1. Water/Fluorine Systembigair conditioner

water system

A large water system air conditioner refers to an air conditioning system in which water or an aqueous solution is used as the refrigerant, and the cooling or heating load of the room is largely borne by water. Due to the fact that the end device of the all water air conditioning system is a fan coil unit, the all water air conditioning system is also known as the all water fan coil unit system, commonly referred to as a water machine in the industry.

Fluorine system

The fluorine based air conditioning system assumes that the cooling or heating load of the room is entirely borne by the fluorine medium. This type of system is also known as a fluorine machine, and the common one is the variable frequency one to many system, which is also widely used in households.

2. Refrigeration compressor

The refrigeration compressor is one of the core components of the refrigeration system, and common types include:

3. Refrigerant (refrigerant, snow seed)

In refrigeration systems, the circulating working medium is called refrigerant, also known as refrigerant working fluid. It circulates between various components of the system to achieve energy conversion and transfer, specifically manifested as the refrigeration machine releasing heat to a high-temperature heat source and absorbing heat from a low-temperature heat source, thereby achieving the purpose of refrigeration.

ODP (Ozone Depletion Potential): Based on the value of CFC -11 at 1.000, it is used to indicate the degree to which refrigerants deplete the potential of atmospheric ozone molecules.

GWP (Greenhouse Effect Index): It is an indicator value that measures the degree of impact of refrigerants on climate change. In the early days, the value of CFC -11 was selected as the benchmark value 1.0, which was called HGWP. In recent years, people have used CO ₂ with a lifespan of 100 years as a benchmark and set the greenhouse effect potential of CO ₂ at 1.0, which is called GWP or GWP100.

Common refrigerants: Common refrigerants include R22, R410A, R404A, R32, R290, R744, R717, etc. It should be noted that different refrigerants should not be mixed, otherwise it may cause serious damage to the system.

4. Concepts related to subcooling and superheat

Subcooling temperature: refers to the temperature of the supercooled liquid that has been cooled below the saturation temperature before throttling.

Subcooling degree: It is the difference between the supercooling temperature and the saturated liquid temperature corresponding to its pressure.

Undercooling cycle: A cycle with liquid subcooling is called a liquid subcooling cycle.

Overheating temperature: The temperature at which the compressor sucks in superheated refrigerant vapor above its saturation temperature corresponding to its pressure.

Overheating degree: The difference between the temperature of superheated steam and the saturation temperature at the same pressure.

Overheating cycle: A cycle with steam overheating is called a steam superheating cycle.

Effective Overheating: When the heat absorbed by overheating comes from the cooled medium, it produces a useful cooling effect.

Harmful overheating: If the heat absorbed by overheating comes from outside the cooling medium, it will not produce a cooling effect.

The impact of temperature changes: Other conditions remain unchanged, but the effect of changes (increases) in condensation temperature tk

The impact of the change (decrease) in evaporation temperature t ₀ under unchanged other conditions

5. Composition of central air conditioning system

Compressor: As the "heart" of the refrigeration system, it can elevate low-pressure gas into high-pressure gas, providing power for the entire refrigeration cycle.

Electronic expansion valve: It belongs to the throttling and pressure reducing device, and is a throttling mechanism similar to thermal expansion valve and capillary tube. It controls the operation of the system by adjusting the flow rate of refrigerant.

Four way directional valve: Its main function is to switch between cooling and heating modes, meeting the usage needs of different seasons.

Heat exchanger: It is a device that transfers the heat of a hot fluid to a cold fluid, playing a key role in heat exchange in air conditioning systems.

Fan coil unit: composed of small fans, motors, coils and other components, it is the end device of the system, responsible for delivering hot and cold air to indoor spaces.

Electric two-way/three-way valve: divided into fully open and fully closed type and regulating type. The fully open and fully closed type can achieve the opening or closing of channels; The regulating type can adjust the valve position opening proportionally and precisely control the flow rate.

Gas liquid separator: installed at the inlet of the gas compressor, used to separate the liquid in the gas and prevent damage to the compressor caused by liquid hammer phenomenon.

Liquid reservoir: mainly used to store refrigerant in refrigeration systems to ensure the normal operation of the system under different working conditions.

Dry filter: capable of filtering impurities and moisture in the system, preventing impurities from blocking pipelines and moisture from causing corrosion to system components.

Pressure controller: used for high and low pressure control and pressure protection in refrigeration systems. When the system pressure exceeds the set range, corresponding measures will be automatically taken to ensure the safe operation of the system.

Temperature controller: It can control the refrigeration system to automatically switch on and off within the set temperature range, achieving precise temperature adjustment.

Liquid sight glass: As an auxiliary accessory, it can clearly display the condition of refrigerant in the system, making it convenient for maintenance personnel to judge the operating status of the system.

Globe valve/gate valve: used to control the flow and switching of refrigerant in the refrigeration system, regulating the operation of the system by opening or closing the valve.

Expansion tank: On the one hand, it can accommodate the expansion of system water due to temperature changes, and on the other hand, it also serves as a constant pressure and replenishes water for the system.

Automatic exhaust valve: used during the operation of HVAC systems to exhaust air from the system and prevent air accumulation from affecting the normal operation of the system.

Automatic water replenishment valve: It can stabilize the water pressure in the waterway system. When the system water pressure is lower than the set value, the automatic water replenishment valve will automatically open to replenish water.

Safety valve: When the system pressure exceeds the set value, the safety valve can automatically release pressure, protect other components from overpressure hazards, and ensure the safe operation of the system.

Pressure gauge: used to measure and indicate the pressure inside the air conditioning pressure product, facilitating maintenance personnel to understand the pressure condition of the system.

Temperature sensor: It can measure and indicate the temperature inside the air conditioner, providing accurate data support for temperature control of the system.

One way valve: used in the system to prevent the reverse flow of refrigerant and ensure that the refrigerant circulates in the specified direction.

Water pump: a mechanical device used to transport or pressurize liquids, in air conditioning systems, for circulating water or other media.

Water flow switch: used for controlling or cutting off fluid flow in pipelines. When the fluid flow reaches the set value, the switch automatically cuts off (or connects) the circuit to protect the safe operation of the system.