The design and principle of operation of the system
Rice. 25. Aircraft A-320
The air conditioning system of the A-320 aircraft (Fig. 25) of an open air cycle with a turbocharger, a loop scheme for separating moisture in the high pressure line and partial cabin air recirculation. Its schematic diagram is shown in fig. 26.
Air sampling in SCR can be performed from engine compressors, APU or high pressure ground air source.
When air is taken from the APU, its consumption is: on a hot day (+38 °С) 3300 kg/h; on a cold day (-23 °C) 4500 kg/h; on a normal day (from -5 to +30 °C) 2950 kg/h.
The nominal values of air supply to the system: on the ground - 3970 kg / h, in flight - 2940 kg / h. It is possible to change the supply within 80 ... 120% of the norm. In case of shutdown of one cooling unit, the air supply is reduced to 60% of the norm.
If the ACS fails during the flight, air is supplied from the velocity pressure through a special air intake located below on the left side of the fuselage. The air intake opens at the command of the pilot, while the pilot must lower the flight altitude (less than 3048 m). The system provides for air supply from a ground-based air conditioner with the engines and APU turned off. In both these cases, the air is supplied directly to the cold air collector.
Rice. 26. Scheme of the air conditioning system of the aircraft A-320
The system provides ventilation of the passenger compartment and cockpit in accordance with JAR, 25.831 (a) and (c), in all flight modes, including in emergency situations.
The air bled into the system from the ringing line is fed through flow regulators to two identical independent cooling units (Packs). The flow regulators can be switched to the following positions:
- “Low” (“low”, 80%), which can be selected for fuel economy purposes at the discretion of the pilot with a reduced number of passengers or when environmental conditions allow;
- “Normal” (“norms”, 100%), which corresponds to normal operating conditions;
- "High" ("high", 120%) - is selected in abnormally hot environments or to remove smoke;
— “closed” — to turn off the unit.
If normal or low mode is selected and one of the air-cooling units fails, the flow controller in the other unit's line will automatically go to high mode.
The composition of the cooling installation, the scheme of which is shown in Fig. 27, includes a primary air-to-air heat exchanger, a main air-to-air heat exchanger, a three-wheeled turbo-chiller (THU), a heat exchanger-superheater, a heat exchanger-condenser, a dehumidifier.
Cold air from the cooling units is fed into the cold air collector (Fig. 26) installed under the cabin floor, where it is mixed with the recirculated air. The cabin air entering the underground space is sucked through the filters by recirculation fans and fed through the check valves to the collector. The recirculation air consumption is from 37 to 51% (under normal conditions) of the total.
Rice. 27. Scheme of the cooling installation (Pack) or secondary cooling unit
The air from the cold and hot air collectors is mixed and enters the distribution system (Fig. 28). The passenger cabin is conditionally divided into two zones - front and rear. Air supply to these zones and temperature control in them is carried out independently. Prepared air is distributed in each zone through pipelines located on the right and left sides in the underground part of the cabin.
Rice. Fig. 28. Scheme of air supply to the passenger compartment of the A-320 aircraft: 1 - air supply through the upper outlets, 2 - air supply through the lower outlets, 3 - air supply pipeline to the upper zone, 4 - air outlet from the cabin, 5 - left air supply pipeline to the front (rear) zone.
From these pipelines, air enters pipelines evenly distributed along the length of the cabin, supplying air to the upper zone of the cabin. Through the upper and lower outlets, located above and below the luggage racks, respectively, air enters the cabin.The air outlet to the underground space is made in the lower zone near the wall.
The advantages of this system are the following original design solutions:
1. Cabin air recirculation mode - depending on the number of passengers;
2. Air intake, depending on the engine operating mode, is carried out either from the 5th or 9th stage of the compressor;
3. Providing in-flight air supply in case of failure of even two engines (due to the intake of outside air directly into the cabin through opening emergency air intakes);
4. Automated system (in terms of management).
Recirculation button VAZ 2110 photo
Manual for using the recirculation button VAZ 2110
Application
Fast warming up of the car, protection from harmful gases, pollen and burning, in the VAZ 2110 is carried out by the recirculation button. In a VAZ car, two different methods of air intake are used:
In the article we will consider in detail the second item of the list. Recirculation was mounted selectively on VAZ 2110 cars, the cars of 2001 were equipped with it, but since 2002 only the button has remained. In such machines, the recirculation system required additional installation and was mounted independently, at the request of motorists.
Working mechanism
When the recirculation button is in the pressed (on) position, the electro-pneumatic valve opens, then a damper extends in the area of the intake piping and blocks the access of outside air to the vehicle interior.
The circulation system starts up exclusively when the engine is running and functions due to the coordinated operation of the valve-damper complex. The circulation in the machine will continue as long as the fan is turned on, in which case the air flow passes through the heater air ducts.
To determine the presence of this device in the car, first of all, chips and a button must be present in the cabin. When the ignition and the recirculation button are on, there should be voltage on the chips.
Then, it is worth checking whether the damper control valve and the electro-pneumatic valve are present. If this system is not available, you can use a fan to block exhaust gases and smoke, but the damper isolates the car from outside air much more effectively.
To adjust the level of humidity in the car and solve the problem of fogging the windows, an air conditioner is recommended in the VAZ model 2110.
Troubleshooting
In the event of a device breakdown, experts recommend diagnosing in the following sequence:
- the ignition and the engine are switched on;
- set the maximum fan speed;
- the recirculation button is pressed;
- the damper mechanism is activated.
With uniform movement and if the damper stopped at the end point, in the first 2-3 seconds, they indicate that the complex is in good condition.
But pops, uneven movement, clicks indicate a malfunction.
To extend the life of the complex, it is required to install a stabilizer. Due to the operation of the stabilizer, where the damper is located, the torque of the electric drive is reduced. To exclude the possibility of damper breakage for a while before the purchase of the stabilizer, the damper is disconnected from the electric drive by a wire.
Flaws
- Fogging of glasses during the operation of the complex;
- Lack of air exchange;
- Air conditioning installation;
- The cost of installing and repairing additional equipment (valve, electric drive, stabilizer, etc.).
Advantages
The recirculation mode allows you to quickly reduce the temperature in the VAZ 2110, due to the coordinated operation of the mechanisms (valve-electric drive). This is realized by a long run of air through the climate control complex, the temperature of which is much lower than outside the car.
Cooling in the VAZ model 2110 due to recirculation is economically beneficial, because.the energy consumption for starting the compressor drive to the widow is less than during the intake of air from outside.
By activating recirculation, the possibility of pollen, unpleasant odors and gases entering the VAZ 2110 interior is excluded.
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Features of the air recirculation system VAZ-2110
When the recirculation button is pressed, an electro-pneumatic valve is activated, which extends the damper located in the area of the inlet pipeline, thereby blocking the entry of outside air into the cooling system. Like the air conditioning system, recirculation only works when the engine is running. The well-coordinated functioning of the VAZ-2110 recirculation valve and the damper will ensure the operation of the circulation mode while the fan is on, while the air flow circuit will be limited to the stove air duct.
How to determine if this mode is present in a particular car?
As a rule, the recirculation button in the VAZ-2110 family is almost always present. The second necessary condition for the presence of SR is the presence of a chip: when the ignition is turned on and the recirculation key is turned on, voltage must be applied to the chip, which can be checked with a tester. It is also necessary to check whether an electro-pneumatic valve is installed in the machine that closes the damper. If not, there is no recirculation mode, and in order to prevent exhaust gases and dust from entering the passenger compartment, turn off the fan. At the same time, external air is not injected into the VAZ-2110, but some of it will still fall into the cabin by gravity. Using the recirculation mode guarantees better protection.
Advantages and disadvantages
Note that the recirculation mode is useful only in certain cases. It has a number of disadvantages, due to which blocking the access of outside air is allowed for a short time:
- rapid fogging of windows, especially if there are several passengers in the cabin;
- lack of air exchange, leading to a decrease in the amount of oxygen in the cabin;
- installation of an air conditioning system is required in its absence;
- you will have to bear additional costs for the maintenance / repair of the system (valve, damper drive mechanism).
At the same time, air recirculation in a VAZ-2110 car makes it possible to lower the temperature inside the car much faster, since the air circulation circuit is limited to climate control ducts, where the temperature is obviously lower than outside. From the point of view of efficiency, the use of this mode at the initial stage of movement is more profitable, since the energy costs for setting the damper in motion are significantly lower than when the compressor is operating with an open damper.
Diagnosis of malfunctions of the recirculation system
If outside air continues to flow when the button is pressed, this indicates a malfunction in the system. You can determine the cause of the breakdown by diagnosing the cooling system, which involves the following steps:
- turning on the ignition, starting the power unit;
- setting the maximum fan speed mode;
- pressing the recirculation key.
This causes the valve to actuate and the damper to close. If the vehicle is moving at a constant speed and the damper is fully closed within a few seconds, the system is working properly. If there are suspicious sounds (clicks, pops) and jerky movement of the damper, we can talk about the presence of problems.
