mixture after heating. At the same time, the steam generation part and the heat exchange system are separated, which reduces the water volume of the heat exchange system. After the water volume is reduced, the contaminated steam quickly heats the clean water into a steam-water mixture through the indirect heat exchanger. After the steam-water mixture is separated into steam and water in the steam generator, new steam is formed. At the same time, the non-condensable gas in the contaminated steam is dynamically discharged in time during the heat exchange process to reduce the thermal resistance, and the steam is allowed to flow and be disturbed. The heat transfer coefficient is increased during the flow of the steam, so the heat transfer efficiency is improved, and thus the contaminated steam is quickly and dynamically converted into new steam.

7. The control method of the system for dynamically converting polluted steam into new steam according to claim 6, characterized in that It includes the following operation steps: The first step: indirect heat exchange between the contaminated steam and the clean water; The second step: steam generation; The third step: discharging the condensed water and the contaminated steam rich in non-condensable gas during the heat exchange process; The fourth step: recovering the heat energy of the discharged contaminated steam rich in non-condensable gas for preheating the make-up water; The fifth step: replenishing water to the steam generator.

8. The control method of the system for dynamically converting contaminated steam into new steam according to claim 7, characterized in that: Softened water is added to the soft water tank (6) through the softened water supply pipe (7). After adding the softened water, the make-up water pump (9) is started to supply water to the steam generator (2). After the steam generator (2) is filled with water, contaminated steam is first introduced into the primary evaporation indirect heat exchanger (11) through the contaminated steam supply pipe (3), and is circulated and heated by the steam generator (2) and the evaporation circulation pump (12). The contaminated steam exchanges heat indirectly in the primary evaporation indirect heat exchanger (11). Since the system water capacity is very small, the low-pressure contaminated steam quickly heats the softened water in the evaporation system into a steam-water mixture. The steam-water mixture enters the steam generator (2) for steam-water separation. The separated steam forms new steam, and the new steam can be dynamically supplied to the autoclave or other processes that require clean steam through the new steam discharge pipe (1). The water then flows back into the lower part of the steam generator (2) and is circulated and heated by the evaporation circulation pump (12) to achieve dynamic steam supply. As the softened water continuously evaporates, the water level gradually decreases. When it reaches the lower limit water level, the make-up water pump (9) is started to supply water to the steam generator (2) to the control water level; during the heat exchange process of the contaminated steam in the primary evaporation indirect heat exchanger (11), water vapor and odor gases continuously condense into condensate. Most of the air, hydrogen, and odor gases in the contaminated steam are gradually enriched except for some dissolved in the condensate, forming an enriched contaminated steam containing a relatively high concentration of non-condensable gases. The enriched contaminated steam is continuously transported into the waste heat recovery module (5) through the regulation of the regulating valve (4); the high-temperature condensate flowing out of the primary evaporation indirect heat exchanger (11) is discharged to the process water tank (16) through the primary steam trap (10). Since the primary steam trap (10) itself has a certain small ability to discharge non-condensable gases, the condensate still contains some air, hydrogen, and odor gases; the softened water reheated in the waste heat recovery module (5) returns to the soft water tank (6) and is supplied to the steam generator (2) through the make-up water pump (9).

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