Flat panel solar water heater solar water heaters as the main product types, its superiority at home and abroad, especially the history of the application of foreign countries for many years. In recent years, in China, the flat plate solar water heater market share is gradually increasing. Manufacturers for the production of flat plate solar collectors will be increased.
In order to better promote the flat plate china solar water heater, we should improve the performance and quality of the flat plate solar collectors, it is necessary to improve its thermal performance, but also improve its durability, reliability, or even to improve the quality of its appearance.
Improve the performance of flat plate solar collectors and the way of quality are many and this article only in respect of the phenolic composite insulation board and its application to explore the optimized design of the flat plate solar collectors with thermal insulating layer.
Two flat plate solar collectors and insulation measures
Flat-plate solar collector is mainly composed of: 1. Absorber plate. Transparent cover. Insulation and the shell composed of several parts (Figure 1).
The insulation layer is to inhibit the absorber plate collector through the pass-oriented ambient cooling components. Generally used for thermal insulation layer of material such as rock wool, glass wool, polyurethane, polystyrene. Currently using more glass wool or polyurethane foam. Use of polyurethane foam generally will be a layer of rock wool or glass wool, polyurethane, polystyrene and other materials with low thermal conductivity, but are not high temperature, usually 90 ° C will begin to shrink, the impact of flat solar collectors thermal insulation properties and use.
The thickness of the insulation layer should be based on the selection of the types of materials, the operating temperature of the collector, the use of regional climate conditions and other factors to determine. Should follow such a principle: the greater the thermal conductivity of the material, the higher the operating temperature of the collector, the lower the temperature region, the thickness of the insulation requirements of the greater. In general, the thickness of the insulating layer at the bottom of selected 30 ~ 50mm, about the same side of the insulation layer thickness.
There enclosure backplane generally use about 0.4mm galvanized steel or aluminum and other materials. Fixed together by rivets and side of the border profiles.
At present, these insulation in the form, although not much of a problem, but still has some drawbacks. First of all, glass wool, rock wool and other materials, there is a small fiber, resulting in the workshop and production operations of workers unsanitary not ring temperature performance is limited, compared with polyurethane foam class insulation material or a certain gap. The use of polyurethane foam, have relatively high requirements of the technology, equipment, personnel, and polyurethane is also faced with issues such as CFC-free foam. Another point is that the rivets back plate there is a certain "loose", does not affect the use, but easy for the customer to the product appearance and quality of "cut points".
3 phenolic compound insulation board in the flat
The general structure of the solar collectors on the phenolic composite insulation board: under the surface of galvanized steel or aluminum, in the middle of phenolic foam insulation layer on the surface of aluminum foil. Its application in flat plate solar collectors is also very simple, direct phenolic compound insulation board fixed to the side of the border by rivets or other forms of can. The insulation board used in the set of flat plate solar
Characteristics in the heat: First, a new type of phenolic foam as the insulation material; is the phenolic foam has been preformed, and the insulation board composite back plate of the collector. Why phenolic foam insulation materials, phenolic foam is a highly effective fire insulation materials, known as the "third generation of new insulation materials, has been widely used in various fields at home and abroad. It has better insulation than glass wool, and the temperature reached 180 ° C, and contain no fiber, clean, environmentally friendly, CFC-free foam insulation materials.
Why recommend the use of composite galvanized steel or aluminum steel surface phenolic composite insulation board, insulation layer and the backplane steel plate composite together to simplify the production process of the manufacturers, so that the back of the collector have high strength .
4 a comparative analysis of all aspects of technology, performance and other
Be seen from Figure 1, the use of phenolic composite insulation board to give the flat plate solar collectors to bring improvement and change in quality, performance and appearance. The phenolic compound insulation board is a material well suited for flat plate solar collectors.
Solar water heater products universal homogenization of today, we have the need for technical innovation. Products of flat plate solar collectors on the phenolic composite insulation board, not only can improve the insulation performance of the collector, and simplify the process, more environmentally friendly, look more beautiful in the flat plate solar collectors on the product and should therefore be vigorously promote the use of a phenolic compound insulation board.