In recent years, in most regions of the country, the summer period has a significant number of extremely hot days. To the rescue of drivers come built-in car air conditioners. They are already being installed by many auto companies, even in a budget class model, therefore, it is desirable for almost every motorist to know how a car air conditioner works in order to properly care for and operate the installation.

Content

• 1 Ensuring favorable driving conditions
• 2 Cooling system operation
• 3 Components
• 4 Application of safety devices
• 5 Applications of various types of refrigerant
• 6 Control methods
• 7 Service of the climatic equipment
• 8 Self-check air conditioner

Ensure favorable driving conditions

In any situation, the creation of comfortable conditions has a positive effect on health and safety. It is especially important to create the right atmosphere in the car, because in the absence of climate systems, all areas of the body overheat. The upper body is more prone to negative thermal factors.

This factor is especially noticeable during long journeys. Schematic diagrams clearly demonstrate the possible danger. The negative effects of heat weaken the reaction of the driver, interfere with concentration.

Classic installations that use only interior blowers do not have sufficient efficiency in reducing the temperature. They only distill the warm air and do not remove excess moisture.

Cooling system operation

In modern installations, the principle of operation of a car air conditioner has the maximum similarity to the work of a conventional household refrigerator. At the heart of the system is the circulation of the refrigerant, in the role of which Freon often acts. According to the school knowledge in physics, matter is forced to take energy (heat) from a liquid to a gas, and during the reverse process of vaporization, energy (heat) is given to the environment.

The task of any refrigerant is to take excess heat from the interior of the car and remove it outside. Being in the form of gas, Freon is trying to extract maximum energy from the air, cooling it.

Constituent elements

Analyzing how the air conditioner in the car, you need to familiarize yourself with the main components. Most designs have in their list the following mandatory elements:

• powerful compressor;
• capacitor;
• blower fans;
• built-in evaporator.

The compressors built into the car air conditioner can be of different types. The main difference between the two is the supply of refrigerant to the system in a piston or rotor method. Also devices have various designs of drives. In most cases, the rotation of the drive shaft is due to the work of the power plant of the car. This scheme has established itself as the most simple to manufacture, which reduces the total cost, and has a high efficiency in comparison with other types of drives.

If you have your own drive, the climatic equipment increases the cost of installation, but the autonomy of the system appears. It can work even with the engine off. Cars equipped with stop / start systems have compressors that, if necessary, start up from the vehicle’s power plant or from a personal drive while standing.

The device air conditioner in the car involves two types of work patterns. In the first embodiment, the refrigerant flow is regulated. For this operation a thermostatic fan and receiver dryer are used. This design is found in many French, Korean, Japanese and Italian automotive brands. For the second version of the scheme, a throttle and a battery are needed. This type is popular in American cars, and is also used in individual brands of German automakers.

The increase in the density of the refrigerant is carried out in a condenser. It is made of light-alloy materials based on copper or aluminum.

The source of coolness is the evaporator. The principle of its operation is the same as that of a heat exchanger. In its aluminum or copper case, freon is converted into gas from a liquid state.

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Fans are responsible for removing excess heat. They direct the flow of air through the condenser directly into the vehicle interior.

At the outlet of the pipeline is mounted receiver-dryer. It is the main tank in which the refrigerant is present in a liquid form. Inside the tank, the working substance is cleaned from moisture and possible contaminants. As an additional informant, he may have a built-in viewing window through which the amount of freon is monitored.

With the help of a thermostatic valve (expansion valve), the refrigerant is metered to the evaporator. It controls the flow rate depending on the performance of the system.

Application of safety devices

As in all closed hydraulic systems, various bypass valves, automatic fuses and control sensors are used in the air conditioner. Their work increases the reliability of equipment operation.

With a decrease in pressure to a critical level of 2 kg / cm² The compressor is turned off by a low pressure sensor. Recovery is performed after a set of 2.3 kg / cm³. Such an algorithm prevents jamming of the compressor unit.

During the pressure increase in a closed medium to 30 ... 34 kg / cm² high pressure sensor automatically blocks the operation of the compressor. It resumes after lowering the value to 26 kg / cm². As a rule, the pressure increases due to clogging of the flow channels, malfunctioning of the valves, or problems with heat exchange in the condenser.

The compressor housing is equipped with a temperature sensor on the discharge side. It closes the voltage supply to the electromagnetic coupling when the temperature reaches 90 ... 100WITH.

In some models of air conditioners, manufacturers use combined sensor designs. In this case, they combine the functionality of several devices.

Applications of various types of refrigerant

Ранние модели автомобилей с кондиционерами используют фреон маркировки R12. Это более старый тип рабочего вещества. Для перестройки системы под новый фреон T 134 понадобится использовать другие элементы системы:

• a condenser is needed with greater heat dissipation;
• connecting flexible pipe due to penetration ability T 134 must have a synthetic inner layer;
• for an updated receiver, material XH7 will be required as a filler;
• The new expansion valve must withstand more pressure;
• unlike old threaded connections, new quick-release elements must be used;
• connecting pipes will not have a pipe thread, but a metric one, in order to eliminate errors during refueling.

These two types of refrigerant are incompatible with each other. T 134 is more environmentally friendly, although as a result its turnover is lower relative to 10 ... 15%. Unlike R12, использующем для смазки масла на минеральной основе, в R114A применяют полиалкиленово-гликолевое смазку (PAG). При смешивании таких масел в системе произойдет неизбежный и скорый выход из строя рабочего компрессора. В подкапотном пространстве даже информационные таблички для T 134 и R12 отличаются по цвету, соответственно зеленые и желтые.

Control methods

It is customary to divide the systems according to the method of control into automatic and manual ones. In the first case, the equipment is called "climate control".

The manual unit is started by the standard A / C button from the instrument panel. Adjusting the air supply is performed by a rotating knob from the minimum to the maximum values ​​indicated by “min” and “max”. The flow direction is carried out by moving the gratings in the desired direction.

With these devices, the driver adjusts the comfortable atmosphere inside the cabin. The effective operation of the air conditioner reflects various external and internal factors, including the air temperature outside the cabin, the speed of the vehicle, crankshaft speed, and the power of the compressor unit.

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During manual adjustment, the driver is forced to periodically be distracted by the adjustment parameters. In some cases, this causes certain inconveniences for motorists.

Modern car models are equipped with automatic air conditioning control. The driver is only required to set the desired temperature parameters on the device. The system will independently bring the climate to the required values, adjusting the intensity and distribution of cold air flows.

Automation has the ability to create and maintain in the cabin auto zone with different temperature conditions.

Climate control is equipped with a large number of sensors and diagnostic electronics than manual air conditioners. Various additional dampers, valves, valves are installed in it. Also among the automatic modes provides the ability to manually adjust the settings.

The working temperature range, which is able to provide climate control, is usually within 18 ... 28WITH.

Data on the current system settings are displayed on the work display. While reducing the ambient temperature to +5With the air conditioner is turned off.

Service of the climatic equipment

To ensure the smooth operation of the system helps proper and timely maintenance of automotive air conditioners. It is advisable to carry out seasonal cleaning especially in the spring during flowering, for example, from poplar fluff.

It is possible to control the possible leakage of freon with the help of fluorescent lamps, if special markers are included in the composition of the working substance. The presence of a sufficient amount of refrigerant is determined through the viewing window or during the diagnostics at the service station.

Detection of gas bubbles indicates depressurization of the pipeline. Often this occurs at the connecting joints.

Capacity of the compressor depends on the tension of the drive belt. In some brands of cars it is combined with the main drive of the car.

It is impossible to leave the air conditioner without switching on for a long time. Due to the presence of a small amount of oil in the refrigerant, the compressor and the rest of the system are lubricated. For proper further operation, it is necessary to turn on the installation at least a quarter of an hour once a month. This will ensure lubrication of the seals and keep the parts from drying out.

Dozapraka freon is performed on cars every 2 ... 3 years, along with service.

It is advisable to select service stations using vacuum systems. You can refill the car with a refrigerant yourself, but you will definitely need to apply the brand of substance that is indicated on a special plate in the engine compartment. It also contains the value of the working volume.

Self-check air conditioner

When buying a car in the secondary market, it is necessary to control, apart from other parameters, the operation of the climatic equipment. To check it is enough to take a room thermometer. His testimony will be objective data during the diagnosis, in contrast to the subjective sensations of the driver.

Mount the thermometer in front of the driver's side of the grille. We start the engine and let it work for 5 ... 10 minutes at a speed of 1000-1500 rev / min. Then you can turn on the air conditioner at maximum speed. To do this, scroll the tuning knob to the stop.

Turn on the recirculation mode (blocking the flow from the outside) and in the settings set the air flow in the direction indicated by the "face" icon. In this case, all windows and doors must be closed.

After the temperature stabilizes, which comes in a few minutes, we fix the readings of the degrees and measure the temperature outside the cabin. If the obtained information shows a significant run-up with theoretical data, then the system needs to be repaired.