First, what is
Boiler tubes are used in fire-tube boiler, a type of boiler in which hot gases from a fire pass through one or more tubes running through a sealed container of water.
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It is equipped with a compartment with a thermal insulation structure and a refrigeration unit for a private van for refrigerated transport.
Second, the classification of refrigerated trucks
Refrigerated cars are actually called refrigerated cars. They are divided into refrigerated trucks and insulated cars. Insulation cars are cars with insulated cars that are suitable for short-distance heat preservation and transportation. A refrigerated car is a car that has an insulated car and is equipped with a refrigeration device.
According to the refrigeration method of refrigeration equipment, mechanical refrigerated trucks, frozen-plate refrigerated vehicles, liquid-nitrogen refrigerated trucks, dry ice refrigerated vehicles, ice-cold refrigerated vehicles, etc. Among them, mechanical refrigerated vehicles are the main models in refrigerated trucks, and most domestic refrigerated trucks are also It is a mechanical refrigerator car.
According to the chassis carrying capacity classification: micro-refrigerated cars, small refrigerators, medium-sized refrigerated trucks, large-scale refrigerated trucks.
By compartment type: bread-type refrigerated trucks, van-type refrigerated trucks, semi-trailer refrigerated trucks.
Third, the domestic major refrigerated truck manufacturers
Xiamen Xigong Chu Sheng, Hubei Cheng Li, Zhengzhou Hongyu, Henan Ice Bear, Henan Xinfei, Zhenjiang Feichi, Beijing Chenguang Tianyun and so on.
Fourth, the composition of the refrigerated truck
The refrigerated truck is mainly composed of an automobile chassis, a heat insulation and insulation body, a refrigeration unit, and a temperature recorder in the compartment. For vehicles with special requirements, such as meat hooks, meat hooks, belts, aluminum alloy rails, ventilation slots can be installed. And other options.
Refrigerated truck chassis: The common domestic refrigerator truck chassis is mainly liberation, Dongfeng, Qingling, Jiangling, Jianghuai, Futian and so on.
Refrigerated car body: Generally made of polyurethane materials, glass steel, but also color steel, stainless steel and so on. The production techniques include: "sandwich" plate bonding type (commonly used) assembled by slicing, injection foaming type assembling by slicing, injection-foaming of integral skeleton, and vacuum-adhesive bonding.
Refrigerator vehicle refrigeration unit: The refrigeration unit is divided into non-independent refrigeration units and independent refrigeration units. Domestic units and imported units. General models use external coolers, and a few mini-refrigerators use built-in coolers. For refrigerators with lower temperature requirements, a built-in cold plate (functionally equivalent to an evaporator) can be used.
Fifth, refrigeration principle of refrigerated truck
Refrigerator vehicles have a variety of cooling methods. The following five types of cooling methods are more common:
1, water ice and salt ice refrigeration: water ice refrigeration device investment is small, the operating cost is low, but the ordinary water (salt) ice unit mass of heat absorption is small, the car cooling is limited, and the melting of salt ice will pollute the environment, Food, corroded cabins and goods are damp, so water (salt) ice cooling is mainly used for refrigerated transport of fish and other aquatic products.
2. Dry ice cooling: The equipment is simple, the investment and operation costs are low, the use is convenient, and the goods are not affected by moisture. The CO2 gas produced by the sublimation of dry ice can inhibit the reproduction of microorganisms, slow the oxidation of fat, and weaken the respiration of fruits and vegetables. However, the sublimation of dry ice can cause frost formation. Excessive CO2 gas will lead to difficulty in breathing and necrosis of cold products such as fruits and vegetables. Moreover, the temperature inside the car is difficult to adjust, the cost of dry ice is high, and the consumption is large, so the actual application is less.
3, cold plate cooling: the device itself is heavier, larger volume, occupying a certain volume of the compartment, and the cold plate cooling once only sustainable work 8 ~ 15H. Therefore, cold plate refrigeration is suitable for medium and short-distance transportation of medium and light refrigerated vehicles. In recent years, with the increasingly prominent problems of energy and environmental pollution, the application of cold plate cooling has developed rapidly and has become the second only to mechanical refrigeration. the way.
4, liquid nitrogen refrigeration: device structure is simple, reliable, no noise and pollution; liquid nitrogen refrigeration capacity, rapid cooling, suitable for quick freezing. Liquid nitrogen vaporization does not make the cabin damp, and nitrogen is good for keeping food fresh and preventing drying. In addition, liquid nitrogen refrigeration temperature control (positive and negative two degrees). However, the liquid nitrogen has a high cost and needs to be filled frequently, so the promotion is limited. Similarly, other low-temperature vaporized liquid gases can also be used as refrigerants, such as liquid carbon dioxide.
5. Mechanical refrigeration: Mechanical refrigeration methods include vapor compression, absorption, and steam injection. At present, the vapor compression type is the most widely used. Compression refrigeration units are mainly composed of compressors, condensers, throttle valves (or expansion valves) and evaporators.
Sixth, the purchase of refrigerated trucks
Refrigerated trucks are key equipment in an important part of low-temperature cold chain logistics. The refrigerated truck is reliable in the refrigerated transport process and has stable performance. It is the key to ensuring the safety of perishable and fresh foods in the transportation process. Road transport refrigerated trucks usually consist of three parts: the vehicle chassis, the insulation cabin and the refrigeration unit. Therefore, the choice of refrigerated trucks also starts from these three parts.
(a), the choice of refrigerated truck chassis:
The chassis of the car is relatively easy to select. Because we can only select the automobile chassis that meets the national standards for environmental protection in China, regardless of the size of the tonnage, domestic or imported car chassis are the same requirements. For the car chassis, whether the customer purchases the private car Body manufacturers buy the same.
(B), the choice of refrigerator body:
The choice of the car body is related to the delivery of the specific goods. Different goods have different requirements for the car body. For example, refrigerated trucks that carry fresh meat need to be custom-made hooks on the car body; refrigerated trucks that distribute fresh food for the stores have small batches, many varieties, and require multi-temperature refrigerated trucks; the temperature needs are different, and frequent loading and unloading require more refrigerated trucks. All of these, the user can customize the car body according to specific needs.
(III) Selection of refrigeration units for refrigerated trucks:
(1) Choose according to the size of the refrigerated compartment: Independent units or non-independent units can be selected. In general, the 6-meter-plus car body is suitable for selecting independent units, and the size of the independent unit can be determined according to the length of the car body. Non-independent units shall be used for the carriages below 6 meters, where the room temperature is to reach -20 °C.
(2) According to the temperature requirements of the goods shipped by the refrigerated truck: The cryogenic unit or the fresh-keeping unit can be selected. In terms of price, it is more expensive and fresher units are relatively cheap. For an inexpensive fresh-keeping unit, the unit itself does not have a defrosting function, and even if some fresh-keeping units claim to be below minus ten degrees, it is an exaggeration.
(3) Choose according to the requirements of distribution of refrigerated trucks: For example, when refrigerated trucks are used to distribute ice-creams from point to point in the cities, then it is necessary to choose regenerative cooling units or independent units. Only long-distance or point-by-point distributions with long distances in the city are required. Only suitable for fan-type refrigeration units.
(4) According to the origin and brand of the refrigerator: You can use imported or domestic brands.
There is also to tell everyone that regardless of domestic or imported units, we must pay attention to the unit's temperature sensor is enough to install in the return air position of the evaporator, because the unit's temperature sensor installed in the return air or exhaust position in two cases, The temperature reading will differ by 5°C.
VII. Maintenance of Refrigerated Vehicles
About the use of refrigerated truck precautions:
1, pay attention to the pre-cooling of goods and cold storage before loading cargo
The transport equipment is transported while maintaining the temperature at which the cargo is loaded. It is not possible to reduce the temperature of the cargo or freeze it in the cold storage. If the cargo is loaded at high temperatures or when the temperature of the cold storage is high, it is difficult to reduce it to the temperature of interest. Therefore, it is important to pre-cool the goods and cold storage to the transport temperature of the matter.
2, the cold air circulation in the goods smoothly
To reverse the temperature in the cold room to maintain a uniform temperature, we must pay full attention to the stacking of goods. In particular, it is important to note that it is not possible to pile cargo to the roof or to stack cargo at the air outlets or inlets of air-conditioning.
3, the rapid import and export of goods
The cold storage door is opened, and the external air flow will cause the temperature inside the refrigerator to rise. Please move in and out of the goods as soon as possible. In addition, stop the operation of the refrigeration unit during cargo handling operations.
4. Pay special attention when loading fruits and vegetables
Fruits and vegetables, etc., will produce heat for breathing. If the circulation of cold air is not good, the temperature in the central part of the compartment will increase, which will affect the quality of the goods. In addition, the upper cargo near the air-conditioner outlet may suffer from frostbite due to cold air. Therefore, please cover it with a cover cloth beforehand to protect it.
5, please keep clean in the cold room
It must be kept clean when transporting food. If salt, fat, etc. adhere to the inner wall or the door seal, not only unhygienic, but also corrosion of the car, shortening the life of the freezer.
Refrigerated trucks, refrigerated trucks, warm car purchase must know common sense
Refrigerated trucks, refrigerated trucks, warm car purchase must know common sense