WO2006077360A1

WO2006077360A1 - An improved radiator

Info

Publication number: WO2006077360A1
Application number: PCT/GB2005/004519
Authority: WO
Inventors: Leo Lamb
Original assignee: Leo Lamb
Priority date: 2005-01-20
Filing date: 2005-11-24
Publication date: 2006-07-27
Also published as: EP1839008A1; GB0501163D0

Abstract

A radiator comprising a sealed container (2) that is at least partially evacuated and contains a small amount of working fluid, the container comprising a first chamber (4) and a second chamber (8) linked by a plurality of vertical microbore heatpipes (6) wherein adjacent heatpipes are staggered with respect to each other, the first chamber being in contact with suitable heating means.

Description

An improved radiator.

DESCRIPTION

The present invention relates to an improved radiator.

It is known to provide portable heaters, such as gas, electric or oil-filled heaters that are moveable to a desired position at a given time. Whilst these heaters provide a satisfactory means of heating, gas heaters may be hazardous due to the presence of a flame. Electric heaters and oil-filled heaters often require over 30 minutes to heat up to the required temperature. This is clearly undesirable given that portable heaters are generally used to provide a source of immediate heat in a particular room, rather than having to switch on the main central heating system and wait for the system to heat up the entire building. Additionally, pressure may build up in an oil-filled radiator during heating of the oil This means that the material of the heater has to be of sufficient strength to withstand the pressure exerted thereon. This leads to an increase in the price of the heater and may result in the heater being more difficult to move. The oil also has to be re-cycled which, again, increases the price of the appliance.

Additionally, buildings may be heated by means of fixed radiators that are provided at intervals throughout the building. Water is heated by a main boiler and then delivered via pipes to the individual radiators. The water flows into subsidiary pipes provided in the radiator which results in the radiator heating up and releasing heat to the surroundings by means of radiation, conduction and convention.

However, the overall use of energy using these heaters is wasteful, requiring a great deal of energy to be expended in heating and maintaining the temperature of the water and pumping it around the building and then along the convoluted pipes contained within each radiator. The radiators are also subject to the build up of pressure. This can result in damage occurring to the radiator and is potentially hazardous. Additionally, heating up of the radiators is quite slow and it is not possible to direct the hot water to only a single radiator.

Whilst attempts have been made to provide partially evacuated radiators that reduce the amount of energy wasted, there is still a need for an improved design of radiator that increases the efficiency of heat transfer to the surroundings.

It is an object of the present invention to provide an improved radiator that aims to alleviate the abovementioned drawbacks and provide enhanced transfer of heat to the surroundings.

Accordingly, the present invention provides a radiator comprising a sealed container that is at least partially evacuated and contains a small amount of working fluid, the container comprising a first chamber and a second chamber linked by a plurality of vertical microbore heatpipes wherein adjacent heatpipes are staggered with respect to each other, the first chamber being in contact with suitable heating means.

Internal heating means may be provided within the first chamber or external heating means may be provided to which the first chamber can be brought into contact.

Internal heating means preferably comprises an electrical heating element that is provided within the first chamber. This will provide a stand-alone, portable radiator. Such a radiator is preferably provided with feet at the base thereof to support the unit. The first chamber may be any suitable shape, such as circular, square or oval in cross- section. However, preferably the chamber is circular in cross-sections.

Alternatively, the first chamber may be brought into contact with a chamber or conduit through which a heat transfer medium, such as hot water, flows. This will provide a stand-on radiator. In such an embodiment, it is preferable for the surface of the first chamber that contacts the conduit to be profiled to correspond to the profile of the conduit. Thus, if the conduit is cylindrical, it is preferable to provide a first chamber with a base that is concave in profile. Means for securement of the radiator to the conduit should be provided. The vertical microbore pipes are preferably cylindrical but may be, for example, rectangular or oval. Preferably, the pipes are seamless.

In a further embodiment of the present invention, a conduit may pass through the first chamber, i.e. being formed integrally therewith. However, it should be appreciated that the first chamber, microbore heatpipes and second chamber should form a sealed unit around the conduit that can be partially evacuated.

The first chamber may include two types of heating means to provide alternative sources of heat for heating the fluid in the chamber. For example, the first chamber may be divided into compartments wherein one heating means is provided in one compartment and the other heating means is provided in another compartment. Preferably, one compartment is in fluid communication with the internal cavity of the chamber and the other is separate thereto. Preferably, a first pipe extends through the compartment that is separate to the internal cavity of the chamber. This pipe may be connected to a conventional hot water pipe system for delivering hot water to the chamber. Preferably, the end of the pipe within the compartment is open to allow water to flow into the compartment. The compartment is preferably provided with an outlet that may be connected to a return pipe to deliver water away from the first chamber. The other heat source, such as an electrical heating element, is preferably provided in the other compartment of the chamber that is in fluid communication with the main internal cavity of the chamber.

Preferably, the container is made from a conductive material, such as a lightweight metal and is provided with means for partial evacuation thereof, such as a valve. More preferably, the components of the radiator are comprised of aluminium or copper. The first and second chambers may be formed of an appropriate plasties material provided with suitable seals to ensure the required vacuum is maintained. The valve may be provided on the first or second chamber. The working fluid is preferably water.

The ratio of working fluid to the volume of the first internal cavity of the container is preferably 1 :8 to 1 : 12. A partial vacuum of approximately 99898.5Nm^"2 (29 inch/Hg) is preferably provided within the cavity.

The inner sides of the internal cavity of the container should be protected against corrosive influence due to the presence of the working fluid therein.

The microbore heatpipes provided between the first and second chambers are preferably less than 10mm in diameter, more preferably less than 5mm in diameter, especially less than 3mm. The microbore heatpipes are preferably arranged in two rows wherein alternate heatpipes lie in the same plane and adjacent heatpipes are staggered with respect to each other. It is preferable for a distance of between 0.5cm and 1.5 cm to be provided between alternate heatpipes, with adjacent heatpipes that lie in different planes being provided approximately midway between the alternate heatpipes. In a preferred embodiment of the present invention, the distance between the centre of one heatpipe and the centre of the next heatpipe that is in line with it is 1.0cm, with a staggered heatpipe being provided halfway between the two.

It is preferable to provide fins on the radiator. More preferably, lateral fins are provided extending transversely across the heatpipes. It is preferable for each set of heatpipes that lie in the same plane to be provided with multiple rows of fins. More preferably still, each row of fins is less than 5mm apart, especially less than 3mm apart, ideally being lmm apart.

In a preferred embodiment, the fins are provided with a series of bumps or pimples at spaced apart intervals along the length thereof. More preferably, the bumps or pimples are provided between the heatpipes that are in the same plane, i.e. approximately corresponding in position to the adjacent, staggered heatpipe that lies between the heatpipes that are in the same plane. The unit may be provided with cover. Additionally, it is preferable to provide at least one fan within the radiator, such as behind the first chamber. More preferably, a variable speed fan is used. The radiator may be thermostatically controlled.

It is advisable to provide enabling means within the radiator to prevent kettling of the radiator, preferably being placed around the heating means. The enabling means preferably comprises a confined heat transfer medium that has pores or passages for the flow of fluid therethrough whilst acting as a damper to aid dissipation of heat. More preferably, the heat transfer medium is a fibrous material, such as metal wool, especially wire wool, such as needlemat wire wool, formed of a non-corrosive metal, such as stainless steel.

In a preferred embodiment of the present invention, enabling means is also provided in the second chamber. To this end, the internal depth of second chamber is preferably around 1 inch (2.54cm) for receiving the enabling means, such as wire wool.

For a better understanding of the present invention and to show more clearly how it may be carried into effect reference will now be made by way of example only to the accompanying drawings in which:

Figure 1 is a front view of a radiator according to one embodiment of the present invention; Figure 2 is an end view of the radiator of Figure 1;

Figure 3 is a front view of a radiator according to a second embodiment of the present invention;

Figure 4 is a schematic diagram of a fin that may be incorporated into a radiator according to the present invention;

Figures 5a to 5d are respectively front, top, side and perspective views of a radiator according to a third embodiment of the present invention; and

Figures 6a to 6c are respectively front, top and perspective views of a radiator according to a fourth embodiment of the present invention.

Figures 1 and 2 of the accompanying drawings illustrate one embodiment of the present invention. The radiator 2 comprises a sealed, self-contained unit 2 that is partially evacuated and contains a small volume of working fluid, such as water. The unit 2 comprises an expansion chamber or heat exchanger 4 that is linked by a network of microbore heatpipes 6 to a top chamber or heat exchanger 8. The base of the expansion chamber 4 is curved in profile to enable it to sit on a conduit 10, such as a conventional hot water pipe (see Figure 2).

The hot water pipe heats the working fluid in the first chamber which evaporates below its normal boiling point due to the partial vacuum that exists in the system. The reduced pressure inside the radiator also allows the fluid to move rapidly therethrough and, as it does so, condenses to release latent heat of condensation thereby transferring heat to the heatpipes and the top chamber and hence, to the surrounding atmosphere. The network of microbore heatpipes is particularly important for providing a highly efficient radiator. It should be appreciated that the accompanying drawings are not to scale and that the heatpipes are smaller relative to the expansion chambers than is illustrated. The heatpipes have a diameter of around l-2mm and at least 30 columns of heatpipes would generally be provided across the radiator but the exact number will depend upon the size of the radiator. Additionally, at least two sets of vertical heatpipes are provided extending between the expansion chambers, one set 6a positioned towards the front of the radiator and one set 6b positioned towards the rear of the radiator 6b (see Figure 2). The positioning of the two sets of heatipes is offset or staggered such that, when viewed from the front, a rear vertical heatpipe is positioned in between two front vertical heatpipes.

The spacing between the heatpipes is important for providing efficient airflow and maximum heat transfer to the surroundings. Alternate heatpipes (i.e. those in the same plane) are approximately 10mm apart, with the staggered heatpipe in between being positioned substantially midway between the two.

Additionally, multiple rows of lateral fins 12 are provided across the vertical heatpipes. The exact number of fins is not important but the spacing between the rows should be less than 5mm, more preferably around 2mm. The fins are provided with dimples at spaced apart intervals, the dimples being positioned between the heatpipes to which they are attached. Each row of heatpipes has their own set of fins.

In this manner, the multi-array of microbore heatpipes and fins creates a honeycomb heat exchanger core between the chambers that has a large number of small air passages. This is designed to provide maximum thermodynamics with extremely efficient heat transfer. The arrangement provides for multiple, small air passages through the main body of the radiator. This increases the resistance to airflow up through the radiator which results in around 90% of the heat being transferred by radiation and only around 10% being transferred by convection. It has been found that the radiator can reach temperatures of in excess 7O⁰C with a reduced energy input as compared to units that do not have the multi-array arrangement of heatpipes and fins. Furthermore, the radiator has a capacity to store and release energy for a short period once the heating means has been switched off and tends to direct warm air out to the surroundings at knee-level rather than above the height of the radiator.

A radiator according to this embodiment of the present invention does not require water to flow around the internal pipework running throughout the evacuated chamber. This reduces the pressure on the pump of the main heating system that delivers hot water around a building since it no longer has to pump the water around the convoluted pipes of a conventional radiator, it only has to deliver water to the base of the radiator. Additionally, the radiator will normally operate at negative pressures up to approximately 100°C depending on the fluid in the chamber. Thus, the unit will only have to withstand low pressures even at high temperatures. In contrast, the radiators of the prior art always have a positive pressure that increases as the temperature of the medium in the radiator rises. Not only does this result in the heating apparatus of the present invention being safer to use but the radiator may also be made of a lighter and thinner material due to the reduced pressure of the interior of the unit caused by the partial vacuum. A reduced volume of water also has to be heated and transported around the building thereby providing a far more efficient heating system. The improved heating system may also be run off existing pipework in buildings. Furthermore, it is possible to include an electrical heating element within the first chamber to enable the user to select a single radiator for heating using the electrical heating element without hot water having to be delivered around the whole system.

Referring to Figure 3 of the accompanying drawings, a radiator 20 according to another embodiment of the present invention is illustrated. Identical features to those shown in Figures 1 and 2 are given the same reference numerals and only the differences will be discussed in details. The radiator consists of a self-contained partially evacuated unit 2 comprising a first chamber 4 linked by a network of microbore heatpipes 6 as hereinbefore described linked to a second chamber 8. The unit forms a stand-alone radiator being supported on feet 20 and having an internal electrical heating element 21 provided through the first chamber which is surrounded by wire wool 22. Fins 12 are provided across the heatpipes, the fins having dimples 30 at spaced apart intervals (see Figure 4).

The actual volume of the fluid contained in the interior cavity of the radiator will depend upon the particular dimensions of the unit. It is important to ensure that the heating element is immersed in the working fluid to obtain efficient operation of the radiator. However, whilst the heating element should always be immersed in the fluid, it is preferable to use as little working fluid as possible since the less working fluid, the lower the vacuum required and the shorter the time for the radiator to heat up. Accordingly, it is preferable to use an element that does not extend too high in the radiator. Generally, the ratio of fluid to the volume of the internal cavity of the radiator is preferably 1:8 to 1:12. However, the exact amount will depend upon the position of the heating element and dimensions of the radiator and heating element. Furthermore, the provision of enabling means around the heating element to prevent kettling may also enable a reduced quantity of working fluid to be used. The amount of vacuum that exists in the heater is also important for efficient operation thereof. Generally, quite a high vacuum is required, such as 29 inch/Hg (99898.5Nm^"2). The exact amount of vacuum and fluid required will depend upon the size of the chambers and ductwork and may be obtained by the law of thermodynamics. The radiator according to this embodiment is portable and relatively inexpensive to produce. The operation of the system at negative pressure provides a safer appliance since it does not have to withstand the positive pressures that are generally experienced when the medium in a radiator is heated to a high temperature. The radiator of the present invention may achieve temperatures in excess of 70°C and still be at a negative pressure. This also enables the radiator to be made of a lighter and thinner material due to the reduced pressure of the interior of the unit caused by the partial vacuum. Additionally, the radiator heats up far more quickly than conventional portable heaters. For example, an oil-filled radiator takes around forty minutes to heat up whereas a radiator according to the present invention takes around five to nine minutes to heat up.

Figures 5a to 5d of the accompanying drawings illustrate a further embodiment of the present invention. Identical features to those shown in Figures 1 to 3 are given the same reference numerals and only the differences will be discussed in detail. The radiator unit 2 again comprises a sealed, partially evacuated unit having a first or bottom chamber 4, a second or top chamber 8' linked by a large number of staggered microbore heatpipes 6. In this embodiment, the fins 12' are straight and the interior of the top chamber 8' is provided with wire wool. This prevents a "sucking" noise occurring as working fluid is "sucked" back down the naiτow microbores. The embodiment shown in Figures 5a to 5d is for placing on a hot water pipe (not shown) as occurs in the embodiment of Figures 1 and 2. Figures 6a to 6b illustrate a further stand-alone radiator 2. Again identical features to those previously described are given the same reference numerals and only the differences will be discussed in detail. The outer profile of the bottom or lower chamber 4' is square in cross-section and the inner profile is circular for receiving a heating element in the form of a cartridge (not shown). The heating element has needlemat wire wool wound around it to act as an enabling device. Additionally, wire wool is also placed in the top or second chamber 8'. The provision of wire wool in the top prevents the sucking noise that may be created when gas as the top of the unit liquefies and travels back from the pipes to the bottom chamber. The fibrous nature of the wire wool provides for a capillary action to slow down the passage of the fluid and reduce or eliminate any sucking sound.

Claims

1. A radiator comprising a sealed container (2) that is at least partially evacuated and contains a small amount of working fluid, the container comprising a first chamber (4) and a second chamber (8) linked by a plurality of vertical microbore heatpipes (6) wherein adjacent heatpipes are staggered with respect to each other, the first chamber being in contact with suitable heating means (10, 21).

2. A radiator as claimed in claim 1 wherein internal heating means (21) are provided within the first chamber.

3. A radiator as claimed in claim 2 wherein the internal heating means comprises an electrical heating element (21) that is provided within the first chamber.

4. A radiator as claimed in claim 1 wherein external heating means (10) is provided for contacting the first chamber.

5. A radiator as claimed in claim 4 wherein the first chamber is brought into contact with a chamber or conduit (10) through which a heat transfer medium flows.

6. A radiator as claimed in claim 5 wherein the outer surface of the first chamber that contacts the conduit is profiled to correspond to the profile of the conduit.

7. A radiator as claimed in any one of claims 1 to 6 wherein cylindrical, seamless microbore pipes (6) are provided between the first and second chambers (4, 8).

8. A radiator as claimed in claim 1 wherein the first chamber (4) includes two types of heating means to provide alternative sources of heat for heating the fluid in the chamber.

9. A radiator as claimed in any one of the preceding claims wherein the container (2) is made from a conductive material and is provided with means for partial evacuation thereof.

10. A radiator as claimed in claim 9 wherein the components of the radiator are comprised of aluminium or copper.

11. A radiator as claimed in any one of the preceding claims wherein the working fluid is water.

12. A radiator as claimed in any one of the preceding claims wherein the ratio of working fluid to the volume of the first internal cavity of the container is 1:8 to 1:12.

13. A radiator as claimed in any one of the preceding claims wherein a partial vacuum of approximately 99898.5Nm^"2 (29 inch/Hg) is provided within the cavity.

14. A radiator as claimed in any one of the preceding claims wherein the microbore heatpipes (6) provided between the first and second chambers are less than 10mm in diameter.

15. A radiator as claimed in claim 14 wherein the heatpipes (6) are less than 5mm in diameter.

16. A radiator as claimed in any one of the preceding claims wherein the microbore heatpipes (6) are arranged in two rows wherein alternate heatpipes Ke in the same plane and adjacent heatpipes are staggered with respect to each other.

17. A radiator as claimed in claim 16 wherein a distance of between 0.5cm and 1.5 cm is provided between alternate heatpipes, with adjacent heatpipes that lie in different planes being provided approximately midway between the alternate heatpipes.

18. A radiator as claimed in claim 17 wherein the distance between the centre of one heatpipe and the centre of the next heatpipe that is in line with it is 1.0cm, with a staggered heatpipe being provided halfway between the two.

19. A radiator as claimed in any one of the preceding claims wherein fins (12) are provided on the radiator.

20. A radiator as claimed in claim 19 wherein lateral fins are provided extending transversely across the heatpipes.

21. A radiator as claimed in claim 20 when dependent from claim 16 wherein each set of heatpipes that lie in the same plane are provided with multiple rows of fins.

22. A radiator as claimed in claim 21 wherein each row of fins (12) is less than 5mm apart.

23. A radiator as claimed in any one of claims 19 to 22 wherein the fins are provided with a series of bumps or pimples at spaced apart intervals along the length thereof.

24. A radiator as claimed in any one of the preceding claims further comprising a cover.

25. A radiator as claimed in any one of the preceding claims further comprising at least one fan within the radiator.

26. A radiator as claimed in any one of the preceding claims further comprising enabling means within the radiator to prevent kettling of the radiator.

27. A radiator as claimed in claim 26 wherein the enabling means comprises a confined heat transfer medium that has pores or passages for the flow of fluid therethrough whilst acting as a damper to aid dissipation of heat.

28. A radiator as claimed in claim 27 wherein the heat transfer medium is a fibrous material.

29. A radiator as claimed in claim 28 wherein the fibrous material is metal wool.

30. A radiator as claimed in any one of claims 26 to 29 wherein the enabling means is provided around the heating means in the first chamber (4).

31. A radiator as claimed in any one of claims 26 to 30 wherein the enabling means is provided in the second chamber (8).