Fluid radiator with external heating body

Abstract

The invention relates to an electric radiator (100) comprising a housing (102), a face of the housing (102) constituting the front (103) of the electric radiator (100), a heating body (104) arranged inside the housing (102) and a control device (105) for controlling the heating of the heating body (104), characterized in that the front (103) is a closed hollow body made of heat-conducting material, the hollow body forming inside the front (103) an autonomous container filled with heat transfer fluid, the heating body (104) being mounted opposite the internal face called the heat transfer face (103a) of the front (103) to transfer heat to the heat transfer fluid in the container.

Description

[0001] The invention relates to the field of heating, in particular electric heating, and relates to a fluid radiator with an external heating body.

[0002] Among the existing radiators, we can distinguish in particular the so-called fluid radiators which are composed of a hollow structure filled with a heat transfer fluid heated by a heating element, called an immersion heater, immersed in the fluid of the hollow structure. The heating element located in the lower part of the radiator first heats the fluid which, by convection, circulates to distribute the heat throughout the structure. The structure then dissipates the heat into the air.

[0003] There are also so-called "dry" radiators, which consist of a casing closed by a front and in which a heating element is placed. The heating element is arranged so as to heat the front. The front is often metallic, made from steel or aluminum sheet or sometimes made of ceramic, glass, resin, stone, or any other temperature-resistant material. An air inlet is provided at the bottom of the casing to let in fresh air and an air outlet is provided at the top of the casing to let the air heated by the heating element escape by convection.

[0004] Fluid radiators have the advantage, thanks to the circulation of the fluid, of having a very uniform temperature on all the external surfaces of the radiator. This allows for gentle heat generation without hotter surfaces that can produce dry air with a lot of localized convection and the risk of burns. The inertia of the fluid can also have the advantage of producing stable heating because the heat stored in the fluid is released slowly. However, fluid radiators with an immersed heating element do not provide immediate heat because it takes time for the fluid to heat up.

[0005] "Dry" radiators, on the other hand, provide more responsiveness because the heating element heats up quickly and is in direct contact with the air. However, it is difficult to heat the facade evenly. It is common practice to create more or less emissive zones on the heating element to partially radiate onto the facade and thus avoid having hot spots, but this solution has the effect of increasing the temperature of the heating element.

[0006] Documents FR2824386A1, FR2997167A1, WO2005080886A1 and FR2742524A1 describe radiators according to the state of the art.

[0007] The objective is therefore to find a solution allowing both good heating responsiveness and gentle, even heat on the facade, allowing better thermal performance.

[0008] The invention proposes to overcome the disadvantages of existing radiators by an electric radiator having a facade, which is in the form of a closed hollow body made of heat-conducting material, the hollow body forming inside the facade a self-contained container filled with heat transfer fluid. The heating body is arranged inside a housing and is mounted opposite the internal face of the facade to transfer heat to the heat transfer fluid in the container by radiation while heating the air flow passing through the radiator by convection. By conduction at the fluid / solid interface, the fluid contained in the container is also heated. The fluid circulates by convection in the facade, which has the effect of standardizing the surface temperature. The heating body being outside the fluid container and directly in contact with the air, part of the power quickly heats the air.The power dissipated by radiation is used to heat the fluid.

[0009] The subject of the invention is therefore an electric radiator comprising a housing having a lower air inlet and an upper air outlet, a face of the housing constituting the front of the electric radiator, a radiant heating body arranged inside the housing and a control device for controlling the heating of the heating body, characterized in that the front is a closed hollow body made of heat-conducting material, the hollow body forming inside the front a self-contained container filled with heat transfer fluid, the heating body being mounted opposite the internal so-called heat transfer face of the front to transfer heat to the heat transfer fluid in the container by radiation and being arranged in the air flow between the lower air inlet of the housing and the upper air outlet of the housing to heat the air flow by convection.

[0010] The radiator according to the invention therefore has good responsiveness, thanks to the electric heating body which heats the air flow passing through the radiator casing by convection, and also has the advantages of so-called fluid radiators, namely a uniformity of surface temperature and thermal inertia, by the presence of a facade filled with fluid which can circulate in the facade by convection, and heated by radiation by the radiating heating body. The heating body therefore has a dual role: to heat (indirectly) by radiation the fluid in the facade and to heat (directly) by convection the air passing through the radiator. It is therefore essential that the air can circulate in the radiator around the heating body, and in particular between the heating body and the facade. The heating body is not immersed in the fluid container: the heating body is indeed external to the fluid.

[0011] It is understood that at least one watertight orifice can be provided on the facade to, if necessary, allow the fluid in the facade to be changed.

[0012] According to one embodiment, the container is one of a single-compartment container and a container with multiple insulated compartments.

[0013] According to one embodiment, the single-compartment container is formed of several chambers connected in fluid communication by a collector. A single chamber is thus formed, with a single fluid, facilitating the change of the fluid in the facade if necessary.

[0014] According to one embodiment, the surface area of the heating body opposite the heat transfer face of the facade represents at least 30% of the surface area of the facade.

[0015] Optimal heat transfer between the heating body and the facade is thus established. The invention is not limited in this respect and the person skilled in the art will be able to size the heating body according to the expected performance of the radiator, the nature and volume of heat transfer fluid. According to one embodiment, the heating body is mounted in the lower part of the housing to transfer heat to the lower part of the heat transfer face of the facade.

[0016] Heating the lower part of the facade facilitates the convection movements of fluid in the facade.

[0017] According to one embodiment, the thickness of the container envelope is between 5 mm and 50 mm.

[0018] According to one embodiment, the facade is made of one of steel and aluminum.

[0019] According to one embodiment, the heat transfer fluid is one of water, optionally with the addition of ethylene glycol or propylene glycol, an oil and a mixture of oils.

[0020] According to one embodiment, the heat transfer fluid comprises one or more types of fillers among conductive fillers, such as graphene, metallic fillers and carbon-based fillers.

[0021] According to one embodiment, the heating body is spaced from the facade by at least 5 mm, in order to allow heating of the air passing through the radiator by convection.

[0022] To better illustrate the object of the present invention, particular embodiments will now be described, for informational and non-limiting purposes, in conjunction with the appended drawings.

[0023] On the drawings: [ Fig. 1 ] is a schematic view of an electric radiator according to the state of the art. [ Fig. 2 ] is an exploded schematic view of a fluid radiator with an external heating body according to a first embodiment of the invention. [ Fig. 3 ] is a schematic cross-sectional view showing the fluid radiator with external heating body of the Figure 2 . [ Fig. 4 ] is an exploded schematic view similar to the Figure 2 of a fluid radiator with external heating body according to a second embodiment of the invention. Fig. 5 ] is a diagram showing the temperature distribution obtained with a radiator according to the invention, on the interior face and on the exterior face of the facade.

[0024] There Figure 1 represents the state of the art for an electric radiator 1, which comprises a housing 2 closed in the front part by a facade 3 and in which is placed a heating body 4, visible behind the tear-away of the facade 3 on the Figure 1 . The heating body 4 is arranged so as to heat the facade 3 by radiation, the heating body 4 being in the form of a metal sheet 4a (aluminum or cast iron) in which two longitudinal channels 4b are formed, crossed by an electrical heating resistor (not shown) to form a central part between the two channels 4b and a lateral fin on each of the two channels 4b. The facade 3 is often metallic, made from steel or aluminum sheet or sometimes made of ceramic, glass, resin, stone, or any other temperature-resistant material. An air inlet 6, in the form of a grid formed at the base of the housing 2, is provided in the lower part of the housing 2 to allow fresh air to enter and an air outlet 7 is provided in the upper part of the housing 2 to allow the hot air heated by convection by the heating body 4 to escape.A control device 5 is placed in the upper part of the housing 2 to control the heating of the heating body 4, by any conceivable human-machine interface, for example a control button 5a. The heating body 4 rises rapidly in temperature and is in direct contact with the air, which makes it possible to quickly provide heat, by convection of the air coming from the grids 6.

[0025] THE Figures 2 And 3 represent a radiator 100 according to a first embodiment of the invention.

[0026] The radiator 100 comprises a housing 102 with an open front face, the front 103 of the electric radiator 100 closing this front face of the housing 102, a heating body 104 arranged inside the housing 102 and a control device 105 for controlling the heating of the heating body 104, and openings and grilles 106 and 107 in the lower part and in the upper part of the housing 102, similar to the openings and grilles 6 and 7 described in connection with the Figure 1 and constituting respectively an air inlet and an air outlet for the air passing through the radiator. As for the heating body 4 described in connection with the Figure 1 , the heating body 104, in this embodiment, is in the form of a metal plate 104a crossed by two longitudinal channels 104b, each channel 104b being traversed by an electrical heating resistor (not shown). The heating body 104 is fixed to the housing 102 by means of screws (not shown) inserted into holes 104c formed through the heating body 104, which screws are then fixed in the bottom of the housing 102. The front 103 is a closed hollow body made of heat-conducting material, in particular steel or aluminum, the hollow body forming inside the front 103 an autonomous container filled with heat transfer fluid, the heating body 104 being mounted opposite the internal face 103a called the heat transfer face of the front 103 to transfer heat to the heat transfer fluid in the container formed by the front 103.

[0027] The thickness of the container envelope may in particular be between 5 mm and 50 mm, without the invention being limited in this respect.

[0028] The heating body 104 is of the radiant type and is spaced from the internal face 103a of the facade 103 by at least 5 mm, in order to allow a flow of air between the internal face 103a of the facade 103 and the heating body 104 between the air inlet 106 and the air outlet 107, which flow of air is heated by convection by the heating body 104.

[0029] The radiator 100 has good responsiveness thanks to the electric heating body 104 and also has the advantages of so-called fluid radiators, namely a uniformity of surface temperature and thermal inertia, by the presence of a facade 103 filled with fluid which can circulate in the facade 103 by convection.

[0030] The container formed by the facade 103 is a single-compartment container or a container with several isolated compartments. Where appropriate, the single-compartment container is formed of several chambers connected in fluid communication by a collector 109. In the embodiment of the Figure 2 , the front 103 is made up of seven independent blades 108, connected in fluid communication by a collector 109 on which the blades 108 are fixed, for example by welding, the collector 109 being fixed in the lower part of the blades 108 and communicating fluidly with the blades 108, generally by means of one or more openings formed between each blade 108 and the collector 109. A rounded cutout 102a may be formed in the housing 102 to accommodate the collector 109 when the front 103 is mounted on the housing 102. A single space is thus formed, with a single fluid, facilitating the changing of the fluid in the front 103 when necessary. It is understood that at least one sealed orifice (not shown) may be provided on the facade 103 to, if necessary, introduce the heat transfer fluid into the facade 103 and allow the heat transfer fluid to be changed in the facade 103.

[0031] The surface of the heating body 104 facing the internal face 103a of the facade 103 represents at least 30% of the surface of the facade 103, thus making it possible to establish optimal heat transfer between the heating body 104 and the facade 103.

[0032] The heating body 104 is mounted in the lower part of the housing 102 to transfer heat to the lower part of the heat transfer face 103a of the facade 103.

[0033] Heating the lower part of the facade 103 facilitates the convection movements of fluid in the facade 103.

[0034] The temperature of the internal heat transfer face 103a of the facade 103 is not very uniform because the heating body 104 radiates only over a limited area of the facade 103. Thanks to the thermal conductivity of the heat transfer fluid circulating in the facade 103, the temperature of the external face of the facade 103 is relatively uniform over its entire height, by convection inside the facade 103.

[0035] Different heat transfer fluids can be used in the context of the present invention. Water will preferably be used, which has the advantage of being an inexpensive heat transfer fluid with good thermal capacity and good thermal conductivity.

[0036] The water may optionally be supplemented with ethylene glycol or propylene glycol to prevent freezing and to increase the boiling point of the heat transfer fluid. Oils may also be used. They generally have a lower heat capacity than water, which allows the facade 103 to heat up more quickly but reduces the inertia of the radiator 101. Their lower thermal conductivity does not allow for as good a temperature uniformity as with water as the heat transfer fluid.

[0037] The facade 103 will not be completely filled with heat transfer fluid, an air space being provided to accommodate changes in volume of the heat transfer fluid in the facade 103 with temperature variations.

[0038] The thermal conductivity of the fluid can be improved by adding conductive fillers, such as graphene, or any other metallic or carbon-based fillers, or even mixtures of fillers of different types.

[0039] As can be seen on the Figure 3 , the heating body 104, once mounted in the housing 102, is not glued to the internal face 103a of the facade 103, but is arranged opposite and at a distance from it to heat it by convection, the openings 106 and 107 in the lower part and in the upper part of the housing 102 facilitating the circulation of air by convection inside the housing 102.

[0040] The heating body 104 is mounted opposite the internal face known as the heat transfer face 108 of the facade 103 to transfer heat to the heat transfer fluid 107 in the container.

[0041] The facade 103 is a closed hollow body made of heat-conducting material, the hollow body forming inside the facade 103 an autonomous container filled with heat transfer fluid 107, the heating body being mounted opposite the internal face called the heat transfer face 108 of the facade to transfer heat to the heat transfer fluid in the container.

[0042] The surface area of the heating body 104 facing the heat transfer face 108 of the facade 103 represents at least 30% of the surface area of the facade 103, thus making it possible to establish optimal heat transfer between the heating body 104 and the facade 103.

[0043] The heating body 104 is mounted in the lower part of the housing 102 to transfer heat to the lower part of the heat transfer face 103a of the facade 103.

[0044] Heating the lower part of the facade 103 facilitates the convection movements of fluid in the facade 103.

[0045] The temperature of the internal heat transfer face 103a of the facade 103 is not very uniform because the heating body 104 radiates only over a limited area of the facade 103. Thanks to the thermal conductivity of the heat transfer fluid circulating inside the facade 103, the temperature of the external face of the facade 103 is relatively uniform over its entire height by convection inside the facade 103.

[0046] There Figure 4 represents a fluid radiator with an external heating body according to a second embodiment according to the invention.

[0047] Elements of the same structure as the first embodiment will bear the same reference numeral increased by 100, and will not be described in further detail herein if they have the same structure as in the first embodiment.

[0048] The difference between the second embodiment and the first embodiment lies in the fact that the facade 203 is formed of a single blade 208, forming a single chamber containing the heat transfer fluid, with a collector 209 in the lower part of the blade 208 to facilitate the circulation of the heat transfer fluid in the blade 208. The container formed inside the blade 208 is a single-compartment container formed of a single chamber, with a single fluid, facilitating the changing of the fluid in the facade 203 if necessary. As for the first embodiment, at least one fluid filling / changing orifice (not shown) is provided to fill the facade 203 and change the heat transfer fluid if necessary.

[0049] As for the first embodiment, the heating body 204 is of the radiant type and is spaced from the internal face 203a of the facade 203 by at least 5 mm, in order to allow a flow of air between the internal face 203a of the facade 203 and the heating body 204, between the air inlet 206 and the air outlet 207, which flow of air is heated by convection by the heating body 204.

[0050] There Figure 5 illustrates the temperature homogeneity obtained with a radiator according to the invention, on the inside of the facade in the left part and on the outside of the facade in the right part. It is thus possible in particular to note that if the temperature is not uniform on the inside face, in particular a warmer dark zone appears in the central part corresponding to the location of the heating body, the temperature on the outside face is uniform over the entire height of the blades.

Claims

1. An electric radiator (100; 200) comprising a housing (102; 202) having a lower air inlet (106; 206) and an upper air outlet (107; 207), a face of the housing (102; 202) constituting the front (103; 203) of the electric radiator (100; 200), a radiating heating body (104; 204) disposed inside the housing (102; 202) and a control device (105; 205) for controlling the heating of the heating body (104; 204), characterized by the fact thatthe facade (103; 203) is a closed hollow body made of heat-conducting material, the hollow body forming inside the facade (103; 203) an autonomous container filled with heat transfer fluid, the heating body (104; 204) being mounted opposite the internal face called the heat transfer face (103a; 203a) of the facade (103; 203) to transfer heat to the heat transfer fluid in the container by radiation and being arranged in the air flow between the lower air inlet (106; 206) of the housing (102; 202) and the upper air outlet (107; 207) of the housing (102; 202) to heat the air flow by convection.

2. Electric radiator (100; 200) according to claim 1, characterized by the fact that the container is one of a single-compartment container and a container with multiple insulated compartments.

3. Electric radiator (100) according to claim 2, characterized by the fact thatthe single-compartment container is formed of several chambers (108) connected in fluid communication by a collector (109).

4. Electric radiator (100; 200) according to one of claims 1 to 3, characterized by the fact that the surface of the heating body (104; 204) opposite the heat transfer face (103a; 203a) of the facade (103; 203) represents at least 30% of the surface of the facade (103; 203).

5. Electric radiator (100; 200) according to one of claims 1 or 4, characterized by the fact that the heating body (104; 204) is mounted in the lower part of the housing (102; 202) to transfer heat to the lower part of the heat transfer face (103a; 203a) of the facade (103; 203).

6. Electric radiator (100; 200) according to one of claims 1 to 5, characterized by the fact that the thickness of the container envelope is between 5 mm and 50 mm.

7. Electric radiator (100; 200) according to one of claims 1 to 6, characterized by the fact thatthe facade (103; 203) is made of one of steel and aluminum.

8. Electric radiator (100; 200) according to one of claims 1 to 7, characterized by the fact that the heat transfer fluid is one of water, optionally with the addition of ethylene glycol or propylene glycol, an oil and a mixture of oils.

9. Electric radiator (100; 200) according to one of claims 1 to 8, characterized by the fact that the heat transfer fluid comprises one or more types of fillers among conductive fillers, metallic fillers and carbon-based fillers.

10. Electric radiator (100; 200) according to one of claims 1 to 9, characterized by the fact that the heating body (104; 204) spaced from the front by at least 5 mm.

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