CN201837088U - Double-flow flat-plate type solar air heat collector - Google Patents

Abstract

The utility model relates to a double-flow planar solar air heat collector, which belongs to the energy-saving technical field. The solar air heat collector is composed of a hot air outlet, an upper header, an air inlet, a transparent glass cover plate, a finned tube, a solar spectrum selective absorption coating, a back plate, an insulation board and a collector frame. The upper end of each finned tube is connected with the upper header to form a flat heat absorbing plate. The transparent glass cover plate is placed above the heat absorbing plate through the frame of the heat collector, and the cavity between the glass cover plate and the heat absorbing plate is used as the first process of heat exchange between the air and the heat collecting plate. The inner space of each finned tube is used as the second process of heat exchange between the air and the heat collecting plate. The utility model can effectively increase the heat exchange process and area of the air, has excellent convective heat exchange performance between the air and the heat exchange wall, has strong practicability, and can be widely used in the fields of building heating, agricultural products and food drying, etc.

Description

A dual-flow flat-plate solar air collector

technical field

The utility model relates to a double-flow flat-plate solar air heat collector used for heating or hot air drying, which belongs to the energy-saving technical field. the

Background technique

The inexhaustible solar radiation resource is one of the most important renewable energy sources in the world. Rational development and utilization of solar energy can effectively reduce the use of conventional energy, which is of great significance to energy conservation and emission reduction. The solar air collector is an important component of the solar thermal conversion and utilization system. Due to the advantages of low manufacturing cost, corrosion resistance, and low pressure requirements on the system, solar air collectors have very broad application prospects in building heating, agricultural products, and food drying. At present, solar air collectors can be divided into two categories: permeable and non-permeable. The permeable solar air heat collector adopts a porous mesh solar heat absorber, and the air is heated when it flows through the porous mesh solar heat absorber, thereby generating hot air. Non-permeable solar air collectors use metal plates or glass tubes sprayed with solar absorbing coatings as heat-absorbing components, and the air is heated when it flows through one side of the metal plates or glass tubes, thereby generating hot air. the

Solar air collectors use air as the heat transfer medium. Due to the low density of air (only 1/300 of water), small heat capacity (only 1/4 of water), and small thermal conductivity (only 1/25 to 1/20 of water), air flows through solar air The convective heat transfer coefficient between the air and the heat exchange wall is low during the collector, which leads to the low heat collection efficiency of the solar air collector. Therefore, rationally improving the air channel structure of the solar air collector and strengthening the convective heat transfer performance between the air and the heat exchange wall become the key to improving the light-to-heat conversion efficiency and heat collection efficiency of the solar air collector. the

Contents of the invention

The purpose of this utility model is to improve the air channel structure of the solar air heat collector, strengthen the convective heat transfer performance between the air and the heat exchange wall, so as to effectively improve the light-to-heat conversion efficiency and heat collection efficiency of the solar air heat collector. the

The purpose of this utility model is achieved through the following technical solutions: a flat plate composed of multiple finned tubes is used as a heat-absorbing component, and a solar spectrum selective absorption coating is sprayed on the surface of the finned tubes to improve the efficiency of solar radiation absorption. Solar air collectors. the

In the technical scheme of the utility model double-flow flat-plate solar air heat collector, the air heat collector consists of a hot air outlet (1), an upper header (2), an air inlet (3), a transparent glass cover plate (4), Finned tube (5), solar spectrum selective absorption coating (6), back plate (7), insulation board (8), air collector frame (9) components and fan components; finned tube (5) The upper end of the fan is connected with the upper header (2), the hot air outlet (1) is connected with the middle part of the upper header (2), and the fan is connected with the hot air outlet (1). the

The transparent glass cover plate (4) is placed above the heat absorbing plate formed by the finned tubes (5) through the frame (9) of the air heat collector, and the cavity between the transparent glass cover plate (4) and the heat absorbing plate The heat exchange cavity of the first process is formed for the heat exchange between the air and the heat absorbing plate; the space inside the tube of the finned tube (5) forms the heat exchange cavity of the second process for the heat exchange between the air and the heat collecting plate. the

The working principle of the double-flow flat-plate solar air collector is: the solar radiation is projected on the heat absorbing plate through the glass cover plate, and the heat absorbing plate absorbs the solar radiation energy, and the temperature rises. Under the traction of the fan, the air first flows through the finned tube outside the tube from top to bottom (that is, the first process), and is preliminarily heated. When the air flows to the lower part of the heat collector, it flows through the finned tube from the bottom to the top (that is, the second process) to be further heated. The air flowing in the tube is in a vigorous turbulent state, which can improve the convective heat transfer performance between the air and the heat exchange wall. After the air is heated by two processes, it is collected in the upper header, and then flows out of the heat collector through the hot air outlet. the

The utility model has a reasonably designed structure of the solar air heat collector, the air of which is drawn by the fan firstly flows through the finned tube outside the tube from top to bottom, and then flows through the finned tube in the tube from bottom to top. The air is heated by two processes and flows out of the collectors, thus generating hot air. the

The utility model can effectively increase the heat exchange process and area of the air, has excellent convective heat exchange performance between the air and the heat exchange wall, has strong practicability, and can be widely used in the fields of building heating, agricultural products and food drying, etc. the

Description of drawings

Below in conjunction with accompanying drawing and embodiment the utility model is further described. the

Figure 1 is a schematic diagram of the structure of a double-flow flat-plate solar air heat collector. the

Fig. 2 is a schematic diagram of direction A in Fig. 1 . the

The numbers in the figure indicate in order: 1-hot air outlet, 2-upper header, 3-air inlet, 4-transparent glass cover, 5-finned tube, 6-solar spectrum selective absorption coating, 7-back plate , 8-insulation board, 9-collector frame. the

Detailed ways

The structural diagram of the double-flow flat-plate solar air collector is shown in Figure 1. The double-flow flat-plate solar air collector consists of a hot air outlet, an upper header, an air inlet, a transparent glass cover, finned tubes, and a selective absorption of solar spectrum. Coating, backboard, insulation board and collector frame. The solar spectrum selective absorption coating is sprayed on the surface of the finned tube. The upper end of each finned tube is connected with the upper header to form a flat heat absorbing plate. The hot air outlet is connected to the middle of the upper header. The transparent glass cover plate is placed above the heat absorbing plate composed of finned tubes through the frame, and the cavity between the glass cover plate and the heat absorbing plate is used as the first process of heat exchange between air and the heat collecting plate. The inner space of each finned tube is used as the second process of heat exchange between the air and the heat collecting plate. An insulation board is arranged under the heat absorbing plate and around the frame of the heat collector. The back plate is placed under the insulation board through the frame of the collector. the

The finned tube 5 is made of all-aluminum finned tube or copper-aluminum composite finned tube, the frame of the heat collector is made of aluminum profile, and the insulation board is made of polystyrene foam board or polyurethane. The height of the cavity between the transparent glass cover plate 4 and the heat-absorbing plate is 1.5-3 cm, and the thickness of the insulation board is 2.5-5.0 cm. the

The solar spectrum selective absorption coating 6 is sprayed on the surface of the finned tube 5 to improve the photothermal conversion efficiency of the heat collector to the solar radiant energy. The upper end of each finned tube 5 is connected with the upper header 2 to form a flat heat absorbing plate. The hot air outlet 1 is connected with the middle part of the upper header 2 . The air flowing out from the finned tube 5 first gathers in the upper header 2, and then flows out of the heat collector through the air outlet 1. The transparent glass cover plate 4 is placed above the heat absorbing plate made of finned tubes 5 through the heat collector frame 9, and the cavity between the transparent glass cover plate 4 and the heat absorbing plate is used as a space for heat exchange between the air and the heat absorbing plate. first process. The tube inner space of each finned tube 5 is used as the second flow process of air and heat-collecting plate heat exchange. Thermal insulation boards 8 are arranged below the heat-absorbing plate and around the frame 9 of the heat collector. The back plate 7 is placed under the insulation board 8 through the collector frame 9 . the

Claims (2)

1. double-current journey plate type solar air collector, it is characterized in that: air collector is made up of hot air outlet (1), upper header (2), air intake (3), clear glass cover plate (4), finned tube (5), solar spectral selective absorbing coating (6), backboard (7), warming plate (8), air collector frame (9) parts and fan part; The upper end of finned tube (5) links to each other with upper header (2), and hot air outlet (1) links to each other with the middle part of upper header (2), and blower fan and hot air outlet (1) join.

2. double-current journey plate type solar air collector according to claim 1, it is characterized in that: the frame (9) of clear glass cover plate (4) by air collector places the top of the absorber plate that is made of finned tube (5), and the cavity between clear glass cover plate (4) and the absorber plate constitutes first flow process heat exchange cavity of air and absorber plate heat exchange; The space constitutes second flow process heat exchange cavity of air and the heat exchange of thermal-arrest plate in the pipe of finned tube (5).

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