Environmentally friendly air conditioning system

Abstract

The present invention provides an environmentally friendly air conditioning system, including a vacuum evaporation system, a vacuum condensation system and a cold water circulation system, characterized in that the vacuum evaporation system includes a vacuum evaporator and a cold water tank, the vacuum evaporator is provided with a circulating water inlet, a cold water outlet and a water vapor outlet, the cold water outlet is connected to the cold water tank through a pipeline, the circulating water inlet of the vacuum evaporator is connected to a water replenishment tank through a pipeline, and a water replenishment valve is provided on the pipeline between the vacuum evaporator and the water replenishment tank. The present invention provides an environmentally friendly air conditioning system, which only needs to use softened water or pure water as a working medium, and most of the working medium water can be recycled, saving water resources, and does not require additional paid heat or cold energy supply, and can achieve high-efficiency heating, overcoming the disadvantage that the previous water air conditioner cannot take into account heating.

Description

Technical Field

[0001] The invention relates to the field of air conditioning, and in particular to an environmentally friendly air conditioning system. Background Art

[0002] With the development of national economy and science and technology, people's requirements for quality of life are increasing day by day, and air conditioners have become a daily necessity for people. Whether in private homes, office buildings, commercial buildings, indoor tourist attractions, cultural and educational buildings, factories, mines, hospitals, stations, and cinemas, air conditioners can be seen everywhere, bringing comfortable temperature experience to people's work and life. Air conditioners are a kind of heat pump, which consumes a lot of energy in the process of bringing coolness or warmth to people. According to statistics, in China, the energy consumption of heating, ventilation, and air conditioning systems accounts for 40% to 60% of the total energy consumption of buildings, 59% in Canada, and about 55% in Malaysia. Among them, air conditioning systems, especially those in cooling mode, are the equipment with the largest power consumption. In the summer when the use rate of air conditioning refrigeration is the highest, the concentrated use of household air conditioners may even cause the power supply network to be in an overloaded state and cause the latter to collapse. In order to prevent the collapse of the power supply system, some production units are sometimes required to limit power and stop production, which has an obvious impact on the national economy. To this end, exploring new cooling methods, reducing the energy consumption of air conditioners, and reducing greenhouse gas emissions are important issues in building a green, sustainable and harmonious society.

[0003] At present, the mainstream refrigeration technology in the field of air conditioning is compressor refrigeration, and its principle is: a suitable working fluid vaporizes at low pressure to absorb heat, and then liquefies at high pressure to release the absorbed heat, and then the working fluid circulates back to the low pressure, repeating the process, so as to realize the continuous transfer of heat from a lower temperature to a higher temperature. At present, the commonly used working fluids are Freon refrigerants, hydrocarbon refrigerants, inorganic compound refrigerants and azeotropic mixture refrigerants, among which Freon refrigerants are the most widely used. Freon is a general term for a series of fluorine-containing organic substances, which have a low freezing point, are easy to vaporize at low pressure, and are easy to liquefy at high pressure, and have the best comprehensive performance. However, it is well known that Freon has a serious destructive effect on the atmospheric ozone layer, causing the ozone layer to lose its barrier effect against ultraviolet rays, and ultimately causing fatal damage to the creatures on the earth. In addition, some Freon products are also greenhouse gases, which will aggravate climate warming like carbon dioxide. At present, Freon products that will seriously damage the ozone layer have been banned from use as air conditioning refrigerants internationally, and even production has been banned. Freon refrigerants that are still in use have all been improved to a certain extent, while ensuring their acceptable performance as air conditioning fluids, and minimizing their harm to the environment and human body. However, in general, as a synthetic chemical substance, Freon still has potential harm to the environment and human body during production and use.

[0004] Another major category of refrigeration technology in the air-conditioning industry can be summarized as non-compressor technology. This type of technology actually also utilizes the endothermic effect of the working fluid during the evaporation phase change process, but evaporation usually occurs under normal pressure or negative pressure, and the evaporated working fluid is not liquefied by compression. Since the most energy-consuming compressor is omitted, non-compressor air conditioners may be able to achieve lower operating energy consumption, especially in the field of high-power air conditioning, which has special advantages. This type of refrigeration and air-conditioning equipment usually uses water or aqueous solution as the working fluid, thus avoiding the use of freon, which is potentially harmful to the environment. Non-compressor air conditioners can be divided into direct evaporative cooling and throttling expansion. Direct evaporative non-compressor air conditioners usually promote the evaporation of the working fluid by dry air blowing or vacuuming to improve efficiency. Throttling expansion non-compressor air conditioners are represented by lithium bromide absorption units. During operation, additional heat sources are required to evaporate the working fluid first and provide pressure, and then use external cold sources to liquefy the working fluid vapor at a higher pressure, and then throttle the liquefied water to expand to achieve vaporization cooling.

[0005] The most classic direct evaporative non-compressed air conditioning equipment using air purge is the cooling tower, which has the following characteristics: simple process, large processing capacity, low cost, but usually not good enough effect. In summer, the maximum outlet water temperature of ordinary cooling towers in many places in China exceeds 28°C, and cannot be directly used as central air conditioning water. It can only be used as industrial process cooling water, and needs to be assisted by compressed air conditioning refrigeration equipment to further cool to the required temperature of air conditioning. The most important limiting factor of purge direct evaporation equipment is the relative humidity (or corresponding wet bulb temperature) of the purge air. If the relative humidity is too high and the wet bulb temperature is too high (i.e., in a high temperature and high humidity environment), the cooling effect of this type of equipment is poor; the lower the relative humidity, the lower the wet bulb temperature, and the easier it is for this type of equipment to obtain a low temperature. In order to improve the cooling effect of this type of equipment, it is usually necessary to dehumidify the purge air. For example, the patent CN207849601U describes a heat recovery and high-efficiency cooling air conditioning system for a data room. After the fresh air is dehumidified by the solution absorption tank, it undergoes indirect evaporation heat exchange and direct evaporation heat exchange, and then heat exchanges with the return air of the data room to heat up. After reaching the required temperature and humidity of the data room, air is supplied to the data room. The working fluids for indirect evaporation and direct evaporation are both water. The dehumidification working fluid of the solution absorption tank is a solution desiccant, and the return air of the data room is used for heating and purging to dehydrate and regenerate during operation. During the operation of the entire system, water needs to be added to the evaporation heat exchange pool on time. The patent CN104154611A describes a solar dehumidification type evaporative cooling air conditioning unit, which is equipped with a rotary dehumidifier. The new air is treated by the rotary dehumidifier to obtain dry air, a part of which enters the water spray chamber for humidification and cooling, and is mixed with another part of the dry air that has not been humidified and cooled to obtain air that meets the treatment requirements and is supplied to the building for use. During the operation of the unit, the return air from the building is heated by a solar collector and then supplied to a rotary dehumidifier for dehydration and regeneration of dehumidification materials. As mentioned above, the key to the two patent solutions is the dehumidification link. If the dehumidification effect is not good, the cooling effect of the air conditioner will not meet expectations. In addition, the energy consumption index of the dehumidification link is also crucial, and even determines the economic feasibility of this type of cooling air conditioner. Patent CN207849601U adopts the method of purging the return air in the machine room to solve this problem, but the return air temperature in the machine room is generally not too high, and the regeneration capacity requirements of the desiccant will be very harsh. Patent CN104154611A adopts the method of solar energy collection, but solar energy is not so reliable in many places. It can be seen that the current purging and cooling method still has certain defects. In addition, in both schemes, water is directly discharged into the exhaust gas, and a large amount of water is consumed during use, which is not conducive to saving water resources.

[0006] Direct evaporation non-compression air conditioning equipment that uses vacuum pumping uses the liquid equilibrium vapor pressure and the absolute pressure difference in the evaporation chamber as the driving force for evaporation. In theory, it is not affected by the external environment. As long as the absolute pressure in the evaporation chamber is low enough and the evaporation time is long enough, the working medium temperature can be reduced to a sufficiently low level. Many patents have been published in this field. For example, patent CN101922769B describes a water evaporation type environmentally friendly refrigeration air conditioner and its refrigeration method, which uses an exhaust fan to form a certain negative pressure, draws air into an evaporation chamber with a curtain-type water absorption structure, evaporates water into the air under a negative pressure environment, and cools the water and air at the same time. The cooled and humidified air is discharged to an environment that needs to be cooled through an exhaust fan. Patent CN201811365U describes an energy-saving and environmentally friendly central air conditioner, which consists of an evaporator, a compressor, a condenser, a throttle, a vacuum pump, a spraying device and connecting pipes to form a closed host system. The vacuum pump and the compressor are connected to the evaporator respectively and are not connected to each other. The vacuum pump provides a vacuum environment, and the spraying device sprays the working medium water to evaporate and cool down. The evaporated water vapor is compressed by the compressor and then heated and pressurized to reach a supersaturated state. It is cooled and condensed by spraying cold water on the condenser. The condensed water is cooled by the cooling tower supporting the central air conditioner and partially returned to the evaporator. Patent CN203907841U describes a water-cooled air conditioner, including a water storage tank, an expansion valve, an evaporator, a vacuum suction machine and an electronic control system. The water storage tank is connected to the evaporator, and an expansion valve is set in the middle. The vacuum suction machine is connected to the evaporator to directly pump the water vapor in the evaporator into the atmosphere, thereby achieving the purpose of cooling. Patent CN204717946U describes a solar vacuum air conditioner, which is equipped with solar panels, evaporator, water ring vacuum pump, fan, steam condensation chamber air blocking and liquid drain valve, etc. It uses solar energy to convert into electricity to drive the water ring vacuum pump, evaporate the water in the evaporator at low pressure to cool it down, discharge the water vapor into the steam condensation chamber, cool it with a fan, and then return it to the evaporator. The above patents all have certain defects. Among them, patent CN101922769B is actually still a purge-type evaporative air conditioner, and its improvement over the latter is not obvious; patent CN201811365U vacuum pump and compressor work at the same time, and the energy consumption required for steam condensation is actually only transferred to the cooling tower, which does not save any energy. In addition, the heat energy increased by the compressor work needs to be transferred away, and the power consumption of the vacuum pump and compressor has not been considered, so it is not feasible; patent CN203907841U relies entirely on a vacuum suction machine to suck the evaporated water vapor into the atmosphere. Under the conventional cooling target (about 20°C) and acceptable efficiency, the power consumption of the vacuum pump will be very large, far greater than the power consumption of conventional compression air conditioners; patent CN204717946U, like patent CN203907841U, requires very large air extraction energy consumption. The solution attempts to use solar power generation to obtain cheap energy in order to solve this problem, but it does not fundamentally solve the problem of refrigeration efficiency, not to mention that the reliability of solar energy itself is a problem.In addition, the processes described in patents CN101922769B and CN203907841U both cause loss of working fluid water. Therefore, the existing vacuum-assisted evaporation process still generally has the problems of low refrigeration efficiency and water loss, which limits the practical application of the solution.

[0007] Throttling expansion non-compressor air conditioners have been commercialized and are usually divided into steam type, direct-fired type, hot water type and solar type according to the type of external heat source. Due to the need for an additional heat source, this type of air conditioner is only suitable for use in areas with cheap, stable steam or hot water as a heat source, or areas with unstable electricity supply, sufficient fuel supply, and sufficient solar energy. As the country's control over carbon emissions becomes more stringent, the scope of application of this type of air conditioner is shrinking. At the same time, since this type of air conditioner uses a brine solution as a circulating working fluid, corrosion to the equipment is also an unavoidable challenge.

[0008] In summary, both compression air conditioning refrigeration technology and non-compression air conditioning refrigeration technology are still not perfect. Compression air conditioning refrigeration technology has been developed and used for many years, and its advantages and disadvantages have been solidified. It is not easy to achieve a revolutionary breakthrough in technology. Non-compression air conditioning, especially direct evaporation non-compression air conditioning with water as the working fluid, has an essential advantage over compressor air conditioning in terms of the safety and availability of the working fluid. If its refrigeration efficiency can be improved in a practical way, it will inevitably bring about a revolution in the field of air conditioning refrigeration.

[0009] As mentioned above, direct evaporative non-compressor air conditioners using water / water solution as working fluid are one of the most promising breakthroughs in the development of the air conditioning and refrigeration industry, but there are still many difficulties to overcome before large-scale use. The following are the key technical issues in the application of direct evaporative non-compressor air conditioners using water / water solution as working fluid:

[0010] 1. Refrigeration efficiency issues

[0011] As mentioned above, refrigeration efficiency is the core issue that determines whether direct evaporative water air conditioners (using water / water solution as working fluid) can be actually used on a large scale. Before this problem is completely solved, water air conditioners can only be used as an auxiliary and limited air conditioning and cooling technology, and must be supplemented by additional heat sources to have limited application space. The present invention can achieve the refrigeration efficiency of water air conditioners that reaches or even exceeds that of ordinary compressor air conditioners without the need for additional heat source assistance through the design and optimization of the process.

[0012] 2. Regeneration of working fluid

[0013] As mentioned above, the current direct evaporative water air conditioning scheme is difficult to achieve the reuse of working water, and all of it is directly discharged into the atmosphere along with the purge gas and cannot be recycled.

[0014] 3. Dependence on additional heat or cooling sources

[0015] As mentioned above, water air conditioners with dehydration devices often require additional energy for regeneration of adsorbents, and some must also be equipped with additional cold sources, such as cooling towers, deep well water, etc.

[0016] 4. Heating function and efficiency issues

[0017] As mentioned above, current direct evaporative water air conditioners only consider the cooling problem.

[0018] 5. Issues with overall process optimization

[0019] Considering the different conditions in different seasons and geographical environments, energy consumption will increase. Summary of the invention

[0020] In view of the above-mentioned deficiencies in the prior art, the present invention provides an environmentally friendly air-conditioning system, which can save water resources, has a low investment cost, and can achieve high-efficiency heating, thus overcoming the disadvantage that previous water air conditioners cannot take into account heating.

[0021] In order to achieve the above-mentioned object of the invention, the technical solution adopted by the present invention is:

[0022] An environmentally friendly air conditioning system, comprising a vacuum evaporation system, a vacuum condensation system and a cold water circulation system, characterized in that the vacuum evaporation system comprises a vacuum evaporator and a cold water tank, the vacuum evaporator is provided with a circulating water inlet, a cold water outlet and a water vapor outlet, the cold water outlet is connected to the cold water tank through a pipeline, the circulating water inlet of the vacuum evaporator is connected to a water supply tank through a pipeline, and a water supply valve is provided on the pipeline between the vacuum evaporator and the water supply tank;

[0023] The vacuum condensation system mainly includes a secondary vacuum pump, a heater, a condenser, a primary vacuum pump, a heater and a condensate tank. The air inlet of the secondary vacuum pump is connected to the steam outlet of the vacuum evaporator through a pipeline, the air outlet of the secondary vacuum pump is connected to the heater, the outlet of the heater is connected to the inlet of the condenser, the outlet of the condenser is respectively connected to the air inlet of the primary vacuum pump and the liquid inlet of the condensate tank, the exhaust port of the primary vacuum pump is directly facing the atmosphere, the liquid outlet of the condensate tank is connected to the circulating water inlet of the vacuum evaporator, and a spray tank for cooling is provided on the pipeline between the primary vacuum pump and the condensate tank;

[0024] The cold water circulation system includes a water supply pump, a gas-liquid heat exchanger, a cold air blower and a pressure relief valve. The water supply pump is connected to the water outlet of the cold water tank and then to the inlet of the gas-liquid heat exchanger. The outlet of the gas-liquid heat exchanger is connected to the circulating water inlet of the vacuum evaporator through the pressure relief valve.

[0025] As an improvement, the vacuum evaporator is a packed tower, an inclined plate tower or a tank container with a spray device, or a hydrophobic membrane evaporation device with a porous structure, and a non-porous membrane device that preferentially permeates water vapor, etc., which can maintain the necessary vacuum degree and is conducive to creating a rich gas-liquid interface required for the evaporation of the working fluid.

[0026] As an improvement, the primary vacuum pump is any type of vacuum pump selected from the group consisting of a water ring pump, a suspension plate pump, an oil-free vertical pump and a claw pump.

[0027] As an improvement, the primary vacuum pump is preferably an oil-free vertical reciprocating vacuum pump.

[0028] As an improvement, the secondary vacuum pump is preferably a Roots vacuum pump.

[0029] As an improvement, the condenser is any one of an air surface cooler, a shell and tube heat exchanger, a plate heat exchanger, a spirally wound tube heat exchanger or a spiral plate heat exchanger, or a combination of multiple thereof.

[0030] As an improvement, the condenser is preferably an air surface cooler.

[0031] As an improvement, the gas-liquid heat exchanger can be any one of a surface cooler, a shell and tube heat exchanger, a plate heat exchanger, and a spiral tube heat exchanger.

[0032] As an improvement, the gas-liquid heat exchanger is preferably a surface cooler.

[0033] The beneficial effects of the present invention are:

[0034] The present invention adopts a two-stage vacuum pump sequence combination to form a vacuum system, condenses the evaporated working fluid between two vacuum pumps in the two-stage vacuum pump sequence, and realizes automatic replenishment of the condensate back to the vacuum evaporation tank by setting the positions of the condensate tank and the vacuum evaporator. Only softened water or pure water needs to be used as the working fluid, and most of the working fluid water can be recycled, saving water resources; a heating device is arranged in front of the condenser to realize steam temperature increase so that the steam can be used for heating, and the renewal of the circulating air and the switching of the cold and warm circulating air can be realized. By attaching a spray tank, air blowing can be directly used to realize cooling under relatively low temperature and dry working conditions; no additional paid heat or cold energy supply is required, and the purpose of cooling can be achieved as long as there is water and electricity; high-efficiency heating can be achieved, overcoming the disadvantage that the previous water air conditioner cannot take into account heating. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is the overall flow chart of the system of the present invention;

[0036] Figure 2 This is a schematic diagram of the cold and warm air circulation of the present invention;

[0037] Figure 3 This is a schematic diagram of the cold and warm air switching process of the present invention. DETAILED DESCRIPTION

[0038] The specific implementation of the present invention is further described below in conjunction with the accompanying drawings, wherein the same components are represented by the same reference numerals.

[0039] It should be noted that the words "front", "rear", "left", "right", "up" and "down" used in the following description refer to directions in the drawings, and the words "inside" and "outside" refer to directions toward or away from the geometric center of a specific component, respectively.

[0040] In order to make the contents of the present invention more clearly understood, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0041] like Figure 1-3 As shown, an environmentally friendly air-conditioning system includes a vacuum evaporator, a cold water tank, a water supply pump, a gas-liquid heat exchanger, a pressure reducing valve, a water supply tank, a water supply valve, an air cooler, a warm air fan, a spray tank, a secondary vacuum pump, a heater, a condenser, a primary vacuum pump and a condensate tank, and is divided into three parts: a vacuum evaporation system, a vacuum condensation system and a cold water circulation system.

[0042] The vacuum evaporation system mainly includes a vacuum evaporator and a cold water tank. The vacuum evaporator should be provided with three connection ports, namely, a circulating water inlet, a cold water outlet and a water vapor outlet. The cold water tank includes a cold water inlet and a cold water outlet, and is located below the vacuum evaporator. After the working medium water or aqueous solution (with or without throttling and decompression) enters the vacuum evaporator, part of the water in the working medium is instantly vaporized under a relatively high vacuum state. During the vaporization process, the temperature of the working medium itself decreases, and cold water at a relatively low temperature is obtained. The cold water flows into the cold water tank by its own gravity. The vacuum evaporator can be, but is not limited to, a packed tower, an inclined plate tower, or other tank containers with a spraying device, or a hydrophobic membrane evaporation device with a porous structure, or a non-porous membrane device that preferentially transmits water vapor, as long as the necessary vacuum degree can be maintained and it is conducive to creating a rich gas-liquid interface required for the evaporation of the working medium. The cold water outlet of the vacuum evaporator is connected to the cold water inlet of the cold water tank by a pipeline. The vacuum evaporator and the cold water tank can also be made into an integrated type, which is equivalent to dividing the vacuum evaporator into a vacuum evaporation section and a liquid storage section. In this case, there is no cold water outlet of the vacuum evaporator and no cold water inlet of the cold water tank.

[0043] The vacuum condensation system mainly includes a secondary vacuum pump, a heater, a condenser, a primary vacuum pump, a heater and a condensate tank. The air inlet of the secondary vacuum pump is connected to the steam outlet of the vacuum evaporator through a pipeline, the air outlet of the secondary vacuum pump is connected to the heater, the corresponding outlet of the heater is connected to the inlet of the condenser, the outlet of the condenser is respectively connected to the air inlet of the primary vacuum pump and the liquid inlet of the condensate tank, the exhaust port of the primary vacuum pump is directly facing the atmosphere, and the liquid outlet of the condensate tank is connected to the circulating water inlet of the vacuum evaporator. The primary vacuum pump and the secondary vacuum pump jointly provide the vacuum required by the vacuum evaporator, and the vacuum degree in the vacuum evaporator in the entire vacuum system is the highest, and the absolute pressure is the lowest, which is about 2000Pa. The secondary vacuum pump selects a vacuum pump with a large suction volume at a higher vacuum degree, preferably a Roots vacuum pump. The primary vacuum pump can select any type of vacuum pump such as a water ring pump, a suspension pump, an oil-free vertical pump, a claw pump, etc., preferably an oil-free vertical reciprocating vacuum pump. Most of the gas in the vacuum evaporator is water vapor formed by vacuum evaporation. After the water vapor passes through the secondary vacuum pump, the temperature increases to a certain extent due to the work done by the secondary vacuum pump, and the absolute pressure increases to about 6000Pa, and enters the condenser under the traction of the primary vacuum pump. The condensation temperature of water vapor under this pressure is about 35°C. In the refrigeration mode, the condenser uses an external refrigerant with a temperature below 35°C to cool the water vapor, so that most of the water vapor condenses into liquid water and flows into the condensate tank. The remaining uncondensed water vapor and non-condensable gas become normal pressure after passing through the primary vacuum pump and are directly discharged into the atmosphere. The condenser can be selected from air surface coolers, shell and tube heat exchangers, plate heat exchangers, spiral wound tube heat exchangers, and spiral plate heat exchangers, preferably air surface coolers; the refrigerant can be selected from natural air, humidified and cooled air, deep well water, tap water, and other refrigerants with a temperature below 35°C, preferably natural air. In the preferred case, the heater drives the air directly to blow through the surface cooler to cool and condense the water vapor. In the case where the dry bulb temperature is higher than 35°C but the wet bulb temperature is lower than 35°C, a spray device can be set to humidify and cool the purge air. The cooling water consumption of the primary vacuum pump and the secondary vacuum pump is relatively small, and the cooling water produced by the equipment of the present invention or the softened water can be directly used for cooling. The used cooling water is collected in the water replenishment tank for water replenishment of the vacuum evaporator. In the heating mode, the heater is turned on, and the water vapor passing through the heater is heated to above 35°C, and then enters the condenser and condenses at this temperature, releasing the heat enthalpy in the water vapor into the air. At this time, the hot air blower directly pulls the air in the building through the condenser to obtain warm air and then supply it to the building. A fresh air inlet can be set in front of the fan, and part of the fresh air enters the warm air circulation system after heat exchange with the exhaust air. The warm air circulation system and the cold air circulation system share a ventilation duct, and a valve is set in the middle to prevent them from interfering with each other during use.In the heating mode, the cooling water from the primary vacuum pump and the secondary vacuum pump is directly introduced into the vacuum evaporator as the evaporation medium, and the heat is fully utilized for evaporation. The insufficient heat is obtained from the atmosphere through the air cooler to purge the gas-liquid heat exchanger (see. Figure 3 ), thereby preparing sufficient low-pressure steam. The gas pressure in the condensate tank is higher than that in the vacuum evaporator. The lowest liquid point of the condensate tank is set about 0.5m below the connection point of the circulating water inlet of the vacuum evaporator. During the operation of the equipment, the condensate in the condensate tank is automatically replenished into the vacuum evaporator.

[0044] The cold water circulation system includes a water supply pump, a gas-liquid heat exchanger, a cold air blower, and a pressure relief valve. The water supply pump is connected to the water outlet of the cold water tank and then connected to the inlet of the gas-liquid heat exchanger. The water supply pump is set lower than the cold water tank to provide sufficient cavitation height. The water supply pump can be any one of a centrifugal pump, a vortex pump, a pipeline pump, etc. The outlet of the gas-liquid heat exchanger is connected to the circulating water inlet of the vacuum evaporator after passing through the pressure relief valve. The cold water is pumped into the gas-liquid heat exchanger after being pressurized by the water supply pump. The gas-liquid heat exchanger can be any one of a surface cooler, a shell and tube heat exchanger, a plate heat exchanger, a spiral tube heat exchanger, etc., as long as it can effectively transfer the coldness of the cold water to the circulating air, preferably a surface cooler. In the cooling mode, the cold air blower drives the air in the closed building to blow through the gas-liquid heat exchanger, the coldness in the cold water is transferred to the air, and the heat in the air is transferred to the cold water, thereby achieving air cooling. The cooled air is supplied to the closed building through the ventilation duct. A fresh air inlet can be set in front of the fan, and part of the fresh air will enter the cool air circulation system after heat exchange with the exhaust air of the building. As mentioned above, the cool air circulation system and the warm air circulation system share a set of ventilation ducts, and the cool air and the warm air are isolated from each other through a series of valve designs. The cool water coming out of the gas-liquid heat exchanger has increased in temperature, and enters the vacuum evaporator through the circulation water inlet of the vacuum evaporator again through the pressure relief valve for evaporation and cooling. The pressure relief valve can be a special valve or a pipeline with a pressure relief function. After passing through the pressure relief valve, the pressure of the cool water is reduced to the working pressure of the vacuum evaporator. In the heating mode, the air intake of the air cooler is completely atmospheric air, and the exhaust air is directly discharged into the air, thereby collecting heat from the air. The air cooler can also be set in every room in the building, and the wind path is appropriately changed at this time.

[0045] For working conditions with relatively dry air, the dry air can be cooled to the required temperature by the cooling water through the attached spray tank, and then supplied to the building through the heating circulating air system, thereby further achieving the purpose of energy saving. The spray tank can also be set as a conventional cooling tower. Example

[0046] A vacuum evaporator with a diameter of 1m, a height of 2m and a spray pipe inside is adopted, a primary vacuum pump with a power of 7.5Kw, a secondary vacuum pump with a power of 37Kw, a surface cooling air heat exchanger and a number of supporting equipment are used. An air conditioner is formed according to the scheme of the present invention to cool the circulating water. The circulating water inlet temperature is 24°C, the output cold water temperature is 18°C, the cold water circulation volume is 22 tons / h, and the comprehensive refrigeration efficiency is about 3.3, reaching the index of Class 2 energy-saving air conditioner.

[0047] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention shall be included in the protection scope of the present invention.

Claims

1. An environmentally friendly air conditioning system, comprising a vacuum evaporation system, a vacuum condensation system and a cold water circulation system, characterized in that: The vacuum evaporation system comprises a vacuum evaporator and a cold water tank, the vacuum evaporator is provided with a circulating water inlet, a cold water outlet and a water vapor outlet, the cold water outlet is connected to the cold water tank through a pipeline, the circulating water inlet of the vacuum evaporator is connected to a water supply tank through a pipeline, and a water supply valve is provided on the pipeline between the vacuum evaporator and the water supply tank; The vacuum condensation system mainly includes a secondary vacuum pump, a heater, a condenser, a primary vacuum pump, a heater and a condensate tank. The air inlet of the secondary vacuum pump is connected to the steam outlet of the vacuum evaporator through a pipeline, the air outlet of the secondary vacuum pump is connected to the heater, the outlet of the heater is connected to the inlet of the condenser, the outlet of the condenser is respectively connected to the air inlet of the primary vacuum pump and the liquid inlet of the condensate tank, the exhaust port of the primary vacuum pump is directly facing the atmosphere, the liquid outlet of the condensate tank is connected to the circulating water inlet of the vacuum evaporator, and a spray tank for cooling is provided on the pipeline between the primary vacuum pump and the condensate tank; The cold water circulation system includes a water supply pump, a gas-liquid heat exchanger, a cold air blower and a pressure relief valve. The water supply pump is connected to the water outlet of the cold water tank and then to the inlet of the gas-liquid heat exchanger. The water supply pump is arranged at a position lower than the cold water tank. The outlet of the gas-liquid heat exchanger is connected to the circulating water inlet of the vacuum evaporator through the pressure relief valve.

2. An environmentally friendly air conditioning system according to claim 1, characterized in that: The vacuum evaporator is a packed tower, an inclined plate tower or a tank container with a spray device.

3. The environmentally friendly air conditioning system according to claim 1, characterized in that: The primary vacuum pump is any type of vacuum pump selected from the group consisting of a water ring pump, a suspension plate pump, an oil-free vertical pump and a claw pump.

4. An environmentally friendly air conditioning system according to claim 3, characterized in that: The primary vacuum pump is an oil-free vertical reciprocating vacuum pump.

5. The environmentally friendly air conditioning system according to claim 1, characterized in that: The secondary vacuum pump is a Roots vacuum pump.

6. The environmentally friendly air conditioning system according to claim 1, characterized in that: The condenser is any one of an air surface cooler, a shell and tube heat exchanger, a plate heat exchanger, a spirally wound tube heat exchanger or a spiral plate heat exchanger, or a combination of multiple types.

7. An environmentally friendly air conditioning system according to claim 6, characterized in that: The condenser is an air surface cooler.

8. The environmentally friendly air conditioning system according to claim 1, characterized in that: The gas-liquid heat exchanger can be any one of a surface cooler, a shell and tube heat exchanger, a plate heat exchanger, and a spiral tube heat exchanger.

9. An environmentally friendly air conditioning system according to claim 8, characterized in that: The gas-liquid heat exchanger is a surface cooler.

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