Overtemperature protection system for a solar water heating system

Abstract

The invention provides a solar hot water heating system including one or more solar energy absorbers (102) having at least a first fluid circulation path wherein, an over temperature path (119) is provided, the over temperature path including a pressure vessel (120) which is normally closed to atmosphere, the over temperature path being connected to the first fluid circulation path (108) so that, in the event that fluid in the solar energy absorber vaporizes, the fluid is forced out of the solar energy absorber and into the pressure vessel. The present invention also provides a temperature sensitive valve leaving a flow path and a valve member operated by a thermal element having thermal expansion characteristic the valve including a support member against which the thermal element expands to force the valve element to close the flow path.

Description

FIELD OF THE INVENTION[0001]This invention relates to an arrangement for dealing with the effects of overheating in solar water heating systems.BACKGROUND OF THE INVENTION[0002]Solar water heating systems include a solar collector which acts to convert solar radiation to heat energy to heat water. Usually this involves a solar panel having a heat transfer fluid which absorbs the solar energy, the heat from the heat transfer fluid being transferred to the water via a heat exchanger. The heat transfer fluid may be water with additives. Solar energy is an unregulated source of input heat energy. Thus, there is a possibility that the heat transfer fluid will boil if the rate of energy input from the solar energy exceeds the rate of heat removal from the heat transfer fluid. Boiling of the heat transfer fluid may damage the solar water heating system due to excessive pressure.[0003]Any reference herein to known prior art does not, unless the contrary indication appears, constitute an adm...

AI Technical Summary

Benefits of technology

[0011]The heat transfer fluid entering the pressure vessel can increase the pressure in the pressure vessel, so that, when the temperature of the heat transfer fluid vapour in the solar collector falls below the vaporization temperature, the pressure in the pressure vessel forces the heat transfer fluid back into the heat transfer fluid circulation path and the solar energy collector is replenished with heat transfer fluid.

Problems solved by technology

Thus, there is a possibility that the heat transfer fluid will boil if the rate of energy input from the solar energy exceeds the rate of heat removal from the heat transfer fluid.

Boiling of the heat transfer fluid may damage the solar water heating system due to excessive pressure.

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