Heat exchanger with integral phase change material for heating and cooling applications

Abstract

A heat exchanger is provided for use in heating and cooling applications. The heat exchanger includes a heat exchange fluid, at least one heating element for heating the heat exchange fluid, and a plurality of heat exchange pipes positioned in the heat exchanger. The heat exchange pipes are filled with an uncrosslinked high density polyethylene phase change material. The heat exchanger may be used in combination with separate shell and tube type heat exchangers to provide residential heating and hot water heating. The heat exchanger may also be used in combination with an absorption air conditioning unit to provide residential cooling.

1 . A heat exchanger for the storage and release of heat comprising:
 a shell;   a plurality of heat exchange pipes positioned in said shell and containing a phase change material therein;   a heat exchange fluid for transferring heat from said phase change material;   at least one inlet and at least one outlet for the transfer of said heat exchange fluid to and from said heat exchanger;   at least one heating element for heating said heat exchange fluid.   
     
     
         2 . The heat exchanger of  claim 1  wherein said phase change material comprises uncrosslinked high density polyethylene. 
     
     
         3 . The heat exchanger of  claim 2  wherein said high density polyethylene has a density of about 0.96 g/cm 3 . 
     
     
         4 . The heat exchanger of  claim 2  wherein said high density polyethylene has a melting temperature of about 132° C. 
     
     
         5 . The heat exchanger of  claim 1  wherein said heat exchange fluid is selected from the group consisting of ethylene glycol, polypropylene glycol, and glycerin. 
     
     
         6 . The heat exchanger of  claim 1  wherein said phase change material includes from about 1 to 30% by weight carbon black. 
     
     
         7 . The heat exchanger of  claim 1  wherein said phase change material includes from about 0.05 to 0.5% by weight of a non-ionic surfactant. 
     
     
         8 . The heat exchanger of  claim 7  wherein said surfactant comprises polyethylene glycol monolaurate. 
     
     
         9 . The heat exchanger of  claim 1  wherein said phase change material includes from about 0.05 to 0.5% by weight zinc stearate. 
     
     
         10 . The heat exchanger of  claim 1  including first and second heating elements positioned at the top and bottom of said heat exchanger. 
     
     
         11 . The heat exchanger of  claim 1  wherein said heat exchange pipes comprise a metal selected from the group consisting of copper, stainless steel, and glass-coated steel. 
     
     
         12 . The heat exchanger of  claim 1  wherein said phase change material is in the form of a cylinder. 
     
     
         13 . The heat exchanger of  claim 1  wherein each of said heat exchange pipes include a cap at each end such that said phase change material is sealed therein. 
     
     
         14 . The heat exchanger of  claim 1  having a three-dimensional rectangular configuration. 
     
     
         15 . The heat exchanger of  claim 1  having a cubic configuration. 
     
     
         16 . The heat exchanger of  claim 1  including a solenoid valve in conjunction with said inlet or outlet to provide pulsatile flow of said heat exchange fluid. 
     
     
         17 . The heat exchanger of  claim 1  further including insulation on the exterior surface of said shell. 
     
     
         18 . The heat exchanger of  claim 17  wherein said insulation is vacuum panel insulation having an R value of about 50 to 60 per inch of thickness. 
     
     
         19 . The water heater of  claim 1  wherein said heat exchange pipes have an outer diameter of from about 0.5 to about 2.5 inches. 
     
     
         20 . A water heater including the heat exchanger of  claim 1  and a separate liquid to liquid heat exchanger including an inlet and outlet for transporting heat exchange fluid and an inlet and outlet for transporting water. 
     
     
         21 . An absorption air conditioning unit including the heat exchanger of  claim 1  and an inlet and outlet for transporting heat exchange fluid and an inlet and outlet for transporting air. 
     
     
         22 . A home heating system including the heat exchanger of  claim 1  and a separate liquid to air heat exchanger including an inlet and outlet for transporting heat exchange fluid and an inlet and outlet for transporting air. 
     
     
         23 . In combination, the heat exchanger of  claim 1  and
 a) a liquid to liquid heat exchanger for heating water; 
 b) a liquid to air heat exchanger for heating air; and 
 c) an absorption air conditioning unit.