Flash evaporation and absorption integrated device for low-temperature waste liquid

Abstract

The utility model discloses a flash evaporation and absorption integrated device for low-temperature waste liquid, which belongs to the technical field of waste heat recovery and is characterized in that a demisting cavity and a flash evaporation cavity are arranged in a flash evaporation box body, and a demister is arranged in the demisting cavity; dead steam of the flash evaporation cavity enters the demisting cavity and then is communicated with a heat exchange cavity which is arranged in a heat exchange box body of the absorber and is provided with a narrow channel and a long flow path through a dead steam steam channel, and the flash evaporation box body is provided with a first low-temperature waste liquid inlet communicated with the flash evaporation cavity. Low-temperature dead steam generated by the flash evaporation box body passes through the narrow-channel long-flow-path heat exchange cavity design of the absorber, the absorption efficiency and the waste heat recovery capacity of the low-temperature dead steam are remarkably improved, and the contact path of a concentrated solution and flash evaporation steam is prolonged through the narrow-channel long-flow-path structure.

Description

Technical Field

[0001] This utility model belongs to the field of waste heat recovery technology, and in particular, it is a low-temperature waste liquid flash evaporation and absorption integrated device. Background Technology

[0002] Waste heat recovery and utilization is an important branch of energy conservation and environmental protection. my country has abundant industrial waste heat resources, especially in industries such as coal-fired power generation, steel, non-ferrous metals, chemicals, cement, building materials, petroleum and petrochemicals, and light industry. Waste heat resources account for approximately 17% to 67% of their total fuel consumption, of which about 60% are recoverable, indicating significant potential for increased waste heat utilization. Taking the cogeneration industry as an example, coal-fired power plants burn large amounts of coal during operation, and the generated heat energy is mainly used for power generation and heating. However, a large amount of waste heat is still emitted into the atmosphere with the flue gas after desulfurization. Because the flue gas contains a large number of pollutants and impurities, and suffers from severe corrosion and blockage problems, it cannot be heat exchanged using conventional closed-loop absorption methods.

[0003] An absorption heat pump is a thermal device driven by thermal energy, which achieves the "transfer" or "temperature increase" of thermal energy through an absorption-desorption cycle. Its core function is to absorb heat from a low-temperature heat source and transfer it to a high-temperature user end with the help of an external driving heat source, achieving efficient utilization of thermal energy. It is an effective device for recovering and utilizing low-temperature thermal energy. Absorption heat pumps can be divided into closed-loop heat pumps and open-loop heat pumps, with closed-loop heat pumps currently being widely used. However, compared to closed-loop heat pumps, open-loop heat pumps have advantages such as simpler structure, flexible absorbent replacement, direct utilization of environmental media, efficient treatment of low-concentration pollutants, and reduced secondary pollution.

[0004] Closed-loop absorption heat pumps employ a fully enclosed cycle, using a water-lithium bromide working fluid pair as the core. Low-temperature waste heat enters the evaporator, causing the refrigerant to evaporate and absorb heat. The generated water vapor is absorbed by a concentrated lithium bromide solution in the absorber, releasing heat. Subsequently, the dilute solution is regenerated by an external high-temperature heat source. The separated water vapor releases heat in the condenser, and the liquid water returns to the evaporator after throttling. The working fluid is completely closed, relying on high temperature to drive the heat source, making it suitable for industrial waste heat recovery and high-temperature heating. In contrast, open-loop absorption heat pumps interact directly with the ambient medium. Flash vapor directly contacts the concentrated solution, where water vapor is absorbed and releases heat. The dilute solution is regenerated by waste heat heating, water evaporates and is discharged, and the solution is restored to its concentration for reuse. The working fluid is partially open, allowing the use of low-grade heat sources, making it suitable for low-temperature waste heat recovery. Therefore, open-loop absorption heat pumps can be used to recover and utilize low-grade energy from low-temperature exhaust steam, such as flue gas from coal-fired power plants.

[0005] To address the problems of low contact area between the working fluid and exhaust steam in traditional absorbers and low mass transfer efficiency, a low-temperature exhaust steam absorber device is proposed. Utility Model Content

[0006] Purpose of the utility model: To provide a low-temperature waste liquid flash evaporation and absorption integrated device to solve the above-mentioned problems existing in the prior art.

[0007] Technical solution: A low-temperature waste liquid flash evaporation and absorption integrated device, comprising: a flash evaporation chamber, wherein a demister chamber and a flash evaporation chamber are provided in the flash evaporation chamber, a demister is provided in the demister chamber, and the exhaust steam of the flash evaporation chamber enters the demister chamber and is connected to a narrow-channel long-flow heat exchange chamber in the heat exchange chamber of the absorber through the exhaust steam channel, and a first low-temperature waste liquid inlet connected to the flash evaporation chamber is provided on the flash evaporation chamber.

[0008] Furthermore, the flash evaporation chamber is separated into a high-efficiency flash evaporation chamber and a stable flash evaporation chamber by a first isolation plate and a second isolation plate, and both the high-efficiency flash evaporation chamber and the stable flash evaporation chamber are connected to the demister chamber.

[0009] Furthermore, the first low-temperature waste liquid inlet is connected to the high-efficiency flash evaporation chamber.

[0010] Furthermore, the flash evaporation chamber is provided with a second low-temperature waste liquid inlet that communicates with the stable flash evaporation chamber, and the position of the second low-temperature waste liquid inlet is lower than the liquid level of the medium inside the stable flash evaporation chamber.

[0011] Furthermore, multiple second cryogenic waste liquid inlets are connected in parallel and are also connected in parallel with the first cryogenic waste liquid inlet.

[0012] Furthermore, valves are installed at multiple second cryogenic waste liquid inlets and at the first cryogenic waste liquid inlet.

[0013] Furthermore, the flash evaporation chamber is provided with at least one first observation window and a waste liquid outlet.

[0014] Furthermore, the flash evaporation chamber is provided with a demister cleaning port that communicates with the demister chamber.

[0015] Furthermore, a cooling water pipe assembly is provided inside the heat exchange chamber, a concentrated solution inlet is provided on the top of the heat exchange chamber or near the top side wall, and a channel communicating with a dilute solution collection tank is provided on the bottom of the heat exchange chamber or near the bottom side wall.

[0016] Furthermore, the heat exchange box is provided with a vacuum pump interface that communicates with the heat exchange chamber.

[0017] Beneficial effects:

[0018] The low-temperature exhaust steam generated by the flash evaporation chamber in this application is significantly improved in terms of absorption efficiency and waste heat recovery capability through the narrow channel long flow heat exchange chamber design of the absorber. The narrow channel long flow structure extends the contact path between the concentrated solution and the flash steam.

[0019] This application achieves both high-efficiency flash evaporation chamber and low-temperature flash evaporation chamber through coordinated operation, thus satisfying the requirements of flash evaporation efficiency while also addressing the issue of insufficient demisting capacity of the demister leading to the entry of non-clean media into the absorber, thereby making the system more stable. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the structure of this utility model;

[0021] Figure 2 This is a schematic diagram of the structure of this practical absorber;

[0022] Figure 3 This is a schematic diagram of the installation position of the second observation window of this utility model.

[0023] The attached figures are labeled as follows: flash evaporator 100, demister 101, flash evaporator 102, demister 103, steam exhaust channel 104, first low-temperature waste liquid inlet 105, first isolation plate 106, second isolation plate 107, high-efficiency flash evaporator 108, stable flash evaporator 109, second low-temperature waste liquid inlet 110, valve 111, first observation window 112, waste liquid outlet 113, demister cleaning port 114, absorber 200, heat exchanger 201, heat exchanger 202, cooling water pipe assembly 203, concentrated solution inlet 204, dilute solution collection tank 205, channel 206, liquid distribution unit 207, vacuum pump interface 208, gas pressure connecting pipeline 209, second observation window 211, dilute solution outlet 212, density meter interface 213, liquid distribution pipe 271, liquid distribution plate 272. Detailed Implementation

[0024] In the following description, numerous specific details are set forth in order to provide a more thorough understanding of the present invention. However, it will be apparent to those skilled in the art that the present invention can be practiced without one or more of these details. In other instances, certain technical features well-known in the art have not been described in order to avoid confusion with the present invention.

[0025] like Figures 1 to 3 As shown, a low-temperature waste liquid flash evaporation and absorption integrated device includes: a flash evaporation chamber 100, wherein a demisting chamber 101 and a flash evaporation chamber 102 are provided inside the flash evaporation chamber 100, a demister 103 is provided inside the demisting chamber 101, and the exhaust steam of the flash evaporation chamber 102 enters the demisting chamber 101 and communicates with the heat exchange chamber 202 of the absorber 200, which has a narrow channel and long flow, through the exhaust steam channel 104. A first low-temperature waste liquid inlet 105 communicating with the flash evaporation chamber 102 is provided on the flash evaporation chamber 100.

[0026] The flash evaporation chamber 100 is made of high-strength, corrosion-resistant material to ensure long-term operational stability. Its inner wall can be coated with an anti-corrosion coating to enhance corrosion resistance and extend service life. The demister 103 is a baffle plate demister or other type selected according to actual needs to ensure efficient demisting. The demisting chamber 101 is located above the flash evaporation chamber 102, forming a reasonable airflow path, reducing steam carryover, improving demisting efficiency, and ensuring the purity of the steam entering the absorber. The heat exchange chamber 202 adopts a narrow channel long flow design to increase the heat exchange area, improve heat exchange efficiency, reduce pressure drop, optimize overall thermal energy utilization, and ensure efficient and stable system operation.

[0027] This application further reduces the risk of liquid carryover in steam by optimizing the relative positions of the flash evaporation chamber and the demister chamber. At the same time, by setting up a heat exchange chamber 202 with a narrow channel and long flow path, the heat exchange efficiency is significantly improved, energy loss is reduced, the efficient and stable operation of the system is ensured, the overall thermal energy utilization rate is further optimized, and the comprehensive performance of the device is enhanced.

[0028] The flash evaporation chamber 102 is separated into a highly efficient flash evaporation chamber 108 and a stable flash evaporation chamber 109 by a first isolation plate 106 and a second isolation plate 107. Both the highly efficient flash evaporation chamber 108 and the stable flash evaporation chamber 109 are connected to the demister chamber 101. This arrangement allows the highly efficient flash evaporation chamber 108 to enhance heat transfer, while the stable flash evaporation chamber 109 maintains pressure balance. This synergistic effect improves the flash evaporation effect, ensuring efficient and stable wastewater treatment, and further optimizing the thermal energy utilization and operational flexibility of the device. The first isolation plate 106 and the second isolation plate 107 are made of high-temperature resistant, high-strength alloy to ensure long-term durability. The steam inlet entering the demister chamber 101 is located at the bottom, preventing direct steam impact on the demister, reducing droplet entrainment, improving demister efficiency, and optimizing steam distribution to ensure uniform heat exchange, further enhancing the overall system performance and operational stability.

[0029] The first low-temperature waste liquid inlet 105 is connected to the high-efficiency flash evaporation chamber 108. With this configuration, the first low-temperature waste liquid inlet 105 is directly connected to the high-efficiency flash evaporation chamber 108, ensuring that the low-temperature waste liquid quickly enters the high-temperature environment and undergoes a violent flash phase change. The first low-temperature waste liquid inlet 105 sprays the low-temperature waste liquid into the high-efficiency flash evaporation chamber 108, forming a high-speed droplet group for rapid flash evaporation.

[0030] The flash evaporation chamber 100 is provided with a second low-temperature waste liquid inlet 110 that communicates with the stable flash evaporation chamber 109. The position of the second low-temperature waste liquid inlet 110 is lower than the liquid level of the medium inside the stable flash evaporation chamber 109. This arrangement ensures that the waste liquid enters the stable flash evaporation chamber 109 smoothly, avoiding fluctuations caused by droplet impact and maintaining the stability of the flash evaporation process. The second low-temperature waste liquid inlet 110 works in conjunction with the first low-temperature waste liquid inlet 105 to optimize waste liquid distribution, ensure maximum flash evaporation effect, improve heat recovery rate, and further enhance the stability and flash evaporation efficiency of the system operation.

[0031] This application addresses the problem that while traditional flash evaporators achieve high efficiency due to the violent evaporation that occurs after the flash medium is injected into the flash evaporator, the resulting exhaust steam contains a large number of droplets, which reduces the demisting effect of the demister and leads to unclean liquid entering the absorber and contaminating the absorber solution.

[0032] Multiple second cryogenic waste liquid inlets 110 are connected in parallel and in parallel with the first cryogenic waste liquid inlet 105. Valves 111 are provided at both the multiple second cryogenic waste liquid inlets 110 and the first cryogenic waste liquid inlet 105. The valves 111 precisely control the waste liquid flow rate, ensuring that the waste liquid is evenly distributed at each inlet, further optimizing the flash evaporation effect and improving the overall thermal efficiency of the system.

[0033] The flash evaporation chamber 100 is equipped with at least one first observation window 112 and a waste liquid outlet 113. The first observation window 112 facilitates real-time monitoring of the flash evaporation process, while the waste liquid outlet 113 ensures timely discharge of waste liquid, preventing liquid accumulation from affecting the flash evaporation effect and further ensuring stable system operation. The waste liquid outlet 113 is designed to be adjustable, automatically adjusting the discharge rate according to changes in the liquid level within the flash evaporation chamber to ensure stable liquid level, avoid overflow risks, and further improve the safety and reliability of system operation.

[0034] The flash evaporation chamber 100 is provided with a demister cleaning port 114 that communicates with the demister chamber 101. The demister cleaning port 114 facilitates regular cleaning of the demister, maintains its efficient demisting capability, prevents droplet carryover, ensures the purity of the absorber solution, and further improves the safety and reliability of the system operation.

[0035] The heat exchange chamber 202 is equipped with a cooling water pipe assembly 203. A concentrated solution inlet 204 is located on the top or near the top sidewall of the heat exchange chamber 202, and a channel 206 communicating with a dilute solution collection tank 205 is located on the bottom or near the bottom sidewall of the heat exchange chamber 202. The cooling water pipe assembly 203 consists of multiple horizontally arranged cooling water pipes, which are matrixed and filled in the heat exchange chamber 202 to ensure overall heat exchange efficiency. The cooling water pipes can be arranged alternately or randomly, depending on the actual situation. The cooling water pipes can be connected by interlocking clips to avoid difficulties in connection due to small pipe spacing during actual processing. The pipe types can be plain pipes, corrugated pipes, finned pipes, etc. The narrow-channel, long-flow design of the heat exchange chamber 202 means that the concentrated solution can be processed in a relatively short time. Under the action of force, the heat exchanger fully contacts the steam and cooling water pipes within a limited space, achieving sufficient heat exchange after a long process, thus improving heat exchange efficiency. Channel 206 can be a pipeline. When the installation space of the equipment is limited, the heat exchange box 201 and the dilute solution collection box 205 can be connected by a pipeline to meet the installation conditions. At the same time, the dilute solution can be transferred by gravity by placing the space position of the heat exchange box 201 above the dilute solution collection box 205, or the dilute solution can be driven to flow by a melt pump. Channel 206 can also be a port. When the heat exchange box 201 and the dilute solution collection box 205 are designed as an integral part, the dilute solution in the heat exchange box 201 enters the dilute solution collection box 205 through the port by gravity.

[0036] The narrow-channel, long-flow heat exchange chamber 202 of this application defines the flow space of the concentrated solution, forming a thin liquid film that flows slowly along the surface of the cooling water pipes, extending the liquid-vapor contact time and enhancing the mass transfer effect. The long-flow design allows the concentrated solution to travel a longer path under gravity, fully mixing with the counter-current flash vapor and improving absorption efficiency. The narrow-channel structure increases the turbulence of the solution, disrupting the boundary layer and enhancing heat and mass transfer. The matrix arrangement of the cooling water pipes further increases the heat exchange area and optimizes the heat transfer path. This design effectively solves the problems of insufficient contact area and low mass transfer efficiency in traditional absorbers, while reducing the equipment size, making it suitable for the efficient recovery of low-grade heat sources. By controlling the channel size and flow length, it can flexibly adapt to different operating conditions, ensuring stable and efficient operation even at low temperatures.

[0037] The heat exchange chamber 201 is provided with a vacuum pump interface 208 that communicates with the heat exchange cavity 202. The vacuum pump interface 208 is used to connect an external vacuum pump to maintain a stable negative pressure environment in the flash cavity and the high-efficiency flash cavity, so as to ensure that the flash steam is generated smoothly and effectively transferred.

[0038] The heat exchange box 201 is provided with a liquid distribution unit 207 that communicates with the concentrated solution inlet 204. The liquid distribution unit 207 is used to uniformly distribute liquid to the cooling water pipe group 203. The liquid distribution unit 207 includes a liquid distribution pipe 271, which communicates with the concentrated solution inlet 204. The liquid distribution pipe 271 has a plurality of first liquid distribution holes for uniformly distributing liquid to the cooling water pipe group 203. The liquid distribution unit 207 further includes a liquid distribution plate 272, which is located between the liquid distribution pipe 271 and the cooling water pipe assembly 203. The liquid distribution plate 272 has multiple second liquid distribution holes for uniformly distributing liquid to the cooling water pipe assembly 203. The liquid distribution pipe 271 includes a vertical pipe for communicating with the concentrated solution inlet 204, and at least one horizontal pipe is provided at the lower end of the vertical pipe. The horizontal pipe is provided with first liquid distribution holes, and the multiple horizontal pipes are connected by a connecting pipe. In order to improve the uniformity of liquid distribution, the liquid distribution plate 272 is provided below the liquid distribution pipe 271, and the first liquid distribution holes are provided. The concentrated solution discharged from the orifice is then uniformly distributed to the cooling water pipe assembly 203 through the second distribution hole on the distribution plate 272. The distribution plate 272 can stabilize the flow of the concentrated solution discharged from the distribution pipe 271, ensuring the stability of the distribution. When discharged through the second distribution hole, the concentrated solution can be stably and uniformly dripped onto the cooling water pipe, thereby improving the heat exchange efficiency. The distribution pipe 271 and the distribution plate 272 can be used alone or in combination. Any subsequent addition of distribution pipes, distribution plates, or distribution nets to avoid this solution will fall within the protection scope of this application.

[0039] A gas pressure connecting pipe 209 is provided between the dilute solution collection tank 205 and the heat exchange chamber 202. This arrangement makes it easier for the dilute solution in the heat exchange chamber 202 to enter the dilute solution collection tank 205.

[0040] At least one second observation window 211 is provided on the heat exchange box 201. This is used to observe the flow state of the dilute solution and determine the flow rate of the dilute solution. The second observation window 211 is provided with transparent glass and is sealed. The number and arrangement of the second observation windows 211 can be determined according to the length of the heat exchange chamber 202 inside the heat exchange box 201.

[0041] The dilute solution collection tank 205 is equipped with a dilute solution outlet 212 and a densitometer interface 213. With this configuration, the dilute solution outlet 212 can be used for independent collection or connected to the generator or the concentrated / dilute solution heat exchanger. The densitometer interface 213 is used to install a densitometer to obtain the density of the dilute solution in real time and thus know the concentration change of the dilute solution.

[0042] Work process:

[0043] First, the desulfurization slurry enters the high-efficiency flash evaporation chamber 108 and the stable flash evaporation chamber 109 through the first low-temperature waste liquid inlet 105 and the second low-temperature waste liquid inlet 106 respectively, where a phase change occurs, generating a large amount of steam. The steam carries heat into the demister chamber 101, and after separation by the demister 102, the pure steam enters the heat exchange chamber 202. The steam moves upward and exchanges heat with the concentrated solution in the heat exchange chamber 202. After absorbing heat, the temperature of the concentrated solution rises, and after exchanging heat with the cooling water pipe assembly 203, the temperature decreases and the concentration decreases, forming a dilute solution. The dilute solution flows into the dilute solution collection tank 205 under the action of gravity.

[0044] The vacuum pump interface 208 maintains the pressure within the flash chamber 102 within a set range via a vacuum pump, ensuring the flash evaporation effect. The flash evaporation efficiency and stability are controlled by adjusting the flow rates of the first cryogenic waste liquid inlet 105 and the second cryogenic waste liquid inlet 106.

[0045] The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the specific details of the above embodiments. Within the scope of the technical concept of the present invention, various equivalent transformations can be made to the technical solutions of the present invention, and all such equivalent transformations fall within the protection scope of the present invention.

Claims

1. A low temperature waste liquid flash evaporation-absorption integrated device, characterized in that, The utility model relates to a flash tank (100) which is provided with a demisting chamber (101) and a flash chamber (102) inside, the demisting chamber (101) is provided with a demister (103) inside, the steam exhaust of the flash chamber (102) is communicated with the heat exchange chamber (202) provided with a narrow channel long process inside the heat exchange tank (201) of the absorber (200) through a steam exhaust channel (104) after entering the demisting chamber (101), and the flash tank (100) is provided with a first low-temperature waste liquid inlet (105) communicated with the flash chamber (102). The flash chamber (102) is isolated into an efficient flash chamber (108) and a stable flash chamber (109) which are communicated with each other through a first isolation plate (106) and a second isolation plate (107), and the efficient flash chamber (108) and the stable flash chamber (109) are both communicated with the demisting chamber (101).

2. The cryogenic waste fluid flash evaporative absorption integrated device of claim 1, wherein, The first low-temperature waste liquid inlet (105) is communicated with the efficient flash chamber (108).

3. The cryogenic waste fluid flash evaporative absorption integrated device of claim 2, wherein, The flash tank (100) is provided with a second low-temperature waste liquid inlet (110) communicated with the stable flash chamber (109), and the position of the second low-temperature waste liquid inlet (110) is lower than the medium liquid level in the stable flash chamber (109).

4. The cryogenic waste fluid flash evaporative absorption integrated device of claim 3, wherein, A plurality of second low-temperature waste liquid inlets (110) are arranged in parallel and are connected in parallel with the first low-temperature waste liquid inlet (105).

5. The cryogenic waste fluid flash evaporative absorption integrated device of claim 4, wherein, Valves (111) are arranged at a plurality of second low-temperature waste liquid inlets (110) and the first low-temperature waste liquid inlet (105).

6. The cryogenic waste fluid flash evaporator-absorber integrated device of claim 5, wherein, The flash tank (100) is provided with at least one first observation window (112) and a waste liquid outlet (113).

7. The cryogenic waste fluid flash evaporator-absorber integrated device of claim 1, wherein, The flash tank (100) is provided with a demister cleaning port (114) communicated with the demisting chamber (101).

8. The cryogenic waste fluid flash evaporator-absorber integrated device of claim 1, wherein, The heat exchange chamber (202) is provided with a cooling water pipe group (203), a concentrated solution inlet (204) is arranged on the top or the side wall close to the top of the heat exchange chamber (202), and a channel (206) communicated with a dilute solution collecting tank (205) is arranged on the bottom or the side wall close to the bottom of the heat exchange chamber (202).

9. The cryogenic waste fluid flash evaporator-absorber integrated device of claim 1, wherein, The heat exchange tank (201) is provided with a vacuum pump interface (208) communicated with the heat exchange chamber (202).

10. The cryogenic waste fluid flash evaporator-absorber integrated device of claim 1, wherein, ​

Images