GB1270101A - Water heating systems - Google Patents

Abstract

1,270,101. Hot water supply systems. V. OVERGAARD. 3 April, 1969 [8 Jan., 1968], No. 992/68. Heading F4A. [Also in Division F2] In a system for heating consumption water by means of a liquid heating medium in a flowthrough heat exchanger, in which the flow of the heating medium through the heat exchanger is automatically regulated in such accordance with the consumption of the consumption water that the temperature of the consumption water will remain substantially constant irrespectively of the rate of consumption, the regulating means are operatively connected with means for sensing the flow in the consumption pipe so that the flow of heating medium will rise and fall with the flow of consumption water. The heating medium is district heating water which is passed through the primary pass of the heat exchanger via an inlet 46, a slide valve 50 and an outlet 54. Cold water is supplied to the secondary pass of the heat exchanger via an inlet 4, a slide valve 70 and an outlet 6. Both valves are normally closed by a spring 100. The pressure at the inlet 4 is communicated to the underside of a rolling diaphragm 88, while the pressure at the outlet 6 is communicated via passages 18, 86, 28 to the upper side of the diaphragm. When a hot water tap downstream of the secondary pass is turned on, the resultant drop in pressure in the outlet 6 below that in the inlet 4 produces a net upward force on the diaphragm 88 to lift the valves 50, 70 from their closed positions. The resultant flows of cold water and heating water through the heat exchanger are so proportioned that the cold water is heated to a substantially constant temperature irrespective of the rate of consumption of the heated water. The valve port or ports 102 controlled by the valve 50 are contained in a cylindrical sleeve 90 which can be rotated by a handle 96 to adjust the effective shape and size of the port or ports. In another embodiment, Fig. 2 (not shown), the valve 70, the diaphragm 88 and the spring 100 are replaced by a cup-shaped member (12) exposed on its underside to the pressure at the inlet (4) and on its upper side to the pressure in the outlet (6) and acting both as a valve and as an actuating member. In addition, there is an actuating piston (24) exposed on its underside to atmospheric pressure and on its upper side to the pressure at the outlet (6). A spring with adjustable tension may be used instead. An adjustable by-pass is provided to ensure a small flow of heating water even when the valve (50) is closed, whereby the heat exchanger is nver completely cold. The width of the port of one or both of the valves (12, 50) may be controlled by a cylindrical sleeve which is rotated thermostatically in accordance with the temperature of the district heating water. The connection between the piston and the valves may be a rotary one or may be provided with a gear mechanism.