WO2016030729A1

WO2016030729A1 - Heat exchanger for effective energy exchange

Info

Publication number: WO2016030729A1
Application number: PCT/IB2014/066330
Authority: WO
Inventors: Ignas SLAPKAUSKAS; Deivis JOKUBAUSKAS
Original assignee: Uab "Saules Vejo Aruodai"
Priority date: 2014-08-29
Filing date: 2014-11-25
Publication date: 2016-03-03
Also published as: LT2014097A; EP3186565A1; LT6160B

Abstract

A portable or stationary heat exchanger capable of absorbing radiation of different wavelengths, the plate (15) of which has flow forming members (1-14) on both sides of the plate and the said flow forming members are of special shape and at a particular angle relative to the heat exchanger plane, where the said flow forming members are designed to absorb energy from a radiation source, transform it, transfer it via a heat carrier (17), and to control the flow of the heat carrier by directing it along both sides of the heat exchanger along a path that is optimized in three dimensions, where the said heat carrier flow is caused by gravitational and, optionally, forced convection. Such heat exchanger can easily raise heat carrier temperature by 50°C--60°C and in some cases, by 80°C-130°C.

Description

HEAT EXCHANGER FOR EFFECTIVE ENERGY EXCHANGE

Technical Field

This invention is related to heating and transport of different type gas flows that utilize the sun or another heat radiating source for gas heating by means of solid state heat exchanger with a protective barrier, e.g., thermo-insulating barrier, and in which heat flow is formed and controlled by means of flow forming members.

Background Art

A heat exchanger is a technical device, in which heat exchange is taking place, and, more specifically, a device made of a solid state material that absorbs radiation of selected wavelength range, e.g.: sun radiation, visible or infra-red light that reflects from the heat exchanger surface plate, which can be made from aluminium foil coated with heat-absorbing titan layer, e.g.: TiNOX materials. Such heat exchanger is designed to ensure heat exchange with the heat carrier. A heat carrier (the flow of heat-transfer agent) flowing through the heat exchanger is a liquid or gaseous medium that transports thermal energy, e.g.: air flow sweeping a heat exchanger and carrying heat into a room. Thermo-insulating or another type barrier (casing) of the heat exchange system can be, for example, transparent for radiation of certain wavelength and have high or low thermal conductivity coefficient. Heat carrier flow forming members can be attached, cut, bent, or otherwise formed on the heat exchanger plate/frame. These flow forming members of the heat exchanger can be unscrewed, screwed, or otherwise attached to the heat exchanger or make an integral unit with the heat exchanger. Heat carrier flow forming members are designed to divert the flow in the desired direction. A heat carrier flow forming member can be a fin of various shape and covered, for example, with photo-voltaic or heat-absorbing material and directed towards sunlight. Different energy-radiating sources can be used: the sun, a hot engine, a furnace, etc.

The known heat exchanger have the following main shortcoming: (i) heat carrier flow in tubular and plate heat exchangers is laminar with little mixing of the heated layer at the walls with the volume of the heat carrier, thus exchange of heat between the exchanger walls and the heat carrier is insufficient; (ii) perforated and cross-flow heat exchangers suffer from flow speed loss and large local pressure loss due to turbulent gas flow; (iii) sweeping of both heat exchanger sides is uneven as each flow flows on a different side of heat exchanger; (iv) optimal absorption angle between the heat exchanger and the heat source is not maintained when the heat exchanger mounted vertically or at another angle.

Patent No CN101761150, published on June 30, 2010, describes a system for concentration and accumulation of solar energy. In this system, a plate - a heat exchanger - is attached to a building wall. The plate has metal fins at different angles generating vortexes of gas medium. A transparent material e.g., glass, covers this vortex generating plate from the side of an external heat source, e.g., the sun; the heat carrier flow is heated by means of vortexes in the space between the said material and the plate. The invention is used for heating/cooling of premises during correspondingly hot or cold season. The invention should be classified as a one-sided plate heat exchanger, in which the flow of the heat carrier is turbulent, yet mixing of the carrier volume with the hot layer at the walls is of low intensity leading to low efficiency of heat exchange between the heat exchanger walls and the heat carrier; local pressure losses are not significant.

Patent No US2006076008, published on April 13, 2006, describes a passive solar window heater that functions without an external electric power source. The heater is mounted outside a window to heat the room by means of aluminium fins and acrylic plastic glass sheet. Yet the heat carrier flow is unregulated and the flow-forming members of louver type do not ensure turbulent flow of the heat carrier.

The next patent according to the technical level is patent No. US3863621, published February 4, 1975. The described invention is related to a solar energy collection system that utilizes a barrier system, containing collector plates for collection of solar energy and for conversion thereof to thermal energy. The collector plate has slots. One embodiment of the invention is related to transparent solar energy collection system that passes light into the building. Louver type collector plates are utilized inside the transparent barrier system. Another embodiment of the invention is related to effective opaque barrier system for collection of solar energy, in which gang-nail type collector plates are used. This invention does not ensure uniform sweeping of the heat exchanger by the heat carrier flow on both sides, as gas flows only on one side. Moreover, the heat exchanger is not suitable for use in windy conditions. A heat exchanger of this type can raise the temperature of the heat carrier by 20°C at most and is effective only when temperature difference inside and outside is small.

Technical Problem

Technical Solution

The exclusive feature of the heat exchanger according to this invention is fins on both sides of the heat exchanger that are installed as heat carrier flow forming members. The fins have special shapes and are installed at selected angles to the heat exchanger plane. The heat exchanger can be mobile or stationary and is able to absorb electromagnetic waves of different length ranges. The purpose of flow forming members is to absorb radiation energy from sources with different spectra of electromagnetic waves, e.g., visible, infra-red, ultraviolet, to convert it to heat, to transfer it to the heat carrier, and to control the flow of the heat carrier by directing it along both sides of the heat exchanger along a path that is optimized in three dimensions, where the said heat carrier flow is caused by gravitational and, optionally, forced convection. Such heat exchanger can easily raise heat carrier (gas) temperature by 50°C‑-60°C and in some cases, by 80°C-130°C.

Advantageous Effects

Description of Drawings

Fig. 1 - axonometric view of positions of the heat exchanger and a heat source, including a barrier (housing), an internally installed heat exchanger, heat carrier flow-forming members, heat carrier flow and the sun as radiation source.

Fig. 2 - the scheme shows the heat exchanger, a heat source, and the angle between bent flow-forming members and the heat source.

Fig. 3 - general axonometric view of the heat exchanger; the heat exchanger has heat carrier flow forming members that are bent in different directions relatively to the heat exchanger plane.

Fig. 4 - axonometric view of few non-exhaustive embodiments of heat carrier flow-forming members.

Fig. 5 - the heat exchanger with a transparent barrier.

Fig. 6 - cross-section of the heat exchanger with heat carrier flow paths and flow mixing.

Fig. 7- heat carrier flow-forming members, attached to the heat exchanger plate.

Fig. 8 - one of the heat exchanger embodiments, where the system is made of a window glass and a louver of special design with scale-like slats.

Best Mode

Heat carrier is a fluid or gas that is used to carry heat from warmer areas to cooler areas. Some fluids may change the aggregation state during the heat transfer process, i.e., liquids may become gasses or vice versa.

As shown in Fig. 1, heat carrier flow (17) moves alongside the heat exchanger plate (15) and collects energy, which is partially converted into kinetic and potential energy. The heat carrier flow (17) moves alongside the heat exchanger plate (15). After flow forming parts (1-14), showed in Fig. 4, have created a laminar flow, the heat carrier flow (17) is directed alternatively to one, then another side of the heat exchanger plate (15), thus forming a turbulent laminar movement of the heat carrier (17) in a serpentine path. Laminar fluid flow is a flow in which thin layers don't mix between each other. In this case, the term laminar should be understood to mean heat carrier flow alongside heat exchanger plate (15) in serpentine fashion, crossing the plate (15) in locations of installation of flow forming members (Fig. 4, 1-14). Thus the heat carrier (17) moves alongside the heat exchanger plate (15) and its laminar flow is diverted by flow forming members (Fig. 4, 1-14) to the opposite side of the heat exchanger (15). The process is repeated until the heat carrier flow (17) reaches the other end of the heat exchanger plate (15) having accumulated the maximal amount of energy. The heat carrier flow (17) during such process sustains small local pressure loss due to uniform alternation of laminar turbulent gas flow, since the said flow forming members are selected of such dimensions and at such intervals and distances from the barrier (16) as to ensure the optimal flow path of the heat carrier to minimize resistance forces.

The heat carrier flow (17) forming parts (Fig. 4, 1-14) are mechanically bent to selected angle alpha (α), adjusting them to the incoming angle of thermal radiation relatively to the heat exchanger plate (15). When solar radiation (19) is the source of thermal energy, the forming parts (Fig. 4, 1-14) on the heat exchanger plate (15) are bent during installation of the plate on a vertical wall to the angle towards the sun (18) that ensures minimal reflection factor, i.e.: the sun rays should fall on the light absorbing fin at an angle that is as close as possible to the right angle. Such fin position ensures most effective capturing of light energy.

The flow forming members (Fig. 4, 1-14) have different shapes. Their shape depends on the required flow forming angle of the heat carrier and the scope of radiation energy capture. Various shapes of heat carrier flow-forming parts and their arrangement on the heat exchanger plate (15) are described below.

Fig. 4 shows the flow forming members (1), (2), (3), (4), (7), (9), and (10) that are designed to divert heat carrier flow (17) to the opposite side of the heat exchanger plate (15). Fig. 4 shows the flow forming members (1) and (5) that are designed to divert heat carrier flow (17) to the opposite side of the heat exchanger plate (15) and to generate electricity. Fig. 4 shows the flow forming members (5), (6) and (8) that are designed to divert heat carrier flow (17) to the opposite side of the heat exchanger plate (15) and to the right or to the left relative to the front side of the heat exchanger plate (15).

The said flow forming members (Fig. 4, 1-14) are arranged at such intervals relatively to the heat exchanger plate (15) that ensure physical properties of the heat carrier flow (17) that enables formation of laminar movement, i.e., heat carrier flow (17) without partial mixing along the path of least resistance that resembles a serpentine movement, since the gas flow crosses the said heat exchanger plate (15) at locations of the flow forming members (Fig. 4, 1-14). To ensure these conditions, the optimal ratio between the flow forming members (Fig. 4, 1-14) on the same side of the heat exchanger plate (15) should be 1.6H, where H is the height of the flow forming member.

Fig. 1 shows a heat exchanger (23) consisting of a protective barrier (16) and a heat exchanger plate (15) with flow forming members. The protective barrier (16) can be transparent or translucent to the radiation (19) spectrum of a particular source (18). The heat exchanger plate (15) is installed approximately medially along the protective barrier (16) on the internal side thereof; various heat carrier flow (17) forming members (Fig. 4, 1-14) on the said plate (15) can make an integral unit; the flow forming members are bent at selected angle to ensure the optimal path of heat carrier flow. The said flow forming members can also be mounted on the frame of the heat exchanger (15).

A flow forming members (1) consists of two rectangle parts (1.1, 1.2) of equal width and length, where the width is smaller than the length and where the parts are separated by a horizontal slot. The said rectangle parts (1.1, 1.2) of the flow forming member (1) are bent to opposing sides of the heat exchanger plate (15) at a particular angle towards the incoming radiation. The flow forming member (1) is used to ensure the optimal laminar flow path: from the back side of the heat exchanger plate to the front side thereof or vice versa.

The flow forming member (1) usually is located on the lower section of the heat exchanger plate (15). Fig. 4 shows a flow forming member (5) with three bent parts (5.1, 5.2, 5.3) of rectangular shape and of equal width and length, where the width is greater than the length. The parts (5.1, 5.2, 5.3) of the flow forming member (5) are separated by vertical slots in-between. The parts (5.1, 5.3) of the flow forming member (5) in the heat exchanger are bent up to one side of the heat exchanger plate (15), and the part (5.2) of the flow forming member (5) is bent down to the opposite side of the heat exchanger plate (15). The optimal use of the flow forming members (1) and (5) is to divert the heat carrier flow (17) from one side of the exchanger plate (15) to the other when generating energy.

The optimal use of the flow forming member (2), (3), (4), (7), (9), and (10), shown in Fig. 4, is to divert the heat carrier flow (17) from one side of the exchanger plate (15) to the other in a serpentine fashion. These flow forming members usually are used in the lower section of the heat exchanger to accelerate and heat the gas flow as fast and effectively as possible. The part (2.1) of the flow forming member (2) on the heat exchanger plate (15) is bent up at a particular angle. The flow forming member (2) can be bent to either side of the heat exchanger plate (15) as shown Fig. 3 for the case of the flow forming member (4). The two corners of the part (2.1) of the flow forming member (2) are rounded. The part (3.1) of the flow forming member (3) has the shape of a semicircle and is bent upwards at a particular angle to either side of the heat exchanger plate (15), as shown in Fig. 3 for the case of the flow forming member (4). The part (4.1) of the flow forming member (4) has the shape of a rectangle and is bent upwards at a particular angle to either side of the heat exchanger plate (15), as shown in Fig. 3. The part (7.1) of the flow forming member (7) has the shape of a triangle and is bent upwards at a particular angle to either side of the heat exchanger plate (15), as shown in Fig. 3 for the case of the flow forming member (4). The part (9.1) of the flow forming member (9) has the shape of a narrow rectangle and is bent upwards at a particular angle to either side of the heat exchanger plate (15), as shown in Fig. 3 for the case of the flow forming member (4). The part (10.1) of the flow forming member (10) has the shape of a trapezium and is bent upwards at a particular angle to either one side of the heat exchanger plate (15), as shown in Fig. 3 for the case of the flow forming member (4), where the trapezium can be bent along either the short or the long basis.

The optimal use of the flow forming members (5), (6) and (8), shown in Fig. 4, is to divert the heat carrier flow (17) to the opposite side of the heat exchanger plate (15) and to divert it to the left or to the right relatively to the heat exchanger plate (15). The parts (5.1), (5.2) and (5.3) of the flow forming member (5) are of equal width and length and are separated from each other, where the parts (5.1) and (5.2) are bent upwards to one side of the heat exchanger plate (15) and the part (5.3) is bent downwards to the opposite side of the heat exchanger plate (15). The parts (6.1), (6.2) and (6.3) of the flow forming member (6) are of equal width and length (can be of different width), are separated from each other vertically, and all parts are bent upwards, but the parts (6.1) and (6.3) are bent to one side of the heat exchanger plate, while the part (6.2), to the opposite side. The flow forming member (8) has the shape of a vertical non-isosceles rhombus, where the width is smaller that the height, and the parts (8.1) and (8.2) are bent along the diagonal to the opposing sides of the heat exchanger plate (15). The flow forming member (8) is used to divert the heat carrier flow (17) to the right or to the left and, partially, to the opposite side of the heat exchanger plate (15). The flow forming member (8) is used both at the upper and the lower sections of the heat exchanger plate (15) to either expand or concentrate the heat carrier flow (17).

Fig. 4 also shows the heat carrier flow (17) forming members (11), (12), (13) and (14). The flow forming member (11) consists of two rectangular horizontally separated parts (11.1) and (11.2) of equal length, but different width, where the part (11.1) is bent upwards to one side of the heat exchanger plate (15) and the part (11.2) is bent downwards to the opposite side of the heat exchanger plate (15). The flow forming member (12) consists of three diagonally bent rectangular parts (12.1), (12.2) and (12.3) of equal width and length, where parts (12.1) and (12.3) are bent to one side of the heat exchanger plate (15) and the part (12.2), to the opposite side. The flow forming member (13) consists of two triangular parts (13.1) and (13.2), where the part (13.1) is bent upwards to one side of the heat exchanger plate (15) and the part (13.2) is bent downwards to the opposite side of the heat exchanger plate (15). The flow forming member (14) consists of one part (14.1) in the shape of a right triangle that is bent to either side of the heat exchanger plate (15) as shown Fig. 3 for the case of the flow forming member (4).

The flow forming members (5), (6), (11) and (12), shown in Fig. 4, usually are used to turn laminar movement into turbulent movement, when gas flows from up the lower section of the heat exchanger plate (15) or vice versa. The flow forming members (5), (6), (11) and (12) usually are used in the middle section of the heat exchanger plate (15) to reach high temperature of the heat carrier in the most effective way. The flow forming members (8), (13) and (14) are used in the upper section of the heat exchanger plate (15) to divert gaseous heat carrier flow in desired direction.

Fig. 5 shows the protective barrier (16) and the heat exchanger plate (15) with heat carrier flow forming members (Fig. 4, 1-14) inside the barrier. Fig. 5 shows flow the forming members (4) and the passing heat carrier flow (17). Fig. 6 shows movement of heat carrier flow (17) through the flow forming members on the heat exchanger plate (15) that divert heat carrier flow (17) in different directions relative to the heat exchanger plate (15) in a serpentine fashion.

Fig. 7 shows a heat carrier flow (17) forming member (4) that can be attached, e.g. screwed on and off, to the heat exchanger plate (15) and can be exchanged for other heat carrier flow (17) forming members (1-14), shown in Fig. 4. The heat carrier flow (17) forming member (4) is attached by means of screws (20) to a support (21) that is in contact with the heat exchanger plate (15). Other fastening elements can be used instead: rivets, articulate structures, etc. Protective barrier (16) with the heat exchanger plate (15) inside is mounted on a building wall (22).

Fig. 8 shows one of heat exchanger embodiments that is rather interesting from the practical point of view. In this embodiment, the function of the protective barrier (16) is performed by a window glass, the function of the heat exchanger plate (15), by the window louver frame, and the function of the flow forming members, by the louver slats, which are coated with heat absorbing material, e.g., TiNox, on one (the active) side, and light reflective material, e.g., aluminium, on the other. Depending on the angle of the louver slats, the system can switch its function between light absorption and light reflection. The louver slats hang on the louver frame, e.g., the strings, spanning the whole height of the heat exchanger. Behind the louver plate, when looking from the window, is an array of scale-like lamellas (22) that forms a scale wall adjacent to the louver plane. This scale wall is made of scale-like lamellas that form curved indentations, which are responsible for the serpentine movement path of the heat carrier. Let us examine the following example. When solar rays pass the glass and fall on the heat absorbing side of the louver slats, radiation energy is converted to thermal energy. Heated air starts rising and is diverted by a louver slat towards the scale lamella. There, the heat carrier flow is deflected back to the plane of the louver slats by the curved indentation of the scale lamella. Then again, it is diverted back to the scale lamella plane. Thus, the heat carrier flows in serpentine fashion until it reaches the top of the heat exchanger, from where it goes to the room. The said scale-like lamellas can be made from a transparent material, and the louver slats, from heat or electricity generating materials. The elements of the back side (scale wall) and the front side (the louver) can be retracted and deployed as a regular louver. The heat exchanger will pass the light into the room, if the back scales are made from transparent material. The heat exchanger can also be used inside and/or outside of a premise.

The heat exchanger (23) according to this invention can be used inside a building by hanging it on a window sill and directing it towards the sun (18). The warm flow of heat carrier (17) heats up the room and provides micro ventilation that eradicates mould at locations of cold bridges and reduces internal sweating of the windows. The heat exchanger (23) according to this invention can also be used for supply of gas, e.g. warm air, into dryers of organic and non-organic materials, e.g., for drying of herbs, grain, biomass, or gravel. The said heat exchanger (23) can also be used for preheating of air that is fed into furnaces, burners or boilers. Moreover, the heat exchanger (23) can be used for electricity generation and preheating of gas for different purposes. The heat exchanger (23) can be used for preheating of gas that is fed into mechanical devices. The heat exchanger (23) can also be used for preheating of air that is fed into ventilation or heat recovery installations.

The descriptions of the preferred embodiments are provided to illustrate and describe the invention. This description is not exhaustive or limiting and does not seek to define an exact configuration or embodiment scenario. The description above should be regarded as an illustration, rather that a limitation. Professionals of the field may obviously see many modifications and versions of the invention. The selected embodiments were described to better explain the principles of the invention and the best practical application of different embodiment versions fit for specific purposes or applications to the professionals of the field. The scope of the invention is defined by the claims and their equivalents, where all used terms must be understood in their widest meaning possible, unless specified otherwise. It should be acknowledged that modifications of embodiments created by professionals of the field remain in the scope of the invention claims.

Mode for Invention

Industrial Applicability

Sequence List Text

Claims

1. A portable or stationary heat exchanger that absorbs energy from different sources of electromagnetic radiation, is designed for heating and transfer of various fluids and gasses and has:

- a transparent external protective barrier, inside of which a heat exchanger plate is installed at a distance to the protective barrier;

- a heat exchange plate made from material in a solid state that absorbs energy from a radiation source and converts it to thermal or electric energy;

characterized in that flow forming members (1-14) are installed on the heat absorbing plate (15) of the heat exchanger that divert heat carrier flow to one, then another side of the heat exchanger plate (15), where the flow crosses the plate (15) through flow forming members (1-14), creating a laminar turbulent flow along a serpentine path.

2. A heat exchanger according to claim (1), characterized in that the heat carrier flow (17) forming members on the heat exchanger plate (15) have the shape (8) to divert the heat carrier flow (17) to the right or to the left in the plane of the heat exchanger plate (15) relative to the direction of heat carrier flow movement before the flow crosses the plate from the front side to the back side or vice versa.

3. A heat exchanger according to claim (1), characterized in that the heat carrier flow (17) forming members on the heat exchanger plate (15) have the shapes (5), (6) or (11) to turn laminar movement of the heat carrier flow (17) into turbulent movement.

4. A heat exchanger according to claim (1), characterized in that the heat carrier flow (17) forming members on the heat exchanger plate (15) have one of the shapes (1), (2), (3), (4), (7) or (9).

5. A heat exchanger according to claim (1), characterized in that the heat carrier flow (17) forming members on the heat exchanger plate (15) have the shape (12).

6. A heat exchanger according to claim (1), characterized in that the heat carrier flow (17) forming members on the heat exchanger plate (15) have the shape (13) and are installed in the upper section of the heat exchanger plate (15).

7. A heat exchanger according to claim (1), characterized in that the heat carrier flow (17) forming members on the heat exchanger plate (15) have the shape (14).

8. A heat exchanger according to claim (1), characterized in that the said flow forming members (1-14) and the heat exchanger plate (15) make an integral unit; the said parts of the heat exchanger plate (15) are formed by cutting and bending them to a selected angle or by fastening to the frame of the heat exchanger plate (15).

9. A heat exchanger according to claim (1), where a window glass is used as the protective barrier and a louver frame is used as the heat exchanger plate with the louver slats, characterized in that it is equipped with an additional array of curved scale-like lamellas next and behind the louver slat plane designed to form a heat carrier path that is directed towards the scale lamellas on the way up and, having reached the scale-like lamellas, is directed by to the louver slats by the curvature of the scale-like lamellas, thus moving up the heat exchanger plate in a serpentine fashion and from there to the premise or energy generation systems.