CN117989627A - Clean air conditioner utilizing normal temperature air cold energy in fluidization mode and exhaust steam condensation method - Google Patents

Abstract

A clean air conditioner and exhaust steam condensation method that utilizes cold energy of normal-temperature air by fluidization, so that the air and water mist mixed evaporative cooling mass transfer process is carried out on the surface of fluidized gas-solid particles, and its specific surface area and mass transfer coefficient are more than one order of magnitude higher than those of commonly used fillers and are not affected by dirt. The fluidized system is heated by low-level waste heat to increase the saturated vapor pressure, thereby further enhancing the application effect of normal-temperature air cold energy, greatly improving the refrigeration intensity and operational reliability of the equipment. It is applied to the exhaust fluidization heat absorption auxiliary solar cooling fresh air air conditioner in public spaces, with a comprehensive energy efficiency coefficient COP>3.1 and completely avoiding the hygienic risks of supply and exhaust air; it is applied to assist in the use of low-level waste heat for the vaporization regeneration of process wastewater, so that more than half of the wastewater can be recycled as regenerated condensed water, and the regeneration process does not increase the comprehensive energy consumption of the workshop. The method of the present invention has outstanding low-carbon, energy-saving and environmentally friendly characteristics.

Description

Fluidized clean air conditioning and exhaust steam condensation method using cold energy of normal temperature air

Technical Field

The present invention relates to low-potential energy extraction and application and near-room temperature refrigeration and clean air conditioning technology, in particular to the field of multiphase flow heat and mass transfer technology that is coupled with waste gas and wastewater treatment and efficiently utilizes room temperature air cooling energy.

Background technique

Near-room temperature refrigeration technology is currently mainly used in the field of air conditioning and refrigeration in summer, and its application is very wide. The steam compression heat removal method usually used not only consumes a lot of energy but also significantly aggravates the urban heat island effect. It is urgently needed to be improved in terms of low-carbon energy saving and human settlement environment protection. The evaporative air cooler with significant energy-saving characteristics "uses a fan to make the air directly contact with the water-spraying filler layer, transfers the sensible heat of the air to the water to achieve humidification and cooling", and stipulates that "sensible heat cooling capacity" is "the value of the sensible heat reduction of the air passing through by absorbing heat through water evaporation" (GB/T 25860-2010 Evaporative Air Cooler). The limit of water evaporation heat absorption is the temperature (wet bulb temperature) at which the air moisture content reaches the saturated state. In dry areas, the wet bulb temperature of the ambient air in summer is 23℃, which is lower than the air conditioning design supply air temperature (26℃), and the evaporative air cooler can be used; in humid and hot areas, the wet bulb temperature of the ambient air in summer has reached 28℃, and the evaporative air cooler is not applicable. The latest internationally improved indirect evaporative cooling technology M-Cycle IEC (Indirect evaporative cooling for buildings: A comprehensive patents review, J. of Building Eng., 2022, v50) cannot overcome the above-mentioned environmental conditions. At the same time, IEC technology also has problems such as uniformity of water distribution on the evaporation surface and removal of surface heat transfer dirt.

Air conditioning energy saving also includes measures such as recycling part of the exhaust gas to reduce the fresh air cooling load, or using a rotary wheel to recover the exhaust cooling capacity (Xu Qian et al. Diagnosis and modification of cruise air conditioning ventilation system based on antivirus, Jiangsu Shipbuilding, 2022, v39/n2), but the resulting problem of air pollutants spreading in public spaces is increasingly prohibited.

The principle of the above air conditioning energy-saving measures is to utilize the cooling capacity (cold energy) of normal temperature air itself, especially when it contacts the water surface, it absorbs water vapor to take away the latent heat of water, so as to achieve heat transfer without temperature difference or even negative temperature difference (air temperature is higher than water temperature). The driving force of the process comes from the difference between the saturated vapor pressure ps on the water surface and the water vapor partial pressure pw in the air flow ( ps - pw ). Its physical essence is that this driving force causes water vapor molecules to migrate continuously from the air-water interface to the main body of the air flow and go with the air flow, thereby prompting the water molecules on the interface to continuously absorb heat and vaporize to produce a cooling effect. According to this principle, measures to fully utilize the cold energy of normal temperature air are, first, the overall water vapor partial pressure pw of the air (hereinafter referred to as working air) should be low, and the saturated vapor pressure ps of the air-water interface should be high, so as to obtain the required process driving force ( ps - pw ); under the condition of a certain driving force, the measures to strengthen the process are to increase the air-water direct contact specific surface area a and the mass transfer coefficient kp , so as to increase the vaporization intensity mw = a • kp • ( ps - pw ). To this end, the present invention proposes a fluidization method that comprehensively utilizes the cold energy of normal temperature air, so that the vaporization mass transfer process is carried out on the surface of fluidized gas-solid particles, and its specific surface area a and mass transfer coefficient kp are more than one order of magnitude higher than those of commonly used fillers; at the same time (for application occasions), waste heat transfer is used to make the normal temperature air fluidization system absorb heat and increase the interface saturated vapor pressure ps , thereby increasing the process driving force ( ps - pw ), and strengthening the application effect of normal temperature air cold energy in many aspects, so that the refrigeration intensity calculated by the surface area of the equipment is several times higher than the above-mentioned IEC technology. In addition, since the endothermic vaporization mass transfer process mainly occurs on the surface of fluidized moving particles, it not only overcomes the problem of uneven water distribution, but also protects the surface of the equipment from the influence of dirt, and improves the reliability of equipment operation. This method has a wide range of applications, such as 92~95℃ solar hot water assisted refrigeration and air conditioning. In hot and humid areas in summer, under the condition of an ambient air dry bulb temperature of 38℃, it can achieve fresh air air conditioning at 26℃ and a relative humidity of less than 60%, with an overall energy efficiency coefficient (converted to cooling energy/electric energy) exceeding 3.1. It can also be used to replace air cooling technology, using 60℃ waste heat to vaporize and regenerate wastewater, thereby achieving water resource recycling without increasing the overall energy consumption of the factory.

Summary of the invention

The present invention discloses a fluidization method for comprehensively utilizing the cold energy of normal temperature air. The method of the present invention is applicable to various occasions such as fresh air clean refrigeration and air conditioning, turbine exhaust steam condensation and wastewater regeneration and recycling. As shown in FIG1, the fresh air clean refrigeration and air conditioning uses the air conditioning exhaust of the public space as the working air, cools and dehumidifies the fresh air (clean air), and provides the public space with a dry bulb temperature of 23~25℃ and a relative humidity of 50%~60% (moisture content 11.5~12.5g/kg-DA, DA represents dry air, the same below) fresh air air conditioning air supply. First, the sanitation and disinfection of the air conditioning exhaust is used as a way to utilize the cold energy of air. As shown in FIG1, the air conditioning exhaust is sprayed and mixed with the sanitary disinfection aqueous solution, and evenly distributed from the top pipe box of the exhaust humidification/fresh air cooling heat exchanger 1 into each downcomer to form a gas-fog two-phase flow with a flow rate of 8~10m/s, and the heat is absorbed from the pipe wall to vaporize the droplets in the air flow. The fresh air passes over the fin surface from top to bottom outside the pipe to release heat and cool down. The gas-mist mixture in the pipe flows to the bottom pipe box for separation, the exhaust temperature is reduced to 23~25℃, and the moisture content is increased to 18.5~19.2g/kg-DA, and the corresponding fresh air outside the pipe is cooled to 26~27℃. The separated droplets are condensed and sent back to the top pipe box through the micro-pressurized circulation pump 6 under the bottom pipe box, and merged with the newly added sanitary disinfection water solution for spray circulation. The ratio of the circulating solution mass flow rate to the air conditioning exhaust mass flow rate is 1:50~60, and the newly added sanitary disinfection water solution is equal to the sum of the exhaust humidification vaporization amount and the bottom pipe box disinfection liquid sewage discharge amount (the sewage discharge amount is 50~60% of the vaporization amount).

The fresh air cooled to 26~27℃ continues to release heat and cool down and dehumidify through the outer fin surface of the tube of the falling film evaporator/fresh air cooling and dehumidifier 2. The heat is transferred to the pure water falling film evaporation in the tube through the tube wall. The heat transfer temperature difference between the fresh air cooling and dehumidification heat release on the outer fin surface of the tube and the pure water falling film evaporation heat absorption in the tube is 2~3℃, and the evaporation intensity is not less than 4.5kg/ ^hm2 . At the bottom of the dehumidifier 2, the fresh air outside the tube is cooled to 17~18℃, and the moisture content is reduced to 11.5~12.5g/kg-DA, and it is pressurized by the blower and enters the fresh air distribution main pipe of the clean air conditioner. The falling film evaporation in the tube generates low-pressure water vapor with a temperature not lower than 15°C and a pressure not lower than 1.74 kPa (absolute pressure, the same below). After being separated from the falling film liquid in the bottom tube box, it is sucked into the steam ejector 3 through the low-pressure water vapor outlet control valve 12; the falling film liquid is pressurized by the falling film circulation pump 7 and returned to the top tube box 2 for circulation, and the circulation mass flow rate is 15 to 20 times the falling film evaporation amount.

The working steam of the water vapor ejector 3 is provided by the multi-layer coil evaporator 4, the working steam temperature is 85~90℃, the pressure is 58~68kPa (absolute pressure, the same below), the heat energy for generating the working steam comes from the circulating hot water of the flat plate solar water heater at 92~95℃, the multi-layer coil 4-2 arranged horizontally in the evaporator 4 spirally flows from the top layer to the bottom layer to release heat, the flow rate is 2.0~2.5m/s, and the circulating return water temperature at the outlet of the bottom coil is not less than 86℃. In the evaporator 4, pure water is evenly distributed on the surface of the top two layers of coils through the coil surface water distributor 4-1, while absorbing heat and evaporating, it drips to the surface of the next layer of coils arranged in a staggered manner to continue absorbing heat and evaporating, and the unevaporated pure water falls into the bottom liquid surface, the liquid level is just high enough to completely immerse the bottom two layers of coils below the liquid surface, so that the makeup water added there is heated by the coils to above 85°C and then pressurized and transported to the water distributor 4-1 for circulation through the coil evaporator circulation pump 9; the amount of pressurized water distributed by the circulation pump 9 is 5 to 10 times the amount of working steam generated by the evaporator 4. The generated working steam is accelerated to a supersonic airflow with a pressure lower than 1.7 kPa through the ejector 3, and the low-pressure water vapor from the falling film evaporation is sucked and mixed with it to form a mixed steam with a temperature higher than 36°C and a pressure greater than 6 kPa, and then sent to the fluidized condensation assembly 5 for condensation.

The fluidized condensation assembly 5 includes a finned tube bundle 5-2 immersed in the gas-solid fluidized bed particle layer and a gas distribution plate 5-1 at the bottom of the fluidized bed; the orientation of the finned tube bundle is arranged with one end high and the other end low, so that the tube axis is at an angle of 5° to 8° with the horizontal, and the water vapor to be condensed is evenly distributed through a distributor connected to the high end of the finned tube bundle and flows into each tube, forming an inclined convection condensation heat release in the tube, and the heat is transferred to the fluidized particle layer outside the tube through the fins on the tube wall, and the condensate flowing in the tube and the uncondensed water vapor flow from the tube port at the low end of the tube bundle into the condensation space of the auxiliary condenser 5-3 connected thereto, and in the distribution The fins outside the cooling water pipe (below 35°C) placed therein continue to release heat and completely condense; the condensed water gathered in the auxiliary condenser 5-3 is pressurized by the return water pump 8 and replenished to the top of the falling film evaporator/fresh air cooling and dehumidifier 2 and the bottom of the multi-layer coil evaporator 4 through the low-pressure return water control valve 10 and the coil evaporator return water control valve 11 respectively according to the ratio of the low-pressure water vapor to the working steam; the non-condensable gas in the condensation space is regularly extracted through the non-condensable gas extraction control valve 5-4 connected to the space to keep the ratio of the non-condensable gas partial pressure to the water vapor partial pressure in the condensation space less than (0.5/1000). The completely enclosed pure water and water vapor circulation space is separated into a low-pressure area and a transformer working area by the low-pressure return water control valve 10 and the low-pressure water vapor outlet control valve 12. Valve 10 and valve 12 are closed during the shutdown period and startup period. During the startup period, all devices in the transformer working area (including 4, 4-1, 4-2, 9, 3, 5, 5-1, 5-2, 5-3, 5-4 and 8) are first made to operate normally, and then valve 10 and valve 12 are opened synchronously.

The heat absorption process of the fluidized particle layer outside the finned tube bundle is realized in the following way: in the fluidized bed with a rectangular cross section as shown in FIG. 1 , the particle layer is composed of a spherical wear-resistant particle group uniformly piled outside the finned tube bundle, the particle group has a particle size of 0.8-1.2 mm, a density of 550-650 kg/m ³ , an initial fluidization velocity of 0.3-0.5 m/s, and a particle layer accumulation height (i.e., the distance from the gas distribution plate 5-1 to the upper surface of the static particle layer) of 0.3-0.5 m; the air-conditioned exhaust gas (working air) of 23-25° C. from the exhaust humidification/fresh air cooling heat exchanger 1 uniformly passes through the gas distribution plate 5-1 with an opening diameter of no more than 0.6 mm at 2-5 times the initial fluidization velocity, and the particle layer above it is fully fluidized to become a fluidized bed layer, the upper surface of which rises to more than twice the accumulation height of the static particle layer and completely submerges the finned tube bundle; the lowest point position of the fin below the lower end of the finned tube bundle is 100 m away from the gas distribution plate 5-1. The upper surface of the cloth plate is 35~50mm, and working water (wastewater or tap water that meets environmental emission standards) is sprayed into the fluidized bed from the high end side of the finned tube bundle, and the ratio of the working water mass flow rate to the working air mass flow rate does not exceed 1/30; the working air drives the water mist and the fluidized particle group to churn and mix violently, and continuously collide and transfer heat with the outer surface of the tube bundle and the fin surface, absorbing heat while vaporizing and heating from 23~25℃ to a temperature difference of no more than 5℃ with the heat release medium in the finned tube, forming a high-intensity condensation effect on the 33~36℃ water vapor flowing in the finned tube bundle, and the condensation intensity calculated based on the inner surface area of the finned tube is not less than 6.1kg/ ^hm2 ; the working air absorbs heat in the fluidized bed, heats up and humidifies to its saturated vapor pressure, leaves the upper surface of the bed and continues to flow 0.2~0.3m in the upper free space, and finally passes through the screen with an aperture of no more than 0.2mm set on the top of the fluidized condensation combination 5 for discharge.

The above-mentioned air conditioning exhaust fluidization cold energy utilization assisted by flat-plate solar thermal collection clean refrigeration fresh air air conditioning system completely avoids the hygienic risk problem of air supply in public spaces, and its comprehensive refrigeration performance coefficient COP (cooling load/total of consumed electricity and solar energy equivalent electricity) is greater than 3.1, which is better than the specified value of refrigeration performance coefficient of evaporative cooling compression chiller (heat pump) unit in "GB50189-2015 Public Building Energy Saving Design Standard" (Table 4.2.10).

As shown in Figure 2, a method for realizing exhaust steam condensation and wastewater regeneration by fluidized air cooling is used: the low-pressure saturated steam with a temperature not exceeding 45°C is either exhaust steam from the last stage of the steam turbine or wastewater vaporization regeneration steam; the working gas is exhaust gas that meets atmospheric emission standards or is directly ambient air; and the working water is either wastewater that meets environmental emission standards or regenerated water. Low-pressure water vapor enters the fluidized condensation combination 5 through the inlet control valve 12, and is evenly distributed through a distributor connected to the high end of the finned tube bundle to flow into each tube of the finned tube bundle 5-2 immersed in the gas-solid fluidized bed, forming inclined convection condensation heat release in the tube, and the heat is transferred to the fully fluidized particle layer outside the tube through the tube wall and the fins. The low-pressure water vapor in the tube is completely condensed, and the condensed water and non-condensable gas flow from the lower end of the tube bundle into the end cover 5-5 connected thereto. The condensed water is pressurized and sent out for recycling by the return pump 8, and the non-condensable gas is regularly extracted through the non-condensable gas extraction control valve 5-4 connected to the space so that its partial pressure ratio in the condensation space is less than 0.5/1000.

The gas-solid fluidized bed outside the finned tube bundle and its heat absorption are realized by the following method: -20~35℃ working gas, with particles (particle size 0.8~1.2mm, density 550~650kg/ ^m3 , initial fluidization velocity 0.3~0.5m/s ) A flow rate of 2 to 5 times the initial fluidization speed uniformly passes through the gas distribution plate 5-1 with a hole diameter not exceeding 0.6 mm, so that the wear-resistant particle group with a stacking height of 0.3 to 0.5 m thereon is fully fluidized to form a gas-solid fluidized bed with a height rising to more than 2 times the particle stacking height and completely submerging the fin tube bundle; The arrangement method of the fin tube bundle is the same as the above, and the working water spray is introduced into the fluidized particle layer from its high end side. The ratio of the mass flow rate of the working water to the mass flow rate of the working gas is 1:20 to 50. The working gas drives the water mist and the fluidized particle group to violently churn and mix and continuously flush the outer surface of the tube bundle and the fin surface, forming a cooling effect of absorbing heat while vaporizing and humidifying, strengthening the condensation of water vapor with a temperature not exceeding 45°C in the fin tube, and the condensation intensity calculated based on the inner surface area of the fin tube is not less than 15kg/ ^hm2 The working gas absorbs heat through the fluidized bed particle layer, rises in temperature to no more than 42°C, and increases in humidity to no more than 55g/kg-DA. After flowing out of the bed, it continues to flow in the upper space for 0.2~0.3m, and finally passes through the screen with a pore size of less than 0.2mm set on the top of the fluidized condensation combination 5 for discharge.

BRIEF DESCRIPTION OF THE DRAWINGS

1 is a diagram of a method for clean air conditioning by fluidized cooling using cold energy of normal temperature air provided by the present invention, and 2 is a schematic diagram of a method for realizing exhaust steam condensation and wastewater regeneration using fluidized air cooling.

In Figures 1 and 2: 1 – exhaust humidification/fresh air cooling heat exchanger; 2 – falling film evaporation/fresh air cooling dehumidifier; 3 – water vapor ejector; 4 – multi-layer coil evaporator; 4-1 – coil surface water distributor; 4-2 – multi-layer coil; 5 – fluidized condensation combination; 5-1 – gas distribution plate; 5-2 – fin tube bundle; 5-3 – auxiliary condenser; 5-4 – non-condensable gas extraction control valve; 5-5 – end cover; 6 – micro pressurized circulation pump; 7 – falling film liquid circulation pump; 8 – condensate return pump; 9 – coil evaporator circulation pump; 10 – low-pressure return control valve; 11 – coil evaporator return control valve; 12 – low-pressure water vapor inlet/outlet control valve.

The following further describes the accompanying drawings 1 and 2 in conjunction with the embodiments.

Detailed ways

The following is a description of the specific implementation of the present invention in combination with but not limited to the embodiments.

Example 1: 10000m ³ /h fresh air air conditioning in public space, using fluidized cooling to utilize the cold energy of air conditioning exhaust gas.

Ambient air conditions: dry bulb temperature 38℃, moisture content 21.2g/kg-DA. Fresh air conditioning cooling air supply conditions: dry bulb temperature 23~25℃, moisture content 11.5~12.5g/kg-DA (relative humidity 50%~60%). At the same time, it is required that the air conditioning exhaust of the public space (dry bulb temperature 26℃, moisture content 12.5g/kg-DA) be fully disinfected and then discharged centrally. The flat-plate solar water heater on the roof of the public space heats ^60m3 /h of circulating hot water from 88℃ to 93℃ as a low-level heat cooling heat source.

As shown in Figure 1, a 9.0kW exhaust fan is used to pressurize ^9000m3 /h of 26℃ air-conditioned exhaust to 2.0~2.5kPa and enter the top pipe box of the exhaust humidification/fresh air cooling heat exchanger 1, and is sprayed with 230kg/h of sanitary disinfection aqueous solution to form a gas-mist two-phase flow, which flows into each pipe at a flow rate of 10m/s. The exhaust itself cools down and releases heat, and absorbs heat from the pipe wall to vaporize the droplets, and flows to the bottom outlet with a temperature of 24℃ and humidification to 17.8g/kg-DA; correspondingly, the ^10000m3 /h fresh air passing over the fin surface from top to bottom outside the pipe releases heat and cools to an outlet temperature of 28℃, with unchanged moisture content. The gas-mist flow is separated in the bottom pipe box, and the unvaporized droplets are condensed and 133kg/h is circulated back to the top pipe box through the micro-boosting pump 6 and merged with the newly added 97kg/h sanitary disinfection aqueous solution to enter the spray cycle, and 35kg/h is discharged from the bottom pipe box.

The fresh air cooled to 28°C by the above process continues to release heat, cool and dehumidify from top to bottom through the outer fin surface of the falling film evaporator/fresh air cooling and dehumidifier 2, and is cooled and humidified to 18°C and below 12.5g/kg-DA at the outlet and transported to the public space. The temperature rise of 4~5°C due to the loss of cooling capacity in the air distribution process is allowed, and users get clean fresh air that meets the comfortable air conditioning supply conditions.

The sensible heat and latent heat released by the fresh air in the cooling and dehumidifying device 2 are transferred to the pure water falling film evaporation process with a temperature of not less than 15°C in the tube through the outer surface of the finned tube. The evaporation intensity is not less than 5.0kg/ ^hm2 , and the low-pressure steam of 175 kg/h with a pressure of not less than 1.7kPa is generated, which is sucked into the steam ejector 3 through the low-pressure water vapor outlet control valve 12; the falling film circulation pump 7 transports 2500~3000 kg/h of pure water from the bottom pipe box of 2 back to the top pipe box of 2 for circulation.

The above low-pressure steam is jet-drawn into the steam ejector 3 by 480 kg/h of working steam with a temperature not lower than 87°C and a pressure not lower than 62 kPa, and the two are mixed into 655 kg/h of saturated water vapor at 37°C and sent to the fluidized condensation assembly 5 for condensation. The process of generating working steam is as follows: ^60m3 /h of circulating hot water heated to 93℃ by the flat plate solar collector releases heat by convection from top to bottom through the multi-layer coil 4-2 at a flow rate of 2.2m/s, so that 2800kg/h of pure water evenly distributed on the coil surface through the coil surface distributor 4-1 is partially vaporized to generate 480kg/h of working steam, and the unvaporized pure water drops into the liquid phase outside the two lowest layers of coils of 4-2, merges with 480kg/h of 37℃ condensed water sent by the return pump 8, is heated to above 87℃, and then is pressurized by the coil evaporator circulation pump 9 and sent to the coil surface distributor 4-1 located above the top coil for circulation; the hot water in the coil circulates and releases heat until the return water temperature at the outlet of the lowest coil drops to 88℃, and is sent to the flat plate solar water heater for reheating to 93℃ and returns to the circulating hot water inlet of 4-2.

The condensation process of 37℃ saturated water vapor sent from the water vapor ejector 3 to the fluidized condensation combination 5 is as follows: the water vapor is evenly distributed into each tube through the distributor at the high end of the finned tube bundle 5-2, forming inclined convection condensation heat release in the tube, and the condensate and uncondensed water vapor flow from the low end pipe port of the tube bundle 5-2 into the auxiliary condenser 5-3 connected thereto, and are completely condensed and gathered into 655kg/h of pure water, which is pressurized by the return water pump 8, and 175 kg/h is distributed to the falling film evaporator/fresh air cooling and dehumidifier 2 through the low-pressure return water control valve 10, and 480 kg/h of water is replenished to the bottom of the multi-layer coil evaporator 4 through the coil evaporator return water control valve 11. The condensation heat of the auxiliary condenser 5-3 is taken away by 60 ^m3 /h cooling water (29℃ inlet, 34℃ outlet) through convection absorption in the finned tubes, and the non-condensable gas is regularly extracted through the non-condensable gas extraction control valve 5-4 to keep the ratio of the non-condensable gas partial pressure to the water vapor partial pressure in the condensation space less than (0.5/1000).

The process and method of the fluidized particle layer outside the finned tube bundle 5-2 of the fluidized condensation combination 5 to absorb condensation heat are as follows: the particle group is hollow ceramic microspheres selected from fly ash, with a particle size of 1.1-1.2 mm, a density of 600 kg/m ³ , an initial fluidization speed of 0.42 m/s, and a particle layer stacking height of 0.35 m; the 24°C air-conditioned exhaust gas after cooling and humidification by the heat exchanger 1 evenly passes through the gas distribution plate 5-1 with a hole diameter of 0.5 mm at a speed of 1.6 m/s to fully fluidize the particle layer, and the height rises to 0.8 m to completely submerge the finned tube bundle; 130 kg/h of tap water spray is introduced into the fluidized particle layer from the high end side of the finned tube bundle 5-2, and violently churns and mixes with the fluidized particle group, collides with the outer surface of the tube bundle and the fin surface, and absorbs heat while vaporizing, so that the condensation intensity of the 37°C low-pressure water vapor flowing in the finned tube bundle is not less than 10 kg/hm ² The air-conditioning exhaust absorbs heat through the fluidized particle layer and rises in temperature to 31°C and humidifies to 29g/kg-DA, and is discharged from a screen with a pore size of 0.2mm at 0.2m above the particle layer.

The beneficial effect of fluidized utilization of ^9000m3 /h air conditioning exhaust cooling, auxiliary flat-plate solar collector heating, and water vapor jet cooling of ^10000m3 /h fresh air clean air conditioning in this case is that the solar refrigeration air conditioning with only air and water as working fluids completely avoids the hygienic risks of air supply in public spaces. The cooling load is 160kW, the power consumption is 15.2kW, the flat-plate solar collector is converted to an equivalent electric power of 34.8kW, and the comprehensive refrigeration performance coefficient COP=160/(15.2+34.8)=3.2, which has excellent low-carbon cooling characteristics.

Example 2: Fluidized bed utilizes workshop ventilation exhaust cooling energy and 60°C process waste heat to regenerate 40°C process wastewater.

Process wastewater is 1100kg/h, and the water quality meets environmental emission standards. Workshop sanitary ventilation exhaust is ^10000m3 /h, 20℃, and the moisture content is 8.5g/kg-DA. The 60℃ process waste heat comes from the main pipe connecting the evaporation and concentration waste steam of the chemical workshop and the inlet of the water jet condenser, and the saturated temperature of the waste steam is 60℃.

650 kg/h of 60°C saturated steam is diverted from the above-mentioned evaporation and concentration waste steam main pipe, and used as a heat source to heat and vaporize the process wastewater to generate 620 kg/h of 45°C regeneration steam, which is introduced into the fluidized condensation combination 5 through the low-pressure steam inlet control valve shown in Figure 2, and evenly distributed through the distributor connected to the high end of the finned tube bundle to flow into the inclined tube of the finned tube bundle 5-2 immersed in the gas-solid fluidized particle layer for convection condensation and heat release. The heat is transferred to the fluidized particle layer outside the tube through the fins on the tube wall, and the low-pressure water vapor in the tube is completely condensed. The condensed water and non-condensable gas flow from the lower end of the tube bundle into the end cover 5-5 connected thereto, and 620 kg/h of regeneration condensed water is pressurized and delivered by the return pump 8 for process circulation. The non-condensable gas is regularly extracted through the non-condensable gas extraction control valve 5-4 connected to the space. The heat absorption process of the fluidized particle layer outside the tube is realized by the following method: the particle layer above the gas distribution plate 5-1 is piled with hollow ceramic micro beads selected from fly ash, with a particle size of 1.1~1.2mm, a density of 600kg/ ^m3 , an initial fluidization speed of 0.42m/s, and a particle layer accumulation height of 0.35m; ^10000m3 /h of workshop sanitary ventilation exhaust gas at 20℃ is pressurized to 1.5kPa by a fan as working air, and passes through the gas distribution plate 5-1 with a hole diameter of 0.5mm at a speed of 1.6m/s, so that the particle layer is fully fluidized and its upper surface height rises to 0.8m, so that the finned tube bundle is completely submerged; 480 process wastewater is discharged from the high end side of the finned tube bundle 5-2 to form a heat exchanger, and the heat exchanger is heated to 1.5kPa. kg/h spray is introduced into the fluidized particle layer, and the working air drives the water mist and the fluidized particle group to churn and mix violently, and continuously contact and renew with the outer surface of the tube bundle and the fin surface, absorbing heat while vaporizing and heating from 20℃, and forming a condensation effect of not less than 16kg/ ^hm2 on the 45℃ regenerated water vapor flowing in the fin tube bundle. The working gas absorbs heat and heats up to 40℃, humidifies to 45.7g/kg-DA, leaves the upper surface of the fluidized particle layer and continues to flow in the upper space for 0.2m before passing through a 0.2mm pore screen for discharge.

The energy-saving and emission-reduction effect of this example is that the fluidized bed utilizes 10,000 m ³ /h of sanitary ventilation exhaust cooling energy to achieve 1,100 kg/h of wastewater regeneration treatment (of which 620 kg/h of regenerated condensed water is obtained and 480 kg/h is absorbed by the atmosphere). In this process, the sanitary ventilation exhaust booster fan consumes 6.5 kW.h of electricity and the small centrifugal water pump consumes no more than 3.5 kW.h of electricity. The water jet condenser reduces the waste steam condensation load by 650 kg/h, which can save 15 kW.h of electricity (including 11 kW.h of water pump power consumption and 4 kW.h of cooling tower fan power consumption). It can be seen that the fluidized bed in this example utilizes the workshop ventilation exhaust cooling energy and 60°C process waste heat to achieve wastewater resource regeneration and save the overall energy consumption of the workshop.

The present invention is not limited to the above embodiments, and its technical solutions have been described in the content of the invention.

Claims (3)

1. A fluidization method for comprehensively utilizing cold energy of normal-temperature air is characterized in that water mist is sprayed into a fluidization particle layer, vaporization mass transfer process is carried out on the surface of fluidization gas-solid particles, and water vapor molecules are enabled to continuously migrate from a gas-water interface to a gas flow main body and move along with the gas flow, so that water molecules on the interface are enabled to continuously vaporize and absorb heat to generate cooling and refrigerating effects;

heat is transferred to the spray gas-solid fluidized particle layer, so that the spray gas-solid fluidized particle layer absorbs heat and heats up, the saturated water vapor pressure of an interface is improved, the driving force in the vaporization process is improved, the application effect of normal-temperature air cold energy is enhanced, and the refrigeration intensity calculated according to the surface area of equipment is improved by a plurality of times compared with the prior art;

The fluidization particle layer absorbs heat in the following steps: the particle layer in the fluidized bed with the rectangular cross section is composed of spherical wear-resistant particle groups uniformly stacked outside the fin tube bundles, the particle size of the particle groups is 0.8-1.2 mm, the density is 550-650 kg/m ³, the initial fluidization speed is 0.3-0.5 m/s, and the stacking height of the particle layer is 0.3-0.5 m; uniformly passing normal-temperature working air through a gas distribution plate with the aperture of not more than 0.6mm at an initial fluidization speed of 2-5 times to enable a particle layer above the air distribution plate to become a fluidized bed with sufficient fluidization, raising the upper surface of the air distribution plate to be more than 2 times of the stacking height of a static particle layer, and completely submerging a fin tube bundle; enabling the lowest point of the fins of the fin tube bundle to be 35-50 mm away from the distribution plate, and spraying and introducing working water into the fluidized bed from a position higher than the position, wherein the ratio of the mass flow of the working water to the mass flow of working air is not more than 1/30; the working air drives the water mist and the fluidized particle group to be vigorously stirred and mixed and to continuously collide with the outer surface of the tube bundle and the surfaces of the fins for heat transfer, the temperature is raised to be not more than 5 ℃ with the temperature difference of the exothermic medium in the fin tube while absorbing heat, the working air is heated and humidified to the saturated vapor pressure, the working air leaves the upper surface of the bed layer and continuously flows for 0.2-0.3 m in the upper free space of the bed layer, and finally the working air is discharged through a screen with the aperture not more than 0.2mm arranged at the top.

2. The fluidization method for comprehensively utilizing cold energy of normal-temperature air is characterized by taking the exhaust air of a public space air conditioner as working air, cooling and dehumidifying fresh air, providing fresh air conditioner air supply with dry bulb temperature of 23-25 ℃ and relative humidity of 50-60%, and simultaneously carrying out sanitary disinfection on the exhaust air of the air conditioner;

The air conditioner exhaust and the sanitary disinfection are used as a mode of utilizing air cooling energy, the air conditioner exhaust and the sanitary disinfection aqueous solution are sprayed and mixed, an air-fog two-phase flow with the flow speed of 8-10 m/s is formed in a descending pipe of an exhaust humidifying/fresh air cooling heat exchanger, the heat is absorbed from the pipe wall to enable fog drops in the air flow to be vaporized, and fresh air passes through the surface of a fin from top to bottom outside the pipe to release heat and cool; the gas-fog mixture in the pipe flows to a bottom pipe box, the temperature of exhaust is reduced to 23-25 ℃, the temperature is humidified to 18.5-19.2 g/kg-DA, and fresh air outside the pipe is cooled to 26-27 ℃; the sanitary disinfectant after gas-fog separation and condensation is returned to the top pipe box from the bottom pipe box through a micro pressurizing circulation pump, and is combined with newly-added sanitary disinfectant solution for spraying circulation, wherein the ratio of the mass flow of the circulating solution to the mass flow of air-conditioning exhaust is 1:50-60, the amount of the newly-added sanitary disinfectant solution is equal to the sum of the humidification vaporization amount of exhaust and the discharge amount of the disinfectant of the bottom pipe box, and the discharge amount is 50-60% of the vaporization amount;

The fresh air cooled to 26-27 ℃ is continuously subjected to heat release, cooling and dehumidification through the surface of the outer fin of the tube of the falling film evaporation/fresh air cooling dehumidifier, and heat is transferred to pure water falling film evaporation in the tube through the tube wall, the heat transfer temperature difference is 2-3 ℃, and the evaporation intensity is not lower than 4.5kg/h.m ²; the fresh air outside the pipe is cooled to 17-18 ℃ through a cooling dehumidifier, the moisture content is reduced to 11.5-12.5 g/kg-DA, and the fresh air enters a fresh air delivery and distribution main pipe of the clean air conditioner through the pressurization of a blower; the falling film evaporation generates low-pressure water vapor with the temperature not lower than 15 ℃ and the pressure not lower than 1.74kPa, the low-pressure water vapor is pumped into a vapor injector, the falling film liquid circulates through a falling film circulating pump, and the circulating mass flow is 15-20 times of the falling film evaporation capacity;

The multi-layer coil evaporator provides working steam with the temperature of 85-90 ℃ and 58-68 kPa for the steam ejector, heat energy of the working steam is generated from circulating hot water of a flat-plate solar water heater with the temperature of 92-95 ℃, heat is released by spirally flowing from the uppermost layer to the lower layer at a flow rate of 2.0-2.5 m/s in a multi-layer coil horizontally arranged in the evaporator, and the temperature of circulating backwater from the outlet of the lowermost layer coil is not lower than 86 ℃; pure water is uniformly distributed on the surfaces of the uppermost two layers of coils through the coil surface water distributors, and drops to the surface of the next coil arranged in a staggered way while absorbing heat and vaporizing, unvaporized pure water drops to the liquid level at the bottom of the evaporator, the liquid level just enables the lowermost two layers of coils to be completely immersed below the liquid level, the water added in the uppermost two layers of coils is heated by the coils to be heated to more than 85 ℃, and then the water is pressurized and conveyed to the water distributors for circulation through the coil evaporator circulating pump; the circulating water distribution amount is 5-10 times of the working steam amount generated by the evaporator; the generated working steam is accelerated into supersonic airflow with the pressure lower than 1.7kPa through an ejector, and low-pressure water vapor generated by suction falling film evaporation is mixed with the supersonic airflow with the pressure lower than 1.7kPa to form mixed steam with the temperature higher than 36 ℃ and the pressure higher than 6kPa, and the mixed steam is sent to a fluidization condensation combination for condensation;

The fluidization condensation combination comprises a fin tube bundle immersed in the particle layer of the gas-solid fluidized bed with a rectangular cross section and a gas distribution plate at the bottom of the fluidized bed; the method comprises the steps that a fin tube bundle is arranged, one end of the fin tube bundle is high, the other end of the fin tube bundle is low, the included angle between the tube axis and the horizontal angle is 5-8 degrees, water vapor to be condensed flows into each tube through a distributor connected with the high end of the fin tube bundle, oblique convection condensation releases heat, heat is transferred to a fluidized particle layer outside the tube through fins on the tube wall, condensate and uncondensed water vapor flow into an auxiliary condenser connected with the tube bundle from the tube orifice at the low end of the tube bundle, heat is continuously released and fully condensed on the fins at the temperature below 35 ℃ outside a cooling water tube in the auxiliary condenser, the condensed water is pressurized through a water return pump, and water is supplemented to a falling film evaporation/fresh air cooling dehumidifier and a multi-layer coil evaporator through a low-pressure water return control valve and a coil evaporator water return control valve respectively according to the ratio of low-pressure water vapor quantity to working vapor quantity; the non-condensable gas in the condensation space is periodically pumped out after passing through a non-condensable gas pumping control valve to keep the ratio of the partial pressure of the non-condensable gas to the partial pressure of the water vapor less than 0.5/1000; the low-pressure backwater control valve and the low-pressure water vapor outlet control valve divide the completely sealed pure water and water vapor circulation space in the fluidization condensation combination into a low-pressure area and a pressure-changing working area, the two valves are closed in the stopping period and the starting initial period, and after the two valves are started, all devices in the pressure-changing working area are normally operated, and then the two valves are synchronously opened;

The fluidization is implemented by the steps, the exhaust cold energy is used for assisting the flat plate type solar heat collection refrigeration, the comprehensive refrigeration coefficient of performance COP of the public space fresh air cleaning air conditioner is more than 3.1, the air supply hygienic risk is completely avoided, and the air conditioner exhaust is intensively discharged after being subjected to hygienic disinfection.

3. The fluidization method for comprehensively utilizing cold energy of normal-temperature air according to claim 1, wherein the method is characterized in that the waste steam condensation and the wastewater regeneration are realized by utilizing fluidization air cooling; the low-pressure saturated water vapor with the temperature not exceeding 45 ℃ is any one of steam turbine final stage exhaust steam or waste water vaporization regeneration steam, the working gas is waste gas meeting the atmospheric emission standard or directly adopts ambient air, and the working water is any one of waste water or regenerated water meeting the environmental emission standard; the low-pressure steam enters a fluidization condensation combination through an inlet control valve, flows into each tube of a fin tube bundle immersed in a gas-solid fluidization bed through a distributor connected with the high end of the fin tube bundle to form oblique convection condensation heat release in the tube, heat is transferred to the outside of the tube through the tube wall and the fins to fully fluidize a particle layer, so that the low-pressure steam in the tube is completely condensed, condensed water and noncondensable gas flow into an end cover connected with the low-end tube opening of the tube bundle from the low-end tube opening of the tube bundle, the condensed water is pressurized and sent out for recycling through a water return pump, and the noncondensable gas is periodically pumped out through a noncondensable gas pumping control valve to ensure that the partial pressure ratio of the noncondensable gas in a condensation space is less than 0.5/1000;

The method for absorbing heat of the gas-solid fluidized bed outside the finned tube bundle comprises the following steps: the method comprises the steps that the wear-resistant particles of a gas-solid fluidized bed have a particle size of 0.8-1.2 mm, a density of 550-650 kg/m ³ and an initial fluidization speed of 0.3-0.5 m/s, working gas at the temperature of-20-35 ℃ uniformly passes through gas distribution with the aperture not exceeding 0.6mm at a flow rate which is 2-5 times of the initial fluidization speed of the particles, so that the height of the gas-solid fluidized bed formed by fully fluidizing the particle groups with the stacking height of 0.3-0.5 m on the gas-solid fluidized bed is increased to be more than 2 times of the stacking height and completely submerge fin tube bundles; introducing working water spray into the fluidized particle layer from the high end side of the fin tube bundle, wherein the ratio of the mass flow of the working water to the mass flow of the working gas is 1: 20-50, wherein the working gas drives the water mist and fluidized particle groups to continuously wash the outer surface of the tube bundle and the surface of the fins, and the cooling effect of absorbing heat and vaporizing simultaneously strengthens the condensation of water vapor with the temperature not exceeding 45 ℃ in the fin tubes, and the condensation strength is not lower than 15kg/h.m ² calculated according to the inner surface area of the fin tubes; the working gas absorbs heat through the fluidized bed particle layer, is heated to not more than 42 ℃, is humidified to not more than 55g/kg-DA, and finally passes through a screen with the aperture below 0.2mm arranged at the top of the fluidization condensing combination to be discharged.