A fin heat pipe low-temperature multi-effect evaporation sewage concentration device and its process

Abstract

The present invention discloses a fin heat pipe low temperature multi-effect evaporation sewage concentration device and its process, the device comprises at least two-stage series concentration evaporation system, a first heat exchange chamber, a second heat exchange chamber, a heat pipe, the heat pipe comprises an upper heat pipe condensation end and a lower heat pipe evaporation end, starting from the high temperature wet air inlet end of the first heat exchange chamber, a liquid gas heat exchanger, a heat pipe evaporation end, a high temperature fan, and a heat pump condenser are sequentially arranged according to the flow direction of the high temperature circulating air, and the lower part of the first heat exchange chamber is a high temperature condenser; in the second heat exchange chamber, a medium temperature fan and a heat pipe condensation end are sequentially arranged starting from the medium temperature dry air inlet end according to the flow direction of the medium temperature circulating air, and the second heat exchange chamber air outlet, the medium temperature evaporator air inlet, the medium temperature evaporator air outlet, the medium temperature condenser air inlet, the medium temperature condenser air outlet, and the second heat exchange chamber air inlet are sequentially connected by pipelines. The device of the present invention has low energy consumption, low investment cost, and is popularizable.

Description

Technical Field

[0001] The invention relates to the technical field of sewage treatment, and in particular to a fin heat pipe low-temperature multi-effect evaporation sewage concentration device and a process thereof. Background Art

[0002] The existing wastewater treatment technologies each have their own characteristics. At present, evaporation and concentration are commonly used for difficult-to-treat sewage. Electric / gas / coal boiler evaporation devices are generally used at home and abroad. Due to the high operating temperature, high steam pressure, high corrosion resistance and pressure resistance requirements of equipment materials, pressure-resistant operation is required, and pressure-bearing equipment is very expensive; coal boiler evaporation and concentration devices have been basically eliminated or are being eliminated due to serious environmental pollution; gas-heated boiler evaporation and concentration devices are not widely used due to safety and economy. Due to convenience and environmental protection considerations, electric heating and concentration devices are currently being used more and more. The energy consumption of a single-stage electric boiler is very high. Even if multi-stage evaporation is used, the energy consumption of an electric boiler evaporation and concentration device per ton of water is still about 200-300kwh. The equipment investment of an electric boiler evaporation and concentration device is high, and the energy consumption is still high. For the MVR steam compression evaporation and concentration system, the equipment requirements are high and the process is complex. In particular, the MVR steam compressor is expensive, and the system investment cost is very high, almost three times that of the boiler evaporation and concentration equipment. For the heat pump low-temperature vacuum evaporation and concentration system, the energy consumption per ton of water is still as high as 200kwh, and the process has vacuum pressure equipment, which is expensive and has high investment costs. Using heat pump evaporation dehumidification to concentrate sewage can evaporate and concentrate sewage at low temperature and normal pressure. It has low equipment requirements and less investment. Moreover, since heat pumps can improve energy efficiency by 3-4 times, they can also reduce energy consumption. Therefore, in the field of sewage evaporation and concentration, heat pump evaporation dehumidification and concentration will be the general trend. Summary of the invention

[0003] One of the purposes of the present invention is to provide a fin heat pipe low-temperature multi-effect evaporation sewage concentration device, through which the energy consumption is low, the operation is simple, the degree of automation is high, and standardized production can be achieved, which greatly saves investment and operating costs, and solves the problems of large equipment investment, high energy consumption, complex operating procedures, non-standard manufacturing process of conventional heat pipe heat exchangers, and unstable quality in the prior art.

[0004] The fin heat pipe low-temperature multi-effect evaporation sewage concentration device provided by the present invention comprises at least two stages of concentration and evaporation devices connected in series, the device comprising:

[0005] The first heat exchange chamber, starting from the high-temperature humid air inlet end of the first heat exchange chamber, is provided with a liquid-to-gas heat exchanger, a heat pipe evaporating end of the second heat pipe, a high-temperature fan, and a heat pump condenser in sequence according to the flow direction of the high-temperature circulating air; the fins of the liquid-to-gas heat exchanger are arranged vertically, parallel to the flow direction of the circulating air and perpendicular to the direction of the fin cross tube (the flow path of the sewage raw liquid). The sewage raw liquid absorbs heat through the liquid-to-gas heat exchanger and causes the water vapor in the high-temperature humid air to condense, which increases the amount of condensed water and the heat of the sewage raw liquid, which is beneficial to the subsequent evaporation and can increase System evaporation energy efficiency, the lower part of the first heat exchange chamber is the high-temperature condenser; the liquid-gas heat exchanger is connected to the medium-temperature evaporator through the feed liquid port; the second heat pipe is divided into an upper part and a lower part, the fins of the second heat pipe are arranged horizontally and perpendicular to the direction of the refrigerant pipe, the upper part is located in the second heat exchange chamber to form the heat pipe condensation end, and the lower part is located in the first heat exchange chamber to form the heat pipe evaporation end; the air outlet of the first heat exchange chamber, the air inlet of the high-temperature evaporator, the air outlet of the high-temperature evaporator, and the air inlet of the first heat exchange chamber are connected in sequence by pipelines to form a high-temperature circulating air flow path;

[0006] The second heat exchange chamber, in which a medium-temperature fan and a heat pipe condensing end of the second heat pipe are arranged in sequence from the medium-temperature dry air inlet end according to the flow direction of the medium-temperature circulating air; the second heat exchange chamber air outlet, the medium-temperature evaporator air inlet, the medium-temperature evaporator air outlet, the medium-temperature condenser air inlet, the medium-temperature condenser air outlet, and the second heat exchange chamber air inlet are connected by pipelines in sequence to form a medium-temperature circulating air flow path.

[0007] Furthermore, a high-temperature circulation pump is provided at the liquid outlet of the high-temperature evaporator, a high-temperature liquid circulation loop is formed between the high-temperature evaporator and the high-temperature circulation pump, and the high-temperature evaporator is connected to the medium-temperature circulation pump pipeline.

[0008] Furthermore, a medium-temperature circulation pump is provided at the liquid outlet of the medium-temperature evaporator, and a medium-temperature liquid circulation loop is formed between the medium-temperature evaporator and the medium-temperature circulation pump.

[0009] Furthermore, the heat pump unit includes a heat pump evaporator and a heat pump condenser, and a heat pump unit is arranged between the heat pump condenser and the heat pump evaporator to perform refrigerant circulation and heat exchange.

[0010] Furthermore, a control valve is provided on the pipeline connecting the high-temperature evaporator and the medium-temperature circulation pump.

[0011] The second object of the present invention is to provide a fin heat pipe low-temperature multi-effect evaporation sewage concentration process, which at least includes a medium-temperature concentration evaporation section and a high-temperature concentration evaporation section, wherein:

[0012] The medium-temperature concentration evaporation section includes the following steps: the sewage is heat-exchanged with high-temperature humid air to obtain heated sewage;

[0013] The heated sewage after absorbing heat is atomized to obtain water mist, and the water mist is heated and evaporated by medium-temperature dry air to obtain medium-temperature humid air;

[0014] Heat exchange and dehumidification of medium temperature humid air to obtain low temperature dry air and condensed water;

[0015] The low-temperature dry air is heat exchanged to become the medium-temperature dry air.

[0016] The high-temperature concentration evaporation section includes the following steps: after the high-temperature humid air is heat-exchanged with the sewage raw liquid, part of the water vapor in the high-temperature humid air is condensed, and the relatively high-temperature and relatively high-humid air after partial dehumidification continues to exchange heat with the medium-temperature dry air outside the condensation end of the heat pipe through the heat pipe at the evaporation end of the heat pipe, condenses and becomes relatively high-temperature dry air, and the relatively high-temperature dry air is then heat-exchanged with the heat pump condenser to increase the temperature, thereby obtaining high-temperature dry air;

[0017] The high-temperature liquid is circulated and atomized to obtain water mist, which is then heated and evaporated by high-temperature dry air to obtain the high-temperature wet air and sewage concentrate.

[0018] Furthermore, the steps are specifically as follows: the cold sewage raw liquid flows through the liquid-gas heat exchanger in the second heat exchange chamber provided with the high-temperature condenser of the high-temperature concentration evaporation section, and the sewage raw liquid in the tube absorbs heat and rises in temperature;

[0019] The heated sewage raw liquid enters the medium-temperature concentrated evaporation section, is pressurized by the circulating pump of the medium-temperature section, and is mixed with the circulating liquid from the medium-temperature evaporator. It is sprayed on the top of the medium-temperature evaporator, and the droplets exchange heat with the medium-temperature circulating dry air heated by the condensing end of the heat pipe and evaporate. The medium-temperature circulating dry air absorbs moisture to become medium-temperature wet air, and then flows into the heat pump evaporator in the medium-temperature condenser to release heat and dehumidify. Then it passes through the medium-temperature fan to enter the condensing end of the heat pipe to heat and absorb heat, becoming medium-temperature circulating dry air, and then flows into the medium-temperature evaporator for circulation and moisture absorption. The purified medium-temperature condensed water is discharged from the medium-temperature condensed water outlet at the bottom of the medium-temperature condenser.

[0020] Part of the pre-concentrated sewage enters the high-temperature concentration and evaporation section through the control valve, is mixed with the circulating liquid from the high-temperature evaporator that has been pressurized by the high-temperature circulation pump, and is sprayed on the top of the high-temperature evaporator. The droplets exchange heat with the high-temperature circulating dry air heated by the heat pump condenser and evaporate; it absorbs moisture to become high-temperature humid air, and then flows into the heat pipe evaporation end in the high-temperature condenser to release heat and dehumidify, and then enters the heat pump condenser through the high-temperature fan to heat and absorb heat, becoming high-temperature circulating dry air, and then flows into the high-temperature evaporator for circulation and moisture absorption; the purified high-temperature condensed water is discharged from the high-temperature condensed water outlet at the bottom of the high-temperature condenser; the concentrated liquid is discharged from the concentrated liquid outlet at the bottom of the high-temperature evaporator.

[0021] Principle description: The cold sewage liquid flows through the liquid-gas heat exchanger in the second heat exchange chamber of the high-temperature condenser which is equipped with a high-temperature concentrated evaporation section. The sewage liquid in the tube absorbs heat and heats up, while the high-temperature humid air outside the tube releases heat and condenses, thus increasing the condensation capacity of the high-temperature condenser. At the same time, the sewage liquid absorbs heat to increase the evaporation energy efficiency of the system.

[0022] The heated sewage raw liquid enters the medium-temperature concentrated evaporation section, is pressurized by the circulating pump of the medium-temperature section, mixed with the circulating liquid from the medium-temperature evaporator, and sprayed on the top of the medium-temperature evaporator. The droplets exchange heat and evaporate with the medium-temperature circulating dry air heated by the condensing end of the heat pipe; the medium-temperature circulating dry air absorbs moisture to become medium-temperature humid air, and then flows into the heat pump evaporator in the medium-temperature condenser to release heat and dehumidify, and then enters the condensing end of the heat pipe through the medium-temperature fan to heat and absorb heat, becoming medium-temperature circulating dry air, and then flows into the medium-temperature evaporator for circulation and moisture absorption; the purified medium-temperature condensed water is discharged from the medium-temperature condensed water outlet at the bottom of the medium-temperature condenser.

[0023] Part of the pre-concentrated sewage enters the high-temperature concentration and evaporation section through the control valve, is mixed with the circulating liquid from the high-temperature evaporator that has been pressurized by the high-temperature circulation pump, and is sprayed on the top of the high-temperature evaporator. The droplets exchange heat with the high-temperature circulating dry air heated by the heat pump condenser and evaporate; it absorbs moisture to become high-temperature humid air, and then flows into the heat pipe evaporation end in the high-temperature condenser to release heat and dehumidify, and then enters the heat pump condenser through the high-temperature fan to heat and absorb heat, becoming high-temperature circulating dry air, and then flows into the high-temperature evaporator for circulation and moisture absorption; the purified high-temperature condensed water is discharged from the high-temperature condensed water outlet at the bottom of the high-temperature condenser; the concentrated liquid is discharged from the concentrated liquid outlet at the bottom of the high-temperature evaporator.

[0024] Heat pipes can be simply modified with standardized fin heat exchangers for conventional air conditioners and heat pumps. The inlet and outlet of the refrigerant pipes of the fin heat exchanger are sealed, and a small amount of refrigerant is filled into the pipe after the pipe is evacuated. The amount of refrigerant filled is about 1 / 5 of the mass corresponding to the saturated vapor pressure of the refrigerant at the working temperature of the heat pipe. When installing, keep the refrigerant pipe in a vertical direction to facilitate efficient heat transfer of the heat pipe, and the fins are in a horizontal direction. The fins of the heat pipe are separated by partitions. The upper part is the condensation end of the heat pipe, which is placed behind the medium-temperature fan of the medium-temperature concentrated evaporation section; the lower part is the evaporation end of the heat pipe, which is placed in the high-temperature condenser of the high-temperature concentrated evaporation section. The use of universal fin heat exchangers for heat pipes is conducive to improving the heat exchange efficiency of the heat pipe and reducing equipment costs at the same time.

[0025] The liquid-gas heat exchanger can be modified with a standardized fin heat exchanger for conventional air conditioners and heat pumps. The original liquid flows inside the tube, and the high-temperature humid air from the high-temperature evaporator outside the tube exchanges heat with the fins. The use of a universal fin heat exchanger is beneficial for simultaneously improving heat exchange efficiency and reducing equipment costs.

[0026] The fin heat pipe low-temperature multi-effect evaporation sewage concentration device and process provided by the present invention adopts heat pump countercurrent two-stage evaporation concentration technology under low-temperature and low-pressure evaporation concentration conditions, with low energy consumption and low investment cost; adopts fin heat exchanger heat pipe technology, with high heat exchange efficiency and low cost; the heat pipe adopts a general product fin heat exchanger and is simply modified to improve the heat exchange efficiency and reliability of the heat pipe and reduce the cost; adopts liquid-gas heat exchanger heat recovery technology and has the dual effect of heat recovery / cold recovery; the liquid-gas heat exchanger directly adopts a general product fin heat exchanger, which is beneficial to improve the heat exchange efficiency and reliability and reduce the cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic diagram of the structure of the device of the present invention.

[0028] In the figure, liquid-gas heat exchanger -1, medium-temperature evaporator -2, medium-temperature condenser -3, second heat pipe -4, medium-temperature fan -5, heat pipe condensing end -6, refrigerant pipe -7, heat pipe evaporating end -8, high-temperature condenser -9, heat pump evaporator -10, heat pump condenser -11, high-temperature evaporator -12, medium-temperature circulation pump -13, high-temperature circulation pump -14, control valve -15, high-temperature fan -16, fin -17, spray pipe -18, heat pump unit -19, first heat exchange chamber -20, second heat exchange chamber -21. DETAILED DESCRIPTION

[0029] Embodiment 1: The fin heat pipe low-temperature multi-effect evaporation sewage concentration device provided by the present invention is as follows: Figure 1 As shown, the device includes: a concentration and evaporation device including at least two stages connected in series, the device includes a first heat exchange chamber 20 and a second heat exchange chamber 21, a liquid-gas heat exchanger 1, a medium-temperature evaporator 2, a medium-temperature condenser 3, a second heat pipe 4, a medium-temperature fan 5, a heat pipe condensation end 6, a refrigerant pipe 7, a heat pipe evaporation end 8, a high-temperature condenser 9, a heat pump evaporator 10, a heat pump condenser 11, a high-temperature evaporator 12, a medium-temperature circulation pump 13, a high-temperature circulation pump 14, a control valve 15, a high-temperature fan 16, and a fin 17, wherein:

[0030] Starting from the high-temperature humid air inlet end of the first heat exchange chamber, the liquid-gas heat exchanger 1, the heat pipe evaporation end 8 of the second heat pipe 4, the high-temperature fan 16, and the heat pump condenser 11 are arranged in sequence according to the flow direction of the high-temperature circulating air; the fins of the liquid-gas heat exchanger are arranged vertically, parallel to the flow direction of the circulating air and perpendicular to the direction of the fin cross tube (the flow path of the sewage raw liquid). The sewage raw liquid absorbs heat through the liquid-gas heat exchanger and condenses the water vapor in the high-temperature humid air, which increases the condensed water volume and the heat of the sewage raw liquid to facilitate subsequent evaporation, thereby increasing the evaporation energy efficiency of the system. The lower part of the first heat exchange chamber is the high-temperature condenser 9; the medium-temperature evaporator 2 has a feed liquid inlet, a medium-temperature humid air outlet, a discharge liquid outlet, and a medium-temperature dry air inlet. The liquid-gas heat exchanger is connected with the medium-temperature evaporator through the feed liquid port, and the air outlet of the medium-temperature evaporator is connected with the medium-temperature condenser 3; a second heat pipe is arranged in the second heat exchange chamber, and the fins of the second heat pipe are arranged horizontally and perpendicular to the direction of the refrigerant pipe 7. The second heat pipe is divided into an upper part and a lower part, the upper part is located in the second heat exchange chamber to form a heat pipe condensation end 6, and the lower part is located in the first heat exchange chamber to form a heat pipe evaporation end 8. The second heat exchange chamber is connected with the medium-temperature condenser and the medium-temperature evaporator, and a medium-temperature fan 5 is arranged at the air inlet; a high-temperature fan 16 is arranged at the air outlet of the first heat exchange chamber, and the high-temperature condenser 9 is arranged between the heat pipe evaporation end and the high-temperature fan; a heat pump unit 19 is arranged between the medium-temperature condenser and the high-temperature condenser for heat exchange.

[0031] In this embodiment, a medium-temperature circulation pump 13 is arranged at the outlet of the medium-temperature evaporator, a medium-temperature liquid circulation loop is formed between the medium-temperature evaporator and the medium-temperature circulation pump, and the medium-temperature evaporator is connected to the medium-temperature circulation pump by pipeline.

[0032] In this embodiment, a high-temperature circulation pump 14 is provided at the liquid outlet of the high-temperature evaporator 12 , and a high-temperature liquid circulation loop is formed between the high-temperature evaporator and the high-temperature circulation pump 16 .

[0033] The heat pump unit 19 of this embodiment includes a heat pump evaporator 10 and a heat pump condenser 11. A heat pump unit is arranged between the heat pump condenser and the heat pump evaporator to perform refrigerant circulation and heat exchange.

[0034] In this embodiment, a control valve 15 is provided on the pipeline connecting the high-temperature evaporator and the medium-temperature circulation pump.

[0035] Embodiment 2: A fin heat pipe low temperature multi-effect evaporation sewage concentration process, using the fin heat pipe low temperature multi-effect evaporation sewage concentration device described in Embodiment 1, comprising the following steps:

[0036] The method comprises at least two stages of sewage concentration and evaporation treatment, namely, a medium-temperature concentration and evaporation stage and a high-temperature concentration and evaporation stage, wherein the medium-temperature concentration and evaporation stage comprises the following steps: heat-absorbing sewage is obtained by heat exchange between sewage and high-temperature humid air;

[0037] The wastewater after absorbing heat is atomized to obtain water mist, and the water mist is heated and evaporated by medium-temperature dry air to obtain medium-temperature humid air;

[0038] Condensing the medium temperature humid air to obtain low temperature dry air and condensed water;

[0039] The low-temperature dry air is heat exchanged to become the medium-temperature dry air.

[0040] The high-temperature concentration evaporation section includes the following steps: after the high-temperature humid air is heat-exchanged with the sewage raw liquid, part of the water vapor in the high-temperature humid air is condensed, and the relatively high-temperature and relatively high-humid air after partial dehumidification continues to exchange heat with the medium-temperature dry air outside the condensation end of the heat pipe through the heat pipe at the evaporation end of the heat pipe, condenses and becomes relatively high-temperature dry air, and the relatively high-temperature dry air is then heat-exchanged with the heat pump condenser to increase the temperature, thereby obtaining high-temperature dry air;

[0041] The high-temperature liquid is atomized to obtain water mist, and the water mist is heated and evaporated by high-temperature dry air to obtain the high-temperature wet air and sewage concentrate.

[0042] The steps are specifically as follows: the cold sewage raw liquid flows through the liquid-gas heat exchanger in the second heat exchange chamber provided with the high-temperature condenser of the high-temperature concentration evaporation section, and the sewage raw liquid in the tube absorbs heat and heats up; the high-temperature humid air outside the tube releases heat and condenses, thereby increasing the condensation capacity of the high-temperature condenser, and at the same time, the sewage raw liquid absorbs heat to increase the evaporation energy efficiency of the system;

[0043] The heated sewage raw liquid enters the medium-temperature concentrated evaporation section, is pressurized by the circulating pump of the medium-temperature section, mixed with the circulating liquid from the medium-temperature evaporator, and sprayed through the spray pipe 18 at the top of the medium-temperature evaporator. The droplets exchange heat and evaporate with the medium-temperature circulating dry air heated by the condensing end of the heat pipe; the medium-temperature circulating dry air absorbs moisture to become medium-temperature humid air, and then flows into the heat pump evaporator in the medium-temperature condenser to release heat and dehumidify, and then enters the condensing end of the heat pipe through the medium-temperature fan to heat and absorb heat, becoming medium-temperature circulating dry air, and then flows into the medium-temperature evaporator for circulation and moisture absorption; the purified medium-temperature condensed water is discharged from the medium-temperature condensed water outlet at the bottom of the medium-temperature condenser.

[0044] Part of the pre-concentrated sewage enters the high-temperature concentration and evaporation section through the control valve, is mixed with the circulating liquid from the high-temperature evaporator that is pressurized by the high-temperature circulation pump, and is sprayed on the top of the high-temperature evaporator (a spray pipe 18 is also provided), and the droplets exchange heat with the high-temperature circulating dry air heated by the heat pump condenser and evaporate; it absorbs moisture to become high-temperature humid air, and then flows into the heat pipe evaporation end in the high-temperature condenser to release heat and dehumidify, and then enters the heat pump condenser through the high-temperature fan to heat and absorb heat, becoming high-temperature circulating dry air, and then flows into the high-temperature evaporator for circulation and moisture absorption; the purified high-temperature condensed water is discharged from the high-temperature condensed water outlet at the bottom of the high-temperature condenser; the concentrated liquid is discharged from the concentrated liquid outlet at the bottom of the high-temperature evaporator.

[0045] The second heat pipe 4 of this embodiment is a simple modification of a standardized fin heat exchanger for conventional air conditioners and heat pumps. The inlet and outlet of the refrigerant pipe of the fin heat exchanger are sealed, and a small amount of refrigerant is filled into the pipe after the pipe is evacuated. The amount of refrigerant filled is about 1 / 5 of the mass corresponding to the saturated vapor pressure of the refrigerant at the working temperature of the heat pipe. When installing, the refrigerant pipe is kept in a vertical direction to facilitate efficient heat transfer of the heat pipe, and the fins are in a horizontal direction. The fins 17 of the heat pipe are separated by partitions. The upper part is the condensation end of the heat pipe, which is placed behind the medium-temperature fan of the medium-temperature concentrated evaporation section; the lower part is the evaporation end of the heat pipe, which is placed in the high-temperature condenser of the high-temperature concentrated evaporation section. The fin heat exchanger is a high-efficiency, low-cost mature product produced in large quantities. The use of a universal product fin heat exchanger for the heat pipe is conducive to simultaneously improving the heat exchange efficiency of the heat pipe and reducing equipment costs.

[0046] The liquid-gas heat exchanger 1 of this embodiment is directly modified by using a fin heat exchanger of a standardized product for conventional air conditioners and heat pumps. The original liquid flows in the tube, and a plurality of fins are arranged longitudinally and perpendicular to the flow direction of the sewage. The high-temperature humid air from the high-temperature evaporator outside the tube exchanges heat with the fins. The fin heat exchanger is a high-efficiency, low-cost mature product produced in large quantities. The use of a general product fin heat exchanger is conducive to improving the heat exchange efficiency and reducing the equipment cost at the same time.

[0047] The device and treatment process of Examples 1 and 2 of the present invention can significantly reduce the cost by about 80-40% compared with the electric boiler evaporation concentration / MVR steam compression evaporation concentration / heat pump low-temperature vacuum evaporation concentration device;

[0048] Compared with the conventional heat pump evaporation dehumidification concentration device, which consumes about 250kwh of evaporation energy per ton of water, the low-temperature multi-effect evaporation wastewater concentration technology can achieve an evaporation energy consumption of about 125kwh per ton of water, which can significantly reduce energy consumption by about 50%, saving more energy and reducing costs.

[0049] Compared with other heat pipe heat exchangers, the use of fin heat exchangers as heat pipe heat exchangers has the advantages of high reliability, high efficiency and low cost.

[0050] The above are only preferred embodiments of the present invention, and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A fin heat pipe low-temperature multi-effect evaporation sewage concentration process, characterized in that: A fin heat pipe low-temperature multi-effect evaporation sewage concentration device is adopted, and the concentration process includes at least a medium-temperature concentration evaporation section and a high-temperature concentration evaporation section. The medium-temperature concentration evaporation section includes the following steps: sewage is heat-exchanged with high-temperature humid air to obtain heated sewage, the heated sewage after absorbing heat is atomized to obtain water mist, the water mist is heated and evaporated by medium-temperature dry air to obtain medium-temperature humid air, the medium-temperature humid air is heat-exchanged and dehumidified to obtain low-temperature dry air and condensed water, and the low-temperature dry air is heat-exchanged to become the medium-temperature dry air; the high-temperature concentration evaporation section includes the following steps: the high-temperature humid air is heat-exchanged with the sewage stock solution, the high-temperature humid air is Part of the water vapor in the air condenses, and part of the higher temperature and higher humid air after dehumidification continues to exchange heat with the medium-temperature dry air outside the condensation end of the heat pipe through the heat pipe at the evaporation end of the heat pipe, and condenses to become higher temperature dry air. The higher temperature dry air then exchanges heat with the heat pump condenser to increase the temperature, and obtains high-temperature dry air. Through the circulation and atomization treatment of the high-temperature liquid, water mist is obtained, and the water mist is heated and evaporated by the high-temperature dry air to obtain the high-temperature humid air and sewage concentrate; the concentration process steps are specifically as follows: the cold sewage stock liquid flows through the liquid-gas heat exchanger in the second heat exchange chamber equipped with the high-temperature condenser of the high-temperature stage concentration evaporation section, and the sewage stock liquid in the pipe absorbs The heated sewage raw liquid enters the medium-temperature concentrated evaporation section, is pressurized by the circulating pump of the medium-temperature section, mixed with the circulating liquid from the medium-temperature evaporator, and sprayed on the top of the medium-temperature evaporator. The droplets exchange heat and evaporate with the medium-temperature circulating dry air heated by the condensing end of the heat pipe. The medium-temperature circulating dry air absorbs moisture to become medium-temperature humid air, and then flows into the heat pump evaporator in the medium-temperature condenser to release heat and dehumidify. Then it enters the condensing end of the heat pipe through the medium-temperature fan to heat and absorb heat, becoming medium-temperature circulating dry air, and then flows into the medium-temperature evaporator for circulation to absorb moisture. The purified medium-temperature condensed water is discharged from the medium-temperature condensed water outlet at the bottom of the medium-temperature condenser; part of the pre-concentrated sewage is passed through the heat pump evaporator in the medium-temperature condenser to release heat and dehumidify. It enters the high-temperature concentration and evaporation section through the control valve, is pressurized by the high-temperature circulation pump, mixed with the circulating liquid from the high-temperature evaporator, and sprayed on the top of the high-temperature evaporator. The droplets exchange heat with the high-temperature circulating dry air heated by the heat pump condenser and evaporate, absorb moisture to become high-temperature wet air, and then flow into the heat pipe evaporation end in the high-temperature condenser to release heat and dehumidify, and then enter the heat pump condenser through the high-temperature fan to heat and absorb heat, becoming high-temperature circulating dry air, and then flow into the high-temperature evaporator for circulation and moisture absorption. The purified high-temperature condensed water is discharged from the high-temperature condensed water outlet at the bottom of the high-temperature condenser, and the concentrated liquid is discharged from the concentrated liquid outlet at the bottom of the high-temperature evaporator.

2. The fin heat pipe low-temperature multi-effect evaporation wastewater concentration process according to claim 1 is characterized in that: The fin heat pipe low-temperature multi-effect evaporation sewage concentration device includes at least two-stage series-connected concentration and evaporation systems, and the system includes: a first heat exchange chamber, a second heat exchange chamber, a heat pipe, a medium-temperature evaporator, and a medium-temperature condenser. The heat pipe includes an upper heat pipe condensation end and a lower heat pipe evaporation end. Starting from the high-temperature humid air inlet end of the first heat exchange chamber, a liquid-gas heat exchanger, a heat pipe evaporation end, a high-temperature fan, and a heat pump condenser are arranged in sequence according to the flow direction of the high-temperature circulating air. The lower part of the first heat exchange chamber is a high-temperature condenser; in the second heat exchange chamber, a medium-temperature fan and a heat pipe condensation end are arranged in sequence starting from the medium-temperature dry air inlet end according to the flow direction of the medium-temperature circulating air, and the air outlet of the second heat exchange chamber, the air inlet of the medium-temperature evaporator, the air outlet of the medium-temperature evaporator, the air inlet of the medium-temperature evaporator, the air inlet of the medium-temperature condenser, the air outlet of the medium-temperature condenser, and the air inlet of the second heat exchange chamber are connected in sequence by pipelines to form a medium-temperature circulating air flow path.

3. The fin heat pipe low-temperature multi-effect evaporation wastewater concentration process according to claim 2 is characterized in that: The heat pipe adopts a fin heat exchanger, and a plurality of fins are arranged horizontally and perpendicular to the direction of the refrigerant pipe.

4. The fin heat pipe low-temperature multi-effect evaporation wastewater concentration process according to claim 3 is characterized in that: The heat pipe adopts a standardized fin heat exchanger for conventional air conditioners or heat pumps. The inlet and outlet of the refrigerant pipe of the fin heat exchanger are sealed, and the pipe is filled with refrigerant.

5. The fin heat pipe low-temperature multi-effect evaporation wastewater concentration process according to claim 4 is characterized in that: The amount of the refrigerant is 1 / 5 of the mass corresponding to the saturated vapor pressure of the refrigerant at the working temperature of the heat pipe.

6. The fin heat pipe low-temperature multi-effect evaporation wastewater concentration process according to claim 2 is characterized in that: The liquid-gas heat exchanger adopts a standardized fin heat exchanger for conventional air conditioners or heat pumps. The raw liquid flows in the tubes, and a plurality of fins are vertically arranged and perpendicular to the flow direction of the sewage raw liquid.

7. The fin heat pipe low-temperature multi-effect evaporation wastewater concentration process according to claim 5 or 6, characterized in that: A medium-temperature circulation pump is arranged at the outlet of the medium-temperature evaporator, and a medium-temperature liquid circulation loop is formed between the medium-temperature evaporator and the medium-temperature circulation pump; a high-temperature circulation pump is arranged at the outlet of the high-temperature evaporator, and a high-temperature liquid circulation loop is formed between the high-temperature evaporator and the high-temperature circulation pump.

8. The fin heat pipe low-temperature multi-effect evaporation wastewater concentration process according to claim 7 is characterized in that: A heat pump unit is arranged between the heat pump condenser and the heat pump evaporator for refrigerant circulation and heat exchange.

9. The fin heat pipe low-temperature multi-effect evaporation wastewater concentration process according to claim 8, characterized in that: A control valve is arranged on the pipeline connecting the high-temperature evaporator and the medium-temperature circulation pump.

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