Process and apparatus for the preparation of hot water from solar energy

Claim 1

A process for improving the reliability of operation and the yield of water heating installations with the aid of solar energy, which installations comprise at least one solar collector and a heat exchanger which are traversed in a closed circuit by a first fluid, and an external source of pressurized fluid; the improvement comprising: providing a two-compartment storage container having a moving transmission means separating the compartments, said closed circuit including one said compartment, said external source of pressurized fluid connected to the other said compartment, said external source of pressurized fluid being isolated from communication with said closed circuit; said moving transmission means when subjected to said pressurized fluid serving to reduce the size of said one compartment, and when not subjected to said pressurized fluid, to enlarge said one compartment; interrupting the connection of said other compartment to said external source of pressurized fluid when the temperature of said solar collector decreases to the vicinity of the freezing point of said first fluid, to cause said first fluid contained in said closed solar collector circuit to lose pressure and to flow into said one compartment; and, reestablishing the connection between said other compartment and said external source of pressurized fluid when the temperature of said solar collector rises above the freezing point of said first fluid, to cause said solar collector to be refilled due to the pressure of said pressurized fluid acting against said transmission means.

Claim 3

A system for protection against freezing of heat transfer fluid in a solar heating system comprising: a solar collector and a heat exchanger interconnected by a closed circuit containing a first fluid; an external source of pressurized fluid; a storage container with at least two compartments and having a moving transmission means separating the compartments, said closed circuit including one said compartment, said external source of pressurized fluid being connected to another of said compartments and being isolated from communication with said closed circuit; remote control valve means interposed between said external source of pressurized fluid and the said other said compartment and adapted to permit drainage of pressurized fluid from said other compartment as well as to allow flow of said pressurized fluid into said other compartment; and temperature sensing means adjacent said solar collector and exposed to the external atmosphere and connected to said remote control valve means for actuating the same to drain pressurized fluid from said other compartment when the sensed temperature approaches the freezing point of the first fluid, whereby said moving transmission means will move to increase the capacity of the one said compartment to receive therein all of the fluid in the closed circuit, and to actuate the valve means when the sensed temperature is at a safe operating level to admit pressurized fluid into the other said compartment, displacing said moving transmission means to force some of the first fluid from said one compartment back into the closed circuit, filling the same.

Claim 4

A system for protection against freezing of heat transfer fluid in a solar heating system comprising: a solar collector and a heat exchanger interconnected by a closed circuit containing a first fluid; an external source of pressurized fluid; a storage container with at least two compartments and having a moving transmission means separating the compartments, said closed circuit including one said compartment, said external source of pressurized fluid being connected to another of said compartments and being isolated from communication with said closed circuit; remote control valve means interposed between said external source of pressurized fluid and the said other said compartment and adapted to permit drainage of pressurized fluid from said other compartment as well as to allow flow of said pressurized fluid into said other compartment; and temperature sensing means adjacent said solar collector and exposed to the external atmosphere and connected to said remote control valve means for actuating the same to drain pressurized fluid from said other compartment when the sensed temperature approaches the freezing point of the first fluid, whereby said moving transmission means will move to increase the capacity of the one said compartment to receive therein all of the fluid in the closed circuit, and to actuate the valve means when the sensed temperature is at a safe operating level to admit pressurized fluid into the other said compartment, displacing said moving transmission means to force some of the first fluid from said one compartment back into the closed circuit, filling the same.