GB2301667A

GB2301667A - Thermostatic valve control

Info

Publication number: GB2301667A
Application number: GB9511257A
Authority: GB
Inventors: Patrick Gerard Graham
Original assignee: Individual
Current assignee: Individual
Priority date: 1995-06-03
Filing date: 1995-06-03
Publication date: 1996-12-11
Also published as: GB9511257D0; GB2301667A8

Abstract

A control for a thermostatic hot water valve 1, as used in central heating systems, comprises a bifunctional device 10 which can act alternatively as a heating or a cooling means acting upon the bellows 6 of the valve and where the device 10 consists of a solid state array which operates on the Peltier Effect principle where heating or cooling of its contact plate with the bellows 6 is achieved by simple reversal of the polarity of the low voltage d.c.current by which it is powered and where the cooling mode phase of the device is in a timed circuit which cuts-out when the previously heated bellows 6 has been cooled to ambient temperature after which, with the Peltier Device out of circuit, the valve 1 continues in its designed mode of ambient temperature response.

Description

THERMOSTATIC VALVE CONTROL 2301667 This invention relates to a

thermostatic valve control and in particular - o a control for a thermostatic hot water valve as used in central heating systems.

Thermostatic hot water valves are well known and generally function b- the res- ponse of a liquid or wax filled anaeroid bellows to the air temperature within - cases the required respomse temperature is the room to be heated. In most - set by rotating the toD cover of the valve so that this action compresses a spring on the bellows to the required degree so that a further incredimental rise in ambient temperature expands the bellows and shuts off,or restricts,the flow of heating water in the system.

There are many occasions when it is not desired to heat various rooms in the home,or in a building,and in these cases it is tedious as well as laborious to have to visit each room in turn and shut-off t Uhe valve setting only to later return to turn the valve back to its control setting because of change of circi-unstances. It -'s not only desrablebut expedient to be able to re-notely control such radiator the=nostatic valves and means to accomplish this are tauGht in my patent application G3.92/00854. The latter pa-Uent application teaches the use of a sun-,)lie netinR means to exnnA - he an- aeroid bellows in a thermostatic valve irrespective of the ambient temperature and without disturbing the spring adjustment on the control element. 'LI"h--', st tnis described innovation is an extremely uselful adjunct to a remote con'.ru-L- led central heating system it s-dffers to sore extent,depending upon ambient con- ditions,upon the thermal inertia of the bello-,,,s/supplied heat syste,?, with the result that once the supplied heating means is removed it can take too lon-c- a time for the bellows to return to ambient temDerature in order to assume its normal designed control of the hot water valve.

There is a need therefore for a device which can effect rapid cooling of the bellows system when imposed shut- off conditions are no longer required so that the system is free again to respond C, to the ambient temperature conditions of the room environment. Such a device is the subject of the present invention where there is provided a thermostatic valve control comprising a hot water valve including an adjustable thermostatic control element responsive to the ambient air temperature and an integrated heating and 0 cooling means for initially heating the control ele-nent sufficiently to close the valve irrespective of the ambient air temperature and later to cool the control element for a selected period of ti-me and all without disturbi-ng the adjjstT.en', of the control element.

An embodiment of the invention will now be described by way of example with reference to the accompanying drawing,which is a sectional elevation through tne vaive. The thermostatic valve comprises a valve body 1 whose va-,ve seating L,' can be closed by a seating washer 2 which is fixed to a valve stem 3.

The movements of this stem 3 are determined by the equi- .ibriLun state of two dis-linct forces. The first force is generated by the action - 1 1 of a spring 4 tending to keep the valve open because of its action against a stem stop 5. The second force is a forward,or closing,force and is jenerated by the therm.al expansion of the anaeroid beliows 6 which,via a bellows shaft 7a, pushes the valve stem forward at 7. The valve has an outer cover 8 which is mounted on the valve body 1 for rotation about the axis of the valve stem 3,in particular by means of a fixed external circumferential rib 11 on the valve body which locates in and serves as a bearing for a circumferential groove 12 on the inside surface of the outer cover 8. The inside surface of the outer cover 8 also has a cont- inuous spiral groove 13,which is engaged by the opposite ends of a cross- member 14,such that rotation of the outer cover 8 causes the cross-member 14 to move axially left or right relative to the valve body 1. At its centre the cross- member 14 en:,ages one end of a bellows spring 0,and hence rotation,f the outer 1 1 cover 8 loads the spring 9 to an extent determined by the axial position of the cross-member 14. Thus the valve is adjusted,that is,the control setting for a desired air temperature is obtained,by rotating the outer cover 8 to load the spring 9 of the bellows to a desired degree.

It should be noted that the cross- member 14 has an aperture 14a through which the bellows shaft 7a passes, so that the c--oss--,ne-,n'.-)er only engages the spring 9.

UP to this point in the descr- iption of this embodiment the ialve is cons-,ructec.. in a manner to those of the prior art,but the valve ari,7.it-iona-7l.7 has an electrical heating/cocling control which is obtained by the incorporation of a silicon diode array which is -ween two plates,one of copper and one ceramic,and r.n.arketed normally sandwiched bet as a solid state heat pump under the nomenclature of a Peltier Device because its operation is analogous to the well known Feltier Effect which is more normally ass- ociated with the properties of thermocouples. These Peltier Devices are available as thin miniature packages which operate at low D.C. voltages and which absorb heat on one side of the device and reject it at the other side,hence the analogT to the heat p..Lr.,p. Their innovative employment in the present invention relies on the fact that reversal of the polarity of the D.C. supply to the device reverses the direct- ion of heat flow through the solid state heat pump. Therefore when incorporated into the thermostatic valve 1 of the drawing as item 10,with the bellows 6 and the cover toD 11 as heat sinks.then the bellows can be heated by the Pe'Itier Device.:,,.en the current flows in one direction and cooled by the same device by the si,-,.,ple re,,:,- ersal of the feed polarity.

In practice it has been found convenient to arrange a timing circui t in the thermostatic valve control so that wher- the valve is tc rbe opened and allowed to respond to the ambient temperatures in a roon., the cooling rode of the incorporated Peltier Device is tined so that when the bellows are coo led -,he -).C. vc'T,zce is cut-off and the valve responds as normal to room te,- nzera-ures.

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Claims

1.A thermostatic valve control comprising a hot water valve including an adjustable thermostatic element which is responsive to the ambient air temperature together with an integrated heating or cooling means for initially heating the thermostatic element sufficiently to close the valve irrespective of the ambient temperature and later to cool the thermostatic element for a selective period of time and all this without disturbing the adjustment of the thermostatic element.

2.A thermostatic valve control according to Claim 1 wherein the heating and cooling means is integrated into the thermostativ valve housing and is activated by a low voltage d.c.power supply.

3.A thermostatic valve control according to Claim 2 wherein the heating and cooling means is a bifunctional device known as a Peltier Effect Heat Pump which operates between 3 volts and 16 volts depending upon the pumping wattage selected.

4.A thermostatic valve control according to any of the above Claims wherein the heat- effect of the Peltier device on the thermostatic element within the valve housing is immediately converted to a cooling effect by reversing the polarity of the power supply to the heat pump.

5.A thermostatic control valve according to Claim 4 wherein the cooling mode of the Peltier device is within a timed circuit so that once the thermostatic element within the valve housing is copled the hear pump is turned off and the thermostatic element left to respond to the fluctations of ambient temperature.

6.A thermostatic control valve substantially as described herein with reference to the accompanying drawing.

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