Water heating unit with integral thermal energy storage

Abstract

A water heater is provided which includes a heat exchange unit including heat exchange pipes filled with a phase change material. The phase change material has a freezing / melting temperature from about 58° C. to about 62° C. The water heater provides significantly greater thermal energy storage than conventional water heaters, and the excess heating capacity may be used for residential heating applications by using the water heater in combination with a liquid to air heat exchanger.

Description

BACKGROUND OF THE INVENTION[0001]The present invention relates to a hot water heater, and more particularly, to a hot water heater which utilizes phase change materials for the storage and release of thermal energy.[0002]Conventional water heaters provide heated water by storing heat energy in the water as sensible heat. Because the heat energy is stored in the water, a large portion of the heater must be dedicated to storing the heated water until it is used. Typically, water stores approximately 10 calories / gram of sensible heat per 10° C. increments. By requiring a large portion of the heater for storage of heated water, the water heater must be of a reasonable size to store enough heated water for use in a standard residential environment. Typical residential water heaters have a 40 to 60 gallon capacity. For use in commercial buildings and industry, water heaters must be even larger.[0003]Water heaters consume a high percentage of residential energy heating water for bathing, w...

AI Technical Summary

Benefits of technology

[0007]Embodiments of the invention meet that need by providing a water heater which can more effectively heat water by utilizing phase change materials inside heat exchange pipes which are preferably in cylindrical form. Such a configuration provides improved thermal energy storage and heat transfer.

[0019]In one embodiment, the water heater may include a solenoid valve in conjunction with the water inlet or outlet to provide pulsatile flow of the water and improve heat transfer.

Problems solved by technology

Water heaters consume a high percentage of residential energy heating water for bathing, washing dishes, washing clothes and heating homes.

In homes heated by electricity, the consumption of electric power is even greater.

Overall, a large imbalance in electric power usage exists during daylight hours due primarily to the large amounts of power consumed by industry, businesses and public transportation.

However, a disadvantage of such hydrocarbons is that they tend to sublime, i.e., they transform directly from the solid state to the gaseous state when heated, without forming a liquid phase.

This limits their application in heat storage applications due to the large change in volume from solid to gas which must be accommodated.

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