Serialization: components of basic knowledge about air conditioners in data centers

In the previous phase, we introduced the construction and composition of the air conditioning and cooling system in the data room. For more information about BKJIA, see: serialization: system composition of basic knowledge about air conditioning in the data room ), what we bring to you today is the basic components of the compressed refrigeration system, including the evaporator, condenser, evaporator, expansion valve, and circulation process. If you are interested in basic air-conditioning knowledge, you may wish to take a look at our current knowledge serialization.

1. Evaporator

The liquid refrigerant after throttling absorbs heat in the evaporator, so that the cooling material cools down and achieves the purpose of cooling.

2. Condenser

Under the action of condensation medium, the over-temperature gas discharged from the compressor is not condensed into a liquid state.

3. Compressor

The core of the refrigeration cycle is the power device for the circulation of refrigerant in the system, so that the refrigerant in the evaporator maintains a low pressure, and the refrigerant in the condenser maintains a high pressure.

4. Expansion Valve

The regulation device of refrigerant phantom flow, which reduces the pressure on high-pressure liquid refrigerant, enables the refrigerant entering the evaporator to heat and evaporate under the required low pressure. At the same time, the flow of refrigerant entering the evaporator is automatically adjusted according to the heat load change of the cooling medium.

The role of the expansion valve: thermal expansion valve reduces the pressure of the refrigerant entering the evaporator, controls the flow of the refrigerant flowing into the evaporator, and controls the reasonable air intake and overheating.

5. Cyclic Process

In a closed system connected by a pipeline, the refrigerant continues to flow cyclically in the closed system, and the phase change occurs. The refrigerant is heat exchanged with the surrounding environment to achieve cooling.

The working process is: after the liquid refrigerant absorbs the heat of the cooling material in the evaporator, it is converted into a low-pressure, low-temperature gas, and the compressor is inhaled and compressed into a high-pressure, high-temperature gas, then enter the condenser to heat the cooling material, and the condensation is high pressure, normal temperature liquid, after the throttling device changes to low pressure, low temperature liquid refrigerant, again into the evaporator heat absorption and evaporation, to achieve the purpose of circulating cooling.

6. Liquid Storage Tank

The refrigerant liquid storage device located between the condenser and the evaporator automatically adapts to load changes and adjusts the condensation pressure so that the condenser works in the optimal working conditions. You can automatically adjust the refrigerant capacity in the system cycle. During system maintenance, You can accommodate most of the refrigerant to avoid discharging the refrigerant to the atmospheric environment, this reduces the requirement on the accuracy of refrigerant charge during commissioning.

7. Evaporator

The evaporator consists of heat exchange coils, frame structures, and air boxes. The liquid refrigerant after throttling absorbs heat in the evaporator, so that the cooling material cools down and achieves the purpose of cooling.

8. Drying Filter

The water vapor in the absorption refrigeration system may be filled with silica gel). There are two reasons for the moisture. One is that the drying is not strict, second, the use of unqualified refrigerant will produce ice blocking, And the refrigerant reflects the production of hydrochloric acid and other hazards. It is also necessary to filter out possible metal impurities in the cooling system. When silica gel and zeolite are used in combination, both drying and acid resistance can be achieved, and the molecular sieve adsorption capability is stronger than silica gel. There are two types: the discard type and the filter element rechargeable type.

9. Throttling Device

The throttling device is a step-down device in a refrigeration cycle that provides variable resistance to repair and is lowering the pressure of high-pressure liquid after condensation in the condenser before entering the evaporator. Throttle and reduce pressure on high-pressure liquid cooling to ensure the pressure difference between the condenser and the evaporator. One side causes the liquid refrigerant in the evaporator to evaporate and absorb heat at the saturated temperature corresponding to the required low pressure, in this way, the refrigeration and cooling are achieved, and the gaseous refrigerant in the condenser is put down to heat condensation at the saturated temperature corresponding to the given high pressure. It is achieved according to the heat fit in the best way to the evaporator for liquid capillary ).

10. Capillary Tube

The flow control and throttle relief components of the refrigeration cycle, with a diameter of about 0.7 ~ The length is about 2.5mm. Thin and long copper tube step-down principle for sudden variation), produce the required pressure drop so that the refrigerant can absorb heat in the evaporator.

Non-regulating devices cannot adapt to changes in cooling load), the design process must be carefully selected to avoid excessive evaporator or insufficient liquid supply during operation. Capillary Tubes are generally used for Household Air Conditioners of Small-capacity systems). The refrigerant charge amount is limited, and liquid storage tanks cannot be used in the system. They are static components with high reliability.

After the compressor is shut down, it can quickly balance the high and low voltage, so even if the motor with low blocking torque starts torque), it can ensure that the compressor will start again soon after it is shut down.