Heat storage water tank

Abstract

A heat storage tank suitable for solar house heating systems. The tank includes a rigidly supported bottom panel covered with a layer of stones of substantially uniform size which are bonded together thermally and mechanically at their points of contact with each other, but which have voids forming air passages remaining between them, bottom insulation below said bottom panel, a bottom air passage between the bottom insulation and the bottom panel, and at least one opening in the bottom panel whereby air can pass from said bottom air passage into said layer of stones.

What we claim is the following: 
     
       1. A heat storage tank suitable for solar house heating systems having a solar heat collector, including: a rigidly supported bottom panel covered with a layer of stones of substantially uniform size which are bonded together thermally and mechanically at their points of contact with each other, but which have voids forming air passages remaining between them, bottom insulation below said bottom panel, a bottom air passage between said bottom insulation and said bottom panel, and at least one opening in said bottom panel whereby air can pass from said bottom air passage into said layer of stones;   rigidly braced side panels having an inner layer of outside insulation and an outer layer of outside insulation and a continuous side air passage between them, communicating with the surface of said layer of stones and a plenum chamber near the top of said side panels, whereby air may pass from said bottom air passage through said layer of stones, through said side air passage to said plenum chamber;   a lining impervious to water having a bottom, sides and a top, top insulation mounted above said lining top;   means connected for transferring heat from a heat source to water contained in said tank, and heat delivery fluid means for delivery of heat from said tank;   means for circulating water from a controllable height within said tank to the inside bottom surface of said tank, and means for constraining said circulating water to flow over the inside bottom surface of said tank, whereby the temperature of said tank inside bottom surface is kept substantially equal to the temperature of water at said controllable height; and   control means responsive to the temperature of said heat delivery fluid for adjusting said controllable height, and for adjusting the rate of said means for transferring heat from the solar heat collector responsive to said controllable height and to the temperature at said solar collector.   
     
     
       2. A heat storage tank suitable for solar house heating systems according to claim 1, in which said means for transferring heat from the solar collector includes a piping system and a pump for drawing water from near the bottom of said tank, circulating it through said collector and returning it near the bottom of said tank. 
     
     
       3. A heat storage tank suitable for solar house heating systems according to claim 1, in which said means for transferring heat from a solar collector includes a duct system and a blower for drawing air from said plenum, circulating it through said solar heat collector and returning it to said bottom air passage. 
     
     
       4. A heat storage tank suitable for solar house heating systems according to claim 2, in which said control means controls the means for transferring heat from the solar collector so that, water is circulated through said collector by said pump only when the temperature of said collector is above a minimum useful temperature,   water for circulating to said collector is substantially the coldest water in said tank,   when the coldest water in said tank is below a useful temperature, water is circulated to said collector at a maximum rate, and   when the coldest water in said tank is at least at useful temperature, water is circulated to said collector at a reduced rate, returning to said tank at the highest temperature permissable in said tank.   
     
     
       5. A heat storage tank suitable for solar house heating systems according to claim 3, in which said control means controls the means for transferring heat from a solar collector so that, air is circulated through said collector by said blower only when the temperature of said collector is above a minimum useful temperature,   when the coldest water in said tank is below a useful temperature, air is circulated to said collector at a maximum rate, and   when the coldest water in said tank is at least at useful temperature, air is circulated to said collector at a reduced rate, returning to said tank at the highest temperature permissable in said tank.   
     
     
       6. A heat storage tank suitable for solar house heating systems, including: a rigidly supported bottom panel,   a heat exchanger mounted under said bottom panel,   a bottom air passage connected to said heat exchanger,   rigidly braced side panels connected to said bottom panel having an inner layer of outside insulation and an outer layer of outside insulation, a continuous side air passage between them, a plenum chamber near the top of said side panels communicating with said air passage whereby air may pass from said bottom air passage through said heat exchanger, through said side air passage to said plenum chamber;   means connected for transferring heat from a heat source to water contained in said tank, and heat deliver fluid means for delivery of heat from said tank,   means connected to said tank for circulating water from a controllable height within said tank to the inside bottom surface of said tank, and means in said tank for constraining said circulating water to flow over the inside bottom surface of said tank, whereby the temperature of said tank inside bottom surface is kept substantially equal to the temperature of water at said controllable height. .Iadd. 7. In a liquid filled heat storage tank, a heat exchanger,   means movable in height connected inside the tank and connected to the heat exchanger for drawing liquid from a controllable height within said tank, passing said liquid through said heat exchanger for delivering heat to use,   and means connected to the liquid drawing means for returning said liquid to said heat storage tank at the bottom of said tank,   whereby the temperature of said heat exchanger is kept substantially equal to the temperature of said liquid at said controllable height. .Iaddend. .Iadd. 8. In a liquid-filled heat storage tank according to claim 7, a solar collector, means connected for drawing said liquid from the bottom of said tank and circulating said liquid through said solar collector and returning said liquid to said tank. .Iaddend..Iadd. 9. A liquid-filled heat storage tank according to claim 8 and control means for limiting the rate of flow of said liquid to said collector so that liquid returned from said solar collector to said tank is at maximum allowable storage temperature. .Iaddend..Iadd. 10. A liquid-filled heat storage tank according to claim 7 wherein said heat exchanger is the bottom of said tank and the liquid drawn from said controllable height is constrained beneath a barrier membrane to flow over the area of said bottom of said tank before escaping to the upper side of said membrane. .Iaddend. .Iadd. 11. A liquid-filled heat storage tank according to claim 10 and means for drawing said liquid from the bottom of said tank, circulating said liquid through a solar collector and returning said liquid at maximum allowable storage temperature to said tank. .Iaddend.