Multi-effect evaporation process waste heat staged recovery upgrading utilization system and method

Abstract

This invention relates to the field of environmental protection and energy-saving technology, and discloses a multi-effect evaporation process waste heat graded recovery and quality improvement system and method. The two-stage spray condenser is divided into two series-connected cooling chambers, with corresponding primary and secondary outlets at different temperatures. The primary outlet is connected to the primary heat pump unit, and the secondary outlet is connected to the secondary heat pump unit. The heat pump units produce hot water at different temperatures. The exhaust gas from the two-stage spray condenser enters the steam-water separator through the condenser's exhaust outlet for steam-water separation, and then enters the condenser. The exhaust gas is further condensed in the condenser and then the non-condensable gases are discharged by a vacuum pump. The cooling water for the condenser comes from the tertiary heat pump unit. The tertiary heat pump unit uses part of the heat source water drainage from the secondary heat pump unit as its heat source water. The heat source water drainage is further cooled by recovering heat and then used as the cooling water for the condenser, and finally discharged through the condenser, maintaining the water balance of the entire system.

Description

Technical Field

[0001] This invention relates to the field of environmental protection and energy conservation technology, specifically to a system and method for the graded recovery and upgrading of low-temperature waste heat. Background Technology

[0002] Currently, existing multi-effect evaporation processes all discharge the final low-temperature gas into the atmosphere through circulating cooling water in the last stage. Some processes contain certain pollutants in the exhaust steam, which needs to be condensed and treated according to the nature of the pollutants. According to existing multi-effect evaporation technologies, the exhaust steam in the last stage is around 70°C. Since the discharged steam is under negative pressure, the water vapor contains a large amount of latent heat of vaporization. In order to achieve circulating cooling, a large amount of cooling water and cooling towers are required. Therefore, the energy consumption of multi-effect evaporation processes is huge, consuming a large amount of high-grade steam as well as a large amount of cooling water.

[0003] Waste heat recovery from gases such as exhaust steam typically employs indirect heat exchange or spray heat exchange, using cooling water to recover and utilize the heat contained in the gas. For gases with low temperatures, the cooling water temperature is too low to be usable after using indirect heat exchange or spray heat exchange. A common solution is to use heat pump technology to raise the cooling water temperature. However, due to limitations of heat pump technology, the temperature increase is limited, and the greater the increase, the lower the COP (Coefficient of Performance) of the heat pump, resulting in poorer economics. For indirect heat exchange, the required temperature difference between the hot and cold media makes it difficult to raise the cooling water temperature. Furthermore, when the gas flow rate is large, the volume of the indirect heat exchanger also increases, leading to higher costs. For spray heat exchange, the heat exchange efficiency is greatly improved due to the direct contact between the hot and cold media, and the cost is lower. However, the obtained cooling water temperature is usually much lower than the gas outlet temperature, resulting in low cooling water temperature. Even after using heat pump technology to raise the temperature, it is difficult to reach a high level. To obtain a higher cooling water temperature, the heat pump efficiency is relatively low, meaning higher energy consumption. Moreover, for multi-effect evaporation processes, in addition to recovering waste heat, another important consideration is maintaining a good and stable vacuum throughout the system. As the weather changes, the temperature of the cooling water will also change. For conventional indirect heat exchangers or spray heat exchangers, the change in water temperature will also affect the vacuum of the system. Therefore, for the waste heat recovery system of multi-effect evaporation process, how to maximize the temperature of the cooling water while maintaining the high energy efficiency ratio of the heat pump and maintaining a good and stable vacuum of the multi-effect evaporation process is a new challenge for existing technologies. Summary of the Invention

[0004] In order to recover and utilize more of the heat from the negative pressure steam emitted by multi-effect evaporation and achieve energy saving, water saving and consumption reduction, the present invention aims to provide a multi-effect evaporation process waste heat graded recovery and quality improvement system to solve the problems mentioned in the background technology, such as high energy consumption, water waste, low temperature of waste heat recovery cooling water and low quality of recovered heat energy in domestic and foreign multi-effect evaporation processes.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] In a first aspect, the present invention proposes a multi-effect evaporation process waste heat graded recovery and quality improvement system, including a two-stage spray condenser, a steam-water separator, a condenser, a vacuum unit, a primary circulating cooling water pump, a secondary circulating cooling water pump, a drain pump, a primary heat pump unit, and a secondary heat pump unit.

[0007] The primary water storage tank of the two-stage spray condenser is connected to the inlet of the heat source water of the primary heat pump unit. The outlet of the heat source water of the primary heat pump unit is connected to the primary circulating cooling water pump, which is connected to the inlet of the primary spray cooling water of the two-stage spray condenser. The secondary water storage tank of the two-stage spray condenser is connected to the inlet of the heat source water of the secondary heat pump unit. The outlet of the heat source water of the secondary heat pump unit is connected to the secondary circulating cooling water pump, which is connected to the inlet of the secondary spray cooling water of the two-stage spray condenser. The outlet of the heat pump unit is connected to a steam-water separator, the outlet of which is connected to a condenser, and the outlet of the condenser is connected to a vacuum unit. The outlet pipe of the heat source water of the secondary heat pump unit is connected to the inlet of the heat source water of the tertiary heat pump unit via a drain pump. The outlet of the heat source water of the tertiary heat pump unit is connected to the condenser, serving as cooling water for further condensing the steam discharged from the steam-water separator in the condenser. This cooling water is also discharged from the system after passing through the condenser. The outlet of the steam-water separator is connected to the outlet of the heat source water of the secondary heat pump unit.

[0008] Secondly, the present invention also provides a working method for a multi-effect evaporation process waste heat graded recovery and upgrading system, as follows:

[0009] Exhaust steam from the end of the multi-effect evaporation process enters a two-stage spray condenser, where it undergoes spray condensation. The condensate and spray water from the first-stage condensation zone fall into the lower first-stage water storage tank, while the condensate and spray water from the second-stage condensation zone fall into the lower second-stage water storage tank. Uncondensed exhaust steam, other non-condensable gases, and fine water droplets discharged from the two-stage spray condenser enter a steam-water separator. After passing through the separator, the water droplets are separated and enter the outlet pipe of the heat source water for the second-stage heat pump unit. The uncondensed exhaust steam and other non-condensable gases then enter the condenser, where the uncondensed exhaust steam is further condensed by cooling water from the heat source water outlet of the third-stage heat pump unit. The remaining small amount of exhaust steam and non-condensable gases are discharged into the atmosphere through a vacuum unit.

[0010] In the two-stage spray condenser, the spray water in the first-stage condensing zone comes from the heat source water outlet of the first-stage heat pump unit. This spray water, along with the condensate from the condensed exhaust steam, falls into the first-stage water storage tank. The water in the first-stage water storage tank serves as the heat source water for the first-stage heat pump unit. The water enters the first-stage heat pump unit through the outlet of the first-stage water storage tank. After the heat pump unit absorbs heat, the temperature of this hot water decreases, and it is then pumped back into the first-stage condensing zone of the two-stage spray condenser through the inlet of the first-stage spray water pump, completing the circulation process of the first-stage circulating cooling water. Similarly, the uncondensed exhaust steam from the first-stage spraying process enters the second-stage condensing zone through a series guide channel. The spray water in the second-stage condensing zone comes from the heat source water outlet of the second-stage heat pump unit. This spray water, along with the condensate from the condensed exhaust steam, flows into the second-stage condensing zone. The water falls into the secondary storage tank, which serves as the heat source for the secondary heat pump unit. The water enters the secondary heat pump unit through the outlet of the secondary storage tank. After the heat pump unit absorbs heat, the temperature decreases, and the water is then pumped back through the secondary circulating cooling water pump to the secondary condensing zone of the two-stage spray condenser, completing the secondary circulating cooling water cycle. As the exhaust steam condenses, the amount of condensate in the system increases. A drain pipe is connected to the outlet pipe of the heat source water in the secondary heat pump unit, and the water added by the exhaust steam condensation is pumped into the tertiary heat pump unit. The heat of this water is recovered by the tertiary heat pump unit, reducing its temperature. It then serves as cooling water for the condenser to cool the exhaust steam and is eventually discharged.

[0011] After recovering the heat from the cooling circulating water, the primary, secondary, and tertiary heat pump units heat and improve the quality of the hot water before supplying it to the production process.

[0012] The beneficial effects of this invention are as follows:

[0013] The multi-effect evaporation process waste heat graded recovery and quality improvement system proposed in this invention divides waste heat into three stages for recovery, which not only improves the quality of the recovered heat energy, but also reduces the energy consumption of the heat pump unit. While reducing the waste of cooling water resources, it maintains a good vacuum degree in the multi-effect evaporation process system. The invention's two-stage spray condenser consists of two series-connected cooling chambers, one primary and one secondary, with corresponding outlets at different temperatures. The primary outlet connects to the primary heat pump unit, and the secondary outlet connects to the secondary heat pump unit. The primary and secondary heat pump units produce hot water at different temperatures, allowing for temperature-stage heat recovery within their most economical operating range by utilizing the heat pump units' temperature rise characteristics, thus reducing energy consumption. The exhaust steam from the two-stage spray condenser is separated into steam and water by a steam-water separator before entering the condenser. Further condensation of the exhaust steam in the condenser is followed by the removal of non-condensable gases via a vacuum pump. The condenser's cooling water comes from a three-stage heat pump unit. The tertiary heat pump unit utilizes a portion of the secondary heat pump unit's wastewater as its heat source. The tertiary heat pump unit further recovers heat from excess water in the entire condensation system, lowering its temperature before discharging it as cooling water for the condenser. This maintains the system's water balance, reduces the operating load of the vacuum unit, lowers the vacuum pump's power consumption, stabilizes its operation, and improves the overall operational stability of the cooling and waste heat recovery system.

[0014] The waste heat recovery and quality improvement system for multi-effect evaporation process proposed in this invention can recover the waste heat in the multi-effect evaporation process to the maximum extent. Through the graded recovery of waste heat, the energy is utilized in stages, which improves the quality of the recovered heat energy and reduces the energy consumption of the heat pump unit. At the same time, the system eliminates the cooling tower at the end of the multi-effect evaporation process, which reduces the waste of cooling water resources and maintains a good vacuum degree in the multi-effect evaporation process system. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a schematic diagram of the system of the present invention.

[0017] Explanation of reference numerals in the attached diagram: 1. Two-stage spray condenser; 2. Steam-water separator; 3. Condenser; 4. Vacuum unit; 5. Primary circulating cooling water pump; 6. Secondary circulating cooling water pump; 7. Drain pump; 8. Primary heat pump unit; 9. Secondary heat pump unit; 10. Tertiary heat pump unit; 11. Primary condensing zone; 12. Series flow guide channel; 13. Primary water storage tank; 14. Secondary water storage tank; 15. Secondary condensing zone. Detailed Implementation

[0018] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] It should be noted that the structures, proportions, sizes, etc., shown in the accompanying drawings of this specification are only for the purpose of assisting those skilled in the art in understanding and reading the content disclosed in the specification, and are not intended to limit the conditions under which this application can be implemented. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in the proportions, or adjustments to the size should still fall within the scope of the technical content disclosed in this application, provided that they do not affect the effects and purposes that this application can produce.

[0020] like Figure 1 As shown in the figure, this embodiment discloses a multi-effect evaporation process waste heat staged recovery and quality improvement system, including a two-stage spray condenser 1, a steam-water separator 2, a condenser 3, a vacuum unit 4, a primary circulating cooling water pump 5, a secondary circulating cooling water pump 6, a drain pump 7, a primary heat pump unit 8, and a secondary heat pump unit 9. This system can recover waste heat from the multi-effect evaporation process to the maximum extent. Through staged recovery of waste heat, it achieves cascaded energy utilization, improving the quality of the recovered heat energy while reducing the energy consumption of the heat pump unit. Simultaneously, this system eliminates the cooling tower at the end of the multi-effect evaporation process, reducing the waste of cooling water resources. The connection relationships of the various devices in this system are as follows:

[0021] The two-stage spray condenser 1 is divided into two stages, namely a primary condensing zone 11 and a secondary condensing zone 15. The primary condensing zone 11 and the secondary condensing zone 15 are connected in series by an internal series guide channel 12 to form a two-stage spray. Below the primary condensing zone 11 is a primary water storage tank 13, and below the secondary condensing zone 15 is a secondary water storage tank 14. That is, the condensate and spray water of the primary spray zone 11 fall into the lower primary water storage tank 13, while the condensate and spray water of the secondary spray zone 15 fall into the lower secondary water storage tank 14.

[0022] Furthermore, the primary water storage tank 13 of the two-stage spray condenser 1 is connected to the inlet of the heat source water of the primary heat pump unit 8 via a pipe, and the outlet of the heat source water of the primary heat pump unit 8 is connected to the primary circulating cooling water pump 5. The primary circulating cooling water pump 5 is connected to the inlet of the spray cooling water of the primary condensing zone 11 of the two-stage spray condenser 1. Similarly, the secondary water storage tank 14 of the two-stage spray condenser 1 is connected to the inlet of the heat source water of the secondary heat pump unit 9 via a pipe, and the outlet of the heat source water of the secondary heat pump unit 9 is connected to the secondary circulating cooling water pump 6. The secondary circulating cooling water pump 6 is connected to the inlet of the secondary spray cooling water of the secondary condensing zone 15 of the two-stage spray condenser 1.

[0023] The outlet of the second stage of the two-stage spray condenser 1 is connected to a steam-water separator 2. The outlet of the steam-water separator 2 is connected to a condenser 3 through a pipe. The outlet of the condenser 3 is connected to a vacuum unit 4 through a pipe.

[0024] The outlet pipe of the heat source water of the secondary heat pump unit 9 is connected to the inlet of the heat source water of the tertiary heat pump unit 10 through the drain pump 7. The drain end of the heat source water of the tertiary heat pump unit 10 is connected to the condenser 3. The cooling water of the condenser further condenses the steam discharged from the steam-water separator in the condenser. At the same time, this part of the cooling water is discharged outside the system after passing through the condenser, so as to maintain the water balance problem caused by steam condensation in the entire system.

[0025] The drain end of the steam-water separator 2 is connected to the outlet end of the heat source water of the secondary heat pump unit 9.

[0026] As a further preferred embodiment of this technical solution: since higher temperature waste heat has a wider range of applications, the dual-stage spray condenser 1 is internally divided into two stages in series, namely a primary condensation zone and a secondary condensation zone. The cooling temperature and drainage temperature of the two stages are different, so the temperature graded improvement of heat recovery can be completed in its most economical operating range by utilizing the temperature rise characteristics of the heat pump unit.

[0027] The multi-effect evaporation process waste heat graded recovery and quality improvement system proposed in this embodiment divides waste heat into three levels of recovery, which not only improves the quality of the recovered heat energy, but also reduces the energy consumption of the heat pump unit, and at the same time reduces the problem of waste of cooling water resources. This embodiment of the two-stage spray condenser consists of two series-connected cooling chambers, one primary and one secondary, with two outlet water terminals at different temperatures. The primary outlet water terminal connects to the primary heat pump unit, and the secondary outlet water terminal connects to the secondary heat pump unit. The primary and secondary heat pump units produce hot water at different temperatures, thus utilizing the temperature rise characteristics of the heat pump units to achieve temperature-stage heat recovery within their most economical operating range, reducing the energy consumption of the heat pump. The exhaust steam from the two-stage spray condenser is separated into steam and water by a steam-water separator before entering the condenser. The exhaust steam is further condensed in the condenser and then discharged as non-condensable gas by a vacuum pump. The cooling water for the condenser comes from a three-stage heat pump unit. The three-stage heat pump unit uses part of the heat source water from the secondary heat pump unit as its heat source water. The three-stage heat pump unit further recovers heat from the excess water in the entire condensation system, lowers its temperature, and discharges it as cooling water for the condenser, maintaining the system's water balance. At the same time, it reduces the operating load of the vacuum unit, lowers the power consumption of the vacuum pump, stabilizes its operating conditions, and improves the operational stability of the entire cooling and waste heat recovery system.

[0028] As a further preferred embodiment of this technical solution: the drainage pump 7 delivers the system's drainage to the three-stage heat pump unit 10 as its heat source water, and the three-stage heat pump unit 10 further recovers and cools the drainage water before using it as cooling water for the condenser 3.

[0029] As a further preferred embodiment of this technical solution: the two-stage spray condenser 1 is not limited to two stages, but can also be single-stage or triple-stage, etc. When only one stage is set, the entire system removes the aforementioned single-stage heat pump unit 8 and single-stage circulating cooling water pump 5; everything else remains unchanged. When three stages are set, a triple-stage heat pump unit and a triple-stage circulating cooling water pump are added to the above system. The connection method between the triple-stage heat pump unit, the triple-stage circulating cooling water pump and the two-stage spray condenser 1 is the same as that between the single-stage heat pump unit 8 and the single-stage circulating cooling water pump 5, and everything else remains unchanged.

[0030] As a further preferred embodiment of this technical solution, the two-stage spray condenser 1 is not limited to a mixing heat exchanger, but can also be a surface heat exchanger for heat absorption of the evaporating gas.

[0031] As a further preferred embodiment of this technical solution, the heat pump unit in this embodiment is not limited to a compression unit, but can also be an absorption heat pump unit, etc.

[0032] Based on the above system, the working method of the multi-effect evaporation process waste heat graded recovery and upgrading utilization system proposed in this invention is as follows:

[0033] Exhaust steam from the end of the multi-effect evaporation process enters a two-stage spray condenser 1, where it undergoes spray condensation. The two-stage spray condenser 1 consists of two stages: a primary condensation zone 11 and a secondary condensation zone 15, connected in series by an internal series guide channel 12. The condensate and spray water from the primary condensation zone 11 fall into the lower primary water storage tank 13, while the condensate and spray water from the secondary condensation zone 15 fall into the lower secondary water storage tank 14. The uncondensed exhaust steam, other non-condensable gases, and fine water droplets discharged from the condenser 1 enter the steam-water separator 2. After passing through the steam-water separator 2, the water droplets are separated and enter the outlet pipe of the heat source water of the secondary heat pump unit. The uncondensed exhaust steam and other non-condensable gases enter the condenser 3. The uncondensed exhaust steam is further condensed in the condenser by the cooling water from the heat source water outlet of the tertiary heat pump unit. The remaining small amount of exhaust steam and non-condensable gases are discharged into the atmosphere through the vacuum unit 4. In the two-stage spray condenser 1, the spray water in the first-stage condensing zone 11 comes from the heat source water outlet of the first-stage heat pump unit 8. This spray water, together with the condensate after the exhaust steam is condensed, falls into the first-stage water storage tank 13. The water in the first-stage water storage tank serves as the heat source water for the first-stage heat pump unit 8. It enters the first-stage heat pump unit 8 through the outlet of the first-stage water storage tank. After the hot water absorbs heat from the heat pump unit, its temperature decreases. Then, through the first-stage circulating cooling water pump 5, it enters the first-stage condensing zone in the two-stage spray condenser 1 again through the inlet of the first-stage spray water, completing the circulation process of the first-stage circulating cooling water. Similarly, the uncondensed residual exhaust steam during the primary spraying process enters the secondary condensing zone 15 through the series guide channel 11. The spray water in the secondary condensing zone 15 comes from the heat source water outlet of the secondary heat pump unit 9. This spray water, together with the condensate after the exhaust steam condenses, falls into the secondary water storage tank 14. The water in the secondary water storage tank serves as the heat source water for the secondary heat pump unit 9. It enters the secondary heat pump unit 9 through the outlet of the secondary water storage tank. After the hot water absorbs heat from the heat pump unit, its temperature decreases. Then, through the secondary circulating cooling water pump 6, it enters the secondary condensing zone in the two-stage spray condenser 1 again through the inlet of the secondary spray water, completing the circulation process of the secondary circulating cooling water. As the exhaust steam condenses, the amount of condensate in the system increases. Therefore, a drain pipe is connected to the outlet pipe of the heat source water of the secondary heat pump unit. The water added from the exhaust steam condensation is discharged into the tertiary heat pump unit 10 via drain pump 7. The heat of this water is recovered by the tertiary heat pump unit 10, and its temperature decreases. It is then used as cooling water for the condenser 3 to cool the exhaust steam in the condenser 3 and is eventually discharged. After recovering the heat from the cooling circulating water, the primary, secondary, and tertiary heat pump units heat and upgrade the hot water before supplying it to the production process.

[0034] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A multi-effect evaporation process waste heat graded recovery and upgrading system, characterized in that, It includes a two-stage spray condenser, a steam-water separator, a condenser, a vacuum unit, a primary circulating cooling water pump, a secondary circulating cooling water pump, a drain pump, a primary heat pump unit, and a secondary heat pump unit; The first-stage water storage tank of the dual-stage spray condenser is connected to the inlet of the heat source water of the first-stage heat pump unit, the outlet of the heat source water of the first-stage heat pump unit is connected to the first-stage circulating cooling water pump, and the first-stage circulating cooling water pump is connected to the inlet of the first-stage spray cooling water of the dual-stage spray condenser. The secondary water storage tank of the two-stage spray condenser is connected to the inlet of the heat source water of the secondary heat pump unit. The outlet of the heat source water of the secondary heat pump unit is connected to the secondary circulating cooling water pump, which is connected to the inlet of the secondary spray cooling water of the two-stage spray condenser. The outlet of the two-stage spray condenser is connected to a steam-water separator, the outlet of the steam-water separator is connected to a condenser, and the outlet of the condenser is connected to a vacuum unit. The outlet pipe of the heat source water of the secondary heat pump unit is connected to the inlet of the heat source water of the tertiary heat pump unit via a drain pump. The drain pipe of the heat source water of the tertiary heat pump unit is connected to the condenser, serving as cooling water for further condensing the steam discharged from the steam-water separator in the condenser. This cooling water is then discharged from the system after passing through the condenser. The drain pipe of the steam-water separator is connected to the outlet pipe of the heat source water of the secondary heat pump unit.

2. The multi-effect evaporation process waste heat graded recovery and upgrading system as described in claim 1, characterized in that, The dual-stage spray condenser is internally divided into a primary condensation zone and a secondary condensation zone connected in series, with different cooling temperatures and drainage temperatures in the primary and secondary condensation zones.

3. The multi-effect evaporation process waste heat graded recovery and upgrading system as described in claim 2, characterized in that, The outlet of the two-stage spray condenser is located at the top of the secondary condensation zone.

4. The multi-effect evaporation process waste heat graded recovery and upgrading system as described in claim 2, characterized in that, The primary water storage tank is located at the bottom of the primary condensation zone; the secondary water storage tank is located at the bottom of the secondary condensation zone.

5. The multi-effect evaporation process waste heat graded recovery and upgrading system as described in claim 1, characterized in that, The drainage pump delivers the system's drainage to the tertiary heat pump unit as its heat source water. The tertiary heat pump unit further recovers the heat from the drainage and cools it down before using it as cooling water for the condenser.

6. The multi-effect evaporation process waste heat graded recovery and upgrading system as described in claim 1, characterized in that, The two-stage spray condenser can also be replaced with a three-stage spray condenser.

7. The multi-effect evaporation process waste heat graded recovery and upgrading system as described in claim 1, characterized in that, The two-stage spray condenser is a mixing heat exchanger or a surface heat exchanger.

8. The multi-effect evaporation process waste heat graded recovery and upgrading system as described in claim 1, characterized in that, The heat pump unit is either a compression heat pump unit or an absorption heat pump unit.

9. The method for utilizing the waste heat recovery and upgrading system of the multi-effect evaporation process as described in any one of claims 1-8, characterized in that, as follows: Exhaust steam from the end of the multi-effect evaporation process enters a two-stage spray condenser, where it undergoes spray condensation. The condensate and spray cooling water from the first-stage condensation zone fall into the lower first-stage water storage tank, while the condensate and spray cooling water from the second-stage condensation zone fall into the lower second-stage water storage tank. Uncondensed exhaust steam, other non-condensable gases, and fine water droplets discharged from the two-stage spray condenser enter a steam-water separator. After passing through the separator, the water droplets are separated and enter the outlet pipe of the heat source water for the second-stage heat pump unit. The uncondensed exhaust steam and other non-condensable gases then enter the condenser, where the uncondensed exhaust steam is further condensed by cooling water from the heat source water outlet of the third-stage heat pump unit. The remaining small amount of exhaust steam and non-condensable gases are discharged into the atmosphere through a vacuum unit. In the two-stage spray condenser, the spray cooling water in the first-stage condensing zone comes from the heat source water outlet of the first-stage heat pump unit. This spray cooling water, along with the condensate from the condensed exhaust steam, falls into the first-stage water storage tank. The water in the first-stage water storage tank serves as the heat source water for the first-stage heat pump unit. The water enters the first-stage heat pump unit through the outlet of the first-stage water storage tank. After the heat source water of the first-stage heat pump unit absorbs heat, its temperature decreases, and it is then pumped back into the first-stage condensing zone of the two-stage spray condenser through the inlet of the first-stage spray cooling water pump, completing the circulation process of the first-stage circulating cooling water. Similarly, the uncondensed exhaust steam from the first-stage spraying process enters the second-stage condensing zone through a series guide channel. The spray cooling water in the second-stage condensing zone comes from the heat source water outlet of the second-stage heat pump unit. This spray cooling water, along with the condensate from the condensed exhaust steam... The water flows into the secondary storage tank, which serves as the heat source for the secondary heat pump unit. The water enters the unit through the outlet of the secondary storage tank. After absorbing heat, the water's temperature decreases, and it is then pumped back through the secondary circulating cooling water pump to the secondary condensing zone of the two-stage spray cooling water condenser, completing the secondary circulating cooling water cycle. As the exhaust steam condenses, the condensate volume in the system increases. A drain pipe is connected to the outlet of the secondary heat pump unit's heat source water to pump the increased condensate volume into the tertiary heat pump unit. The heat from the water pumped into the tertiary heat pump unit is recovered by the tertiary heat pump unit, reducing its temperature. This water then serves as cooling water for the condenser, cooling the exhaust steam, and is eventually discharged. After recovering the heat from the cooling circulating water, the primary, secondary, and tertiary heat pump units heat and improve the quality of the hot water before supplying it to the production process.

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