1) compression refrigerator: this refrigerator is provided with mechanical energy by a motor and works on the refrigeration system through a compressor. The refrigeration system is based on the principle that the low boiling point refrigerant absorbs the heat of vaporization when evaporating. Its advantages are long service life and convenient use. At present, 9 1 ~ 95% refrigerators in the world belong to this category.
2) absorption refrigerator: this refrigerator can use heat sources (such as gas, kerosene, electricity, etc.). ) as a driving force. Ammonia-water-hydrogen mixed solution realizes refrigeration in the process of continuous absorption-diffusion. Its disadvantages are low efficiency and slow cooling, which has been gradually eliminated.
3) Semiconductor refrigerator: It is a refrigerator that produces Peltier effect at the junction by applying direct current to PN semiconductor.
4) Chemical refrigerator: It is a refrigerator that uses some chemicals to absorb heat strongly when they are dissolved in water to obtain refrigeration effect.
5) Electromagnetic vibration refrigerator: It is a refrigerator with electromagnetic vibration machine as the main power to drive the compressor. Its principle and structure are basically the same as that of the compression refrigerator.
6) Solar refrigerator: It is a refrigerator that uses solar energy as refrigeration energy.
7) adiabatic demagnetization refrigeration refrigerator.
8) Radiant refrigeration refrigerator.
9) Solid refrigeration refrigerator.
Since most of the refrigerators we use are compression refrigerators, it is necessary for me to further understand their working principle and composition. Next, let's talk about the composition of the compression refrigerator: the refrigeration system of the compression refrigerator consists of five parts: compressor, condenser, drying filter, capillary tube and evaporator. The function of the compressor is to replenish energy, compress the low-temperature and low-pressure Freon steam in the evaporator into superheated steam with high temperature and high pressure, and send it to the condenser. The function of condenser is to condense high-temperature and high-pressure steam into high-pressure and normal-temperature liquid, and the well releases a lot of heat.
The function of drying filter is to absorb moisture in freon, prevent ice blocking, filter impurities in refrigeration system and prevent dirty blocking. Capillary tube also has two functions: one is to throttle and control the Freon cycle of refrigeration system; The second is to reduce the pressure to ensure that the pressure in the condenser meets the condensation pressure and the pressure in the evaporator meets the evaporation pressure. Evaporator is the place where refrigeration system produces cold energy, where liquid freon evaporates into gas and absorbs a lot of vaporization heat.
As refrigerators are high-grade durable goods, service life is an important indicator. Therefore, in the design, the service life is carefully considered from the aspects of structure, material selection and manufacturing technology. Based on China's development situation, economic conditions and living standards in recent 20 years, the design life of household refrigerators should not be less than 15 years. Foreign refrigerators, due to the continuous upgrading of styles and varieties, are often designed with shorter service life.
The following are some concepts that we often encounter in our lives or advertisements, and we will explain them to you here:
Are single-door refrigerator, double-door refrigerator and double-door refrigerator different things?
A single-door refrigerator generally refers to a refrigerator with only one door. It has an evaporator and can store a small amount of frozen food. It is the earliest popular refrigerator in China, and has basically disappeared from the market at present. A double-door single-temperature refrigerator refers to a refrigerator with two doors but only one evaporator. Its internal structure is the same as that of a single-door refrigerator, so some people call it a "fake double door". Two-door and two-temperature refrigerator usually refers to a refrigerator with two doors and two evaporators, one of which is installed in the freezer, often with four-star freezing capacity, and the other evaporator is installed in the freezer. At present, the two-door and two-temperature refrigerator is popular in China.
The meaning of the star symbol on the refrigerator
The star symbol on the refrigerator indicates the storage temperature grade of the frozen part of the refrigerator, which is a symbol of the indoor temperature of the refrigerator uniformly adopted by international standards. Each star indicates that the storage temperature in the freezer should be below -6℃ and the storage time of frozen food should be 1 week.
For example, a three-star refrigerator means that the storage temperature of the freezer should be below-18℃, and it has the ability to quickly freeze a certain amount of food. Simply put, the freezing capacity refers to a certain amount of lean beef at 25℃, which is frozen below-18℃ for 24 hours.
Direct cooling refrigerator and indirect cooling refrigerator.
"Direct cooling" and "indirect cooling" are two cooling methods for refrigerators. Direct-cooling refrigerator uses the natural convection of air in the refrigerator to cool food. Because the evaporator is often installed in the upper part of the refrigerator, the air around the evaporator exchanges heat with the evaporator, the air transfers heat to the evaporator, and the evaporator transfers cold to the air. After air absorbs cold energy, its temperature drops, its density increases and it moves downward. The air in the lower part of the refrigerator exchanges heat with the cooled food, and the food transfers heat to the air. After the air gets heat, the temperature rises and the density decreases, and then it rises around the evaporator to transfer the heat to the evaporator. In this way, cold and hot air repeatedly convects naturally to achieve the purpose of refrigeration.
The evaporator of indirect cooling refrigerator is usually a finned tube type, which is placed in the interlayer between the freezing chamber and the refrigerating chamber or in the rear upper part of the box. Use a small fan to force air convection in the box to achieve the purpose of cooling.
The vast majority of refrigerators produced in China are direct-cooling refrigerators, and the output of indirect-cooling refrigerators is relatively small.
Why does frost-free refrigerator consume more electricity than frost-free refrigerator?
For two refrigerators with the same volume, the frost-free strong cooling type consumes more power than the frost-free direct cooling type. Frost-free electric heater with 150W, heating 2 ~ 3 times a day, each time 20 ~ 3 omin frost type is artificial defrosting, no electric heating is needed, so frost-free type consumes a lot of electricity. Forced cooling type is equipped with a fan to force cold air convection and cool the box; The direct cooling type relies on the natural convection of cold air in the box. After testing, the strongly cooled type with the same volume consumes more power 10% than the directly cooled type.
Fluorine-free "double green" refrigerator;
Fluorine-free "double-green" refrigerator means that chlorofluorocarbons (CFCs) are no longer used as refrigerants and box insulation foam materials, but substitutes are used separately, which will no longer pollute the environment. According to international practice, this kind of refrigerator can be called "double green", that is, it reduces the freon content of 100%, and it is a new refrigerator that completely meets the international environmental protection requirements.
The use effect of fluorine-containing refrigerator is good, why should we promote fluorine-free refrigerator?
In recent years, scientists have found that the widespread use and leakage of freon in refrigeration industry has caused cavitation damage to the atmospheric ozone layer, and excessive ultraviolet rays will endanger human health, such as decreased vision, increased cataract and skin cancer patients, and destroyed ecological balance. Therefore, the Montreal Protocol signed by the United Nations in 1987 declared freon as a controlled substance, which was originally stipulated to be stopped in 2000 at the latest. With the increasing harm of freon in the future, the international community decided to advance the time to stop using freon to 1996.