Enhanced heat transfer type solar air heat collector

Abstract

An enhanced heat transfer type solar air heat collector relates to a solar heat collector and comprises a heat collector body, a straight-through flow channel is arranged in the heat collector body, and a heat absorbing plate is mounted above the straight-through flow channel; the screw pitch P of the spiral fin ranges from 10 mm to 80 mm, the width K of the spiral fin ranges from 10 mm to 20 mm, the diameter D of a middle hole ranges from 5 mm to 10 mm, and the length L of the spiral fin ranges from 300 mm to 800 mm. The length L1 * width K1 * height H1 of the straight-through flow channel is (300-800) mm * (100-500) mm * (10-40) mm, and the length L1 * width K2 * height H2 of the heat absorbing plate is (300-800) mm * (150-550) mm * (0.5-1) mm. According to the utility model, the spiral fins are arranged in the straight-through flow channel, so that the improvement of the thermal performance of the solar air heat collector can be promoted, the heat collection efficiency is improved, and the carbon emission is reduced; compared with a spiral air duct, useless consumption of fan conveying power can be reduced, and heat resistance of a heat transfer boundary layer of the heat collector is damaged.

Description

Technical Field

[0001] The utility model relates to a solar heat collector, in particular to an enhanced heat transfer type solar air heat collector. Background Art

[0002] With the continuous development of society, energy problems have become increasingly prominent, the energy crisis has intensified, and the rising energy prices, decreasing energy access and energy security issues are changing the global energy landscape. Energy is the key to modern life, the cornerstone of sustainable economic and social development, and an important strategic resource that all countries are extremely concerned about. Against the background of the increasing depletion of fossil energy and the increasingly serious environmental problems caused by the use of fossil energy, the development and use of clean energy has begun to become the focus of attention of countries around the world. Solar energy is an inexhaustible, environmentally friendly clean energy. Solar air collectors are heat collectors that use heat-absorbing materials to absorb solar radiation heat to heat the air.

[0003] The inner wall of the traditional solar air collector is smooth, and the heat transfer coefficient of air is small. These factors make the traditional solar air collector have limitations such as low heat collection efficiency. Comparative Document 1 - The invention patent application with application publication number CN102721190A discloses a spiral duct type solar air collector, which has the following shortcomings: although the collector integrates the duct wall and the heat exchange plate for sharing, the contact area between the duct wall and the light receiving surface is small, so the heat exchange effect is small. Secondly, the duct is a spiral duct, which extends the length of the duct, making the fan transmission power required to drive the operation of the solar air collector uselessly consumed. At the same time, the collector does not solve the problem of the boundary layer thermal resistance of the traditional solar air collector hindering the heat flow propagation, that is, the problem of low heat transfer efficiency. Summary of the invention

[0004] The technical problem to be solved by the utility model is to provide a heat transfer enhanced solar air collector so as to solve the problems of low heat collection efficiency, large useless consumption of fan transmission power and boundary layer thermal resistance hindering heat flow propagation existing in the prior art.

[0005] The technical solution to solve the above technical problems is: a heat transfer enhanced solar air collector, including a collector body, a straight flow channel is provided in the collector body, and a heat absorption plate is installed above the straight flow channel; at least one spiral fin for enhancing heat transfer is installed in the straight flow channel along its longitudinal direction.

[0006] A further technical solution of the utility model is: there are multiple spiral fins, and the multiple spiral fins are installed in parallel.

[0007] A further technical solution of the utility model is: the pitch P of the spiral fin is 10-80 mm, the width K is 10-20 mm, the center hole diameter D is 5-10 mm, and the length L of the spiral fin is 300-800 mm; the dimensions of the straight flow channel are length L1×width K1×height H1: (300-800) mm×(100-500) mm×(10-40) mm, and the dimensions of the heat absorption plate are length L1×width K2×height H2: (300-800) mm×(150-550) mm×(0.5-1) mm.

[0008] A further technical solution of the utility model is: the spiral fin is a small pitch spiral fin, the pitch P is 10-30mm, the width K is 10-20mm, the center hole diameter D is 5-10mm, and the spiral fin length L is 300-800mm.

[0009] A further technical solution of the utility model is: the spiral fin is a large-pitch spiral fin, the pitch P is 40-80 mm, the width K is 10-20 mm, the center hole diameter D is 5-10 mm, and the length L of the spiral fin is 300-800 mm.

[0010] Due to the above structure, the enhanced heat transfer type solar air collector of the utility model has the following beneficial effects compared with the prior art:

[0011] 1. High heat collection efficiency

[0012] The utility model has at least one spiral fin for enhancing heat transfer installed in the straight flow channel along the longitudinal direction thereof. The spiral fin structure has excellent fluid mixing and replacement functions. The spiral fin can induce a longitudinal vortex in the solar air collector. Due to the destructive effect of the longitudinal vortex on the heat transfer boundary layer and the long-distance fluid mixing ability, the enhanced heat transfer of the solar air collector is achieved, thereby improving the efficiency of solar thermal utilization.

[0013] Furthermore, the parallel installation of multiple spiral fins in the present invention can enhance heat transfer, thereby further significantly improving the energy absorption efficiency of the working air fluid.

[0014] 2. Reduce carbon emissions

[0015] The utility model can promote the improvement of the thermal performance of the solar air collector and reduce carbon emissions by arranging spiral fins in the straight flow channel.

[0016] 3. It can reduce the useless consumption of fan transmission power and destroy the thermal resistance of the collector heat transfer boundary layer

[0017] The present application adopts a method of adding spiral fins to a straight flow channel to enhance the heat transfer of a solar air collector. Compared with the spiral flow channel, the straight flow channel reduces the useless consumption of the fan transmission power required by the collector. At the same time, the application of the spiral fins induces longitudinal vortices and destroys the thermal resistance of the heat transfer boundary layer of the collector.

[0018] The technical features of the enhanced heat transfer solar air collector of the utility model are further described below in conjunction with the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 : A schematic diagram of the three-dimensional structure of an enhanced heat transfer type solar air collector according to the first embodiment,

[0020] Figure 2 : A schematic diagram of the three-dimensional structure of an enhanced heat transfer type solar air collector according to the second embodiment,

[0021] Figure 3 : The front view of the collector body described in embodiments 1 and 2,

[0022] Figure 4 : Figure 3 A top view of

[0023] Figure 5 : Figure 3 The left view of

[0024] Figure 6 : Schematic diagram of the three-dimensional structure of the collector body described in Examples 1 and 2;

[0025] Figure 7 : The front view of the spiral fins described in Examples 1 and 2,

[0026] Figure 8 : Figure 7 Left view of

[0027] Fig. 9 : Schematic diagram of the three-dimensional structure of the spiral fins described in Examples 1 and 2;

[0028] In the above drawings, the descriptions of the reference numerals are as follows:

[0029] 1-collector body, 101-straight flow channel, 2-heat absorbing plate, 3-spiral fins, 4-wire rope. DETAILED DESCRIPTION Embodiment 1:

[0030] A heat transfer enhanced solar air collector comprises a collector body 1, a straight flow channel 101 is arranged in the collector body 1, a heat absorbing plate 2 is installed above the straight flow channel 101; three spiral fins 3 for enhancing heat transfer are installed in the straight flow channel 101 along its longitudinal direction, the three spiral fins 3 are installed in parallel at equal distances, and both ends of the three spiral fins 3 are suspended and fixed on the heat absorbing plate 2 by steel wire ropes 4.

[0031] The dimensions of the straight-through flow channel are length L1×width K1×height H1: 600mm×300mm×20mm, and the dimensions of the heat absorbing plate are length L1×width K2×height H2: 600mm×300mm×0.5mm.

[0032] The spiral fin is a small pitch spiral fin, with a pitch P of 20 mm, a width K of 15 mm, a center hole diameter D of 7.5 mm, and a spiral fin length L of 500 mm.

[0033] When working, the heat absorbing plate is exposed to the sun and absorbs the sun's radiation energy, which is converted into heat energy to heat the air in the solar air collector. Under the action of the spiral fins, longitudinal vortices are generated when the air flows through the spiral fins, which destroy the heat transfer boundary layer near the wall of the heat absorbing plate and achieve enhanced heat transfer. The disturbance of the longitudinal vortex promotes the mixing of the mainstream fluid and the boundary fluid and improves the heating efficiency. At the same time, due to the obstruction of the spiral fins, the heating time of the air in the solar air collector is prolonged. Embodiment 2:

[0034] A heat transfer enhanced solar air collector comprises a straight flow channel 101 and a heat absorbing plate 2; four spiral fins 3 for enhancing heat transfer are installed in the straight flow channel 101 along its longitudinal direction, and the four spiral fins 3 are installed in parallel at equal distances; and both ends of the four spiral fins 3 are suspended and fixed on the heat absorbing plate 2 by steel wire ropes.

[0035] The dimensions of the straight-through flow channel are length L1×width K1×height H1: 600mm×300mm×20mm, and the dimensions of the heat absorbing plate are length L1×width K2×height H2: 600mm×300mm×0.5mm.

[0036] The spiral fin is a large-pitch spiral fin, with a pitch P of 50 mm, a width K of 15 mm, a center hole diameter D of 7.5 mm, and a spiral fin length L of 500 mm.

[0037] The application method of the second embodiment is the same as that of the first embodiment; compared with the small pitch spiral fins, the large pitch spiral fins can reduce the power of the fan that transports air to the solar air collector, which helps to improve the comprehensive performance of the solar air collector.

[0038] As a variation of the first and second embodiments, the spiral fin pitch P is any value between 10 and 80 mm, the width K is any value between 10 and 20 mm, the center hole diameter D is any value between 5 and 10 mm, and the spiral fin length L is any value between 300 and 800 mm; the straight flow channel dimensions of length L1×width K1×height H1 are: (300-800) mm×(100-500) mm×(10-40) mm, and the heat absorption plate dimensions of length L1×width K2×height H2 are (300-800) mm×(150-550) mm×(0.5-1) mm.

[0039] The working principle of the utility model is as follows: The utility model arranges spiral fins in the solar air collector, taking into account that the traditional solar air collector will form a large boundary layer thermal resistance during operation, which hinders the propagation of heat flow. The utility model strengthens the heat transfer of the traditional solar air collector by destroying the boundary layer thermal resistance. Different from the traditional use of spiral fins to increase the contact area for heating and heat dissipation, the spiral fins designed in the utility model not only increase the heat exchange area but also have a turbulent effect on the working fluid, induce longitudinal vortices to destroy the boundary layer thermal resistance, achieve enhanced heat transfer, and thus improve the heat transfer efficiency of the solar air collector.

Claims

1. A solar air collector with enhanced heat transfer, comprising a collector body (1), characterized in that: A straight flow channel (101) is provided in the heat collector body (1), and a heat absorbing plate (2) is installed above the straight flow channel (101); at least one spiral fin (3) for enhancing heat transfer is installed in the straight flow channel (101) along its longitudinal direction.

2. The enhanced heat transfer type solar air collector according to claim 1, characterized in that: There are a plurality of spiral fins (3), and the plurality of spiral fins (3) are installed in parallel.

3. The enhanced heat transfer type solar air collector according to claim 1, characterized in that: The spiral fin (3) has a pitch P of 10 to 80 mm, a width K of 10 to 20 mm, a center hole diameter D of 5 to 10 mm, and a spiral fin length L of 300 to 800 mm; the straight flow channel has a dimension of length L1×width K1×height H1 of (300 to 800) mm×(100 to 500) mm×(10 to 40) mm; the heat absorption plate has a dimension of length L1×width K2×height H2 of (300 to 800) mm×(150 to 550) mm×(0.5 to 1) mm.

4. The enhanced heat transfer type solar air collector according to claim 3, characterized in that: The spiral fin (3) is a small pitch spiral fin, with a pitch P of 10 to 30 mm, a width K of 10 to 20 mm, a center hole diameter D of 5 to 10 mm, and a spiral fin length L of 300 to 800 mm.

5. The enhanced heat transfer type solar air collector according to claim 3, characterized in that: The spiral fin (3) is a large-pitch spiral fin, with a pitch P of 40 to 80 mm, a width K of 10 to 20 mm, a center hole diameter D of 5 to 10 mm, and a length L of the spiral fin of 300 to 800 mm.

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