CN114739019B - A high-efficiency flat-plate collector based on rotating fins - Google Patents

Abstract

The invention relates to a high-efficiency flat plate collector based on rotary fins, which comprises a PC transparent cover plate, a fixing frame, a heat absorbing plate, an aluminum metal shell, a columnar turbulence component, an air flow inlet and an air flow outlet, wherein the aluminum metal shell is a shell with an open upper port; one side of the aluminum metal shell is provided with an air flow inlet, the other side of the aluminum metal shell is provided with an air flow outlet, the air flow inlet is connected with the fan, and the heat collection cavity is respectively communicated with the air flow inlet and the air flow outlet; the columnar turbulent flow component comprises a columnar turbulent flow element, a plurality of guide vanes and a base. The invention can effectively destroy the boundary layer, enhance the turbulence degree and effectively improve the heat transfer efficiency between the wall surface of the heat absorbing plate and the heat exchange working medium.

Description

A high-efficiency flat-plate collector based on rotating fins

technical field

The invention relates to a solar flat plate heat collector, in particular to a high-efficiency flat plate heat collector based on rotating fins that can enhance heat transfer.

Background technique

As a renewable energy with huge reserves, strong sustainability, green, clean and harmless, and easy access, solar energy has always played an irreplaceable role in the development of human society. The solar collector is the key component of the solar heat utilization device, which is mainly composed of a transparent cover plate, a heat absorbing plate, an insulating material, a bottom plate and a frame. Solar flat panel collectors have the characteristics of simple structure, low cost, and easy installation, and are widely used in building heating, domestic and industrial water supply, and drying equipment development.

The ribs in the existing flat-plate collectors adopt a fixed structure. When the heat exchange working medium flows through the heat exchange channel, the impurities mixed inside will cover the surface of the heat absorbing plate when it flows, making it difficult to clean the heat absorbing plate. The reduction of absorbed heat will seriously affect the heat collection efficiency; at the same time, heat exchange holes will be generated in the heat exchange channel, which will reduce the mixing degree of the heat exchange working medium, and the heat of the heat collection plate cannot be absorbed efficiently and uniformly. This is because when the heat exchange working medium flows in the heat exchange channel, due to the low flow rate, internal impurities will cover the surface of the heat-absorbing plate, resulting in too thick a boundary layer, and heat cannot be quickly transferred from the heat-absorbing plate to the heat-exchanging working medium. At the same time, most of the heat from the heat-absorbing plate is transferred to the underlying working medium, and the heat-exchanging medium farther away from the heat-absorbing plate flows out of the heat-exchanging channel after receiving less heat, resulting in the heat of the heat-absorbing plate not being efficiently and evenly transferred to all Heat exchange medium.

Contents of the invention

The object of the present invention is to provide a high-efficiency flat-plate heat collector based on rotating fins, which is used to solve the problems of uniform mixing of heat-exchanging working fluid and efficient heat exchange with heat-absorbing plates.

The technical solution adopted by the present invention to solve the technical problem is: the high-efficiency flat plate heat collector based on rotating fins includes a PC transparent cover plate, a fixed frame, a heat-absorbing plate, an aluminum metal shell, a columnar spoiler assembly, an airflow inlet, The airflow outlet, the aluminum metal shell is a shell with an open upper port, the inner wall of the aluminum metal shell is provided with a heat-insulating layer, the heat-absorbing plate is laid horizontally on the bottom surface of the heat-insulating layer, and the columnar spoiler components are arranged vertically and horizontally on the light-collecting plate of the heat-absorbing plate On the surface, the PC transparent cover closes the upper port of the aluminum metal casing and forms a heat collecting cavity, and the fixing frame fixes the PC transparent cover and the aluminum metal casing together from all sides; one side of the aluminum metal casing is provided with an air inlet, and the other side The air outlet is set, the air inlet is connected to the fan, and the heat collecting chamber is connected to the air inlet and the air outlet respectively;

The columnar spoiler assembly includes a columnar spoiler element, a plurality of guide vanes, and a base, and the plurality of guide vanes are fixed on the columnar spoiler element along the circumferential direction, and the plurality of guide vanes are rotated around the columnar spoiler element, The lower end surface of the columnar spoiler element is fixed on the bearing inner ring of the base; the base adopts a deep groove ball bearing structure, and the base includes a bearing inner ring, a bearing outer ring, a cage, a plurality of steel balls, and the bearing inner ring and the bearing outer ring. There is a cage in between, the cage is cylindrical, and the body of the cage is evenly equipped with a plurality of ball holes along the circumferential direction, and each steel ball is respectively installed in the ball holes of the cage, and each steel ball can roll freely in the ball hole. The inner ring of the bearing is provided with an arc groove corresponding to each steel ball, the cage is fastened to the outer ring of the bearing, and the outer ring of the bearing is fixed on the heat absorbing plate.

In the above scheme, the columnar spoiler element is welded with four guide vanes, and the four guide vanes are fixed on the columnar spoiler element along the curved surface, forming a vortex shape, and the guide vanes are perpendicular to the flow direction of the working medium to ensure that the air flow When flowing along the pipe, the fins can be driven to rotate at high speed, and the heat exchange working medium can be evenly mixed, greatly reducing the heat exchange cavity.

In the above solution, the columnar spoiler assembly is also coated with a heat-absorbing coating, which can increase the heat exchange area and absorb heat from solar radiation.

In the above scheme, the airflow inlet is composed of 2 rows and 4 rows of circular holes of the same size, and each circular hole is facing the corresponding guide vane. After the fan is started, the airflow flows along the upper row of circular holes to drive the guide vane to rotate; The flow blade guides the airflow flowing from the lower row of round holes. And take away the heat on the heat-absorbing plate, so that the airflow at different positions is fully mixed, and the degree of airflow mixing is further increased to fully exchange heat.

In the above scheme, the air outlet is composed of a row of four circular holes of the same size.

The present invention has the following beneficial effects:

1. The base of the turbulence assembly provided by the present invention acts as a protrusion of the heat absorbing plate, which can effectively destroy the boundary layer of the wall of the heat absorbing plate, improve the degree of turbulence, and enhance the heat transfer efficiency. The fan starts to introduce airflow into the heat collector, and when the airflow flows through the surface of the heat-absorbing plate, a boundary layer will be formed in the near-wall area due to the effect of viscosity. In the boundary layer, heat transfer mainly depends on heat conduction, because the thickness of the boundary layer has a great influence on heat transfer. The thinner the thickness, the smaller the thermal resistance and the more intense the heat transfer. The base of the spoiler assembly in the present invention is in direct contact with the wall surface of the heat absorbing plate, which can effectively destroy the boundary layer and enhance the degree of turbulent flow. Therefore, the present invention can effectively improve the heat transfer efficiency between the wall surface of the heat-absorbing plate and the heat-exchanging working medium.

2. The base of the spoiler assembly in the present invention adopts a deep groove ball bearing structure, the outer ring of the bearing is fixed on the heat absorbing plate, the inner ring of the bearing is connected with the columnar spoiler element, and there are multiple annular arrays between the inner and outer rings of the bearing. The cages are arranged in the same form, and the steel balls are installed in the pockets of the cage unit. This structure can ensure that the outer ring of the bearing is a fixed structure, and the inner ring of the bearing is a movable structure. When the airflow drives the ribs to rotate, it can reduce the sliding friction force generated when the inner ring of the bearing moves relative to each other, so that the ribs rotate at a high speed.

3. The side surface of the columnar spoiler component in the spoiler component of the present invention is welded with four guide sheets fixed at a certain angle and kept perpendicular to the flow direction of the heat exchange working medium. When the fan is started, the airflow is introduced into the collector channel. On the one hand, the airflow entering from the upper row inlet can drive the fins to rotate, and at the same time, the fins guide and transport the heat-exchanged airflow flowing through the lower row inlet to the upper layer of the heat exchange channel. The heat of the heat absorbing plate is efficiently and evenly transferred to all working fluids in the heat exchange channel. This is because the fluid will generate inertia when flowing, and the heat exchange working medium entering the heat exchange channel will maintain a lateral flow out of the heat exchange channel due to inertia, resulting in less heat for the heat exchange medium on the top layer, that is, the heat exchange in the heat exchange channel The heat obtained by the working fluid is uneven, and the fluid density is also uneven, resulting in different degrees of heat transfer. On the other hand, the rotating fins can effectively prevent impurities mixed in the airflow from accumulating on the surface of the heat-absorbing plate, increasing the absorption capacity of the heat-absorbing plate. This is because when the heat-exchanging working medium flows through the heat-exchanging channel, the impurity mixed inside will cover the surface of the heat-absorbing plate while flowing, making it difficult to clean the heat-absorbing plate, reducing the heat absorbed, and seriously affecting the heat collection efficiency. Therefore, the use of the rotating guide fin structure can fully exchange heat between the fluid that initially enters the channel and part of the fluid after heat exchange, and can also fully mix the fluid with a lower temperature after heat exchange and the fluid with a higher temperature, and then Make the fluid in the heat exchange channel exchange heat efficiently and absorb heat more evenly.

4. The upper part of the columnar spoiler assembly in the present invention is also coated with a heat-absorbing coating. After the fan is started, the airflow entering from the lower discharge inlet can not only exchange heat with the boundary layer on the surface of the heat-absorbing plate, but also exchange heat with the columnar spoiler assembly. heat exchange. It can further increase the absorption of solar radiation and the heat exchange with airflow.

5. Compared with the flat plate heat collector with fixed fin structure, the rotating diversion fin structure in the present invention can increase the contact area with the fins, and at the same time, it can further increase the exchange rate when the airflow drives the fins to rotate. The degree of mixing between the thermal working fluids enables it to obtain heat efficiently and uniformly.

Description of drawings

Fig. 1 is a front view of the present invention.

Fig. 2 is a diagram of the position of the air inlet flow channel of the plane A-A.

Fig. 3 is a position diagram of the air outlet flow channel of the B-B plane.

Figure 4 is a top view of the C-C plane.

Fig. 5 is a perspective view of a columnar spoiler assembly.

Fig. 6 is a structural diagram of the base of the spoiler assembly.

Fig. 7 is a structural view of the D-D plane in Fig. 6 .

In the figure: 1PC transparent cover plate, 2 fixed frame, 3 heat absorbing plate, 4 heat insulation layer, 5 aluminum metal shell, 6 columnar spoiler component, 7 base, 8 fan, 9 one-to-eight airflow duct, 10 airflow inlet, 11 air outlet, 6-1 guide vane, 6-2 columnar spoiler element, 7-1 bearing inner ring, 7-2 bearing outer ring, 7-3 cage, 7-4 steel ball.

Detailed ways

Below in conjunction with accompanying drawing, the present invention will be further described:

As shown in Figure 1-7, this high-efficiency flat-plate collector based on rotating fins includes a PC transparent cover plate 1, a fixed frame 2, a heat-absorbing plate 3, an aluminum metal shell 5, a columnar spoiler assembly 6, and an airflow inlet 10. The airflow outlet 11, the aluminum metal shell 5 is a shell with an open upper port, the inner wall of the aluminum metal shell 5 is provided with a thermal insulation layer 4, the heat absorbing plate 3 is laid horizontally on the bottom surface of the thermal insulation layer 4, and the columnar spoiler assembly 6 is vertical and horizontal Alternately arranged on the light-collecting surface of the heat-absorbing plate 3, the PC transparent cover plate 1 closes the upper port of the aluminum metal shell 5 and forms a heat collecting cavity, and the fixing frame 2 fixes the PC transparent cover plate 1 and the aluminum metal shell 5 from all sides Together; one side of the aluminum metal shell 5 is provided with an airflow inlet 10, and the other side is provided with an airflow outlet 11. The airflow inlet 10 is connected to the fan 8 through a one-to-eight airflow pipe 9, and the heat collection chamber is connected to the airflow inlet 10 and the airflow outlet 11 respectively. . The columnar turbulence components 6 are arranged vertically and horizontally on the heat absorbing plate 3, which can effectively destroy the wall boundary layer and further increase the degree of turbulence of the working medium.

The left and right sides of the thermal insulation layer 4 are higher than the upper surface of the heat absorbing plate 3, the PC transparent cover plate 1 is mounted on the upper part of the thermal insulation layer 4, the left and right sides, and the fixing frame 2 is mounted on the PC transparent cover plate 1 and the aluminum metal shell 5. The outside is used for fixing and sealing, and the airflow duct connects the blower fan 8 and the airflow inlet 10.

The columnar spoiler assembly 6 includes a columnar spoiler element 6-2, four guide vanes 6-1, and a base, and the four guide vanes 6-1 are fixed on the columnar spoiler element 6-2 along the circumferential direction, and the four guide vanes The flow vane 6-1 is rotated around the columnar spoiler 6-2, and the lower end surface of the columnar spoiler 6-2 is fixed on the bearing inner ring 7-1 of the base 7.

The base 7 of the cylindrical spoiler assembly 6 adopts a deep groove ball bearing structure, and the base 7 includes a bearing inner ring 7-1, a bearing outer ring 7-2, a cage 7-3, a plurality of steel balls 7-4, and a bearing outer ring 7 -2 is fixed on the heat-absorbing plate 3, the bearing inner ring 7-1 is connected with the columnar spoiler element 6-2, and between the inner and outer rings of the bearing is a cage 7-3 with a plurality of circular holes arranged in an annular array, steel balls 7-4 is installed in the circular hole of the cage 7-3, and the diameter is smaller than the circular hole, and the cage 7-3 is fastened to the bearing outer ring 7-2. This structure can ensure that the bearing outer ring 7-2 is a fixed structure, and the bearing inner ring 7-1 is a movable structure. At the same time, the steel balls 7-4 are evenly distributed between the inner and outer rings by means of the round holes of the cage 7-3 to prevent falling off. , can reduce the sliding friction generated by the inner ring of the bearing during relative motion, make the fins rotate at high speed, and reduce the pressure drop caused by the fins on the air flow; at the same time, it can effectively destroy the wall boundary layer. The base 7 adopts a deep groove ball bearing structure, which has a small dynamic friction coefficient and can bear radial load and axial load at the same time.

The bearing outer ring 7-2 of the spoiler assembly base and the heat absorbing plate 3 are fixed by welding, the cage 7-3 is fastened to the bearing outer ring 7-2, the bearing inner ring 7-1 is connected to the columnar spoiler element 6 The lower end face of -2 is fixed by welding.

The base adopts a deep groove ball bearing structure, and its rolling rotation method can reduce the resistance generated by the ribs when they rotate with the airflow, so that they can rotate at high speed.

The guide vanes 6-1 are ribs, which are guide sheets, and the four guide sheets are seamlessly welded to the side surface of the columnar spoiler element, and are perpendicular to the flow direction of the working medium inlet. When the fan is started, the external airflow flowing in from the upper row inlet enters the heat collecting chamber of the heat collector along with the pipe, and the kinetic energy generated by it drives the fins to rotate and generate a vortex, which increases the degree of airflow mixing. The diversion sheet can guide the heat-exchanged airflow entering the lower row inlet, so that the fluid entering the channel at the initial stage can fully exchange heat with the partially heat-exchanged fluid, and can also make the fluid with a lower temperature after heat exchange The fluid is fully mixed with the higher temperature fluid to make the heat exchange more uniform.

Both the columnar spoiler assembly 6 and the heat-absorbing plate 3 are coated with a heat-absorbing coating, which further increases the heat-absorbing heat of the heat-absorbing plate to solar radiation and the heat exchange with the heat-exchanging airflow.

The airflow inlet is 2 rows and 4 rows of round holes with the same size, and the position of the round hole inlet is facing the guide vanes 6-1 of the rotating fins. Each airflow inlet 10 is connected to the fan 8 through the one-to-eight airflow duct 9. After the fan 8 is started, the airflow flows along the upper row of round holes to drive the fins to rotate; at the same time, the guide vanes 6-1 will carry out the airflow flowing from the lower row of round holes. Guide the flow and take away the heat on the heat-absorbing plate, so that the airflow at different positions is fully mixed, and the degree of airflow mixing is further increased to fully exchange heat. The air outlet consists of a row of four round holes of the same size.

Working principle of the present invention:

In the present invention, columnar spoiler components 6 with bases 7 are fixed vertically and horizontally on the heat absorbing plate. The base of the fins adopts a deep groove ball bearing structure, and the bearing inner ring 7-1 is connected to the bottom of the columnar spoiler element 6-2. The end face, its side surface is welded with four diversion sheets fixed at a certain inclination and kept rotating, and kept perpendicular to the flow direction of the working fluid. The use of this component can maximize the contact area and mixing degree of the heat exchange working fluid. When the fan starts and the airflow flows into the channel, on the one hand, it can drive the fins to rotate, increase the contact area and the degree of mixing, so that the heat exchange medium in each part of the heat exchange channel can obtain heat efficiently and evenly, and solve the problem of heat exchange in the heat exchange channel. Longitudinal flow of working medium; on the other hand, the base adopts a deep groove ball bearing structure, which rotates in a rolling manner, which can reduce the sliding friction generated when the inner ring of the bearing rotates, and ensure that the rib can rotate at high speed; it can also be used as The protrusions of the heat-absorbing plate destroy the surface boundary layer and increase the degree of turbulence; moreover, in addition to the heat-absorbing plate 3, the columnar spoiler assembly 6 is also coated with a heat-absorbing coating, which can increase the heat exchange area and absorb heat from solar radiation .

In the present invention, the rotating fins can use the kinetic energy generated when the airflow flows to drive the fins to rotate, ensuring that the airflow is fully mixed, increasing the heat exchange area, enhancing the heat exchange effect, and realizing efficient heat exchange of the solar panel heat collector.

The structure of the turbulence device in the present invention is simple and easy to assemble. The fins can not only destroy the laminar boundary layer, but also strengthen the exchange of mass and momentum between the fluid microgroups in the boundary layer and the microgroups in the mainstream area. The sliding friction force generated when the fins rotate and the pressure drop caused by the fins to the air flow make the fins rotate at a high speed, further improving the mixing degree and contact area of the heat exchange working medium. Coated with a heat-absorbing coating to increase the absorption of solar radiation and the heat exchange between the airflow. Therefore, the rotating fin spoiler can not only enhance the heat transfer efficiency of the heat collector, but also enable the heat exchange medium to obtain heat efficiently and uniformly, and improve the heat utilization rate of the heat collector.

The invention solves the problems of uneven heat exchange between the heat exchange airflow and the heat-absorbing plate 3 and large pressure drop between the heat exchange airflow and the fixed fins in the existing heat exchange channel of the flat plate heat collector adopting the fixed fin structure. question. In the present invention, the fan 8 introduces airflow into the heat collector, and the airflow drives the fins to rotate, which can not only enhance the degree of air mixing, but also greatly reduce heat exchange cavities and airflow pressure drop.

Claims (5)

1. A high-efficiency flat-plate heat collector based on rotating fins, characterized in that: this high-efficiency flat-plate heat collector based on rotating fins includes a PC transparent cover plate, a fixed frame, a heat-absorbing plate, an aluminum metal shell, a columnar disturbance Flow components, air inlet, air outlet, the aluminum metal shell is a shell with an open upper port, the inner wall of the aluminum metal shell is provided with a thermal insulation layer, the heat absorbing plate is laid horizontally on the bottom surface of the thermal insulation layer, and the columnar spoiler components are arranged vertically and horizontally. On the light-collecting surface of the heat-absorbing plate, the PC transparent cover closes the upper port of the aluminum metal casing to form a heat collecting cavity, and the fixing frame fixes the PC transparent cover and the aluminum metal casing together from all sides; one side of the aluminum metal casing is set Airflow inlet, airflow outlet is set on the other side, the airflow inlet is connected with the fan, and the heat collecting chamber is connected with the airflow inlet and airflow outlet respectively; The columnar spoiler assembly includes a columnar spoiler element, a plurality of guide vanes, and a base, and the plurality of guide vanes are fixed on the columnar spoiler element along the circumferential direction, and the plurality of guide vanes are rotated around the columnar spoiler element, The lower end surface of the columnar spoiler element is fixed on the bearing inner ring of the base; the base adopts a deep groove ball bearing structure, and the base includes a bearing inner ring, a bearing outer ring, a cage, a plurality of steel balls, and the bearing inner ring and the bearing outer ring. There is a cage in between, the cage is cylindrical, and the body of the cage is evenly equipped with a plurality of ball holes along the circumferential direction, and each steel ball is respectively installed in the ball holes of the cage, and each steel ball can roll freely in the ball hole. The inner ring of the bearing is provided with an arc groove corresponding to each steel ball, the cage is fastened to the outer ring of the bearing, and the outer ring of the bearing is fixed on the heat absorbing plate. 2. The high-efficiency flat-plate heat collector based on rotating fins according to claim 1, characterized in that: the columnar spoiler element is welded with four guide vanes, and the four guide vanes are fixed to the columnar spoiler along the curved surface. On the flow element, a vortex shape is formed, and the guide vanes are perpendicular to the flow direction of the working medium. 3. The high-efficiency flat-plate heat collector based on rotating fins according to claim 2, characterized in that: the columnar spoiler assembly is also coated with a heat-absorbing coating. 4. The high-efficiency flat-plate heat collector based on rotating fins according to claim 3, characterized in that: the airflow inlet is composed of 2 rows and 4 columns of round holes of the same size, and each round hole is facing the corresponding Guide vanes, after the fan is started, the airflow flows along the upper row of round holes to drive the guide vanes to rotate; at the same time, the guide vanes guide the airflow flowing from the lower row of round holes, and take away the heat on the heat absorbing plate, so that The airflow at different positions is fully mixed, increasing the degree of airflow mixing and fully exchanging heat. 5. The high-efficiency flat-plate heat collector based on rotating fins according to claim 4, characterized in that: the air outlet is composed of a row of four circular holes of the same size.

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