Cold storage tank

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Drawing sheet — no readable text.

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onto said tray during freezing weather, an intake pipe

COLD STORAGE TANK connected to drain said tray and return the low freezing point fluid to said interior of the inner barrier, whereby

This invention relates to cold storage tanks and more the fluid in said bags will be frozen in freezing weather, particularly to such means for providing cooling for a 5 and heat exchange means connected in heat exchange typical house. relation to said fluid bags, whereby air may be cooled Due to the energy crisis, there is a need for cooling during warm weather for cooling purposes. and air conditioning means which uses a minimum These and other objects of the invention will be ap amount of energy. The present air conditioning load on parent from the following specification and drawing. the utility power systems reaches its greatest peak on 10 Referring to the drawing, the invention comprises a hot summer days and requires large amounts of electri cold storage tank which is mounted in a pit in the cal power to meet these peak demands. ground, which may be of any convenient shape, but The present invention provides means and methods preferably a shape having small surface area in relation for providing air conditioning for a typical house with a to the volume of the tank. The pit may be lined with an negligible energy expenditure. The only power con 5 outer barrier 7, which may be a plastic sheet, for in suming devices required are a relatively small fluid stance, vinyl or polyethylene.

pump, and a blower. The pit 1 or the outer barrier 7, is lined with incom The present invention provides a cold storage tank pressible insulation 2 such as closed cell plastic foams which is adapted to be mounted in a pit in the ground. and is preferably provided with a drain at the bottom to The pit is suitably insulated with plastic foam and plas dispose of water from the soil which may condense on tic barriers and the insulated portion of the pit or tank the outside of the tank. In areas where the soil is dry, contains a plurality of bags of fresh water which are insulation on the bottom of the tank may be omitted. immersed in a brine solution. During the freezing An inner plastic sheet barrier 8, lines the interior weather, the brine is sprayed onto a tray above ground surface of the incompressible insulation. The inner and returns to the tank in order to freeze the water in 25 barrier tank is substantially filled by a large scale cellu the insulated bags. Heat exchange means are provided lar structure 19, plastic bags 10, 11, etc., containing in heat exchange relation with the water bags so that fresh water 12 within the cell compartments, and a during the warm weather, air may be cooled for air lower freezing point liquid such as brine 24, which can conditioning purposes. circulate through the cell structure and around the A tank containing about 700 cubic feet of ice, would 30 outside of the fresh water bags. The bags are sized for be sufficient to air condition a well insulated small adequate heat transfer rate from the brine to the freez house in the summer in the area of the Northeastern ing fresh water within, and may be cylinders about 1 United States. There is more than sufficient freezing foot in diameter. The plastic fresh water bags do not weather to freeze this amount of ice during the winter. completely fill the cell cavities, so that there is room for For instance, it is estimated that in New York there are 35 expansion of the bags when the fresh water freezes. 1,000 degree days of cooling per summer which would The cellular matrix around the bags supports, local require about 5 million BTUs in storage which can be izes and protects them, and withstands the pressures of accomplished with 700 cubic feet of ice. The New the surrounding earth. An economical way to fabricate York winter time has approximately 40 below freezing the cell structure 19 is to cast it in place from sized days so that there is sufficient cold weather to freeze 40 grouted gravel around inflated bags. The inflated bags the required amount of ice. A degree day is a one de may be the fresh water bags, temporarily inflated with gree difference, plus or minus, from the desired tem air or water to form the cell cavities. The bags may be perature for one day. elastically distended to provide extra space for freezing Accordingly, a principal object of the invention is to of the freshwater. Each bag may be fabricated with one provide new and improved cold storage means for air 45 or two filling tubes 25 so that fresh water can be substi conditioning and cooling purposes. tuted for the inflating air after the grouted gravel has Another object of the invention is to provide new and hardened into a rigid cellular structure. improved cold storage means for air conditioning pur Alternatively, the cellular structure may be an assem poses without requiring any mechanical equipment blage of rigid prefabricated pipes, arches or plates except a small liquid pump and blower. SO which contains voids housing the plastic bags of fresh Another object of the invention is to provide new and Water.

improved cold storage tank means for providing house The out-take pipe 14, extends into the brine. A pump air conditioning with a negligible expenditure of en P is connected to the out-take pipe to pump the brine ergy. onto a tray 15, which is exposed to outdoor air. The Another object of the invention is to provide new and 55 tray 15, is drained by an intake pipe 16, which returns improved cold storage tank means mounted in a pit in the cold brine to the tank. This cooling operation only the ground, said pit having continuous sides and a bot takes place during freezing weather. When the brine is tom, an outer barrier having continuous sides and a not being circulated, it provides substantial added insu bottom lining in said pit, a lining of insulation on the lation for fresh water bags near the center of the tank. interior surface of said outer barrier, an inner barrier 60 In the course of a typical winter in the northern portion lining the interior surface of said insulation, a plurality of the United States, there will be more than sufficient of bags of freezable fluid mounted inside of said inner freezing weather to freeze all of the water bags. At New barrier, low freezing point fluid substantially filling said York City, for example, there are about 1,000 hours of inner barrier and the voids between said fluid bags, an freezing weather per year.

out-take pipe extending into said low freezing point 65 The whole assembly may be buried several feet in the fluid, a pump connected to said out-take pipe, a shal ground for better insulation. A plastic barrier 3 above low tray mounted above ground, said outtake pipe the tank may be used to shield the surrounding earth being connected to spray said low freezing point fluid from warm rain water.

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In order to extract the cooling from the frozen ice a a rigid cellular structure substantially filling said heat exchanger 20 is provided. This may comprise a inner tank, covered cement tray 4 having a layer of stones 5 pro a plurality of bags of freezable liquid mounted inside viding an extended surface. Cold brine is circulated in the cells of said rigid cellular structure, the tray, through pipe 14'', and valve V which connects low freezing point liquid substantially filling said the winter and summer circuts. Warm air is blown into inner tank and the voids surrounding said liquid the heat exchanger by the blower 21, which is con bags, nected in the pipe 22. The air passes in heat exchanging first heat exchange means for removing heat from relationship with the stones 5, on tray 4, and cool air said low freezing point liquid to freeze said freez passes out through the pipe 23. This pipe may be con 10 able liquid, nected to air conditioning ducts in the house. There and second heat exchange means for adding heat to fore, during the winter time, sufficientice can be frozen said low freezing point liquid to melt said freezable with the expenditure of negligible energy and in the liquid, thereby producing a useful cooling effect. summer time, sufficient air can be cooled to air condi 2. Apparatus as in claim 1, including an outer barrier tion a house. The volume of ice required depends upon 15 between said insulation and the wall of said pit. the size of the house and its geographical location. It is 3. Apparatus as in claim 2, wherein said barrier is of estimated that an ice volume of 700 cubic feet is suffi plastic sheet.

cient to air condition a small well insulated single fam above 4. Apparatus as in claim 1, including a rain barrier ily house in the New York area during the summer with and extending beyond the sides of said tank so as a negligible expenditure of energy. 20 to prevent rain water from bringing heat to the sides of Since the structure is entirely supported by the said tank.

ground and the insulating lining, no additional struc 5. Apparatus as in claim 1, wherein said freezable tural members are required. The inner and outer barri fluid in said bags is fresh water, and said low freezing ers may be of plastic sheets since there is no strain on point fluid is brine.

them. It may be desirable to filter the circulating brine 25 6. Apparatus as in claim 1, in which said rigid cellular in order to remove any bacteria. structure is cast of sized gravel -bonded by cement Although other equivalent liquids may be used for grOut.

the fresh water and brine, cost will be important for the 7. Apparatus as in claim 1, in which said first heat large quantities required. For water, one needs a liquid exchange means comprises an out-take pipe extending of high latent heat which freezes below comfort tem 30 into said low freezing point liquid, peratures. For brine, one can use any liquid having a a pump connected to said out-take pipe, freezing point sufficiently below the liquid in the bag a shallow tray in heat exchange relation with the and that can be prevented from freezing at winter tem outside air, said out-take pipe being connected to . peratures. For example, ethylene glycol and water or 35 feed during said low freezing point liquid onto said tray freezing weather, glycerine and water might be used instead of brine to freeze fresh water. and in intake pipe connected to drain said tray and The cold storage tank of the present invention may return said low freezing point liquid to said interior be used in cooperation with the Heat Storage, Tank of of the inner tank, whereby the freezable liquid in my co-pending application, entitled "HEAT STOR 40 8.said bags will be frozen in freezing weather. Apparatus as in claim 1, in which said second heat

in order to provide a complete heating and cooling exchange means comprises a chamber containing system for a house with a negligible expenditure of stones as an extended heat exchange surface, means for energy. circulating said low freezing point fluid in heat ex I claim: change relation with said stones, and means for circu 1. Cold storage tank means mounted in a pit in the 45 lating warm air in contact with said stones, whereby ground, said pit having continuous sides and a bottom, said warm air may be cooled during warm weather. a lining of incompressible insulation on the interior 9. Apparatus as in claim 1, in which each of said bags surface of said pit, of freezable liquid is fabricated with at least one tube an inner tanklining the interior surface of said insula adapted for exchanging

theck fluid

inck said bag.

tion,