Some terms from the field of refrigeration equipment: (Solution)

Container

In order for the compressor to only draw in dry, gaseous refrigerant, the collection tank captures the mixture that comes out of the evaporator. Moisture that enters the refrigerant circuit during installation is intercepted by a filter (dryer bag) in the container.
The catch basin is always installed in conjunction with a regulator.



Flammability

Refrigerant is not flammable. It, on the contrary, has fire-retardant or fire-extinguishing properties.



Vapor pressure

Is the pressure exerted on the liquid surface. The vapor pressure is temperature-dependent.



Sparrow

The capillary tube forms a restriction. This restriction reduces the flow, and therefore determines the amount of refrigerant for the evaporator. Additionally, the expansion valve separates the refrigerant circuit into high-pressure and low-pressure sides.



Pressure gauge

The pressure gauge measures the pressure that is evenly distributed from the compressor outlet, through the condenser, to the restriction point (throttle, expansion valve), when the air conditioning system is turned on. Using the low-pressure manometer, the pressure is measured, which evenly spreads from the narrow point (throttle, expansion valve) through the evaporator to the inlet of the compressor when the air conditioning system is turned on.



Pressure switch

Turn on the coolant fan to the appropriate levels and turn the compressor "off" in case of refrigerant loss.



Freezing point

From R134a at -101.6 °C and under normal atmospheric pressure of 1 bar.



Expansion Valve

The expansion valve atomizes the incoming refrigerant and regulates the flow rate so that the steam becomes gaseous only at the outlet of the evaporator, depending on the heat transfer.



Fluid container

The liquid reservoir collects the liquid droplets and then continuously directs them to the expansion valve; otherwise, the expansion valve would not be able to properly seal the evaporator.



Frigen / Freon

Trade names, these also apply to refrigerants that are not permitted for use in vehicles.



Fill Factor

In order for a container not to be overfilled, the Pressure Gas Ordinance specifies how many kilograms of refrigerant, per liter of internal volume of the container, may be filled. This "fill factor" is calculated by multiplying the internal volume by the permissible fill amount. It is 1.5 kg/l for refrigerants.





Using the donor impulses (4 per compressor revolution) and the engine speed, a control unit calculates the belt slip. If the belt slip exceeds a specified value, the compressor is switched off by the control unit via the magnetic coupling.



High-pressure sensor

The pressure sensor generates a rectangular signal when a voltage is applied. This signal changes with the pressure in the system.
Using this signal, downstream control devices (e.g., coolant fan control unit, engine control unit) calculate the pressure in the refrigerant circuit and correspondingly control the magnetic coupling, the coolant fans, and the engine.



Hygroscopic

Strongly water-attracting (Example: Refrigerant oil)



Refrigerant Oil

In connection with R134a air conditioning systems, special synthetic refrigerant oils are used (e.g., PAG oil, Polyalkylene glycol oil).



Refrigerants

We work with a substance that boils at a relatively low temperature, which we refer to as a refrigerant. The refrigerant used, R134a, is tetrafluoroethane. It boils at -26.5°C under normal atmospheric pressure of 1 bar.



Capacitor

The condenser removes heat from the compressed refrigerant gas and transfers it to the ambient air.



Compressor

The compressor is driven by the vehicle engine via a belt. The compressor sucks refrigerant gas from the evaporator, compresses it, and then passes it on to the condenser.



Critical Temperature / Critical Pressure

Up to a pressure of 39.5 bar (this corresponds to a temperature of 101 °C), the refrigerant R134a remains chemically stable, but above this temperature, the refrigerant decomposes.



Lamella Ridge

Used to realign bent capacitor plates.



Leak Detection Device

Small leaks can only be detected with an electronic leak detector. Operate the leak detector according to the accompanying operating instructions.



Magnet Valve

The flow of the refrigerant in the second evaporator is switched on or off by the solenoid valve.



Magnetic Coupling

Establish the connection between the compressor's pulley and the drive shaft.



Manometer battery for nitrogen

The function of the pressure gauge is to reduce the nitrogen's vapor pressure. The vapor pressure in the nitrogen cylinder is approximately 50 bar at room temperature. To check for leaks in the refrigerant circuit, the battery can also be used.



O-rings

These rings seal the connection points between the individual components of the refrigeration cycle.



Regulator Valve for Compressor

In a remotely controlled compressor, the control valve is operated by the control unit (e.g., -E87- Audi), thereby changing the pressure on the low-pressure side.



Retrofit Process

Is the conversion of an air conditioning unit from refrigerant R12 to refrigerant R134a?



Drinking glass

Are there air conditioners that were converted from R12 to R134a (refrigerant)? Manifold is not suitable for R134a because the refrigerant does not completely mix with the refrigerant oil.



Schraderventil

Valves designed for maintenance work in the refrigerant circuit.



Boiling point

R134a boils at -26.5 °C and under normal atmospheric pressure of 1 bar.



Nitrogen

Used for evacuating refrigerant circuits.



Vaporizer Temperature Switch

The temperature switch determines the temperature between the cooling fins of the evaporator to prevent the evaporator from freezing.

tk

This refers to the critical temperature (also known as the critical point). This means that above this temperature, there is no longer a distinct interface between the liquid and the gas. A substance is always in the gaseous state above its critical temperature.
At temperatures below the critical temperature, all types of refrigerants in pressure vessels exhibit both liquid and gas phases, meaning that there is a gas pocket above the liquid. As long as there is still gas present in the vessel in addition to the liquid, the pressure depends on the ambient temperature.



Overpressure relief valve

At a pressure of approximately 38 bar overpressure, the valve opens. For some valves (depending on the compressor), a small piece is attached that falls out when the valve is activated.



Evaporator

As the liquid refrigerants evaporate in the evaporator's tubes. The heat required for this is extracted from the air passing over the evaporator fins.



Moisture Content

Water damages the air conditioner because, under high pressures and temperatures, in combination with other contaminants, acids are formed.