The refrigeration and heat preservation performance of the refrigerated truck is determined by the refrigeration capacity of the refrigerator unit of the Kelly refrigerated truck and the heat insulation performance of the compartment. Usually, the selection of the refrigeration capacity of the refrigeration unit mainly considers factors such as the volume of the refrigerated vehicle compartment, the temperature requirements of the goods being transported, and the transportation distance. The refrigerated car body plays a decisive role in maintaining the temperature in the car compartment and effectively isolating the external heat source. Therefore, the heat insulation performance of the car body determines the special performance of the refrigerated car which is different from the ordinary van truck.
The measures to improve the insulation performance of refrigerated trucks mainly include the following aspects.
1. Optimize the selection of core materials
Improving the insulation performance of refrigerated trucks requires optimizing the choice of core materials. R&D personnel of refrigerated trucks should actively optimize the selection of core materials, using powder, foam, glass fiber, and aerogel materials. Among them, the thermal conductivity of glass fiber materials is very low, and the glass fiber will deteriorate after the temperature exceeds 100°C. In addition, glass fiber materials will deform after vacuuming. If the air barrier structure is damaged during use, the thermal conductivity will increase, which will make it difficult to improve the insulation performance of the refrigerated truck. It is not recommended to use glass fiber core materials; powder materials The production cost is high, the hygroscopicity is poor, the number of aerogel core materials is very small, and the production cost is high. It is not recommended to use powder materials and aerogel materials; foam materials have low density and heat insulation Good performance, low cost, easy operation, no pollution, etc., is the best core material making material.
2. Reasonable selection of gas adsorption materials
At present, there are various kinds of getters on the market. From the point of view of production process, it is considered that Italian SAES getter is a better gas adsorbent. SAES getter can achieve the inhalation effect at room temperature, mainly using the adsorption effect of cobalt oxide, calcium oxide, barium oxide, and barium-lithium alloy to absorb gas, and the inhalation effect is better. Although the SAES getter already includes a dryer and a getter, it is necessary to reserve a hole for placing the SAES getter during the production of the core material, and perform vacuum packaging treatment in time to prevent the getter from failing.
3. Vacuum packaging
Improving the insulation performance of refrigerated trucks requires vacuum packaging. At this stage, the vacuum packaging machine on the market can reach a vacuum of 650Pa, but this vacuum cannot meet the technical requirements of VIP. Therefore, it is necessary to modify the vacuum packaging machines on the market, and transform the original vacuum packaging vacuum pumps into two-stage suction vacuum pumps to make the vacuum degree below 10Pa and meet the technical requirements for vacuum packaging of refrigerated trucks.
4. Choose a suitable surface diaphragm
To improve the insulation performance of refrigerated trucks, it is necessary to choose a suitable surface diaphragm, and the surface diaphragm of the vacuum insulation board of refrigerated trucks must have good durability, good sealing performance, strong resistance to air permeability, and better moisture permeability. Low thermal conductivity. At this stage, the commonly used air barrier structural materials on the market mainly include polyvinyl chloride film, polyethylene film, polyester film, aluminized film, etc. Polyvinyl chloride film has strong mechanical strength, good heat sealability, and price It is cheap and consumes less energy. Polyethylene film is resistant to low temperature, high strength, and moisture-proof. Aluminized film is fragile and easily damaged. Therefore, the surface diaphragm of refrigerated vehicle insulation board can choose polyvinyl chloride film or polyethylene film. Such as gas barrier structure materials, can not use fragile aluminized film.
