Technical field

This invention involves a flow profile with debossed boundaries that can be used in the heat transfer technology and in solar thermal technology.

Current state of the art

At present, materials consisting of foam metal structures with closed and open pores are beginning to be applied in the field of thermal technology. Metal foams with open pore structure can be used - due to their large heat-exchange surface - to build heat exchangers used in various areas of solar thermal technology. The published document DE 10 2009 040 039 Al describes the application of metal foam structure to increase the heat exchange surface between the flat solar collector absorber and heat exchange medium manifold tube, or as a material of the absorber. This is an open plate structure, forming a lamella, with incorporated tube segment forming the flow channel. The hydraulic boundaries are defined by the walls of the tubing. The patent document CN2013921 15 describes a heat exchanger, consisting of a metal foam structure incorporated between the walls of two concentric tubes. This solution represents a design alternative of a heat exchanger with co-axial flow of the media. From hydraulic point of view the foam structure making up the flow channel is defined by the inside and outside wall of the tubes.

This is similar in the case of technical solution described in CN101226021, where the foam metal structure is found also in the inner tube/inner tubes.

Patent document US20099250191 describes various designs of heat exchangers based on metal foams, with hydraulic boundaries formed by the walls of the exchanger body.

These concepts do not address the distribution of the heat exchange medium within the absorber body independent of the circumferential walls of the body containing the metal foam. The continuity of heat exchange between individual hydraulic boundaries depends on the material of the wall and contact with foam structure. Basis of the invention

These drawbacks are essentially eliminated by the proposed flow profile with debossed boundaries that enables hydraulic boundaries of the flow channels to be established without affecting the structure of the metal foam. The advantage lies in the possibility to design large flat plate objects made of metal foams with arbitrary geometrical pattern of the flow channels that have no effect on the continuity of heat exchange through the body consisting of the metal foam. The flow channel may be in the shape of meander or register. The flow profile with debossed boundaries can be used to design flow segments of plate heat exchangers where individual plates can be separated by metal plates representing partition plates or to design full-flow direct insulation absorbers for liquid-medium solar collectors, where the absorber is covered by a transparent plate no the top and inert insulating plate on the bottom.

The flow profile with debossed boundaries consists of a metal foam panel with open pore structure, with columns representing the boundaries of the flow channels made by debossing with inert putty. The putty can be applied either using an application gun or using a template. Colum width depends on the size of the application hole through which the putty was applied and on the resistance of the metal foam structure to permeation of the putty in its pores.

The advantage is that when making flow profile with debossed boundaries, the structure of metal foam cells is left intact thus preserving the continuity of heat-conducting surface.

The advantage is that the columns representing the boundaries of the flow channels can at the same time serve to seal the contact surfaces between the metal foam plate and the partition plate.

The advantage is that the application of columns is a simple process that can be carried out under standard operating conditions without any requirements for special equipment.

The advantage is that the flow profile with debossed boundaries can be routed through the metal foam plate in any direction, enabling any design of blinding, crossing or discontinued path. Description of drawings

In the attached drawings, Fig. 1 shows a flow profile with debossed boundaries in the shape of "S". Fig. 2 shows isometric image of the flow profile with debossed boundaries defining the distribution of fluid in stacked plate heat exchanger. Fig. 3 shows a detail of a column in the plate. Fig. 4 shows the flow profile with debossed boundaries in a full-flow, directly insulated absorber of a liquid-medium solar collector.

Examples of application Example 1

"S" shaped flow profile with debossed boundaries, depicted in Fig. 1 consists of a plate I made of metal foam with open foam structure and columns 2 made by local debossing of inert putty in the pores of the metal foam made of copper. The column material may be silicone putty which remains elastic after vulcanization.

Example 2

Flow profile with debossed boundaries depicted in Fig. 2 and 3 represents a system of fluid distribution in a stacked plate heat exchanger. Plates I are made of metal foam (copper), with flow channels defined by columns 2, made of permanently elastic silicone putty separated by partition plates 3 consisting of metal plates made of copper. The columns divide the plate into distribution flow channels shaped like meander. The columns are designed to rise above the plane of the plate on both sides of the plate, acquiring full hermetic sealing of the fluid path when the stacked plate exchanger is stacked.

Example 3

Flow profile with debossed boundaries represents an alternative design to flow profile with debossed boundaries described in example 2. The columns divide the plate in parallel distribution flow channels with manifolds at the bottom and at the top of the plate.

Example 4

Flow profile with debossed boundaries shown in Fig. 4, consisting of plate , where the flow channels are defined by columns 2, represents a full flow direct insulated absorber of the fluid solar collector, where the absorber is covered on the top by a hydraulically defined transparent cover 4 and on the bottom by an inert plate of the thermal insulation panel 5.

Industrial applicability

Flow profile with debossed boundaries can be used to design various heat exchangers using metal foam with open pore structure with fluids and gas as the heat exchange medium. The flow profile with debossed boundaries can also be used in solar thermal technology as the basic functional unit of a directly insulated full flow absorber of a solar collector based on metal foam.