【 Weak current College 】 understanding air conditioning 17 core components

There are four large air conditioning system, they are compressor, condenser, evaporator and cut parts.
1. the compressor

Compressor is the core of the entire air conditioning system, and also the system power source. The entire air force to provide all the compressor, the compressor is to put a real potential to move from low to high potential areas, in air conditioning and it was the low temperature gas compressor compressed into high-temperature gas last gas in heat exchanger and other media for heat transfer. So that the compressor is good or bad will directly affect the entire air conditioning effect.
According to the principle of steam, the compressor can be divided into the volume and speed of two basic types. Volume compressors by sports institutions work to reduce the compression chamber volume, improve the vapor pressure to complete the compression. Speed type compressor by continuous rotating parts will be converted to steam of angular momentum, and the momentum to pressure. Depending on the compression method, volume can be divided into piston-type compressors and Rotary. Rotary can be divided into rolling piston, Vane, single-screw, two-screw, scroll-type. Velocity centrifugal compressor.
Structurally from the compressor, the compressor can be divided into open-type, semi-enclosed and totally enclosed. Open-type compressor shaft out of the body, through transmission (v-belt or coupling) and the prime mover. In the extended section must have the seal device so that the sealing between the spindle and the body to prevent refrigerant leaks. The structure of the closed-end compressor is the motor and compressor together as a whole, mounted on the same machine, so you can cancel the shaft sealing device, to avoid the leakage of refrigerant. In this way, it is surrounded by electric motor is refrigerant environment, known as the built-in motor. Hermetic compressor can be divided into semi-closed and closed two type. Half-closed connections with bolts of organism, and open-type can be disassembled for maintenance. All closed organism is mounted on a welded shell and cannot be disassembled for maintenance.
2. heat exchanger
According to the role of the air conditioning, can be divided into the condenser and evaporator. Now the condenser and evaporator of classification and the difference between telling about it.
(1), condenser:

Condenser is discharged from the compressor under high pressure and temperature of the refrigerant superheated steam cooling liquid or gas-liquid mixtures. Refrigerants in the condenser heat given off by a cooling medium (water or air). Condenser according to its cooling medium and cooling manner, can be divided into water cooled, air cooled, water and air cooled three types.
①, water-cooled condenser: condenser in refrigerant heat is cooling water remove. Cooling water flow, one at a time can also be recycled. When you recycle, the need to set the cooling tower or cooling water tank. Water-cooled condenser into shell and tube, tube, plate, spiral plate heat several types.
②, air cooled condenser: condenser in refrigerant heat given off by the air across, condensation of refrigerant in the tube. This kind of condenser in natural convection air cooled condensers and forced convection air cooled condenser. Typically, air cooled condensers also called air cooled condenser.
③, water and air cooled condensers combined: condenser in refrigerant heat given off from the cooling water and air, cooling water in the pipe outer spray evaporation, latent heat, gasification of absorption tube cooling and condensation of refrigerants, the less water consumption. This class has a shower in the condenser condenser and evaporative condensers two types.

(2), evaporator:
Evaporator effect is the use of liquid cryogenic refrigerant easily at low pressure, transformed into vapor evaporation and absorption by the heat of the cooling medium, achieve refrigerationpurposes.
Evaporator types:
Evaporator press cooling medium, is divided into the cooling liquid refrigerant, cooling air or other gases of two types.
In the cooling liquid refrigerant of evaporator, a water tank (immersion) evaporator (including vertical tube, spiral tube, snake pattern), plate evaporator, spiral plate evaporator, shell and tube evaporator (including horizontal evaporator, dry type evaporator), etc.
In the cooling air evaporator, air fin evaporator, refrigerated air air cooler (cooler) and drain tube evaporator, etc.
Small villa-style and modular air-cooled heat pump water side heat exchanger type: telescopic, plate and vertical coil. Integral units generally use dry shell and tube heat exchanger. Tube heat exchanger characteristics of simple structure, low prices, heat transfer performance is good, the problem is the large scale resistance loss are clear, the processing time to pay particular attention to the inner pipe rupture or injury, or the water into the refrigeration system, lead to system failure and damage to the compressor. Vertical coil heat exchanger structure is simple, inexpensive, but pay special attention to the return of refrigeration. Plate heat exchanger with high heat transfer efficiency, typically 3 times that of shell and tube, small size, compact structure, the use in question is partitioned space is small, easy to scale, high requirements on water quality, ruoshui blocked, causing the temperature drop in the evaporator, board rooms, ice, Frost, or siding thin prone to mechanical damage, poor water quality, plate heat exchangers of real problems, its price is relatively high. In large integral units using dry shell and tube heat exchanger, go inside the tube, tube refrigerant out water, summer runs the risk of frozen water is small, compact, slow corrosion, but when used as a condenser in winter, the condensation of refrigerant in the tubes, heat transfer coefficient than in tube condensation of refrigerants.Heat pump chiller refrigerant a water heat exchanger to adopt corrugated inner thread pipe is appropriate.
Various water side of the heat exchanger has its own characteristics, telescopic and vertical coil heat exchanger and pay attention in the design and manufacturing time to resolve the main problems, use the plate heat exchanger should enable users to understand its features and attention to water quality problems. Water side of the heat exchanger must have valid antifreeze protection.

3. throttle parts
Throttle part is a refrigeration system is an indispensable one of four parts. Its role is to bring out high pressure fluid condenser of throttling down so that the liquid refrigerant in LV (low temperature) vaporization heat absorption. Therefore, it is to maintainCondenser for high pressure, evaporator for low-voltage of important parts.
Throttle parts according to the form, can be divided into a capillary and throttle valve, the former, is used in smaller refrigeration equipment, such as a refrigerator in the condenser and evaporator between capillary is one of the throttle bodies. The latter is used in large refrigeration equipment. In large and medium-sized device application of throttle bodies for throttle valve, the throttle valve used three, i.e. manual expansion valve, floating ball valve and thermostatic expansion valve, the latter two for automatic adjustment of the throttle valve. Expansion valve according to the type of expansion can be divided into electromagnetic expansion valve and thermostatic expansion valves, etc.
Small wind-cooled heat pump chiller with a thermostatic expansion valve, four-valve control, heating, refrigeration is also useful when the capillary do heating, auxiliary throttle used in refrigeration, heating unit due to the different conditions of refrigerant cycle variation, having two or more thermal expansion valves to accommodate the work condition, in liquid piping resistance big occasions, such as liquid head resistance, it is necessary to pay attention to the appropriate maximum corresponding expansion valve capacity, to avoid for liquid shortage. Use two-way expansion valve unit, you can enable pipeline to simplify and reduce the flow resistance. However, the system sets the reservoir fluid, pipeline toward more difficult. Such as heating, high pressure liquid out of the reservoir fluid into the expansion valve and cooling, gas-liquid throttle back into the reservoir fluid mixture, into the evaporator is difficult to guarantee to liquid. To resolve this problem and also in the pipeline component to increase the one-way valve and so on, so do not use liquid storage systems use bidirectional expansion valve more favourable.

-Gas-liquid separator
In the evaporator, due to the liquid evaporates in the evaporator, the process of liquid into gas, due to changes in load, there may be a part of the refrigerant is not completely evaporated, and directly into the compressor. Due to the liquid of incompressibility, so before you outside of the compressor, first by gas-liquid separator, to ensure access to compressor all vapour, guarantee the normal operation of the compressor.
Gas-liquid separator installation and compressor inlet side, mainly to prevent the return of the low pressure compressor for low-temperature steam carrying too many drops to prevent liquid refrigerant enters the compressor cylinder, separator with filter, oil, liquid, etc.
When used in gas-liquid separator should note:
①, as far as possible * near compressor;
②, at changeover system, gas-liquid separator should be installed on directional control valve and the compressor;
③, correct installation import (from evaporator to) exports (go to the compressor suction port);
④, you must install up;
⑤, suitable for the size of the gas-liquid separator the interface is not necessarily and compressor suction port.

5. fan

Fan is AC single-phase and three-phase inductionmotor and impeller.
Fan into axial fans and centrifugal fans.
Constant speed and variable speed blower consists of two series.
Fan into metal fan, plastic fan blade and metal casting fan, etc., there are a variety of leaf type.
Fan noise include motor electromagnetic noise, mechanical noise and blade aerodynamic noise. Axial fans, blade periodically hold uniform airflow fluctuation effects, generate noise; on the other hand, leaves on uneven pressure distribution, rotation on surrounding gas and parts for constitutes also rotation noise disturbance; in addition, because the gas flowing through the blades generated a turbulent boundary layer, Vortex, which leaves on the detachment of the pressure distribution of pulsation noise generated vortex. Rotation noise and Eddy current noise synthesis the fan aerodynamic noise, and therefore control blade aerodynamic noise is fundamental to reduce fan noise. The other components of the shroud, blower motor bracket structure and fan and air cooled condensers match or not also to a certain extent affected the fan performance, this must also be carefully studied.
In the low pressure flow axial fans, in order to increase the gas flow of parts of the area, the fan wheel than V = d/D generally get smaller. In this case, in order to reduce the distortion level leaves and can take full advantage of the outside diameter and speed of larger leaf to transfer energy, usually uses the index smaller design variable vanishes, this will increase the impeller flow line offset by introversion, in blade roots have always the radial component of the outside, dramatically increased the blade diameter of secondary flow losses, worsening the performance of the work of fan. Use forward-swept distort plate blade, blade axis in the outer section section bending to the direction of rotation and roots as a straight line, so it leaves no additional radial force, which will greatly improve the blade diameter and the root of the gas flow, reducing gas secondary flow loss, noise reduction, improved efficiency.

6. the reservoir fluid

The refrigeration system for high pressure fluid (also known as the reservoir fluid tube) is installed in the condenser and the expansion valve, its functionality can be grouped into several aspects of the
A, Stockpiling condenser condensate
Avoid the condensate in the condenser in the accumulation of too much makes the heat transfer area smaller, affect the condenser heat transfer efficiency.
B, adapted to the evaporator load changes on supply demand
In the evaporator load increases, the supply is increased, the reservoir fluid replenishment of deposit liquid; load variable hours need fluid is also smaller, excess liquids stored in a tank.
C, as the system low pressure side of the liquid seal between the
Because of the fluid pipe is inserted on the surface, it prevents the high-voltage side of steam and Non-Condensable gases into the low pressure side.
At the same time, the reservoir fluid also played the role of filtration and silencers.
Fluid forms of many, there is a distinction between one-way and two-way; there is an export and export Division; vertical and horizontal.
.-Gas separator

Oil and gas separator installed between the compressor and condenser.
It works as follows: the exhaust compressor is freon and lubricants for gas mixture, the oil separator for larger cavity slows down, the oil mist will gather in impact on the surface, while the assembled into larger oil drop, flow to the bottom of the oil separator, and passed back to the compressor oil equipment return.

8. drying filter

Filter is used to prevent refrigerantContains moisture or not reduce elements, the system enters the water coming out from the condenser of high temperature liquids enter the expansion valve, liquid temperature will drop significantly, generally below zero, then if the system contains water, due to the expansion valve through section is very small, would be susceptible to blockage of the phenomenon, affecting the normal operation of the system.
Current market there are three types of drying filter
A, loose fill filling drying filter — Dropwise desiccant filling in with strainer enclosures
B, massive drying filter — — the resin curing together to form the massive driers
C, pressed-Dropwise drying filter — from molecular sieve materials and aluminium oxide mixture consisting of beads being crushed by a steel spring pressed between two glass fibre.

9. four-way reversing valve

4-way reversing valve and is suitable for unitary air conditioners, central air conditioning, and other heat pump air conditioning system, it is used to toggle the refrigerant circulation paths to achieve the purpose of cooling and heating.

10. water pump

Water pump, is used to speed up water flow tools to achieve the strengthening of water in the heat exchanger in the heat.

11. the flow switch

Flow switch for tubes for fluid flow control or disconnection protection, when fluid flow reaches the set value, the switch automatically cut off (or on) circuit.

12. pressure controller
Pressure controller for pressure control and pressure protection, a low pressure and high pressure turbine controller, used to control the system pressure, when the system pressure to set value, the switch automatically cut off (or on) circuit.

13. differential pressure controller
Pressure controller used as a pressure difference of control, when the pressure reaches the set value, the switch automatically cut off (or on) circuit

14. the temperature controller

Temperature controller used as unit of control or protection, when the temperature reaches the set value, the switch automatically cut off (or on) circuit. In our product, temperature control is commonly used to, with water tank temperature to control unit on downtime. Some also require as antifreeze to the temperature controller.

15. as the liquid mirror

Depending on the liquid mirror is used to indicate:
1. refrigeration plant liquid pipeline of refrigerant condition;
2. the water content of the refrigerant;
3, back to the tubing from oil separator in path of lubricating oil flow.
A Visual indicator with a liquid mirror, it changes its color to indicate that the water content of the refrigerant. (Green, yellow is dank drying)

16. the expansion tank
The role of expansion water tank: 1, due to temperature changes caused by changes in the volume of water, expansion tanks used for the storage of this part of the expansive water; 2, the system plays the role of the regulator pressure; 3, can give compensation portion of the water system.

17. the cooling tower
The role of a cooling tower is bringing the heat of cooling water in the tower and air heat so that heat is transferred to the air and powder into the atmosphere. Cooling tower water and air heat one way, through the water surface in direct contact with the air and water, through contact with heat transfer and thermal evaporation, the water in thermal transfer to the air. In this way is called wet cooling towers of cooling. Wet cooling tower for high thermal efficiency, water is the limiting temperature of the cooling air of the wet-bulb temperature. However, water loss due to evaporation; evaporation caused by the circulation of cooling water salinity increase, in order to stabilize water part must drain the salinity of the water; the higher the wind also cause hair loss of water. There must be enough new water continues to add. Therefore, wet cooling towers need supply water sources of water.
Water deficit zone, in supplementary water difficult circumstances, can only use dry cooling towers. Dry cooling tower in air and water heat exchanger is made up of metal pipe radiator surface heat transfer, thermal water pipe is transferred to the radiator, the air flow. Dry cooling towers of heat transfer efficiency than wet cooling towers, cooling of limiting temperature for air dry-bulb temperature. These devices for a one-time investment, and fan energy consumption is very high.
Cooling tower water cooling process in the case of heat and mass transfer processes. Is cooling water spray nozzles, water distributor or the distribution disk allocation to the cooling tower internal packing Department, significantly increase water and air of contact area. Air force by fans, air flow, natural wind or injection of inductive effect while loop.