GB2560964A

GB2560964A - Return temperature limiter remote sensor and actuator

Info

Publication number: GB2560964A
Application number: GB1705119.4A
Authority: GB
Inventors: Richard Brown Phillip
Original assignee: Individual
Current assignee: Individual
Priority date: 2017-03-30
Filing date: 2017-03-30
Publication date: 2018-10-03
Also published as: GB201705119D0

Abstract

A radiator 1 has a conventional valve 46 and thermostatic sensor 46 located on a water inlet, interposed between the valve and sensor is a thermostatic actuator 33 acting on a control spindle Figures 4 and 5, 47. A capillary tube 22 connects the actuator to an adjustable temperature sensor Figure 1, 1 positioned above a lockshield valve 3 on the outlet of the radiator, having a sensing element 17. Capillary windings Figure 1, 22 react to variations in the temperature of the water leaving the radiator. As pressure within the capillary tube varies it moves actuator Fig 5, 35 modulating the incoming flow to the radiator. Further control is achieved the prior art thermostatic control 45 on the inlet. Additional control of the outlet is via dial FIG 1, 29 that acts on a diaphragm or bellows Fig 1, 26 and lever Fig 1,4 acting via piston Fig 1, 7 onto a second diaphragm 6 in fluid connection with the first bellows and the capillary tube.

Description

(71) Applicant(s):

Phillip Richard Brown

Edward Street, Blandford Forum, Dorset, DT11 7QJ, United Kingdom (56) Documents Cited:

DE 019856009 A DE 202010015453 U (58) Field of Search:

INT CLF16K, F24D, G05D Other: WPI, EPODOC, INTERNET (72) Inventor(s):

Phillip Richard Brown (74) Agent and/or Address for Service:

Phillip Richard Brown

Edward Street, Blandford Forum, Dorset, DT11 7QJ, United Kingdom (54) Title of the Invention: Return temperature limiter remote sensor and actuator

Abstract Title: Thermostatic radiator valve with remote sensing of water outlet temperature (57) A radiator 1 has a conventional valve 46 and thermostatic sensor 46 located on a water inlet, interposed between the valve and sensor is a thermostatic actuator 33 acting on a control spindle Figures 4 and 5, 47. A capillary tube 22 connects the actuator to an adjustable temperature sensor Figure 1, 1 positioned above a lockshield valve 3 on the outlet of the radiator, having a sensing element 17. Capillary windings Figure 1, 22 react to variations in the temperature of the water leaving the radiator. As pressure within the capillary tube varies it moves actuator Fig 5, 35 modulating the incoming flow to the radiator. Further control is achieved the prior art thermostatic control 45 on the inlet. Additional control of the outlet is via dial FIG 1,29 that acts on a diaphragm or bellows Fig 1, 26 and lever Fig 1,4 acting via piston Fig 1, 7 onto a second diaphragm 6 in fluid connection with the first bellows and the capillary tube.

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Figure 1

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Figure 2

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Figure 3

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Figure 4

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Figure 5

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Figure 6

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Figure 7

Figure 8

Return temperature limiter remote sensor and actuator

The present invention relates to a thermostatic actuator which cooperates with an existing thermostatic radiator valve and sensor, the device responds to changes in the return flow temperature leaving the connected heat exchanger allowing control of two temperature variables.

A thermostatic valve of this type is known, for example in DE10303828. With this thermostatic valve the flow rate of the heating water is controlled not only as a function of room temperature but also as a function of temperature in the return line. If the temperature of the water in the return line is too high, the flow is throttled. This is particularly advantageous in reducing excessive flow through a heat exchanger, thus reducing energy requirements of system circulating pump. On a system utilising a condensing boiler the opportunity presents itself to increase the energy efficiency of the boiler by ensuring temperatures back to the boiler are kept below 55 degrees Celsius. As flow would be regulated to maintain temperature exiting a heat exchanger, this will improve hydraulic distribution on an unbalanced heating system.

In the known case, both sensing elements are housed in a single unit. A wax element is used to sense the return temperature through conduction. A second sensor takes the form of a bellows that responds to air temperature.

This construction has the consequence that the valve must be fitted on the port exiting the radiator. Thus, if fitting to an existing valve, the valve must already be fitted to the radiator outlet, it would not be possible to safely change the configuration of the radiator without having to drain the heating circuit, which incurs cost to the customer and requires the safe disposal of chemical contaminated water and additional chemical to be added to the system.

The objective of the invention is to make a return temperature responsive valve, using an existing thermostatic valve and sensor fitted to the inlet of a radiator whilst keeping the existing thermostatic valve assembly relatively compact.

This objective is achieved in the case of a thermostatic actuator of the type described at the beginning in that the return temperature sensing element is remote from the existing thermostatic valve.

With this configuration, it is no longer necessary to have the valve sited on the heat exchanger outlet. Instead, the return temperature sensing element is fitted to the heat exchanger outlet and the corresponding actuation is transmitted to a compact actuator which resides between the existing valve body and thermostatic sensing head situated on the heat exchanger inlet. For this reason, it is advantageous, for example the device can be installed without having to drain any fluids and eliminates the need to unnecessarily purchase a new thermostatic valve and sensor, thus reducing environmentally damaging manufacturing.

Preferably, the thermostat element is thermally connected to the sensor housing. The element can then detect the temperature in the line which the housing is arranged.

Preferably, the sensing element is connected to a lever. A lever allows for a calibrated force to be applied in the transmission circuit. It can also advantageously allow for a reduction or gain in axial movement to be realised.

Preferably, the lever movement is sensed by a diaphragm. A sensing diaphragm allows separation of transmission circuit and heat sensing element. Movement of the sensing diaphragm will allow for a movement in the compact actuator.

Preferably, the compact actuator will consist of a chamber with fixed height and two diaphragms. The two diaphragms shall be separated by a thin plate that allows the passage of fluid to enter the cavity between the two diaphragms. This allows for expansion and contraction to be realised in both axial directions, necessary for the operation of the existing thermostatic valve and sensor to be realised. This is advantageous in that the fixed height of the chamber can be minimised.

Preferably, the top diaphragm will be connected to a tappet that will transmit the existing thermostatic sensor movement into the compact actuator. The bottom diaphragm will have a surface that rests against the actuating pin of the existing valve.

Preferably, the compact actuator diaphragms will meet at the top of the chamber when the return temperature is below setting. This will ensure the operation of the existing thermostatic valve is not compromised should the transmission circuit fail.

Preferably, the sensing diaphragm is hydraulically connected to the compact actuator. This allows the axial displacement of the heat sensing element to be converted into an expansion or contraction of the compact actuator.

Preferably, the sensing diaphragm is hydraulically connected to a setting chamber. The setting chamber, which can also be the sensing chamber, allows for a change in permitted hydraulic volume of the transmission circuit. This can be adjusted by a rotary handle on the sensor housing. Thus, the return temperature can be set on the sensor housing. Alternatively, the setting can be adjusted by adjusting the reference base height of the heat sensing element or by adjusting the lever arm fulcrum.

Preferably, the capillary hydraulically linking the sensor and compact actuator will be retractable into the sensor housing. The retractable capillary is a safety feature to prevent trip hazards and reduce possibility of accidental damage.

Preferably, the capillary retracting mechanism will feature a spring that prevents over tightening of the capillary whilst retracting.

The invention is described in more detail below regarding a preferred exemplary embodiment.

Figure 1 shows a schematic cross-section through a return temperature sensor Figure 2 shows an exploded view of the sensor

Figure 3 shows a schematic cross-section through the compact actuator

Figure 4 shows where the compact actuator fits between existing thermostatic sensor and thermostatic valve.

Figure 5 shows an exploded view of the compact actuator

Figure 6 is a view of return temperature sensor and compact actuator connected via capillary

Figure 7 is a visual representation of exiting installation of lock shield valve, thermostatic valve and sensor on a panel radiator without present invention fitted

Figure 8 is a visual representation of return temperature sensor, compact actuator and capillary fitted to a Lock shield valve, thermostatic valve and sensor assembly on a panel radiator.

A return temperature sensor 1 has a housing 8. The housing 8 contains and allows support of the mechanism base 9 that supports all the internal components of the sensor 1. The mechanism base 8 features a mounting void 12. The housing 8 and mechanism base 9 is placed over an existing lockshield valve 30 allowing the lock-shield valve spindle 31 to enter the mounting void 12. Heat is transferred from lock-shield valve body 32 to heat sensing element 17 by conduction through a heat transfer element 14 and over travel spring 18. Heat loss of the heat transfer element 14, over travel spring 18 and heat sensing element 17 is minimised by an insulating jacket 19.

The heat transfer element 14 has a tapered edge allowing for variations in lock-shield valve body 32 dimensions. The tapered edge also allows a push fit of sensor 1 onto lock-shield valve 30 to be realised. The contour of mounting void 12 and sensor housing 8 allows for fitment to angle or straight pattern types of lock-shield valve. The heat transfer element 14 extends between mounting void 12 and sensor housing 8. The heat sensing element 14 is positioned vertically until the insulating jacket 19 contacts reference base 20 of the mechanism base 8.

Actuator pin 16 of sensing element 17 is connected to lever 4 by rod 15. Rod 15 connects into slotted groove 23. Lever 4 is pivoted around fulcrum 11. Rod 7 is connected to slotted groove 10. If actuating pin 16 is fully retracted, upward force of rod 7 is realised by moment applied by combined weight of heat sensing element 17, rod 15 and over travel spring 18.

As temperature of lock-shield valve 30 rises, actuator pin 16 extends proportionally to temperature rise pushing heat sensing element 17 towards the reference base 20. As over travel spring 18 contacts heat transfer elements 14 base, the applied upward force to rod 7 increases.

The increase in upward force of rod 7 translates into an increase of pressure within sensing chamber 5. Pressure increase within sensing chamber 5 is a result of an increase in force acting on sensing diaphragm 6. Axial displacement of sensing diaphragm 6 alters the volume of sensing chamber 5. As volume is reduced in sensing chamber 5 fluid pressure is realised in transmission chamber 24 via communication through connecting channel 2. Increasing pressure in transmission chamber 24 causes the volume of transmission chamber 24 to increase until setting diaphragm 26 comes to rest against setting pad 25. Further increase in pressure results in passage of fluid through capillary 22 towards the compact actuator 33.

The passage of fluid to compact actuator 33 causes in increase of fluid volume between head diaphragm 42 and valve diaphragm 38. The fluid passage between head diaphragm 42 and valve diaphragm 38 is achieved by slotted spacer 36. Fluid from capillary 22 enters into a channel 41 in compact actuator housing 35. A hole in valve diaphragm 38 allows passage of fluid into a slot on slotted spacer 36. The slot directs fluid between head diaphragm 42 and valve diaphragm 38.

The change in fluid volume of compact actuator 33 is directly proportional to the change in volume of sensing chamber 5 when fluid volume in transmission chamber 24 is at set capacity.

When fluid volume is minimal in compact actuator 33, valve diaphragm 38 is axially displaced towards head diaphragm 42 by return spring 39 acting on valve plate 40. Head diaphragm 42 will contact the valve diaphragm 38 and cause displacement of the head diaphragm 42 away from the return spring 39 reference. Axial displacement of head diaphragm 42 away from return spring 39 reference is restricted by head plate 43 contacting actuator housing 35.

When fluid volume of compact actuator 33 increases, valve diaphragm 38 is axially displaced away from head diaphragm 42. Axial displacement of valve diaphragm 38 away from head diaphragm 42 is restricted by valve plate 40 contacting actuator housing 35.

The axial displacement freedom of valve plate 40 is such that existing thermostatic valve 46 can achieve nominal and shutoff positions.

By separating existing sensor 45 and valve 46, compact actuator 33 can be installed onto valve 46 by tightening nut 37 onto valve 46 body. Compact actuator housing 35 is held in place against valve body 46 by actuator cap 34. If fluid volume in compact actuator 33 is minimal then valve plate 40 will act on valve pin 47 to maintain flow through valve 46 at nominal rate. As fluid volume increases in compact actuator 33, flow through valve 46 will become throttled due to axial displacement of valve plate 40 being transferred onto valve pin 47. If fluid volume continues to increase in compact actuator 33 then flow will be shutoff as valve pin 47 is further influenced by valve plate 40.

A change in fluid volume of compact actuator 33 is proportional to the change in fluid volume of sensing chamber 5, therefore an increasing temperature of valve body 32 will result in axial movement of valve plate 40 toward valve pin 47. Conversely a reduction in temperature of valve body 32 will result in axial movement of valve plate 40 away from valve pin 47. Without fitting thermostatic sensor 45 to compact actuator 33 allows control of temperature at valve body 32.

Fitting thermostatic sensor 45 to actuator cap 34 allows control of flow through valve 46 proportional to temperature at valve body 32 and to the temperature variable sensed by thermostatic sensor 45. Actuator cap 34 has an external thread compatible with the union nut of thermostatic sensor 45.

Prior art temperature sensor 45 control is achieved due to actuator pin 44 protruding through actuator cap 34 opening and extending onto prior art senor 45. Actuator pin 44 is connected to head plate 43. If prior art sensor 45 senses a temperature rise, actuator pin 44 will be axially displaced toward valve pin 47. If fluid volume of compact actuator 33 is minimal, the effect on prior art valve 46 flow rate due to axial displacement of sensor 45 tappet will be unaffected by the inclusion of compact actuator 33. If temperature of valve body 32 is being controlled then compact actuator 33 fluid volume will not be minimal. In this instance, sensor 45 tappet axially displaces actuator pin 44, however fluid volume of compact actuator 33 remains constant, therefore movement of valve diaphragm 38 is realised due to hydraulic action. As valve 46 flow rate throttles further, due to an increasing temperature sensed by sensor 45, the temperature sensed at valve body 32 will start to reduce, therefore sensing chamber volume 5 will increase, allowing fluid volume in compact actuator 33 to reduce.

An over travel spring 18 is provided to protect the temperature sensing element 17 from excessive force should an increase in fluid volume of compact actuator 33 be unachievable during a rise in sensed temperature.

Setting of return temperature sensor 1 is achieved by turning setting handle 29. Rotation of setting handle 29 around handle stem 28 engages an internal thread with setting stud 27. Rotation of handle 29 axially displaces setting pad 25 through equal displacement of setting stud 27. Axial displacement of setting pad 25 effectively changes the permitted hydraulic volume of the transmission chamber 24. This is achieved by adjusting the movement range of setting diaphragm 26. Increasing the volume of transmission chamber 24 allows a higher temperature to be sensed by heat sensing element 17 before increasing fluid volume of compact actuator 33. Reducing the volume of transmission chamber 24 reduces the temperature to be sensed by heat sensing element 17 before increasing fluid volume of compact actuator 33.

Capillary 22 hydraulically connects transmission chamber 24 and compact actuator 33. As capillary 22 exits chamber 24 a route through the centre of spool 13 is observed and exits central shaft perpendicular to axis. Rotation of worm gear 21 rotates spool 13 around axis. In rotating spool 13, capillary 22 is wound around spool 13 central shaft, retracting the capillary 22 into the housing 8. Tension springs either side of worm gear 21 on adjustment shaft 50 allow axial movement of worm gear 21 if excessive tension is applied to capillary 22. Axial movement of worm gear 21 disengages worm gear 21 from teeth of spool 13. Rotation of worm gear 21 is achieved by rotation of shaft 50. Capillary 22 can be extended from housing 8 by gently pulling on capillary 22 from outside of sensor housing 8.

Filling point 3 allows for maintenance of transmission circuit. Filling point 3 is an integral part of chamber cap 48. Sensing diaphragm 6 and setting diaphragm 26 are formed as a single piece and held in position between chamber cap 48 and chamber base 49. A hole through the one piece diaphragm allows passage of fluid through channel 2.

Claims

Claims [1] A thermostatic actuator interacts with prior art thermostatic valve (46) and prior art thermostatic sensor (45) using a compact actuator (33) connected via capillary (22) to a remote sensor (1) which is responsive to the temperature exiting a heat exchanger allowing modulation of prior art valve (46) proportional to either prior art thermostatic sensor (45) or remote sensor (1).
[2] A thermostatic actuator according to claim 1, characterised in that the remote sensor (1) is shaped to fit over straight or angle patterns of lock-shield valve.
[3] A thermostatic actuator according to claim 2, characterised in that remote sensor (1) contains a temperature sensing element (17) that is thermally connected to the heat exchanger outlet valve (30).
[4] A thermostatic actuator according to any of claims 1 to 3 characterised in that temperature sensing element (17) actuation is realised by a lever (4).
[5] A thermostatic actuator according to any of claims 1 to 4 characterised in that temperature sensing element (17) actuation is realised by a sensing diaphragm (6).
[6] A thermostatic actuator according to claim 1 characterised in that compact actuator (33) is fitted between prior art thermostatic sensor (45) and prior art valve (46).
[7] A thermostatic actuator according to claim 6 characterised in that compact actuator (33) contains two diaphragms separated by a spacer (36) to realise axial movement and expansion in both directions.
[8] A thermostatic actuator according to any of claims 1 to 7, characterised in that the compact actuator (33) is hydraulically connected to a sensing chamber (5) in remote sensor (1) via fixed length capillary (22).
[9] A thermostatic actuator according to any one of claims 6 to 8 characterised in that the compact actuator (33) has a tappet extending into prior art thermostatic sensor (45).
[10] A thermostatic actuator according to any of claims 6 to 9 characterised in that the compact actuator (33) has a tappet extending on to actuating pin (47) of prior art valve (46).
[11] A thermostatic actuator according to any of claims 1 to 10, characterised in that fixed length capillary (22) is retractable into remote sensor (1).
[12] A thermostatic actuator according to any of claims 1 to 11 characterised in that adjustment of permitted hydraulic volume adjusts temperature setting.
[13] A thermostatic actuator according to claim 4 characterised in that adjustment of fulcrum point (11) adjusts temperature setting.
[14] A thermostatic actuator according to claim 5 characterised in that adjustment of reference base height (20) adjusts temperature setting.

Intellectual

Property

Office

Application No: GB1705119.4 Examiner: Gareth Jones