Abstract:
The cold island effect belongs to a phenomenon of climate change. At present, human research on the cold island effect is only limited to the field of science, and does not involve the technical field of invention. The present invention realizes the first application of the cold island effect principle in the technical field. The cold island effect device of the present invention comprises a plurality of reflecting devices. The reflecting devices are installed above the ground, the water surface or the building, and the reflecting planes thereof are parallel to the horizontal plane or are inclined. Most of sunshine can be reflected back to the space, so that a relatively cryogenic cold island is formed on the surface region where the reflecting devices are located and the cold island effect is formed through the interaction of ambient atmosphere, thereby achieving the purposes of heatstroke prevention and temperature reduction and drought resistance and moisture preservation.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a continuation-in-part of International Patent Application No. PCT/CN2014/077108 with an international filing date of May. 9, 2014, designating the United States, now pending, and further claims priority benefits to Chinese Patent Application No. 201310243810.5 filed Jun. 7, 2013. The contents of all of the aforementioned applications, including any intervening amendments thereto, are incorporated herein by reference. 
     
    
     TECHNICAL FIELD 
       [0002]    The present invention relates to a technical device for realizing heatstroke prevention and temperature reduction and drought resistance and moisture preservation by using a cold island effect principle. 
       BACKGROUND OF THE PRESENT INVENTION 
       [0003]    The cold island effect belongs to a phenomenon of climate change. At present, human research on the cold island effect includes: an urban park cold island effect and a desert oasis cold island effect. Moreover, the research on the cold island effect is only limited to the field of science, and does not involve the technical field of invention. The present invention realizes the first application of the cold island effect principle in the technical field. 
         [0004]    The urban park&#39;s cold island effect has an obvious effect on urban heatstroke prevention and temperature reduction in summer. This has been proved in much scientific research literature. But after all, it is a city, and it is not possible to greatly increase the area and the quantity of parks in the city for the purpose of heatstroke prevention and temperature reduction in summer. Therefore, to perform heatstroke prevention and temperature reduction in summer in the city, an air-conditioning unit is generally used by people to reduce the temperature in a room so as to achieve their purpose. Although the air-conditioning unit can reduce the temperature in the room, exhaust hot gas discharged by the air-conditioning unit raises the ambient temperature outside a house. In summer, a large number of air-conditioning units are operated simultaneously, so that the ambient temperature of the whole city is raised. Then, more people cannot bear the hot weather and are forced to follow to use the air-conditioning units, causing higher urban ambient temperature. It shows that the air-conditioning unit is a technical device for heatstroke prevention and temperature reduction with vicious circle. The energy sources consumed by the usage of the air-conditioning unit are finally converted into heat energy, and the air in the ambient environment is heated, thereby making higher whole ambient temperature and wasting a large number of energy sources. 
         [0005]    The desert oasis cold island effect has an obvious effect on drought resistance and moisture preservation in dry regions. This has also been proved in much scientific research literature. The oasis cold island effect can reduce the atmospheric temperature of an oasis surface and reduce the water evaporation of the oasis, thereby maintaining and expanding the area of the oasis. However, if the oasis is required to be formed in a desert, there must be a large amount of water, while the water is just the material which is the most lacking in the desert. Therefore, the desert oasis is naturally formed, and there is no artificial oasis at present. Currently, due to the influence of human activities and climate change, many regions on land become drier and drier and there is an urgent need for a new technical invention to resist the drought. 
       SUMMARY OF THE PRESENT INVENTION 
       [0006]    Because the park and the oasis contain a large amount of water and the specific heat of water is greatly higher than the specific heat of an urban building and desert grit, the temperature of the park and the oasis is slowly raised in the day under the irradiation of sun, while the temperature of the surrounding region is raised rapidly so that the park and the oasis become relatively cryogenic cold islands. After the cold islands are formed, according to the size of the area of the cold islands, a temperature inversion cold storage type atmospheric environment with a hot upper part and a cold lower part is formed above the small cold island; and a convectional refrigeration type atmospheric environment with high-altitude cold air sinking and hot air of surrounding surface rising is formed above the large cold island. This is the cold island effect principle. 
         [0007]    Due to the influences of greenhouse effect and heat island effect, the global climate has a trend of drying and warming, and is becoming increasingly hotter and drier. At present, the major technical way to cope with the climate change for people is to reduce the emission of greenhouse gas. Such method takes effect slowly, making it difficult to play an immediate effect, so the social and economic development is hindered. However, the application of the cold island effect is neglected by people. The cold island effect can effectively suppress the greenhouse effect and the heat island effect so that the climate becomes cool and moist. It has an immediate effect on the climate change and is of great significance to the improvement of the global climate environment. 
         [0008]    To obtain the cold islands, it is not necessarily the park and the oasis. Because the sun is the root of raising the surface temperature, the purpose of the present invention is to reflect the sunshine back to the space by installing a certain area of reflecting devices by using the cold island effect principle so as to obtain the relatively cryogenic cold islands. 
         [0009]    The device of the present invention can be a single reflecting device or formed by arranging and combining a plurality of reflecting devices. The reflecting area of the single reflecting device is from a few square meters to hundreds of square meters. The overall reflecting area of a plurality of reflecting devices is from hundreds of square meters to tens of millions of square meters, or even greater. Each reflecting device can adopt a roller shutter structure. The roller shutter can be unfolded and rolled. It can be unfolded in a fine day for light reflection to form a cold island, and can be rolled in the night or in a cloudy and rainy day for the need of ground daylighting or can be rolled in time in adverse climate so as to avoid damaging equipment. 
         [0010]    According to the size of the overall reflecting area, the cold island effect device can be divided into a large type, a medium type and a small type: 
         [0011]    Small type—The reflecting area is less than 10000 square meters. It is a cold island with the main purpose of temperature inversion cold storage. 
         [0012]    Large type—The reflecting area is greater than 10 000 000 square meters. It is a cold island with the main purpose of convectional refrigeration. 
         [0013]    Medium type—The reflecting area is between 10000 square meters and 10 000 000 square meters. It is a cold island which integrates temperature inversion cold storage and convectional refrigeration. 
         [0014]    Because the sinking of high-altitude cold air can bring high-altitude cold quantity and water vapor, convectional refrigeration can fare stronger heatstroke prevention and temperature reduction and drought resistance and moisture prevention effects than temperature inversion cold storage. 
         [0015]    The present invention has the specific technical solution that: a cold island effect device is characterized in that a single reflecting device or a plurality of reflecting devices are combined and installed on the ground, water surface or building to form a space with a shield on the top. The reflecting device comprises a bracket and a reflecting plane (plane or curved surface) positioned on the bracket, wherein the reflecting plane is parallel to a horizontal plane or is inclined. The overall area of the reflecting plane on the single or a plurality of reflecting devices is not less than 20 square meters. 
         [0016]    The present invention has the further technical solution that: a motor and a guide rail are also arranged on the bracket; the reflecting plane is a reflecting roller shutter: and the reflecting roller shutter is unfolded or rolled along the guide rail under the driving of the motor. The overall area, of the reflecting roller shutter on the single or a plurality of reflecting devices is not less than 20 square meters. Meanwhile, the reflecting plane can also be any or more of a reflecting folding curtain, a reflecting venetian blind, a reflecting flat plate, a reflecting film, a reflecting aluminum foil and a reflecting tin foil. 
         [0017]    To further enhance the cold island effect of the present invention, isolating walls or isolating vertical plates are also arranged around the cold island effect device to isolate the convection of cold and hot air and enhance the cold island effect of the temperature inversion cold storage type cold island. 
         [0018]    Much further, a solar power generation device or solar water heater is installed under the reflecting plane, and a wind power generation device is also arranged in the middle of or around the cold island effect device. In this way, not only light reflection and temperature reduction of cold islands can be realized, but also the usage of the photoelectric energy, photothermal energy, wind power, etc., can also be realized. 
         [0019]    In the fields of industry and commerce, the cold island effect device can be used in combination with a steam condenser of a power station boiler or a cooling tower of a central air-conditioning unit and provides a cooling medium with lower temperature for the boiler and the air-conditioning unit, thereby reducing the thermal pollution of the boiler and the air-conditioning unit and increasing the energy efficiency of the boiler and the aft-conditioning unit. It can be seen that the cold island effect device can be widely applied to the condenser and the cooling tower of the boiler, the air-conditioning unit, a heat pump, a centralized energy system and a distributed energy system, thereby eliminating the thermal pollution of the equipment and increasing the energy efficiency of the equipment. 
         [0020]    In the city, the cold island effect device can be made of directional reflecting material. After a light ray is reflected by a microprism, the light ray returns to a light source so as to avoid light pollution of light reflection on surrounding buildings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0021]      FIG. 1  is a diagram of unfolding and rolling of a single reflecting roller shutter; 
           [0022]      FIG. 2  is a diagram of combination of a cold island effect device with a solar power generation device, a solar water heater and a wind power generation device; 
           [0023]      FIG. 3  is an effect diagram of a temperature inversion cold storage principle of a small cold island effect device: 
           [0024]      FIG. 4  is an effect diagram of a convectional refrigeration principle of a large cold island effect device; and 
           [0025]      FIG. 5  is a top view of combined application of a cold island effect device with a condenser of a power station boiler and a cooling tower of a central air-conditioning unit. 
       
    
    
       [0026]    In the figures:  1 . reflecting roller shutter;  2 . motor;  3 . guide rail;  4 . bracket;  5 . isolating vertical plate;  6 . solar power generation device;  7 . solar water heater;  8 . wind power generation device; and  9 . directional reflecting plane 
       DETAILED DESCRIPTION OF THE EMBODIMENTS 
     Embodiment 1  
     Heatstroke Prevention and Temperature Reduction of Changsha Railway Station 
       [0027]    Changsha has hot weather in summer, and has been called the “stove”. The whole station of Changsha railway station has a total area of more than 77000 square meters, including 19000 square meters of house area, 37000 square meters of the area of station square and 21000 square meters of the area of platforms and railway between the platforms. A master station room of the railway station has a height of 23 meters and a width of 151 meters and a bell tower has a height of 63 meters. 
         [0028]    In a fine day of summer, an air-conditioning unit is adopted in a waiting building of Changsha railway station for reducing the temperature, but there is no any heatstroke prevention and temperature reduction device in the station square. Under the direct irradiation of the sunshine, the ground of the square is so hot that people feel uncomfortable. 
         [0029]    Reflecting devices which adopt reflecting roller shutters  1  can be installed above the square of Changsha railway station. The reflecting roller shutter  1  of a single reflecting device has an area of 50 square meters. A total of 750 reflecting roller shutters are installed. The height from the roller shutters to the ground is 10 meters. The roller shutters are installed above the square through a steel bracket  4 . A motor  2  and a guide rail  3  are installed on the steel bracket  4 . The reflecting roller shutters  1  are unfolded or rolled along the guide rail  3  under the driving of the motor  2 . In a fine day of summer, when the atmospheric temperature exceeds 30° C., the motor  2  can be started and a part of reflecting roller shutters  1  are unfolded for reflecting the sunshine; and when the atmospheric temperature exceeds 35° C., all the reflecting roller shutters  1  can be unfolded. Through the cold island effect, a relatively cool local environment can be formed on the square. 
         [0030]    If the reflecting devices of the roller shutters are installed on all of the roofs of the waiting building, a ticketing building, the platforms, etc., the cold island effect can be formed on the surface region of the whole railway station to greatly reduce the energy consumption of the air-conditioning unit in Changsha railway station in summer. In autumn and winter, the roller shutters can be disassembled from the square of the railway station, and the bracket can also be disassembled. 
       Embodiment 2  
     Drought Resistance and Moisture Preservation of Dunhuang Crescent Spring 
       [0031]    The crescent spring is in a position 5 kilometers southwest from Dunhuang city of Gansu province, and is located under singing sands mountain. Underground water gushes out to form a lake, Within the encirclement of sand dune, it is called crescent spring because it is like a new crescent moon. In the 1950s, the crescent spring has an east-west length of 218 meters, a middle widest size of 54 meters, an average water depth of 5 meters and a deepest size of 7 meters. Due to the influences of human activities and climate change. the area of the lake is increasingly reduced. At present, the crescent spring has an east-west length of about 100 meters, a width of about 25 meters, an average water depth of 3 meters and a deepest size of 5 meters. 
         [0032]    To achieve drought resistance and moisture preservation, the reflecting devices which adopt the reflecting roller shutters  1  can be installed above the lake surface of the crescent spring and the surrounding ground. The reflecting roller shutter  1  of a single reflecting device has an area of 30 square meters. A total of 400 reflecting roller shutters  1  are installed. The total reflecting area is 12000 square meters. The height from the roller shutters to the ground is 6 meters. 
         [0033]    When the sun blazes down in a fine day, the motor  2  can be started to unfold the reflecting roller shutters to form the cold island effect, so that the temperature of the region where the crescent spring is located is reduced and the water evaporation is reduced, thereby achieving the purposes of drought resistance and moisture preservation. 
       Embodiment 3  
     Drought Resistance and Moisture Preservation of Mu Us Desert 
       [0034]    Mu Us Desert is located in the transition zone of Erdos plateau to Shanbei plateau, having a sandy land area of about 40000 square kilometers, On administrative division, it includes 13 counties, cities and banners of south of Erdos of Inner Mongolia Autonomous Region, north of Yulin district of Shanxi province, Yanchi county of Ningxia Hui Autonomous Region, etc. Mu Us Desert is inclined from northwest to southeast. The northwest includes some ridge land which extends from the central and western highland of Erdos to the southeast. The ridge land has flat ridge surface. Because the ridge land is cut, a plurality of valleys are formed among ridges. From northwest to southeast is an oblique alluvial plain, called beach land locally. In this way, an alternating landform where “ridges” and “beaches” are arranged in parallel is formed. Mu Us Desert is a kind of sandy land under the steppe climate condition, and is located in a transition zone of wilderness-prairie-forest. Most of Mu Us Desert belongs to a temperature zone, located in the west frontier of the monsoon region of China with a mean annual temperature of 6.1 to 8.2° C. and a mean annual precipitation of 400 to 440 mm in southeast of the land zone that is gradually decreased to the northwest to about 250 mm. Mu Us Desert was a place with plenty of water and lush grass in history. Due to human activities, the forest and the grassland are destroyed; the natural cold island effect is weakened; the evaporation of surface water is aggravated; and agricultural water gets increasingly scarce. At present, each county of Mu Us Desert is unstable in grain production. Peasants lack of confidence in agricultural development, causing to adopt a policy of extensive cultivation. It results in regional ecological damage, causing that the economic development and the environmental evolution of the region fall into vicious circle. 
         [0035]    By installing a large area of reflecting devices on dry and flat “ridge” land, the total water evaporation of Mu Us Desert can be greatly reduced and a condition is created for obtaining more water resources for valleys and beach land of agricultural production. The reflecting devices are arranged in different zones according to topography and geomorphology, covering most of ridge land of the region. The total reflecting area is 20000 to 30000 square kilometers, so as to form a plurality of large cold island regions in the region. The cold island effect thereof can generate an obvious drought resistance and moisture preservation effect. 
       Embodiment 4  
     Combination Mode of “Cold Island+Photovoltaic+Wind Power” 
       [0036]    Because the cold island effect device needs to occupy a large amount of ground while a solar photovoltaic generation device, a solar water heater and a wind power generation device also need to occupy a large amount of ground, if they are combined to implement, more benefits can be generated on the same land. 
         [0037]    Because the cold island effect device is mainly used in summer while the solar power generation device and the solar water heater can be used in winter, spring and autumn, they are complementary in time. The wind power generation device can reduce the wind power interference outside the cold island and enhance the sinking stability of cold air at an inversion layer or high-altitude above the cold island. The specific combination mode thereof is that: the solar power generation device  6  or the solar water heater  7  is installed under the reflecting devices; after the reflecting devices are rolled or disassembled, the solar power generation device  6  or the solar water heater  7  can be put into service, or a plurality of wind power generation devices  8  are arranged around the cold island. Such combination mode of “cold island+photovoltaic (photothermal)+wind power” develops an enormous market space for photovoltaic industry, wind power generation industry, steel industry, reflecting material industry, etc. which fall into superfluous productivity. 
       Embodiment 5  
     Application of the Cold Island Effect Device in the Condenser of the Power Station Boiler or the Cooling Tower of the Central Air-Conditioning Unit 
       [0038]    In the boiler system of a thermal power station and a nuclear power station, the steam from a steam turbine is required to be condensed into water. In the prior art, the water or air in the ambient environment of the stations is used as a cooling medium. The water or air is inputted into the condenser. After absorbing the heat of the steam, the water or air is discharged into the ambient environment, while after the steam is condensed into liquid water, the steam is inputted into the boiler to perform the next round of power generation circle. Because a large amount of water or air in the ambient environment of the thermal power station and the nuclear power station is discharged into the ambient environment after being heated by the boiler condenser, the thermal power station and the nuclear power station have enormous thermal pollution to the ambient environment. In summer, because of high ambient temperature, the vacuum degree of the condenser is reduced so that the power generation efficiency of the power stations is reduced. 
         [0039]    For example, when two 600 MW supercritical power station boilers in Wangcheng of Changsha are operated at full load in summer, 75000 tons of water is required to be extracted from Hsiang River per hour for cooling the condenser; after the heat is absorbed by 75000 tons of water, the temperature is raised by about 20° C.; and then, the water is drained into Hsiang River, causing enormous thermal pollution. If two to three square kilometers of cold island effect devices are arranged on the open ground around the power station boiler, the temperature of 75000 tons of water can be reduced by 15 to 20° C. per hour, thereby greatly reducing the thermal pollution of the power stations, enhancing the vacuum degree of the condenser and increasing the power generation efficiency of the power stations. Similarly, a certain area of cold island effect devices are arranged on the open ground around the condenser or the cooling tower of the air-conditioning unit, the heat pump, the centralized energy system and the distributed energy system, thereby effectively reducing the ambient temperature, eliminating the thermal pollution of the equipment and increasing the energy efficiency of the equipment. 
         [0040]    It can be seen from embodiments 1, 2, 3, 4 and 5 that the cold island effect device has an obvious energy-saving and environment-protective effect. 
         [0041]    The present invention can be widely applied to the industrial and commercial fields of the thermal power station, the nuclear power station, the central air-conditioning unit, etc., provides a cryogenic cooling medium for the condenser or the cooling tower of large energy equipment, greatly reduces the thermal pollution of the equipment to the environment, and increases the energy efficiency of the equipment. 
         [0042]    The present invention can be widely applied to the regions of urban squares, residential areas, business zones, etc. In summer, the heatstroke prevention and temperature reduction effect thereof can improve the urban living environment and save a large amount of air-conditioning energy, having great significance of energy saving and emission reduction. 
         [0043]    The present invention can be widely applied to drought resistance and moisture preservation of dry land, wilderness and desert. By installing a large area of reflecting devices, the cold island effect is formed within the region of tens to thousands of square kilometers (or even greater), and the water evaporation is reduced; the soil water content of the region is gradually increased: the air humidity is increased; and thus, artificial oasis is formed so that wilderness becomes farmland, grassland and forest. 
         [0044]    In general, after the present invention is widely implemented, a series of recently emergent strategic industries emerge, which will generate great benefit for the transformation of the economic structure, energy saving and emission reduction, response to climate change, guard of 1.8 billion mu of warning limit of arable land and the like in China and the world.