GB2490500A

GB2490500A - Variable output pump having an override facility

Info

Publication number: GB2490500A
Application number: GB1107247.7A
Authority: GB
Inventors: Nicholas Julian Jan Francis Macphail
Original assignee: Individual
Current assignee: Individual
Priority date: 2011-05-03
Filing date: 2011-05-03
Publication date: 2012-11-07
Also published as: GB201107247D0

Abstract

The pump 6 is used in a heating system and has a first output. An override facility senses when an increase in the output of the pump is required. When an increase is required, the override facility overrides the pump to increase the output of the pump from the first output to a second, higher output in order to meet the required increase. The pump returns to the first output when the increase in output is no longer required. The override facility may comprise an override input 2 that receives a signal from a sensor. The override input may feed the signal to an adjusting circuit 4, which is connected with an output power circuit 3 and changes the speed of a motor 5 of the pump in order to change the pump output. The sensor may comprise a voltage or changing resistance signal triggered by actuation of a high-resistance circuit, such as a domestic hot water demand. The sensor may be wireless.

Description

IMPROVEMENTS IN CIRCULATING PUMPS

I, NICHOLAS JTJLIAN JAN FRANCIS MACPHAIL, a British subject of Mas des Sables, Grandes Rocques, Guernsey of the Channel Islands do hereby declare the invention for which we pray that a patent may be granted to me and the method by which it is to be performed to be particularly described in and by the following statement:-

TWS TNVENTION RELATES TO IMPROVEMENTS JN CTRCULATING PUMPS

To improve the efficiency of central heating circulating pumps, types are increasingly being produced that better match the varying circuit resistance of a central heating system by sensing the increased resistance across the system when part or proportionally shut down under the system's controls occurs and reducing the pump's output and therefor power demand accordingly. As a heating system is rarely at full load demand, a variable output circulating pump of this type can operate effectively at much reduced power input most of the time offering both monetary and environmental savings.

A disadvantage exists however with this type of variable output circulating pump when applied to any of the millions of combination boiler installations and indeed any other heating system that has widely different circuit resistances and flow requirements. If at least one heating circuit has a high flow demand and/or high resistance at or close to the circulating pumps maximum output then the pump will have to be set to a high setting to ensure that the, often infrequent, demand from such a high flow/resistance circuit is met. Otherwise, when the high flow/resistance circuit is actuated its flow/resistance requirement will not be met and heating and or hot water provision by, for example a plate heat exchanger will be reduced and unsatisfactory. Setting the pump to a, most often not needed, high setting loses the very saving advantages a variable output pump is intended to produce. Combi boilers are often used in flats and other small premises commonly having small, low flow/resistance space heating circuit/s. Combi boilers commonly have a domestic hot water producing plate heat exchanger that has exactly the high flow/resistance demand described above and if used with a variable output pump set to a low setting to meet its space heating load will slow the flow rate or reduce the temperature of domestic hot water to an unacceptable level. As described above, if set low the domestic hot water production will suffer.

It is the object of the present invitation to obviate or overcome the above problems.

According to the present invention there is provided a variable output circulating pump having an override facility such that when the actuation of at least one high flow and/or high resistance heating circuit/s in the heating system it serves is actuated this actuation is sensed and the pump's variable system is overridden and the pump runs at maximum or other pre-set setting.

The pump returning to its variable output once the high flow and/or high resistance heating circuit/s is/are no longer actuated.

Advantageously the said sensing means is a voltage or changing resistance signal triggered by the control actuation of the high flow and or high resistance circuit/s.

Conveniently the said sensing means is a radio or other wireless signal triggered by the actuation of the high flow and or high heating resistance circuit/s.

The invention will now be described by way of example with reference to the accompanying drawing which shows a diagrammatic representation of a variable output pump 6 motor 5 having a load sense and variable power output circuit 3. Override and, if required, high output adjust circuit 4 within housing 9 having power input 1 and override input 2 from high flow and/or high resistance heating circuit sensor (for example from a flow swftch on the plate heater exchanger circuit actuating control). Hydraulic input 7 and output 8 ports are conventional.

Claims

CLAIMS1. A variable output circulating pump having an override facility such that when the actuation of at least one high flow and/or high resistance heating circuit/s in the heating system it serves is actuated this actuation is sensed and the pump's variable system is overridden and the pump runs at maximum or other pre-set setting. The pump returning to fts variable output once the high flow and/or high resistance heating circuft/s is/are no longer actuated.
2. Advantageously the said sensing means is a voltage or changing resistance signal triggered by the control actuation of the high flow and or high resistance heating circuit/s.
3. Conveniently the said sensing means is a radio or other wireless signal triggered by the actuation of the high flow and or high resistance circuit/s.