High-temperature condensate water recycling device

Abstract

The utility model discloses a high temperature condensate water recycling device, including flash tank and liquid inlet, the outside of flash tank is provided with vacuum phase change heat transfer device and organic rankine cycle generator, and the heat source export is connected with the liquid storage tank, and the condensate water export of organic rankine cycle generator is linked with the cold source import of vacuum phase change heat transfer device, and the bottom of flash tank is linked with the liquid storage tank through the liquid discharge pipe, and the liquid storage tank is connected with the preheater, and the outlet of preheater is connected with the water supply tank, and the water outlet of water supply tank is linked with the cold water import of preheater, and the hot water export of preheater is connected with deaerator and steam boiler in proper order, and the steam export of steam boiler is connected with steam heat exchange equipment, and the condensate water export of steam heat exchange equipment is linked with flash tank. Above all, the utility model has the advantages of high heat utilization rate, good recycling effect and less heat energy waste.

Description

Technical Field

[0001] This utility model relates to the field of high-temperature condensate recycling technology, specifically to a high-temperature condensate recycling and reuse device. Background Technology

[0002] Steam, as a clean and safe energy carrier, is widely used in various industries. After releasing its latent heat of vaporization in various steam-using equipment, steam will form saturated condensate at almost the same temperature and pressure. The heat contained in condensate can reach 20% to 30% of the total heat of steam. If it is discharged directly, it will not only pollute the environment, but also cause serious waste of water resources and energy.

[0003] In existing coking plants, due to the large amount of waste heat in the system and the lack of low-grade heat users, high-temperature condensate cannot be directly utilized and requires additional external cooling water treatment. Currently, the recycling process of high-temperature condensate mostly involves cooling it with circulating water before sending it back to users for recycling, thus achieving heat energy recovery. However, in this process, when cooling the high-temperature condensate to a suitable temperature for recycling, a large amount of heat energy from the condensate is often wasted, and a large amount of circulating cooling water is consumed, which is both uneconomical and wasteful. Therefore, it is objectively necessary to develop a high-temperature condensate recycling device with high heat utilization rate, good recycling effect, and low heat energy waste. Utility Model Content

[0004] The purpose of this invention is to provide a high-temperature condensate recycling and reuse device with high heat utilization rate, good recycling effect, and low heat energy waste.

[0005] The purpose of this utility model is achieved as follows: It includes a flash tank and a liquid inlet. A vacuum phase change heat exchanger and an organic Rankine cycle generator are installed on the outside of the flash tank. The heat source inlet of the vacuum phase change heat exchanger is connected to the top of the flash tank via a steam pipe, and the heat source outlet is connected to a storage tank. The cold source outlet of the vacuum phase change heat exchanger is connected to the steam inlet of the organic Rankine cycle generator, and the condensate outlet of the organic Rankine cycle generator is connected to the cold source inlet of the vacuum phase change heat exchanger. The bottom of the flash tank is connected to the storage tank via a drain pipe. The liquid outlet of the storage tank is connected to a preheater, and the liquid outlet of the preheater is connected to a water supply tank. The water outlet of the water supply tank is connected to the cold water inlet of the preheater. The hot water outlet of the preheater is sequentially connected to a deaerator and a steam boiler. The steam outlet of the steam boiler is connected to a steam heat exchanger, and the condensate outlet of the steam heat exchanger is connected to the flash tank.

[0006] Furthermore, a steam distribution pipe is installed on the steam pipe, and the end of the steam distribution pipe is connected to the steam inlet of the deaerator.

[0007] Furthermore, a heat accumulator and a steam-water separator are sequentially installed on the steam pipe along the steam flow direction. The steam outlet of the steam-water separator is connected to the heat source inlet of the vacuum phase change heat exchanger, and the liquid outlet of the steam-water separator is connected to the liquid storage tank.

[0008] Furthermore, agitators are installed inside the water replenishment tank and the storage tank.

[0009] Furthermore, an impurity filter is installed on the drain pipe.

[0010] Furthermore, a remote liquid level sensor is installed at the top of the flash tank, and temperature sensors are installed on both the steam pipe and the drain pipe.

[0011] In operation, high-temperature condensate is fed into a flash tank for flash evaporation, generating a large amount of low-pressure steam. This low-pressure steam serves as the heat source for a vacuum phase-change heat exchanger. The steam cools and condenses into condensate, which flows into a storage tank. The cooled water in the vacuum phase-change heat exchanger then enters an organic Rankine cycle generator to exchange heat with the working fluid inside the generator. The working fluid temperature rises, generating electricity. Simultaneously, the remaining condensate in the flash tank also flows into the storage tank. The condensate from the steam condensation and the condensate discharged from the flash tank are mixed in the storage tank and then sent to a preheater to preheat the boiler feedwater. After cooling, the preheated water is sent to a feedwater tank to mix with fresh boiler feedwater. It is then fed back into the preheater to raise the temperature. After deoxygenation by a deaerator, the preheated water is fed into a steam boiler to produce steam. The steam is then sent to a steam heat exchanger, where it condenses into high-temperature condensate, which is then sent back to the flash tank, completing the cycle of steam and water resources. In this invention, high-temperature condensate is flash-evaporated in a flash tank, separating it into low-pressure steam and remaining condensate. The heat from the low-pressure steam is used to generate electricity in an organic Rankine cycle generator, achieving the first stage of heat recovery. Then, the condensate from the steam condensation and the condensate discharged from the flash tank are fed into a preheater, where the heat from the condensate and condensate is used to preheat the boiler feedwater, increasing its temperature, achieving the second stage of heat recovery. Finally, the cooled hot water is fed into a feedwater tank, mixing with the fresh boiler feedwater there. This reduces the amount of fresh boiler feedwater needed and increases its temperature, achieving the third stage of heat recovery. In summary, this invention utilizes the heat in high-temperature condensate in three stages: the first stage is used for power generation, and the second and third stages are used for preheating boiler feedwater. This improves heat utilization efficiency, minimizes heat waste, and reduces energy consumption in steam boilers, demonstrating good energy recovery and utilization effects. Furthermore, while fully recovering and utilizing the heat in the high-temperature condensate, it also recycles the condensate, eliminating the need for cooling water mixing and reducing the consumption of large amounts of circulating cooling water. This multi-stage energy utilization improves water resource utilization efficiency, reduces water consumption and usage costs, and enhances the economic benefits for enterprises. In conclusion, this invention has the advantages of high heat utilization efficiency, good energy recovery and utilization effect, and minimal heat waste. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the overall structure of this utility model; In the diagram: 1-Flash tank, 2-Vacuum phase change heat exchanger, 3-Organic Rankine cycle generator, 4-Steam pipe, 5-Storage tank, 6-Drain pipe, 7-Make-up water tank, 8-Deaerator, 9-Steam boiler, 10-Steam heat exchange equipment, 11-Steam distribution pipe, 12-Accumulator, 13-Steam-water separator, 14-Agitator, 15-Impurity filter, 16-Remote liquid level sensor, 17-Temperature sensor, 18-Preheater. Detailed Implementation

[0013] The present invention will be further described below with reference to the accompanying drawings, but this description is not intended to limit the present invention in any way. Any changes or improvements made based on the present invention shall fall within the protection scope of the present invention.

[0014] like Figure 1 As shown, this utility model includes a flash tank 1 and a liquid inlet. A vacuum phase change heat exchanger 2 and an organic Rankine cycle generator 3 are installed on the outside of the flash tank 1. Both the vacuum phase change heat exchanger 2 and the organic Rankine cycle generator 3 are existing devices. The vacuum phase change heat exchanger 2 uses the principle that the working fluid water absorbs a large amount of latent heat during the condensation and heat release process to transfer heat. It has strong heat transfer capacity and constant temperature. The organic Rankine cycle generator 3 uses low-boiling-point organic working fluids instead of water. These organic working fluids can vaporize at a lower temperature to generate high-pressure steam, thereby efficiently driving the turbine to generate electricity, perfectly matching the characteristics of medium and low temperature heat sources. The heat source inlet of the vacuum phase change heat exchanger 2 is connected to the top of the flash tank 1 via a steam pipe 4. The heat source outlet is connected to a storage tank 5. The cold source outlet of the vacuum phase change heat exchanger 2 is connected to the steam inlet of the organic Rankine cycle generator 3. The condensate outlet of the organic Rankine cycle generator 3 is connected to the cold source inlet of the vacuum phase change heat exchanger 2. The bottom of the flash tank 1 is connected to the storage tank 5 via a drain pipe 6. The outlet of the storage tank 5 is connected to a preheater 18, which is an existing heat exchange device utilizing the storage tank. 5. The condensate discharged from the boiler preheats the boiler feedwater. The outlet of the preheater 18 is connected to the feedwater tank 7. The outlet of the feedwater tank 7 is connected to the cold water inlet of the preheater 18. The hot water outlet of the preheater 18 is connected to the deaerator 8 and the steam boiler 9 in sequence. The steam outlet of the steam boiler 9 is connected to the steam heat exchanger 10. The steam heat exchanger 10 is a device that uses steam for heating and temperature rise. The steam does not come into direct contact with the medium to be heated. The condensate outlet of the steam heat exchanger 10 is connected to the flash tank 1.

[0015] In operation, high-temperature condensate is introduced into flash tank 1 for flash evaporation, generating a large amount of low-pressure steam. This low-pressure steam serves as the heat source for vacuum phase-change heat exchange device 2, undergoing vacuum phase-change heat exchange. The steam cools and condenses into condensate, which flows into storage tank 5. The cooled water in vacuum phase-change heat exchange device 2 then enters organic Rankine cycle generator 3, where it exchanges heat with the working fluid. The working fluid temperature rises, generating electricity. Simultaneously, the flash evaporation... The remaining condensate in tank 1 also flows into storage tank 5. The condensate after steam condensation and the condensate discharged from flash tank 1 are mixed in storage tank 5 and then sent to preheater 18 to preheat the boiler feedwater. After cooling, it is sent to feedwater tank 7 to mix with fresh boiler feedwater. Then it is passed through preheater 18 again to raise the temperature. After deoxygenation by deaerator 8, it is sent to steam boiler 9 to produce steam. The steam is then sent to steam heat exchange equipment 10, where it is condensed to form high-temperature condensate, which is sent to flash tank 1 to complete the cycle of steam and water resources.

[0016] In this invention, high-temperature condensate is flash-evaporated in flash tank 1, separating it into low-pressure steam and remaining condensate. The heat from the low-pressure steam is used to generate electricity in the organic Rankine cycle generator 3, achieving the first stage of heat recovery. Then, the condensate from the steam condensation and the condensate discharged from flash tank 1 are fed into preheater 18, where the heat from the condensate and condensate is used to preheat the boiler feedwater, increasing its temperature, achieving the second stage of heat recovery. Finally, the cooled hot water is fed into feedwater tank 7, mixing with the fresh boiler feedwater in feedwater tank 7. This reduces the amount of fresh boiler feedwater used and increases its temperature, achieving the third stage of heat recovery. In summary... In this invention, the heat in the high-temperature condensate is utilized in three stages: the first stage is used for power generation, and the second and third stages are used for preheating boiler feedwater. This maximizes the recovery and utilization of the heat in the high-temperature condensate, improving heat utilization efficiency, minimizing heat waste, and reducing energy consumption in the steam boiler 9, demonstrating a good recovery and utilization effect. Secondly, while fully recovering and utilizing the heat in the high-temperature condensate, the condensate is also recycled. The high-temperature condensate does not need to be mixed and cooled with cooling water, eliminating the need for consuming large amounts of circulating cooling water. This completes the energy cascade utilization, improves water resource utilization efficiency, reduces water consumption and usage costs, and enhances the economic benefits of the enterprise.

[0017] A steam distribution pipe 11 is installed on the steam pipe 4. The end of the steam distribution pipe 11 is connected to the steam inlet of the deaerator 8. A portion of the steam discharged from the flash tank 1 is used by the deaerator 8 to deaerate and heat the boiler feedwater without consuming additional high-quality steam, thus improving the utilization rate of low-pressure steam.

[0018] A heat accumulator 12 and a steam-water separator 13 are sequentially arranged along the steam flow direction on the steam pipe 4. The steam outlet of the steam-water separator 13 is connected to the heat source inlet of the vacuum phase change heat exchanger 2, and the liquid outlet of the steam-water separator 13 is connected to the liquid storage tank 5. The heat accumulator 12 is used to store low-pressure steam and output it stably and continuously for subsequent use. The steam-water separator 13 is used to separate the water contained in the low-pressure steam to improve the utilization rate of steam. The separated condensate is fed into the liquid storage tank 5 for heat recovery and utilization again.

[0019] Agitators 14 are installed in both the water supply tank 7 and the liquid storage tank 5. The water supply tank 7 has two sources: one is the condensate discharged from the preheater 18 after further cooling, and the other is the newly added boiler feedwater. The temperature of the condensate is higher than that of the newly added boiler feedwater. Stirring it can even out the water temperature, which is beneficial for subsequent use. Similarly, the liquid storage tank 5 also has two sources: one is the condensate discharged from the flash tank 1 after flash evaporation, and the other is the cooling water after providing heat for power generation. The two water sources have different temperatures, and stirring them can even out the water temperature, which is beneficial for subsequent heat exchange.

[0020] An impurity filter 15 is installed on the drain pipe 6. The impurity filter 15 is an existing impurity removal device used to remove solid particles and dissolved impurities carried in the condensate, preventing these impurities from accumulating, depositing, corroding and polluting in the system, thereby causing a chain of failures.

[0021] A remote liquid level sensor 16 is installed at the top of the flash tank 1, and temperature sensors 17 are installed on both the steam pipe 4 and the drain pipe 6. Both the remote liquid level sensor 16 and the temperature sensor 17 are existing detection instruments. The remote liquid level sensor 16 is used to monitor the liquid level in the flash tank 1. If the liquid level is too low, the condensate in the flash tank 1 will be pumped out. If the liquid level is too high, or even the tank is full, the effective flash space will be reduced, the steam cannot be effectively separated, and pressure runaway will occur, affecting the flash evaporation effect of the condensate. The temperature sensor 17 is used to detect low-pressure steam and discharge. The temperature of the condensate is crucial because the low-pressure steam is used to power the vacuum phase-change heat exchanger 2 and the organic Rankine cycle generator 3, requiring the steam temperature to be controlled within a reasonable range to meet power generation needs. Simultaneously, temperature sensor 17 also detects the temperature of the discharged condensate. Theoretically, under equilibrium conditions, the temperature of the condensate inside the tank should equal the saturation temperature at the current tank pressure, indicating sufficient flash evaporation and that the water has released all its latent heat, achieving thermal equilibrium. Excessive temperature indicates insufficient flash evaporation, with hot water being discharged prematurely. The combined detection of both temperatures allows for monitoring the operation within the flash tank 1 and also provides temperature parameters to downstream applications.

Claims

1. A high-temperature condensate recycling and reuse device, comprising a flash tank (1) and a liquid inlet, characterized in that: The flash tank (1) is equipped with a vacuum phase change heat exchanger (2) and an organic Rankine cycle generator (3) on its outer side. The heat source inlet of the vacuum phase change heat exchanger (2) is connected to the top of the flash tank (1) through a steam pipe (4), and the heat source outlet is connected to a liquid storage tank (5). The cold source outlet of the vacuum phase change heat exchanger (2) is connected to the steam inlet of the organic Rankine cycle generator (3), and the condensate outlet of the organic Rankine cycle generator (3) is connected to the cold source inlet of the vacuum phase change heat exchanger (2). The bottom of the container is connected to the storage tank (5) via a drain pipe (6). The outlet of the storage tank (5) is connected to a preheater (18). The outlet of the preheater (18) is connected to a water supply tank (7). The outlet of the water supply tank (7) is connected to the cold water inlet of the preheater (18). The hot water outlet of the preheater (18) is connected to a deaerator (8) and a steam boiler (9) in sequence. The steam outlet of the steam boiler (9) is connected to a steam heat exchanger (10). The condensate outlet of the steam heat exchanger (10) is connected to the flash tank (1).

2. The high-temperature condensate recovery and reuse device according to claim 1, characterized in that: A steam distribution pipe (11) is provided on the steam pipe (4), and the end of the steam distribution pipe (11) is connected to the steam inlet of the deaerator (8).

3. The high-temperature condensate recovery and reuse device according to claim 1, characterized in that: A heat accumulator (12) and a steam-water separator (13) are sequentially arranged along the steam flow direction on the steam pipe (4). The steam outlet of the steam-water separator (13) is connected to the heat source inlet of the vacuum phase change heat exchange device (2), and the liquid outlet of the steam-water separator (13) is connected to the liquid storage tank (5).

4. The high-temperature condensate recovery and reuse device according to claim 1, characterized in that: A stirrer (14) is installed inside the water replenishment tank (7) and the liquid storage tank (5).

5. The high-temperature condensate recycling and reuse device according to claim 1, characterized in that: An impurity filter (15) is provided on the drain pipe (6).

6. The high-temperature condensate recovery and reuse device according to claim 1, characterized in that: A remote liquid level sensor (16) is installed on the top of the flash tank (1), and temperature sensors (17) are installed on the steam pipe (4) and the drain pipe (6).

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