Integrated slurry flash evaporation spraying heat exchange tower and waste heat utilization system

Abstract

The invention provides an integrated slurry flash evaporation and spray heat exchange tower and a waste heat utilization system, and the integrated slurry flash evaporation and spray heat exchange tower is characterized in that a spray chamber (31) and a flash evaporation chamber (32) are arranged in a tower body (3) and are communicated through a ventilation waterproof cap layer (6); a waste heat water spraying layer (4) is arranged in the spraying chamber (31); a waste heat water collecting box (19) on the side face is communicated with the spraying chamber (31) and collects waste heat water on the ventilation waterproof cap layer (6). A slurry spraying layer (7) is arranged in the flash chamber (32), and a slurry descending pipe (11) is arranged at the bottom of the flash chamber (32); and the top of the spraying chamber (31) is connected with a vacuum pump (1). Flashing and spraying are integrated in one tower body (3), and flashed exhaust gas can be in contact with waste heat water to release heat without passing through an exhaust gas pipeline, so that the cost of the exhaust gas pipeline is saved; the ventilation waterproof cap layer (6) enables exhaust gas to enter the spraying chamber (31) with low resistance, and loss of exhaust gas pressure and condensation temperature is reduced. Waste heat water is in direct contact with exhaust gas for heat exchange, and the influence of non-condensable gas on exhaust gas condensation heat exchange is reduced.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of heat resource utilization, and particularly relates to an integrated slurry flash evaporation and spray heat exchange tower and a waste heat utilization system. BACKGROUND

[0002] In a lithium bromide absorption heat pump and an electric heat pump of an inverse Carnot cycle, low-temperature waste heat is used to produce hot water, which has the advantages of energy saving and environmental protection compared with a traditional boiler. There is a large amount of waste heat in nature and actual production and life. However, a lot of waste heat exists in the form of slurry, sewage, slag water and geothermal water. These media contain a large amount of particulate matter and other impurities. When these media are used as a waste heat source, a conventional heat exchanger has a small medium flow cross section to ensure a certain heat exchange area and heat exchange intensity, and is prone to dirt and blockage. At the same time, the heat exchange metal surface is prone to scale or sticky dirt to form a scale thermal resistance, thereby reducing the heat transfer coefficient.

[0003] There are generally three kinds of waste heat utilization modes for such waste heat or slurry waste heat, for example, a patent with publication number CN119958142A uses coarse and fine grids to filter raw sewage, and then uses a sewage heat exchanger and an electric heat pump to extract waste heat; a patent with publication number CN114797407A adopts a two-stage vacuum extraction mode, first extracts a vacuum before slurry flashing, the steam flashed in the slurry flash evaporation tower is connected with the spray tower through a pipeline, and the second vacuum extraction is performed in the spray tower, and the vacuum degree of the first vacuum extraction is lower than the temperature of the slurry flashing; and a patent with publication number CN119983355A adopts a multi-stage flash evaporator and a multi-stage condenser to communicate and perform geothermal cascade utilization.

[0004] The connection mode of the flash evaporation tower and the spray tower through an external pipeline also has major problems. The main problems are that the flow rate of the exhaust gas is fast, the pipeline resistance is large, the temperature of the slurry after flashing is higher than the condensation temperature of the exhaust gas, and the energy utilization rate is reduced. In addition, the cost of the exhaust gas pipeline is high, the land occupation is large, and the arrangement is difficult. Moreover, there is at least a small amount of non-condensable gas such as air in the slurry. If this heat exchange mode of in-pipe or out-pipe condensation is used, when the exhaust gas after flashing is mixed with non-condensable gas, the non-condensable gas will form a gas film near the wall surface of the heat exchange pipe, and the thermal conductivity coefficient of the gas film is much lower than that of liquid water. Generally, 1% of non-condensable gas will reduce the heat exchange coefficient by about 60%, which seriously reduces the heat exchange efficiency. SUMMARY

[0005] In the prior art, the flash evaporation tower and the spray tower are connected through an external exhaust gas pipeline, which causes the flow rate of the exhaust gas to be fast, the pipeline resistance to be large, the temperature of the slurry after flashing to be higher than the condensation temperature of the exhaust gas, and the energy utilization rate to be reduced. In addition, the cost of the exhaust gas pipeline is high, and the exhaust gas after flashing is mixed with non-condensable gas, which will form a gas film near the wall surface of the heat exchange pipe, and the thermal conductivity coefficient of the gas film is much lower than that of liquid water.

[0006] To solve the above technical problems, according to some embodiments, the application provides an integrated slurry flash spray heat exchange tower, comprising:

[0007] a tower body, which is internally provided with a spray chamber and a flash chamber arranged in an up-down manner;

[0008] the spray chamber and the flash chamber are communicated through an air-venting waterproof cap layer, which can prevent the residual heat water in the spray chamber from flowing to the flash chamber below and can make the steam in the flash chamber enter the spray chamber;

[0009] the spray chamber is internally provided with a residual heat water spray layer;

[0010] a residual heat water collecting box is arranged on the side of the spray chamber, which is communicated with the spray chamber and is used for collecting and discharging the residual heat water collected on the air-venting waterproof cap layer;

[0011] the flash chamber is internally provided with a slurry spray layer, and the bottom of the slurry spray layer is provided with a slurry descending pipe;

[0012] the top of the spray chamber is connected with a first exhaust pipe, and a vacuum pump is arranged on the first exhaust pipe.

[0013] Further, a demister is arranged in the spray chamber, and the demister is located above the residual heat water spray layer.

[0014] Further, a filler layer is arranged below the residual heat water spray layer in the spray chamber.

[0015] Another aspect of the application provides a residual heat utilization system, which comprises the integrated slurry flash spray heat exchange tower in any of the above technical solutions, a slurry tank, a desulfurization tower and a heat exchange device;

[0016] the desulfurization tower is internally provided with a flue gas spray layer, and the bottom of the desulfurization tower is provided with a slurry outlet, the slurry outlet is communicated with the slurry spray layer in the flash chamber through a slurry output pipe, and a slurry output pump is arranged on the slurry output pipe, which is used for conveying and boosting the pressure of the slurry;

[0017] the slurry tank is located below the slurry descending pipe and is used for collecting the slurry, and the slurry tank is communicated with the flue gas spray layer through a slurry return pipe;

[0018] the heat releasing side of the heat exchange device is used for making the residual heat water discharged from the residual heat water collecting box release heat and return to the residual heat water spray layer, and the heat absorbing side of the heat exchange device is used for circulating external water or refrigerant.

[0019] Further, the outlet end of the slurry descending pipe extends below the liquid surface of the slurry in the slurry tank to a preset height;

[0020] a slurry overflow pipe is arranged on the upper side of the slurry tank.

[0021] Further, the distance between the bottom of the flash chamber and the liquid surface of the preset height in the slurry tank in the vertical direction is greater than 10 meters.

[0022] Further, the slurry output pipe is provided with a gas-liquid separator, and the gas-liquid separator is provided with a second exhaust pipe, and the outlet end of the second exhaust pipe is communicated with the first exhaust pipe.

[0023] Further, the system further comprises:

[0024] A waste heat water tank is arranged below the waste heat water collection box.

[0025] The waste heat water collection box is connected with a waste heat water descending pipe at the lower part, and the outlet end of the waste heat water descending pipe extends into the liquid surface of the preset height in the waste heat water tank.

[0026] The waste heat water tank is provided with a waste heat water return pipe at the lower part, and the waste heat water return pipe is communicated with the inlet of the heat releasing side of the heat exchange device.

[0027] The upper side of the waste heat water tank is provided with a waste heat water overflow pipe.

[0028] Further, the distance between the bottom of the waste heat water collection box and the liquid surface of the preset height in the waste heat water tank in the vertical direction is greater than 10 meters.

[0029] Further, the waste heat water return pipe is connected with a waste heat water filter and a waste heat water pump.

[0030] Further, the heat exchange device is a heat pump or a plate heat exchanger.

[0031] The above technical scheme of the present application has at least the following beneficial technical effects:

[0032] The integrated slurry flash spray heat exchange tower of the present application integrates the flash and the spray in one tower body, the sprayed waste heat water absorbs the heat of the flue gas formed by the slurry flash, the flue gas (low-temperature and low-pressure steam) flashed out by the slurry can contact the sprayed waste heat water above to release heat and condense without passing through the flue gas pipeline, thereby saving the investment and land occupation of the flue gas pipeline; the air venting and waterproof cap layer enables the flue gas to enter the spraying chamber above with low resistance, reduces the loss of flue gas pressure and condensing temperature, and improves the energy utilization rate. Meanwhile, the direct contact of the sprayed waste heat water with the flue gas to absorb the condensing heat replaces the wall heat exchange between the multiple heat exchange pipes, and reduces the influence of the non-condensable gas on the flue gas condensing heat exchange. BRIEF DESCRIPTION OF DRAWINGS

[0033] In order to more clearly illustrate the technical solutions in the embodiments of the present application or in the prior art, the accompanying drawings needed in the embodiments will be briefly introduced as follows. Obviously, the accompanying drawings in the following description only constitute some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained from these drawings without any creative effort.

[0034] Figure 1 is a waste heat utilization system structure diagram in an embodiment of the present application.

[0035] wherein, Figure 1 The correspondence between the reference signs and the component names in the drawings is as follows:

[0036] 1: vacuum pump; 101, first exhaust pipe; 2: demister; 3: tower body; 31, spray chamber; 32, flash chamber; 4: waste heat water spray layer; 5: packing layer; 6: venting and waterproof cap layer; 7: slurry spray layer; 71: valve; 72: gas-liquid separator; 73, second exhaust pipe; 8: slurry output pump; 9: desulfurization tower; 91, slurry output pipe; 92, slurry return pipe; 10: flue gas spray layer; 11: slurry downcomer; 12: slurry tank; 121: slurry overflow pipe; 13: slurry return pump; 14: waste heat water tank; 141: waste heat water overflow pipe; 15: waste heat water filter; 16: waste heat water pump; 17: heat exchange device; 171, waste heat water output pipe; 172, waste heat water return pipe; 18: waste heat water downcomer; 19: waste heat water collection box. DETAILED DESCRIPTION

[0037] In order to make the objectives, technical solutions and advantages of the embodiments of the present application clearer, the embodiments of the present application will be described in detail below with reference to the drawings. However, those skilled in the art can understand that in the embodiments of the present application, many technical details are proposed in order to make the readers better understand the present application. However, even without these technical details and various changes and modifications based on the following embodiments, the technical solutions claimed by the present application can be implemented. The division of the following embodiments is for the convenience of description, and should not constitute any limitation on the specific implementation of the present application. The embodiments can be combined with each other and mutually referenced without contradiction.

[0038] At present, the split flash tower and spray tower in the prior art are connected through an external exhaust gas pipeline, which causes the exhaust gas flow rate to be fast, resulting in large pipeline resistance. The temperature of the slurry after flashing will be higher than the condensation temperature of the exhaust gas, causing the energy utilization rate to decrease. Secondly, the cost of the exhaust gas pipeline is high, and the exhaust gas after flashing is mixed with non-condensable gas. The non-condensable gas will form a gas film near the wall surface of the heat exchange tube, and its thermal conductivity is much lower than that of liquid water.

[0039] To solve the above problems, one embodiment of the present application provides an integrated slurry flash spray heat exchange tower, which specifically comprises:

[0040] The tower body 3 is internally provided with a spray chamber 31 and a flash chamber 32 arranged in an up-down manner.

[0041] The spray chamber 31 and the flash chamber 32 are communicated through an air-venting waterproof cap layer 6, which can prevent the residual hot water in the spray chamber 31 from flowing to the flash chamber 32 below and can make the steam in the flash chamber 32 enter the spray chamber 31.

[0042] The spray chamber 31 is internally provided with a residual hot water spray layer 4; the spray chamber 31 is provided with a residual hot water collecting box 19 on the side surface, which is communicated with the spray chamber 31 and is used for collecting and discharging the residual hot water collected on the air-venting waterproof cap layer 6. Preferably, the bottom wall of the residual hot water collecting box 19 is at the same height as the surface of the air-venting waterproof cap layer 6 for collecting residual hot water.

[0043] The flash chamber 32 is internally provided with a slurry spray layer 7, and the bottom of the slurry spray layer 7 is provided with a slurry descending pipe 11.

[0044] In use of the integrated slurry flash spray heat exchange tower, relatively, the slurry sprayed by the slurry spray layer 7 is a high-temperature heat source (usually with a temperature higher than 35℃ and with a high utilization rate), and the residual hot water sprayed by the residual hot water spray layer 4 is a low-temperature heat exchange medium (normal temperature or outdoor water source with an initial temperature), i.e., the residual hot water absorbs the heat of the spent gas converted by the slurry. It should be noted that the slurry can be formed by absorbing the heat of flue gas in a subsequent desulfurization tower 9 or can be formed by other natural or industrial ways to form other heat source resources with a certain temperature (such as power plants, metallurgy, manufacturing, etc. to form slurry, sewage, slag water, geothermal water, etc.). The temperature of the slurry needs to be higher than the temperature of the sprayed residual hot water, and after being sprayed into the low-pressure flash chamber 32 through the slurry spray layer 7, the saturation temperature of the slurry rapidly decreases with the rapid decrease of the pressure, and the slurry is rapidly separated into low-temperature low-pressure steam (spent gas) and low-temperature low-pressure slurry, and the low-temperature low-pressure slurry is discharged through the slurry descending pipe 11 at the bottom of the flash chamber 32. The temperature of the low-temperature low-pressure steam is still higher than the temperature of the residual hot water in the spray chamber 31, and the low-temperature low-pressure steam enters the spray chamber 31 above through the air-venting waterproof cap layer 6, releases heat to the sprayed residual hot water and condenses, and the residual hot water absorbing the heat drops to the air-venting waterproof cap layer 6 and then flows into the residual hot water collecting box 19, and finally is discharged through the residual hot water descending pipe 18. The residual hot water absorbing the heat of the slurry can be used as a heat exchange medium or a heat source.

[0045] The top of the spraying chamber 31 is connected with the first exhaust pipe 101, and the first exhaust pipe 101 is provided with a vacuum pump 1. The first exhaust pipe 101 and the vacuum pump 1 provide the pressure condition for the flash evaporation of the lower flash evaporation chamber 32, and are also used for discharging the non-condensable gas, and of course, the non-condensed steam can also be discharged, so as to avoid the increase of the resistance of the steam flow into the spraying chamber 31 caused by the accumulation of the non-condensable gas or the steam in the spraying chamber 31 due to the pressure rise, and also avoid the mixing of the residual heat water with too much non-condensable gas. According to the type of the slurry (distinguished according to the harmful and harmless), the gas absorbed by the vacuum pump 1 can be directly discharged into the atmosphere or connected with an external gas collection and treatment device; the vacuum pump 1 can be a water ring pump or a Roots water ring pump.

[0046] The integrated slurry flash evaporation spraying heat exchange tower of the present application integrates the flash evaporation and the spraying in one tower body 3, the residual heat water of the spraying absorbs the heat of the waste gas formed by the slurry flash evaporation, and the waste gas (low-temperature and low-pressure steam) flashed out by the slurry can contact the residual heat water of the spraying above to release heat and condense without passing through the waste gas pipeline, thereby saving the investment and the land occupation of the waste gas pipeline; the venting and waterproof cap layer 6 enables the waste gas to enter the spraying chamber 31 above with low resistance, reduces the loss of the waste gas pressure and the condensation temperature, and improves the energy utilization rate. Meanwhile, the direct contact of the residual heat water of the spraying with the waste gas to absorb the condensation heat replaces the wall heat exchange between the existing multiple heat exchange pipes, and reduces the influence of the non-condensable gas on the waste gas condensation heat exchange.

[0047] In an embodiment of the present application, the venting and waterproof cap layer 6 comprises a plate-shaped water isolation part, and the profile of the plate-shaped water isolation part can be circular, or the profile is sealingly matched with the inner wall of the installation position of the tower body 3. A plurality of venting holes are arranged on the plate-shaped water isolation part, and a through cylinder is connected to the upper side of the venting hole. A conical cap is hollowed out and connected to the upper side of the cylinder, the outer diameter of the conical cap is larger than the outer diameter of the cylinder, and the conical cap can block the opening of the upper end of the cylinder in the vertical direction, so as to prevent the residual heat water in the spraying chamber 31 from flowing to the lower flash evaporation chamber 32, and enable the steam in the flash evaporation chamber 32 to enter the spraying chamber 31.

[0048] In an embodiment, a demister 2 is arranged in the spraying chamber 31, and the demister 2 is located above the residual heat water spraying layer 4, which can reduce the mist droplets entering the vacuum pump 1. Preferably, in order to facilitate the collection of the gas from the top of the tower body 3 and the collection of the slurry from the bottom of the tower body 3, the top of the spraying chamber 31 and the bottom of the flash evaporation chamber 32 are both conical. The demister 2 is located in the conical head of the flash evaporation chamber 32.

[0049] Preferably, a filler layer 5 is arranged below the residual heat water spraying layer 4 in the spraying chamber 31. The filler layer 5 can increase the contact area and contact time between the residual heat water and the flue gas. Generally, the filler layer 5 is stacked by blocks of thin sheets (e.g. corrugated sheets) of specific geometric shapes. The sheets can be provided with holes, slits or textures to facilitate the distribution and flow of the residual heat water and the flue gas. The sheets can be made of polypropylene, stainless steel, polyvinyl chloride, ceramic or the like. The residual heat water and the flue gas can exchange heat in the filler layer 5, thereby improving the heat exchange efficiency, reducing the tower height and saving the cost. The residual heat water spraying layer 4 can not use high-pressure nozzles (which have narrow holes inside to achieve liquid film dispersion), thereby reducing the demand for the residual heat water head, saving the nozzle cost and the operating power consumption of the residual heat water pump 16. The residual heat water spraying layer 4 of the embodiment can use low-resistance nozzles (which have large flow area; can be open spiral nozzles without internal small holes or hollow cone nozzles with internal vortex devices). The residual heat water is not strongly atomized under the action of the low-resistance nozzles and the filler layer 5, thereby reducing the requirement for the demister 2 and the cost of the demister 2.

[0050] Another aspect of the present application provides a residual heat utilization system, which comprises the integrated slurry flash spraying heat exchange tower in any of the technical solutions described above, and the slurry tank 12, the desulfurization tower 9 and the heat exchange device 17. The basic principle of the residual heat utilization system is as follows: the low-temperature slurry in the desulfurization tower 9 absorbs the heat of the high-temperature flue gas to become high-temperature slurry, the high-temperature slurry is transported by the slurry output pump 8 to the flash chamber 32 of the integrated slurry flash spraying heat exchange tower to be flashed, the flue gas formed is discharged into the upper spraying chamber 31 to be condensed by heat release, the residual heat water sprayed absorbs the heat of the flue gas and is then discharged into the heat exchange device 17 to release heat to external water, which can be used by heat users. The residual heat water releases heat in the heat exchange device 17 and then returns to the integrated slurry flash spraying heat exchange tower to enter the cycle. The pressure and temperature of the flashed slurry are reduced to a certain extent, the low-temperature slurry is collected in the slurry tank 12 and then returned to the desulfurization tower 9 to enter the cycle. The residual heat utilization system can provide the heat of the flue gas in the desulfurization tower 9 to heat users through the conversion of the integrated slurry flash spraying heat exchange tower and the heat exchange device 17. The specific structure is as follows:

[0051] The desulfurization tower 9 is internally provided with a flue gas spraying layer 10, the high-temperature flue gas enters from the middle flue gas inlet of the desulfurization tower 9, the slurry is directly sprayed onto the high-temperature flue gas to exchange heat, the flue gas after heat release is discharged from the flue gas outlet at the top of the desulfurization tower 9, and the slurry after heat absorption is accumulated in the desulfurization tower 9. The desulfurization tower 9 is internally provided with a slurry outlet, the slurry outlet is communicated with the slurry spraying layer 7 in the flash chamber 32 through a slurry output pipe 91, and the slurry output pump 8 is arranged on the slurry output pipe 91. The slurry output pump 8 is used to transport and increase the pressure of the high-temperature slurry, so that the slurry enters the low-temperature and low-pressure environment of the flash chamber 32 to be flashed.

[0052] The slurry tank 12 is located below the slurry downcomer 11 for collecting the slurry, and is communicated with the flue gas spraying layer 10 through a slurry return pipe 92; the slurry return pipe 92 is provided with a slurry return pump 13 for conveying the slurry in the slurry tank 12 to the desulfurization tower 9.

[0053] The heat-releasing side of the heat exchange device 17 is used for releasing heat of the waste heat water discharged from the waste heat water collecting box 19 and returning the waste heat water to the waste heat water spraying layer 4 in the spraying chamber 31; the outlet end of the heat-releasing side of the heat exchange device 17 is communicated with the waste heat water spraying layer 4 in the spraying chamber 31 through a waste heat water output pipe 171; the heat-absorbing side of the heat exchange device 17 is communicated with the external water, and the external water can be provided to the heat user after absorbing the heat of the waste heat water.

[0054] In an embodiment of the present application, the outlet end of the slurry downcomer 11 extends below the liquid surface of the slurry at a preset height in the slurry tank 12, wherein the preset height is not limited in specific value, and is only the height of the waste heat water maintained in the slurry tank 12 during normal circulation operation of the system; the upper side of the slurry tank 12 is provided with a slurry overflow pipe 121. Preferably, one end of the slurry overflow pipe 121 inserted into the slurry tank 12 is below the liquid surface of the slurry at the preset height, and the other end of the slurry overflow pipe 121 outside the slurry tank 12 is higher than the liquid surface at the preset height, so as to prevent the slurry from accumulating in the integrated slurry flash spraying heat exchange tower or filling the slurry tank 12 when the flow of the slurry into the integrated slurry flash spraying heat exchange tower is greater than the flow of the slurry return pump 13 or the system is shut down.

[0055] Preferably, the distance between the bottom of the flash chamber 32 and the liquid surface at the preset height in the slurry tank 12 in the vertical direction is greater than 10 meters, and the lower end of the slurry downcomer 11 is inserted below the liquid surface of the slurry tank 12, so as to ensure that the slurry downcomer 11 is filled with the slurry during startup, operation and shutdown, and prevent air from entering the inside of the integrated slurry flash spraying heat exchange tower from the slurry downcomer 11 (when the system is shut down, the negative pressure of the flash chamber 32 can keep the slurry in the slurry downcomer 11 from flowing into the slurry tank 14).

[0056] In an embodiment of the present application, the slurry output pipe 91 is provided with a gas-liquid separator 72, and the gas-liquid separator 72 is provided with a second exhaust pipe 73, and the outlet end of the second exhaust pipe 73 is communicated with the first exhaust pipe 101. The gas-liquid separator 72 can be a steam pocket or an ultrasonic degassing device, which is mainly used to separate the non-condensable gas in the slurry before flashing and discharge through the second exhaust pipe 73 and the first exhaust pipe 101; the vacuum pump 1 connected with the first exhaust pipe 101 can extract the non-condensable gas in the integrated slurry flash spray heat exchange tower and the gas-liquid separator 72, and provide a pressure environment for the slurry flashing. When the gas-liquid separator 72 is a steam pocket, the slurry output pump 91 can pressurize the slurry, and after entering the steam pocket, the steam and the liquid are separated by gravity, inertia and centrifugal force, and the steam is collected at the top of the steam pocket to be discharged through the second exhaust pipe 73. The second exhaust pipe 73 is provided with a valve 71, and the pressure in the gas-liquid separator 72 can be controlled by adjusting the vacuum pump 1 and the valve 71, and preferably the pressure is controlled to be slightly higher than the saturation pressure corresponding to the temperature of the slurry, so as to remove the non-condensable gas in the slurry as much as possible. The gas-liquid separator 72 can also be an ultrasonic degassing device, and the ultrasonic degassing device has a horizontal cylinder, the top of the horizontal cylinder is provided with an exhaust port communicated with the vacuum pump 1, the bottom of the horizontal cylinder is provided with a slurry outlet, the inside of the horizontal cylinder is provided with a slurry pipeline connected with the slurry output pipe 91, the slurry pipeline is provided with a slurry inlet at a position close to the cylinder wall of the horizontal cylinder, and the bottom of the slurry pipeline is provided with a first diffusion nozzle, and the lower side of the slurry pipeline is provided with a plurality of ultrasonic oscillation assemblies arranged in a staggered manner, so as to promote the gas oscillation in the slurry to form bubbles in an ultrasonic vibration manner, and the non-condensable gas is caused to overflow rapidly under the action of the vacuum pump 1 and is discharged through the second exhaust pipe 73 and the first exhaust pipe 101.

[0057] In an embodiment of the present application, the system further comprises a waste heat water tank 14 which is located lower than the waste heat water collecting box 19; the lower part of the waste heat water collecting box 19 is connected with a waste heat water descending pipe 18, and the outlet end of the waste heat water descending pipe 18 extends into the waste heat water tank 14 below a preset height of the liquid surface. It should be noted that the height of the liquid surface of the waste heat water tank 14 and the height of the liquid surface of the slurry tank 12 have no relationship, and the preset heights of the two can be the same or different. The lower part of the waste heat water tank 14 is provided with a waste heat water return pipe 172, and the waste heat water return pipe 172 is communicated with the inlet end of the heat releasing side of the heat exchange device 17. The upper side of the waste heat water tank 14 is provided with a waste heat water overflow pipe 141, and the outlet end of the overflow pipe is higher than the preset height of the liquid surface of the waste heat water tank 14. Preferably, the interface between the waste heat water return pipe 172 and the waste heat water tank 14 is higher than the bottom wall of the waste heat water tank 14, and the bottom wall of the waste heat water tank 14 is provided with a blowdown port, and the blowdown port is provided with an on-off valve, so that the impurities in the waste heat water can be deposited at the bottom, and can be discharged through the blowdown port when needed.

[0058] Preferably, the distance between the bottom of the waste heat water collecting box 19 and the preset height of the liquid surface in the waste heat water tank 14 in the vertical direction is greater than 10 meters.

[0059] Preferably, the waste heat water return pipe 172 is connected with a waste heat water filter 15 and a waste heat water pump 16, in combination with the waste heat water overflow pipe 141 of the waste heat water tank 14, which can not only avoid the particles brought into the heat exchange device 17 by the slurry flashing, but also make the waste heat water of the spray chamber 3 overflow from the water tank; it can also avoid the influence of the non-condensable gas on the heat exchange of the heat exchange device 17, and form a liquid seal in the pipeline to prevent air from entering the tower to corrode the equipment, thereby improving the service life of each equipment in the system.

[0060] In an embodiment of the present application, the heat exchange device 17 is a heat pump or a plate heat exchanger, and can also be other forms of water source heat exchanger. When the heat exchange device 17 is a heat pump, the heat pump evaporator is connected with the waste heat water tank 14 and the integrated slurry flashing spray heat exchange tower.

[0061] In the description of the present application, the terms "one embodiment", "some embodiments", "specific embodiments", etc. mean that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present application, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0062] It should be understood that the above specific embodiments of the present application are only used for illustrative or explanatory purposes of the principles of the present application, and do not constitute a limitation of the present application. Therefore, any modification, equivalent replacement, improvement, etc. made without departing from the spirit and scope of the present application shall be included in the protection scope of the present application. In addition, the claims of the present application are intended to cover all variations and modifications falling within the scope and boundary of the appended claims, or the equivalent forms of such scope and boundary.

Claims

1. An integrated slurry flash spray heat exchange tower, characterized in that: include: The tower body (3) is provided with a spray chamber (31) and a flash chamber (32) arranged vertically therein; The spray chamber (31) and the flash chamber (32) are connected via a ventilated waterproof cap layer (6), and the ventilated waterproof cap layer (6) can prevent the residual hot water in the spray chamber (31) from flowing to the flash chamber (32) below, and can allow the steam in the flash chamber (32) to enter the spray chamber (31); A waste hot water spray layer (4) is provided in the spray chamber (31); A waste hot water collection box (19) is provided on the side of the spray chamber (31), and the waste hot water collection box (19) is communicated with the spray chamber (31) and is used to collect and discharge the waste hot water collected on the ventilation and waterproof cap layer (6); A slurry spraying layer (7) is provided in the flash chamber (32), and a slurry downpipe (11) is provided at the bottom thereof; The top of the spray chamber (31) is connected to a first exhaust pipe (101), and a vacuum pump (1) is provided on the first exhaust pipe (101).

2. The integrated slurry flash spray heat exchange tower according to claim 1, characterized in that: A demister (2) is provided in the spray chamber (31), and the demister (2) is located above the waste hot water spray layer (4).

3. The integrated slurry flash spray heat exchange tower according to claim 1, characterized in that: In the spray chamber (31), a filler layer (5) is provided below the waste hot water spray layer (4).

4. A waste heat utilization system, characterized in that: It comprises the integrated slurry flash spray heat exchange tower according to any one of claims 1 to 3, as well as a slurry tank (12), a desulfurization tower (9) and a heat exchange device (17); The desulfurization tower (9) is provided with a flue gas spray layer (10) inside and a slurry outlet at the bottom. The slurry outlet is communicated with the slurry spray layer (7) in the flash chamber (32) through a slurry output pipe (91). The slurry output pipe (91) is provided with a slurry output pump (8). The slurry output pump (8) is used to transport and increase the pressure of the slurry. The slurry tank (12) is located below the slurry downpipe (11) and is used to collect slurry. The slurry tank (12) is connected to the flue gas spray layer (10) through a slurry return pipe (92); The heat-releasing side of the heat exchange device (17) is used to release heat and cool the waste water discharged from the waste water collection box (19) and return it to the waste water spraying layer (4), and the heat-absorbing side of the heat exchange device (17) is used to circulate external cold water or refrigerant.

5. The waste heat utilization system according to claim 4, characterized in that: The outlet end of the slurry downpipe (11) extends below the liquid level of the slurry at a preset height in the slurry tank (12); A slurry overflow pipe (121) is provided on the upper side of the slurry box (12).

6. The waste heat utilization system according to claim 4, characterized in that: The vertical distance between the bottom of the flash chamber (32) and the liquid level at a preset height in the slurry tank (12) is greater than 10 meters.

7. The waste heat utilization system according to claim 4, characterized in that: The slurry output pipe (91) is provided with a gas-liquid separator (72), and the gas-liquid separator (72) is provided with a second exhaust pipe (73), and the outlet end of the second exhaust pipe (73) is connected to the first exhaust pipe (101).

8. The waste heat utilization system according to claim 4, characterized in that: Also includes: A waste heat tank (14), which is located lower than the waste heat collection box (19); The lower part of the waste hot water collection box (19) is connected to a waste hot water downpipe (18), and the outlet end of the waste hot water downpipe (18) extends below the liquid level at a preset height in the waste hot water tank (14); A waste heat return pipe (172) is provided at the lower portion of the waste heat tank (14), and the waste heat return pipe (172) is communicated with the heat release side inlet of the heat exchange device (17); A waste hot water overflow pipe (141) is provided on the upper side of the waste hot water tank (14).

9. The waste heat utilization system according to claim 8, characterized in that: The vertical distance between the bottom of the waste hot water collection box (19) and the liquid level at a preset height in the waste hot water tank (14) is greater than 10 meters.

10. The waste heat utilization system according to claim 8, characterized in that: The waste heat return pipe (172) is connected to a waste heat filter (15) and a waste heat pump (16).

11. The waste heat utilization system according to claim 4, characterized in that: The heat exchange device (17) is a heat pump evaporator.

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