Field of the invention

The invention concerns the field of heat transfer. More specifically, the invention concerns a heat exchange system as set out by the preamble of claim 1.

Background of the invention

Marine vessels, such as boats, ships, offshore platforms and plants, that operate in environments where they may be exposed to temperatures below the freezing temperature, are required to have de-icing equipment to ensure that ice does not form on installations such as walkways, ladders, stairways and handrails.

Known de-icing equipment includes electric heat tracing, in which electric heating cables are either embedded in the installation to be heated (e.g. in the case of walkways) or attached to it by suitable mechanical means (e.g. in the case of stairways or ladders). Electric heat tracing on board marine vessels is associated with certain disadvantages. Generating the required electricity is costly and contributes to depleting limited onboard fuel supplies. Also, the saline environment and the vessel's motions in the sea tend to subject the heating cables to mechanical loads and corrosive processes that over time lead to short-circuiting and earth faults.

Known de-icing equipment also includes liquid-based heating systems, where a heated liquid is circulated through a network of hoses embedded in or attached to the installation to be heated. The heated liquid may for example be water (heated by e.g. the ship's engine), or a mixture of water and glycol. These systems generally comprise a heat source, a heat exchanger and a circulation pump which drives the heated liquid through the network of hoses. As the liquid gradually loses heat as it flows through the hoses, through dissipation into the cooler installation, continuous circulation is required, often at high flow rates. Disadvantages with such liquid-based systems include the potential for leaks, a continuous power demand (e.g. for the circulation pump), and the need for frequent maintenance. It is therefore a need for a de-icing system that is more reliable and efficient than those of the prior art.

Summary of the invention

The invention is set forth and characterized in the main claim, while the dependent claims describe other characteristics of the invention.

It is thus provided a heat exchange system, comprising at least one object to be heated or cooled, and a heat exchanger, and wherein the heat exchanger is connected to the at least one object via heat-transferring means, and is also connected to a heat source or a cooling source, characterized in that the object comprises at least one compartment which is fluidly connected to the heat exchanger via the heat-transferring means, and the compartment is configured to accommodate a gas gas having a certain thermal conductivity, whereby the heat is transferred by conduction within the gas, and is not depending on gas circulation; and there is no circulation pump between the heater and the compartment. In one embodiment, the heater is a heat exchanger and the heat- transferring means is a pipeline, and the heat exchanger is fluidly connected to a heat source.

In one embodiment, the compartment and the heat-transferring means (9) form a closed volume. In one embodiment, the heat-transferring means comprises a portion extending into said heater.

The object may be a step in a staircase, a walkway/deck element or a cargo deck element. The system may comprise one or more cartridges that each comprise at least one compartment and wherein the cartridges comprise interconnection means.

In one embodiment, a plurality of objects are fluidly interconnected. In one

embodiment, each compartment comprises a tubular element. The compartment may be made of a metal.

The invented system is particularly useful as a de-icing system on a marine vessel.

In use, when the heat exchanger is connected to a heat source, the object is heated. When the heat exchanger is connected to a cooling source, the object is cooled. Brief description of the drawings

These and other characteristics of the invention will become clear from the following description of a preferential form of embodiment, given as a non-restrictive example, with reference to the attached schematic drawings, wherein:

Figure 1 is a perspective view of a staircase incorporating an embodiment of the invention;

Figure 2 is a side view and partly transparent drawing of the staircase shown in figure 1;

Figure 3 is a perspective view of a step in the staircase illustrated in figure 1;

Figure 4 is a plan view and partly transparent drawing of a portion of the staircase shown in figure 1, illustrating a heat exchanger and a staircase step

incorporating the invention;

Figure 5 is a perspective exploded view of an alternative embodiment of a staircase step incorporating the invention;

Figure 6 is a perspective view of a walkway element incorporating an embodiment of the invention;

Figure 7 is a plan view and partly transparent drawing of the walkway element shown in figure 6;

Figure 8a is a perspective view and partly cut-away drawing of a cargo deck incorporating an embodiment of the invention, and figure 8b is an enlargement of the area marked "D" in figure 8a.

Detailed description of a preferential embodiment

The following description will use terms such as "horizontal", "vertical", "lateral", "back and forth", "up and down", "upper", "lower", "inner", "outer", "forward", "rear", etc. These terms generally refer to the views and orientations as shown in the drawings and that are associated with a normal use of the invention. The terms are used for the reader's convenience only and shall not be limiting.

Figures 1 and 2 illustrate a staircase 5 incorporating an embodiment of the invention, in use as a de-icing system on a marine vessel (not shown). The staircase comprises a number of steps 6 and a banister (railing) 8 supported by posts 10. Each step 6 is connected to its adjacent step via a tube 16 in a manner which is described below. One of steps (in the figures, the lower step) is connected to a heat exchanger 4 via a pipe 9. Reference numbers 14, 15 indicate pipelines to a heat source (not shown), for example heated water from the marine vessel's engines. It should be understood, however, that any heat source may be used.

Figure 3 illustrates a staircase step, seen from below. Underneath and connected to the step's framework 11, a number of tubular members 3 are arranged. These members, which do not necessarily need to have a tubular shape, are in fact hollow compartments, and will therefore in the following also be referred to as such. The compartments 3 are interconnected via fittings 13, such that the compartments and the fittings form one cavity. In the embodiment shown in figure 3, this cavity has only one opening, i.e. the connector 12 to which the above mentioned pipe 9 (figures 1 and 2) may be connected.

Turning now to figure 4, which illustrates how one step 6 is connected to the heat exchanger 4, it is seen how the pipe 9 extends from the connector 12 and into the heat exchanger 4. The pipe portion 9a inside the heat exchanger 4 is closed off at the end 9b. This figure therefore illustrates how the compartments 3, fittings 13 and the pipe 9, 9a form a closed volume. The heat exchanger 4 may be of a type known in the art. The embodiment shown in figure 4 is merely a vessel having a fluid inlet 14 and a fluid outlet 15. In use, therefore, a liquid, heated by for example by an engine, circulates through the heat exchanger and delivers heat to the pipe end 9b, which is of a material having a good thermal conductivity, for example a metal material.

It should be understood that a plurality of steps 6 may be interconnected in series via tubes 16, for example as shown in figure 2. In that configuration, the closed volume will comprise the compartments 3 and fittings 13 of each step 6, the interconnecting tubes 16, and the pipe 9, 9a. Although figures 1, 2 and 4 show the heat exchanger 4 in close proximity to the staircase steps for which is providing heat, it should be understood that the heat exchanger in principle may be located anywhere on the marine vessel. In any case, the pipe 9 between the heat exchanger and the step 6 to which it is connected is preferably provided with thermal insulation.

A key feature of the invention is thus that the closed volume is brought into contact with a heat source (e.g. the heat exchanger), and that the closed volume is configured to be filled with a gas having a certain thermal conductivity. The heat is thus transferred by the gas per se, i.e. by conduction within the gas, and is not depending on gas circulation. In the invention, the gas inside the closed volume is not circulated through the heat exchanger (as is required with the known liquid heaters) and, consequently, no circulation pump is needed. Tests have shown that the gas pressure increases

proportionally with the increase in temperature.

Figure 5 shows an alternative embodiment of a staircase step 6' in which the

compartments 3 are embedded in the step structure. The figure shown a plurality of compartments (closed off at each end), stair connection brackets 17, a pipe portion 9 leading to heat exchanger and a tube portion 16 for connection to subsequent step.

Referring now to figures 6 and 7, the invention is also suitable for use in a walkway or deck element 7 on a marine vessel. In the illustrated embodiment, the element 7 (which may be connected to a deck (not shown) comprises a frame 18 holding two heating cartridges 19 connected in series via a fitting 13. Each cartridge 19 comprises a meandering compartment 3 and the compartments are interconnected via a fitting 13. The compartment 3 in the left-hand (in figures 6 and 7) cartridge is connected to a heat source (e.g. a heat exchanger, not shown) via the pipe 9. Although not illustrated in figures 6 and 7, it should be understood that several walkway and/or deck elements may be connected in series, via the connector 16, similar to the steps described above.

Similar to the steps described above, the compartments 3 in the cartridges 19 are configured to be gas-filled. The fittings 13 and connectors 12 are of a type which known in the art and may comprise pressure-operated valves that close automatically when disconnected and open when connected to an adjacent connector and/or pipe. Therefore, the compartment 3 of each cartridge 19 may be pre-filled with the desired gas (at another location) and installed into element 7 by interconnecting it to the pipe 9 and (if applicable) other cartridges. The similar modular principle also applies to the staircase steps described above.

Referring now to figures 8a and 8b, the invention is also suitable for incorporation in a cargo deck 20 on a marine vessel. In the illustrated embodiment, beams 21 are placed on a deck plate 22. Gas-filled compartments, of the type described above, are arranged between the beams, and are interconnected and connected to a heat exchanger (not shown) in a manner similar to that described above. The compartments 3 are fixated and protected by retaining members 23, which also serve as supports for (wooden) slats 24. Although not illustrated, fins of a thermally conductive material may be connected to the retaining members and arranged to extend between adjacent slats.

Although the invention has been described and illustrated with reference to a heating system, particularly for use as a marine de-icing system, it should be understood that other applications are possible, both on-shore and offshore. For example, referring to figure 4, if the heat exchanger is connected to a cold source (i.e. a heat sink or a reservoir that absorbs energy), the compartments 3 will work as a cooling element, by virtue of the gas-filled, closed volume. The invented system is therefore in its broadest sense a heat exchange system, wherein the heat exchanger is connected either a heat source or a cooling source.

The cartridges 19 and ancillary parts shown in figure 6, or equivalent variants, may for example be installed as floor elements, wall elements or ceiling elements in any room, such as a ship's bridge, a ship's cabin, a cargo container, and be used as a heater or a cooler, depending on whether the heat exchanger is connected to a heat source or a cooling source. The invention may find use in providing decentralised temperature control systems in e.g. facilities for transporting and storing produce, battery packs, and living quarters.