Pressure regulating apparatus for a closed water circuit

A method for regulating the pressure of water in a closed hot water circuit comprising the steps of:

• heating the water in said closed hot water circuit at a first location in said hot water circuit;
• withdrawing heat from the water in said hot water circuit at a second location in said hot water circuit;
• absorbing pressure and volume fluctuations of the hot water which fall within a specified range in an expansion tank;
• sensing the pressure of the water in said hot water circuit;
• and
• regulating the pressure of the water in said circuit by admitting water to said circuit when the pressure of the water in the circuit falls below a preselected value by opening an inlet valve, and withdrawing water from said circuit when the pressure of the water in the circuit exceeds a preselected value by opening a drain valve.

In a closed hot water circuit of the type including a heat exchanger for absorption of a waste gas heat and at least one heat exchanger for a transfer of heat from relatively hot water in the closed hot water circuit to a medium to be heated, and a pressure regulating device for regulation of water pressure in said circuit, the improvement wherein said pressure regulating device comprises:

• a steam circuit which conducts both steam and water, which steam circuit includes a relatively high pressure zone, and a relatively low pressures zone;
• a source of heat which heats a portion of said steam circuit, and a portion of said hot water circuit;
• valve means communicating with said hot water circuit for admitting water to, and withdrawing water from, said circuit, said valve means including
• a water inlet line which is connected to the steam circuit and the water circuit to provide a flow path between the steam circuit and the water circuit, and which water inlet line is connected to the steam circuit at the relatively high pressure zone,
• a water drain line which is connected to the steam circuit and the water circuit to provide a flow path between the steam circuit and the water circuit, and which water drain line is connected to the steam circuit at the relatively low pressure zone,
• a valve in the water inlet line, which valve regulates a flow of water through said inlet line,
• a valve in the water drain line, which valve regulates a flow of water through said drain line;
• and
• pressure regulating means for sensing the water pressure in said hot water circuit and for actuating the valve in the water inlet line when the water pressure falls below a preselected value to admit water to said water circuit, and for actuating said valve in the water drain line when the water pressure exceeds a preselected value to withdraw water from said water circuit.

In a closed hot water circuit of the type including a heat exchanger for absorption of a waste gas heat and at least one heat exchanger for a transfer of heat from relatively hot water in the closed hot water circuit to a medium to be heated, and a pressure regulating device for regulation of water pressure in said circuit, the improvement wherein said pressure regulating device comprises:

• a steam circuit which conducts both steam and water, which steam circuit includes a relatively high pressure zone, and a relatively low pressure zone;
• a source of heat which heats a portion of said steam circuit, and a portion of said hot water circuit;
• valve means communicating with said hot water circuit for admitting water to, and withdrawing water from, said circuit, said valve means including
• a water inlet line which is connected to the steam circuit and the water circuit to provide a flow path between the steam circuit and the closed hot water circuit, which water inlet line is connected to the steam circuit at the relatively high pressure zone,
• a water drain line which is connected to the steam circuit and the water circuit to provide a flow path between the steam circuit and the closed hot water circuit, which water drain line is connected to the steam circuit at the relatively low pressure zone,
• a first relatively small valve and a first relatively large valve in the water inlet line, which first valves regulate a flow of water through said inlet line, and which first relatively large valve is opened only after the first relatively small valve is opened,
• a second relatively small valve and a second relatively large valve in the water drain line, which second valves regulate a flow of water through said drain line, and which second relatively large valve is opened only after the second relatively small valve is opened;
• and
• pressure regulating means for sensing the water pressure in said hot water circuit and for actuating at least the first relatively small valve when the water pressure falls below a preselected value to admit water to said water circuit, and for actuating at least the second relatively small valve when the water pressure exceeds a preselected value to withdraw water from said water circuit.

Apparatus for regulating the pressure of a fluid in a closed fluid circuit comprising:

• a closed fluid circuit;
• first heat exchange means for adding heat to the fluid in said closed fluid circuit;
• second heat exchange means for withdrawing heat from the fluid in said closed fluid circuit, said second heat exchange means including
• at least one heat exchanger arranged in said fluid circuit,
• bypass means for sensing a temperature of the fluid in said heat exchanger, and for bypassing the fluid around said heat exchanger if the temperature exceeds a predetermined value;
• valve means communicating with said closed fluid circuit for admitting fluid to, and withdrawing fluid from, said circuit;
• and
• pressure regulating means for sensing the pressure of the fluid in said circuit and for actuating the valve means when the pressure falls below a preselected value to admit fluid to said circuit, and for actuating said valve means when the pressure exceeds a preselected value to withdraw fluid from said circuit.