CN115920439A - Integrated multi-effect condensation low temperature evaporation concentration system - Google Patents

Abstract

The invention belongs to the field of energy environmental protection, and particularly relates to an integrated multi-effect condensation low-temperature evaporation concentration system. The system integrates material heating evaporation and steam condensation in a container tank, adopts a three-level steam condensation scheme, has good heat transfer effect of a heat exchange part, high steam condensation efficiency, low operation energy consumption, low maintenance cost and long service life, and effectively utilizes different grades of energy sources such as solar energy, natural cold source and the like to improve the energy efficiency of the system. The system can efficiently condense secondary steam to maintain vacuum degree, and can also improve the heat exchange environment at the evaporator side during initial start. Compared with the prior art, the system can achieve the purposes of energy conservation, emission reduction and carbon reduction.

Description

Integrated multi-effect condensation low temperature evaporation concentration system

technical field

The invention belongs to the field of energy and environmental protection, and in particular relates to an integrated multi-effect condensation low-temperature evaporation concentration system.

Background technique

Evaporation and concentration is a common process in the industrial field. This process obtains a high concentration of solute by enhancing the evaporation of water in the solution. The common method at present is to heat the solution to the boiling point temperature of the solvent water, and the solvent water becomes steam to escape by boiling. When there is no high-quality waste heat source or the material is sensitive to high temperature, the use of reverse Carnot cycle heat pump vacuum low-temperature evaporation concentration system is currently a more efficient treatment method. This method has low operating temperature for material evaporation and high utilization rate of primary energy. It has become a An important technical measure for energy saving and carbon reduction in the evaporation and concentration process.

There are still some problems in the existing technology, so that the advantages of heat pump vacuum low-temperature evaporation and concentration technology have not been brought into play, which are mainly reflected in the following aspects:

(1) The heat pump vacuum low-temperature evaporation and concentration system has a low integration level, not only occupies a large area, but also has a large total volume to be vacuumed.

(2) Since the heat output side of the heat pump cycle has more heat produced by the compressor than the heat absorption side, in order to maintain the heat and cold balance of the heat pump cycle, the existing practice is to attach an air cooling device in front of the expansion valve to discharge this part of the heat This part of the heat is not used as heat loss, which reduces the energy efficiency of the system.

(3) The boiling of the material needs to maintain a certain degree of vacuum. The maintenance of the degree of vacuum requires the high-efficiency condensation of the secondary steam and the vacuum system. The existing system cannot efficiently condense the rapidly produced secondary steam, which not only reduces the This not only improves the condensation heat recovery effect on the side of the heat pump evaporator, but also increases the pumping burden of the vacuum system and increases energy consumption.

(4) In the traditional process, during the initial start-up material heating process, due to the non-boiling and evaporation, the heat exchange parts have no steam contact, which makes the refrigeration cycle condition worse. At present, the method of adding auxiliary electric heaters is generally adopted to solve this problem, and further increase system energy consumption.

(5) The existing technology does not consider the problem of cascade utilization according to the grade of heat energy. Due to the high temperature of the steam, the temperature gradient between the condensation temperature of the steam and the evaporation temperature of the refrigerant is very large, and the cascade condensation cannot be realized by relying on a single refrigerant cooling method, reducing the the energy efficiency of the system.

(6) The existing heat pump vacuum low-temperature evaporation concentration technology does not fully consider the use of high-efficiency secondary steam condensation heat exchange, resulting in the need to rely on lower evaporation temperatures to recover condensation heat, resulting in low energy efficiency of the heat pump cycle system.

Contents of the invention

The invention aims to solve the problems and shortcomings of the prior art, and the invention provides an integrated multi-effect condensation low-temperature evaporation and concentration system.

The integrated multi-effect condensing low-temperature evaporation and concentration system of the present application includes a condensing low-temperature evaporation and concentration tank, a heat pump cycle compressor, a primary heat exchanger, and evaporative cooling equipment, wherein,

The interior of the condensing low-temperature evaporation concentration tank is equipped with a heating coil, a stirring plate, a defoaming device, a primary condensation coil, an atomizing nozzle, an evaporator coil, a partition plate, and a diffuser fin;

The bottom plate of the separating tube plate is welded together with the inner wall of the condensing low-temperature evaporation concentration tank to form a hollow annular cylindrical structure, and the cylinder of the separating tube plate is a steam flow channel;

The diffusion fins are arranged on the top of the cylinder of the partition plate;

The defoaming device is arranged between the liquid surface of the material and the bottom plate of the separating cylinder plate;

The evaporator coil is arranged between the partition tube plate and the inner wall of the multi-effect condensation low-temperature evaporation concentration tank;

The high-temperature and high-pressure refrigerant is pumped into the heating coil through the heat pump cycle compressor, and the dilute material sent to the condensing low-temperature evaporation concentration tank is heated under vacuum conditions. During the heating process, the agitating blade continuously stirs the dilute material, The generated secondary steam is purified by the defoaming device, and condensed after passing through the cylinder of the separating cylinder plate and the diffuser fins;

The primary condensing coil utilizes the cooling water produced by the evaporative cooling equipment to perform cascade condensation heat exchange on the secondary steam;

The cooled refrigerant is sent to the primary heat exchanger, and circulated to the evaporator coil in the condensing low-temperature evaporation concentration tank for heat recovery, and then sent to the heat pump cycle compressor, and the dilute material is heated The generated steam is pre-cooled by the primary condensing coil to generate part of condensed water, and then the atomized water sprayed by the atomizing nozzle is directly contacted for condensation and absorption, and then sprayed to the evaporator coil, and stored in the bottom of the dividing tube plate;

The condensate low-temperature evaporation concentration tank is equipped with a condensate pump, the inlet pipe of the condensate pump is connected to the upper part of the bottom plate of the partition plate, and the outlet pipe is connected to the atomizing nozzle, which atomizes the condensed water into fine particles. Liquid droplets, direct contact with condensation to absorb water vapor;

The cooling water generated by the evaporative cooling equipment is input into the primary condensing coil to pre-cool the secondary steam evaporated from the multi-effect condensing low-temperature evaporative concentration tank.

According to the integrated multi-effect condensation low-temperature evaporation and concentration system of the present application, the system includes a vacuum unit to discharge the non-condensable gas treated by the multi-effect condensation low-temperature evaporation and concentration tank through vacuuming.

According to the integrated multi-effect condensation low-temperature evaporation and concentration system of the present application, the pumping unit includes a vacuum circulating pump, a water tank, and a vacuum ejector, wherein,

The water tank is provided with a porous pipe and immersed in water;

The vacuum circulation pump draws the water in the water tank, a part of the non-condensable gas after the evaporation and condensation of dilute materials is sucked by the vacuum ejector, and then discharged into the water tank through the porous pipe; the other part is sent to the primary heat exchanger to exchange with the refrigerant. hot.

According to the integrated multi-effect condensation low-temperature evaporation and concentration system of the present application, a liquid blocking baffle is arranged at the suction port of the vacuuming pipeline of the vacuum ejector.

According to the integrated multi-effect condensation low-temperature evaporation concentration system of the present application, the vacuum unit further includes a circulating water temperature control device for regulating the water temperature in the water tank.

According to the integrated multi-effect condensation low-temperature evaporation and concentration system of the present application, the outside of the condensation and low-temperature evaporation and concentration tank is connected with a thin feed liquid inlet pipe and a concentrated feed liquid outlet pipe.

According to the integrated multi-effect condensation low-temperature evaporation and concentration system of the present application, the outer wall of the integrated multi-effect condensation low-temperature evaporation and concentration tank is provided with an insulation layer.

According to the integrated multi-effect condensation low-temperature evaporation and concentration system of the present application, the water inlet pipe of the condensate pump is connected to the upper part of the bottom plate of the partition plate, and the water outlet pipe is connected to the atomizing nozzle.

According to the integrated multi-effect condensation low-temperature evaporation and concentration system of the present application, the heating coil and the evaporator coil are inner finned tubes that enhance heat exchange in the tubes.

According to the integrated multi-effect condensation low-temperature evaporation concentration system of the present application, the system further includes a solar material preheating unit, and the solar material preheating unit includes a solar collector, a dilute liquid preheating tank, and a preheating circulation pump . The temperature control device of the preheating tank, wherein the solar heat collector provides a heat source, and the hot water in the preheating coil in the thinner liquid preheating tank is heated by circulation to reach the set temperature, and then sent to the multi-effect condensing In the low-temperature evaporation concentration tank, the temperature control device of the preheating tank is used to control the temperature of the inlet water of the preheating coil, and the preheating circulation pump is used to provide hot water circulation power.

The advantage of the technical solution of the present application:

Aiming at the above-mentioned problems in the prior art, this application provides an improved heat pump vacuum low-temperature evaporation and concentration system, which integrates material heating, evaporation and steam condensation in a container tank, and adopts a three-stage steam condensation scheme, heat exchange The heat transfer effect of the components is good, the steam condensation efficiency is high, the energy consumption is low, the maintenance cost is low, and the service life is long. At the same time, different grades of energy such as solar energy and natural cooling sources are effectively used to improve the system energy efficiency. The system efficiently condenses secondary steam to maintain vacuum and improves the heat transfer environment on the evaporator side during initial start-up. Compared with the existing technology, the system can achieve the purpose of energy saving, emission reduction and carbon reduction.

1. Integrating the heating evaporation of the material and the condensation of the secondary steam in a container tank, shortening the flow of the steam, reducing the space volume that needs to maintain the vacuum degree, and reducing the overall footprint of the system.

2. Make full use of the heat produced by the compressor to heat the material. On the premise of ensuring the heat and cold balance of the heat pump cycle, the heat of material heating is increased.

3. The secondary steam is condensed through the primary condensation coil, the water spray of the atomizing nozzle and the evaporator coil respectively. The three-stage condensation can quickly and efficiently absorb the secondary steam produced by the boiling of the material, reducing the impact of a large amount of steam output on vacuum The disturbance of the vacuum degree in the container reduces the steam extraction load of the vacuum system.

4. The condensed water circulation spraying part is set up. When the system is initially started, there is no stage of absorbing steam heat, and the evaporator coil can be sprayed circularly to realize the normal operation of the heat pump cycle.

5. Taking into account the technical measures of cascaded utilization of heat energy, the high-temperature steam is first condensed with high-temperature cooling water generated by evaporative cooling equipment, and then directly contacted with condensed water spray to condense, and finally the low-temperature evaporator coil is further absorbed and condensed. The heat transfer temperature gradient is reduced and the energy efficiency level is improved.

6. The high-efficiency absorption method of direct contact with condensation by condensate spray is adopted, which improves the absorption efficiency of steam and the efficiency of condensation heat exchange.

7. Using solar energy to preheat the dilute material reduces the sensible heat heating link of the dilute material in the integrated multi-effect condensation low-temperature evaporation concentration tank. The heating coil of the heat pump circulation system directly performs boiling evaporation heat exchange, which improves the The heat transfer efficiency of material evaporation.

Description of drawings

Fig. 1 is the structural representation of the integrated multi-effect condensation low-temperature evaporation concentration system of the present invention;

Reference signs:

1: Integrated multi-effect condensation low-temperature evaporation concentration tank, 11: Stirring motor, 12: Defoaming device, 13: Stirring plate, 14: Thin material liquid inlet pipe, 15: Concentrated material liquid outlet pipe, 16: Separation tube plate, 161 : Separation tube plate bottom plate, 162: Separation tube plate cylinder, 17: Diffusion fins, 18: Condensate water pump, 19: Condensate water outlet pipe, 110: Atomizing nozzle, 111: Insulation layer,

2: Compressor, 21: Heating coil, 22: Expansion valve, 23: Primary heat exchanger, 24: Evaporator coil, 3: Evaporative cooling equipment, 31: Cooling water pump, 32: Cooling water temperature control device, 33 : primary condensing coil,

4: Vacuum circulating pump, 41: Ejector, 42: Liquid blocking baffle, 43: Porous tube, 44: Water tank, 45: Circulating water temperature control device,

5: thinner liquid preheating tank, 51: preheating coil, 52: preheating circulation pump, 53: solar collector, 54: temperature control device for preheating tank, 55: preheating tank vent, 56: thinner liquid Pump, 57: preheat tank insulation.

Detailed ways

The technical solutions of the present application are described in detail below in conjunction with specific embodiments.

The integrated multi-effect condensation low-temperature evaporation and concentration system of the present application includes a condensation low-temperature evaporation concentration tank, a heat pump cycle compressor, a primary heat exchanger, and an evaporative cooling device, wherein the inside of the condensation low-temperature evaporation concentration tank is provided with a heating coil, Stirring plate, defoaming device, primary condensing coil, atomizing nozzle, evaporator coil, separating tube plate, diffuser fin.

A stirring motor is arranged above the exterior of the multi-effect condensation low-temperature evaporation concentration tank for driving the stirring blades.

The outside of the multi-effect condensation low-temperature evaporation concentration tank is connected with a thin feed liquid inlet pipe and a concentrated feed liquid outlet pipe.

The condensing low-temperature evaporation concentration tank is provided with a partition tube plate and diffuser fins to form steam flow and treatment channels. The diffuser fins are arranged on the top of the partition plate cylinder for steam diffuser. The condensing low-temperature evaporation concentration tank is equipped with a condensate pump, an atomizing nozzle and a condensate outflow pipe, which are used for direct contact condensation of steam and discharge of excess condensate. The defoaming device is arranged between the liquid surface of the material and the bottom plate of the separating cylinder plate. The water inlet pipe of the condensed water pump is connected to the upper part of the bottom plate of the partition tube, and the water outlet pipe is connected to the atomizing nozzle, which atomizes the condensed water into fine droplets and directly contacts the condensation to absorb water vapor.

The heating coil, primary condensation coil, atomizing nozzle, and evaporator coil are all arranged in the integrated multi-effect condensation low-temperature evaporation concentration tank to realize spatial integration of heating evaporation and secondary steam condensation. The heating coil and the evaporator coil employ inner finned tubes that enhance heat transfer within the tubes.

The outer wall of the condensation low-temperature evaporation concentration tank is provided with an insulation layer.

The heat pump cycle is realized by a heat pump compressor, heating coil, expansion valve, primary heat exchanger, and evaporator coil, wherein the heat pump compressor provides power for the heat pump cycle, and the heating coil is set at the condensing low-temperature evaporation In the concentration tank, it is used to heat the material. The evaporator coil is arranged between the separation cylinder plate and the inner wall of the multi-effect condensation low-temperature evaporation concentration tank, and is used to cool the condensed water and further absorb the steam by falling film; the primary exchange The heater is used to cool the circulating water of the vacuum unit. The high-temperature and high-pressure refrigerant at the outlet of the heat pump compressor enters the heating coil in the integrated multi-effect condensation low-temperature evaporation concentration tank, heats the material, and then sends it into the primary heat exchanger after being throttled by the expansion valve. It then goes through the evaporator coil for further heat absorption and returns to the compressor.

The condensing low-temperature evaporation concentration tank is used to store the dilute material that undergoes boiling evaporation. The dilute material fed into the condensing low-temperature evaporation concentration tank is heated to the boiling point under vacuum conditions and begins to boil and evaporate. During the heating process, the stirring motor rotates to drive the stirring The sheet continuously stirs the material liquid, and the secondary steam generated is purified by the defoaming device, and then condensed after passing through the separating cylinder, plate cylinder and diffuser fins.

Primary condensation is realized through evaporative cooling equipment, cooling water pump, cooling water temperature control device and primary condensation coil, and primary condensation is performed on the secondary steam evaporated from the condensing low-temperature evaporation concentration tank to ensure the cold and heat balance of the heat pump cycle , the evaporative cooling equipment produces circulating cooling water, the cooling water pump provides cooling water circulation power, and the cooling water temperature control device is used to control the inlet water temperature of the primary condensing coil when the outdoor weather conditions change, so as to control its heat dissipation . The primary condensing coil is arranged in the front stage of the secondary steam condensation treatment, and uses the cooling water produced by the evaporative cooling equipment to perform cascade condensation heat exchange on the secondary steam.

The evaporative cooling equipment generates cooling water lower than the temperature of the steam, which is pumped into the primary condensation coil, and the heat dissipation is adjusted by the cooling water temperature control device.

Condensation The purified steam in the low-temperature evaporation concentration tank is condensed and dissipated by the primary condensation coil to ensure heat balance. The excess steam after the primary condensation is absorbed by the spray droplets formed by the atomizing nozzle, and then passed through the evaporator coil. After further falling film absorption and cooling, low-temperature condensed water is formed, which is stored at the bottom plate of the partition tube plate for circulating spraying, and excess condensed water is discharged through the condensed water outlet pipe.

Vacuum circulating pump, ejector, liquid blocking baffle, porous pipe, water tank, circulating water temperature control device realize vacuuming, and are used to form negative pressure, so as to suck the excess water in the integrated multi-effect condensation low-temperature evaporation concentration tank. Remaining steam and non-condensable gas ensure the vacuum environment in the condensing low-temperature evaporation concentration tank. The vacuum circulating pump extracts the circulating water and sprays it through the ejector to extract the excess steam and non-condensable gas after the condensation process in the integrated multi-effect condensation low-temperature evaporation concentration tank. The liquid blocking baffle is set at the suction port of the vacuum tube to prevent the suction of condensed water. The porous tube is set in the water tank and immersed in the circulating water, and the vacuum circulating pump sends part of the circulating water to the primary heat exchanger at the same time. Heat, increase the heat absorption of the heat pump circulation system while dissipating heat for the water tank. The branch of the vacuum jet is connected to the vacuum pipeline, the outlet pipe of the vacuum jet is connected to the porous pipe, the bottom of the porous pipe is closed, and a plurality of jet round holes are arranged around it.

It also includes a solar material preheating unit, the solar material preheating unit includes a solar collector, a thinner liquid preheating tank, a preheating circulation pump, a temperature control device for the preheating tank, and a thinner liquid pump, wherein the solar heat collection The heat source is provided by the device, and the hot water in the preheating coil in the thinner liquid preheating tank is heated to the set temperature by circulation, and then sent to the multi-effect condensation low-temperature evaporation concentration tank, and the temperature control device of the preheating tank is used In order to control the water inlet temperature of the preheating coil, the preheating circulation pump is used to provide hot water circulation power. The solar material preheating unit uses the hot water produced by the solar collector to preheat the diluted material to be concentrated, so as to reduce the heating load of the heat pump circulation system.

The technical solutions of the present application are described below in conjunction with the accompanying drawings.

As shown in Figure 1, the dilute material is preheated before entering the condensing low-temperature evaporation concentration tank 1 to make it reach the boiling point temperature under the designed vacuum degree. The hot water in the preheating coil 51 in the preheating tank 5 is circulated and heated to a set temperature, and is sent to the condensing low-temperature evaporation concentration tank 1 through the thinner liquid pump 56 . The temperature control device 54 of the preheating tank is used to control the temperature of the water entering the preheating coil 51 to prevent the temperature from being too high. The preheating circulation pump 52 is used to provide hot water circulation power.

The dilute material sent to the condensing low-temperature evaporation concentration tank 1 is heated to the boiling point by the heating coil 21 under vacuum condition and starts to boil and evaporate. Cohesion and coking are reduced while exchanging heat and escaping steam. After being purified by the defoaming device 12, the generated steam enters the condensation link through the flow channel formed by the partition tube plate 16 and the diffuser fin 17. The concentrated material that meets the treatment requirements is discharged through the concentrated material liquid outlet pipe 15.

The generated steam is pre-cooled by the primary condensing coil 33, and the temperature is lowered to produce part of condensed water, and then the atomized water sprayed by the atomizing nozzle 110 is directly contacted for condensation absorption, and then sprayed to the evaporator coil 24, after cooling Stored at the bottom of the partition plate 16, the condensed water pump 18 provides power for condensed water circulation. The excess condensed water is discharged through the condensed water outlet pipe 19. Before the system runs, the bottom of the partition tube plate 16 should be filled with tap water first, so as to ensure that the evaporator coil 24 can absorb heat and realize the heat pump cycle.

The high-temperature and high-pressure refrigerant at the outlet of the heat pump compressor 2 enters the heating coil 21 to heat the material, and then is throttled by the expansion valve 22 and sent to the primary heat exchanger 23 and the evaporator coil 24 for heat recovery. The heating coil 21 is submerged in the material of the condensing low-temperature evaporation concentration tank 1 . Preferably, the heating coil 21 and the evaporator coil 24 adopt internal finned tubes to enhance heat exchange in the tubes.

The cold source of the primary condensation system used for the cooling of the primary condensation coil 33 adopts an efficient evaporative cooling method, and the secondary steam evaporated from the integrated multi-effect condensation low-temperature evaporation concentration tank 1 is pre-heated by the cooling water generated by the evaporative cooling device 3. Cooling to ensure the heat and cold balance of the heat pump cycle system. When the outdoor weather conditions change, the cooling water temperature control device 32 is used to control the inlet water temperature of the primary condensing coil 33 to control its cooling capacity.

The remaining steam, air and other non-condensable gases processed by the condensed low-temperature evaporation concentration tank 1 are vacuumized and discharged, and the vacuum pump 4 extracts the water in the water tank 44, and a part of the above components are sucked by the vacuum ejector 41. It is discharged into the water tank 44 through the porous pipe 43, and the other part is sent to the primary heat exchanger 23 to exchange heat with the refrigerant, so as to increase the heat recovered by the heat pump system and reduce the water temperature in the water tank 44. A liquid-blocking baffle 42 is provided at the suction port of the vacuuming pipeline of the vacuum ejector 41 to prevent the suction of condensed water. The porous pipe 43 is arranged in the water tank 44 and immersed in water for directly absorbing the remaining steam. The circulating water temperature control device 45 is used to regulate the water temperature in the water tank 44 so that it is at a lower level, so as to improve the efficiency of the vacuuming system.

According to the integrated multi-effect condensation low-temperature evaporation and concentration system of the present application, the liquid blocking baffle of the vacuum pumping system is arranged at the suction port of the vacuum pumping pipe to prevent the suction of condensed water, and the porous pipe is arranged in the water tank and submerged In the circulating water, the vacuum circulating pump simultaneously sends part of the circulating water to the primary heat exchanger for heat exchange, which increases the heat absorption of the heat pump circulating system while dissipating heat for the water tank.

According to the integrated multi-effect condensation low-temperature evaporation concentration system of the present application, the branch of the vacuum ejector is connected to the vacuum pipeline, the outlet pipe of the vacuum ejector is connected to the porous pipe, and the bottom of the porous pipe is closed, A plurality of jet circular holes are arranged around.

The edge of the bottom plate of the partition tube plate is welded and sealed with the inner wall of the integrated multi-effect condensation low-temperature evaporation concentration tank 1. The secondary steam rises to the diffuser fin through the interior of the partition tube plate cylinder, and after being diffused by the diffuser fin, it turns back To the primary condensation coil 33 for condensation. The annular cavity formed by the bottom plate of the partition tube plate, the partition tube plate cylinder and the inner wall of the integrated multi-effect condensation low-temperature evaporation concentration tank 1 is used to accommodate the primary condensation coil 33, the atomizing nozzle 110 and the evaporator coil 24 , and at the same time separate the bottom plate of the tube plate to undertake condensed water.

The above is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto, any person familiar with the technical field within the technical scope disclosed in the present invention, according to the technical solution of the present invention Any equivalent replacement or change of the inventive concepts thereof shall fall within the protection scope of the present invention.

Claims (10)

1. The integrated multi-effect condensation low-temperature evaporation concentration system is characterized by comprising a condensation low-temperature evaporation concentration tank, a heat pump circulating compressor, a primary heat exchanger and evaporation cooling equipment, wherein a heating coil, stirring blades, a defoaming device, a primary condensation coil, an atomizing spray head, an evaporator coil, a separating barrel plate and a flow dispersing fin are arranged inside the condensation low-temperature evaporation concentration tank,

the separating cylinder plate comprises a bottom plate and a cylinder, the bottom plate of the separating cylinder plate and the inner wall of the condensing low-temperature evaporation concentration tank are welded into a whole to form a hollow annular cylindrical structure, and the cylinder of the separating cylinder plate is a steam flow channel;

the flow dispersing fins are arranged at the top of the cylinder of the separating cylinder plate;

the defoaming device is arranged between the liquid level of the material and the bottom plate of the separating cylinder plate;

the evaporator coil is arranged between the separating cylinder plate and the inner wall of the multi-effect condensation low-temperature evaporation concentration tank;

pumping a high-temperature and high-pressure refrigerant into the heating coil through the heat pump circulating compressor, stirring the dilute material which is heated and sent into the condensing low-temperature evaporation and concentration tank by the stirring sheet under a vacuum condition, purifying generated secondary steam by the foam eliminating device, and condensing the secondary steam after the secondary steam passes through the cylinder of the separating cylinder plate and the flow dispersing fins;

the primary condensing coil pipe performs cascade condensation heat exchange on secondary steam by using cooling water generated by the evaporative cooling equipment;

the cooled refrigerant is sent into the primary heat exchanger, circulated to the evaporator coil in the condensation low-temperature evaporation concentration tank for heat recovery, then sent to the heat pump circulating compressor, steam generated by heating of the dilute material is pre-cooled by the primary condensation coil to generate partial condensed water, and then atomized water sprayed by an atomization nozzle directly contacts with the condensation and absorption, is sprayed to the evaporator coil and is stored at the bottom of the separation barrel plate after being cooled;

the condensation low-temperature evaporation and concentration tank is provided with a condensate pump, a water inlet pipe of the condensate pump is connected with the upper part of the bottom plate of the separation barrel plate, a water outlet pipe of the condensate pump is connected with the atomizing nozzle, and the atomizing nozzle atomizes condensate water into fine liquid drops which directly contact with condensation to absorb water vapor;

and cooling water generated by the evaporation cooling equipment is input into the primary condensing coil to pre-cool secondary steam evaporated by the multi-effect condensation low-temperature evaporation concentration tank.

2. The integrated multi-effect condensation low-temperature evaporation concentration system according to claim 1, wherein the system comprises a vacuum pumping unit, and the non-condensable gas treated by the multi-effect condensation low-temperature evaporation concentration tank is discharged through vacuum pumping.

3. The integrated multi-effect condensation cryogenic evaporation concentration system of claim 2, wherein the evacuation unit comprises an evacuation circulation pump, a water tank, a vacuum ejector, wherein,

a porous pipe is arranged in the water tank and is immersed in water;

the vacuumizing circulating pump pumps water in the water tank, and a part of non-condensable gas generated by evaporating and condensing the dilute material is pumped by the vacuum ejector and then is discharged into the water tank through the porous pipe; the other part is sent to the primary heat exchanger to exchange heat with the refrigerant.

4. The integrated multi-effect condensation low-temperature evaporation and concentration system as claimed in claim 3, wherein a liquid blocking baffle is arranged at a suction inlet of a vacuum pumping pipeline of the vacuum ejector.

5. The integrated multi-effect condensation and low-temperature evaporation concentration system as claimed in claim 3, wherein the vacuum pumping unit further comprises a circulating water temperature control device for controlling the temperature of water in the water tank.

6. The integrated multi-effect condensation low-temperature evaporation concentration system according to claim 1, wherein a dilute feed liquid inlet pipe and a concentrated feed liquid outlet pipe are connected to the outside of the condensation low-temperature evaporation concentration tank.

7. The integrated multi-effect condensation low-temperature evaporation concentration system as claimed in claim 1, wherein the outer wall of the integrated multi-effect condensation low-temperature evaporation concentration tank is provided with an insulating layer.

8. The integrated multi-effect condensation and low-temperature evaporation concentration system as claimed in claim 1, wherein the condensate pump is connected with the upper part of the bottom plate of the separation barrel plate through a water inlet pipe, and the water outlet pipe is connected with the atomizing spray head.

9. The integrated multi-effect condensing cryogenic evaporative concentration system of claim 1 wherein the heating coils and the evaporator coils are internally ribbed tubes that enhance heat transfer within the tubes.

10. The integrated multi-effect condensation low-temperature evaporation concentration system according to claim 1, further comprising a solar material preheating unit, wherein the solar material preheating unit comprises a solar heat collector, a thin liquid preheating tank, a preheating circulating pump and a preheating tank temperature control device, wherein the solar heat collector provides a heat source, the heat is heated by hot water circulation in a preheating coil in the thin liquid preheating tank to reach a set temperature, the heat is sent into the multi-effect condensation low-temperature evaporation concentration tank, the preheating tank temperature control device is used for controlling the water inlet temperature of the preheating coil, and the preheating circulating pump is used for providing hot water circulation power.

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