The principle of operation of any air conditioner is based on the property of liquids to absorb heat during evaporation and release it during condensation. To understand how this process takes place, consider the air conditioner circuit and its device using the example of a split system:
The main components of any air conditioner are:
- Compressor- compresses freon and keeps it moving along the refrigeration circuit.
- Capacitor— the radiator located in the external block. The name reflects the process that occurs during the operation of the air conditioner - the transition of freon from the gaseous phase to the liquid phase (condensation).
- Evaporator- a radiator located in the indoor unit. In the evaporator, freon passes from the liquid phase to the gaseous (evaporation).
- TRV (thermal expansion valve)- lowers the pressure of freon in front of the evaporator.
- Fans- create a stream of air blowing around the evaporator and condenser. They are used for more intense heat exchange with the surrounding air.
The compressor, condenser, expansion valve and evaporator are connected by copper pipes and form a refrigeration circuit, inside which a mixture of freon and a small amount of compressor oil circulates. During the operation of the air conditioner, the following process occurs:
- Freon gas enters the compressor from the evaporator at a low pressure of 3-5 atmospheres and a temperature of 10-20°C.
- The compressor compresses the freon to a pressure of 15 - 25 atmospheres, as a result of which the freon heats up to 70 - 90 ° C and enters the condenser.
- The condenser is blown with air having a temperature below the freon temperature, as a result, the freon cools down and passes from the gaseous phase to the liquid phase with the release additional heat. In this case, the air passing through the condenser is heated. At the outlet of the condenser, freon is in liquid state, under high pressure, the temperature of freon is 10 - 20 ° C higher than the temperature of atmospheric air.
- From the condenser, warm freon enters the expansion valve (TRV), which in domestic air conditioners performed in the form of a capillary (a long thin copper tube twisted into a spiral). As a result of passing through the capillary, the freon pressure drops to 3-5 atmospheres and the freon cools down, part of the freon can evaporate.
- After the expansion valve, a mixture of liquid and gaseous freon with low pressure and low temperature enters the evaporator, which is blown with room air. In the evaporator, freon completely passes into a gaseous state, taking heat from the air, as a result, the air in the room is cooled. Further, gaseous freon with low pressure enters the compressor inlet and the whole cycle is repeated.
This process underlies the operation of any air conditioner and does not depend on its type, model or manufacturer. In "warm" air conditioners, a four-way valve (not shown in the diagram) is additionally installed in the refrigeration circuit, which allows you to change the direction of freon movement by swapping the evaporator and condenser. In this case, the indoor unit of the air conditioner heats the air and outdoor unit cools it down.
Note that one of the most serious problems during the operation of the air conditioner occurs if the freon in the evaporator does not have time to completely go into a gaseous state. Then a liquid enters the compressor inlet, which, unlike a gas, is incompressible. As a result, water hammer occurs and the compressor fails. There may be several reasons why freon may not have time to evaporate. The most common are dirty filters (in this case, the blowing of the evaporator and heat transfer worsens) and the operation of the air conditioner when low temperatures ah outside air (in this case, supercooled freon enters the evaporator).
Many of us use air conditioners at home or at work to cool the air in our rooms. But not everyone knows how they function. The purpose of this article is to explain the structure and principle of operation of a split system, which are most often encountered in our daily life.
Household air conditioner device
Modern split-system is divided into two parts - outdoor and indoor units. Each of them performs its function and contains a set of appropriate equipment. Inside the case of the outdoor unit there is a heat exchanger - a condenser, a fan designed to drive air through it, and a compressor - a pressure supercharger. Of the smaller, but no less important functional elements, a dehumidifier, an expansion valve and copper connecting pipes should be distinguished. In addition, the device of this node provides for power supply from the mains, for which it has the necessary electrical elements, as well as automation tools.
Note. In the case when the design provides for the operation of a split system for heating, a four-way valve with an electric drive, a compressor heater and a condensing pressure regulator are additionally installed in the outdoor unit.
The inside of the air conditioner, in addition to the housing, contains a heat exchanger - an evaporator with, filter elements, louvers for directing the air flow and a condensate collection tray. Between the indoor and outdoor units, 2 lines for the refrigerant are laid, along a pipe with large diameter it moves in the form of a gas, with a smaller one - in a liquid state. The figure below shows the device of a split system with an indication of the main elements:
1 - compressor; 2 - four-way valve for switching between winter and summer modes; 3 - electronic block; 4 - axial fan; 5 - heat exchanger - condenser; 6 - lines for the refrigerant; 7- centrifugal fan; 8 - heat exchanger - evaporator; 9 - filter coarse cleaning; 10 - fine filter.
Principle of operation
Split - system, like any refrigeration machine, is very different high efficiency. For example: a cooler that consumes electrical power in the amount of 1 kW, has a cooling capacity of approximately 3 kW. At the same time, no laws of conservation of energy are violated and the efficiency of the installation is not at all 300%, as you might think.
It should be understood that the principle of operation of an air conditioner is not to produce cold, but to transfer thermal energy from one place to another through a refrigerant called a working fluid.
Freon acts as a working fluid, whose boiling point is almost 100 ºС lower than that of water. The trick is that for vaporization, any liquid must receive a large number of thermal energy, its working fluid and takes away from room air in the evaporator. In physics, this energy is called specific heat vaporization.
Freon evaporated in the indoor unit through the tube large diameter enters the compressor, which creates pressure in the split system and further, into the heat exchanger - condenser. The working fluid under pressure condenses intensively in it upon contact with the outside air, releasing previously absorbed heat into the atmosphere. Only now it is called the specific heat of condensation, with a constant amount of freon in the system, its value is equal to the expended energy of vaporization. How the described process takes place is shown by the diagram of the split system air conditioner:
After entering the liquid phase, the refrigerant passes through the dryer to separate moisture and enters the expansion valve. Here, due to a sharp increase in the size of the channel (nozzle), the pressure decreases and the working fluid returns to the evaporator again for another portion of heat.
Of the electrical equipment that consumes significant power, the diagram shows two fans and a compressor, other sources of energy consumption are negligible. That is, the 1 kW of electricity given in the example is spent only on the rotation of the axes of the fans and the compressor, freon does the rest of the work.
All other functions - for automation systems. Upon reaching the set temperature in the room, the sensor sends a signal to the control unit, which stops the compressor and fans, the process stops. Air environment the room has warmed up - and the sensor again initiates the start of the cooler, such cyclic operation goes on continuously. In the same time inverter split– systems, whose design is slightly different from conventional air conditioners, never stop the process. Such units are characterized by a smooth temperature change and a quiet operation of the compressor.
Note. During intensive heat exchange processes, the moisture contained in the air falls on the fins of the evaporator and condenser; for its collection and removal, the design of the air conditioner provides for a bath and a system of pipes.
To switch the unit to the air heating mode, the direction of movement of the working fluid is switched, as a result of which the heat exchangers change functions, the outer one becomes an evaporator and takes heat from environment, and the internal one acts as a capacitor, transferring this energy to the room. To redistribute flows, a four-way valve was introduced into the circuit so that you do not have to be tricky with the compressor.
Conclusion
Split system, like others refrigeration machines, is very economical due to the efficiency of its work. It is for this reason that they have gained wide popularity for creating comfortable conditions in buildings for various purposes.
How does the chiller-fan coil system work?
What is an inverter air conditioner
How to turn on the air conditioner for heating
How is antibacterial cleaning of the air conditioner
When buying a room air conditioner, it is very important to choose the right one. specifications and be responsible for the installation. According to statistics, most of the breakdowns of air conditioners occur due to their incorrect and unskilled installation. Correct sequence connecting the electrical circuit of the air conditioner is a guarantee of its high-quality and long-term performance. If the air conditioner is still installed incorrectly, the following may subsequently appear. negative characteristics: condensate leakage into the room, freon leakage, etc.
There are two types of installation of air conditioners in the premises: standard and non-standard. Standard installation- the most common, installation of air conditioning near the window, as the compressor is located on the street. It is possible to perform installation in rooms with completed repairs. Such installation is not expensive and does not take much time.
Non-standard installation of an air conditioner is quite expensive and painstaking work, which is recommended to be done only in the process of repairing the premises, since it involves the chasing of the walls.
Regardless of which installation option you choose, in order to avoid all negative consequences, before starting the installation of the air conditioner and fixtures, it is worth finding out important points. For example, such as outer join scheme and circuit diagram, the power supply system of the device, the location of input devices, the cross-section of wires and future cable routes, find out the characteristic of the wall used for the wiring route. The electrical circuit of the air conditioner must comply with the rules for the installation of electrical installations and regulatory documents. The participation of a professional team of specialists with the necessary equipment is also important.
Air conditioner connection diagram
The electrical connection diagram of the air conditioner includes the laying of external wiring, fixed every 50 cm with special clamps. The electrical wiring that fits into the boxes is attached to the wall using glue and screws, and concealed wiring located in recesses in the wall corrugated pipes attached with clamps.
When choosing a place to install an air conditioner, first of all, you need to take care of aesthetic characteristics: design and interior. It is recommended to install the air conditioner in the under-ceiling area in a place where a lot of time is not spent, as direct currents of cold air can lead to colds.
Refrigerant circuit diagram
Below is a diagram of the refrigeration circuit of the air conditioner.
The diagram was taken not from a textbook, but from the manufacturer's service documentation, therefore the designations are given in English.
Compressor- compressor, "the heart of the air conditioner." The compressor compresses the refrigerant and pumps it around the circuit.
heat exchanger- heat exchanger,
- outdoor unit - outdoor unit, that is, a condenser, cools the compressed freon below the condensation temperature
- indoor unit- indoor unit - evaporator, in it the working substance evaporates, lowering the temperature
expansion valve- expansion valve
In another way, TRV is a thermostatic expansion valve. Provides supply required amount coolant.
AT simple air conditioners its role is played by a capillary tube, without any adjustment, in inverter systems- electronic expansion valve.
2 way valve- a two-way valve, that is, a conventional valve, with two positions - open and closed
3 way valve - three-way valve, in the air conditioner, this is the service port to which the pressure gauge hose is connected to measure pressure or charge.
4 way valve- four-way valve, provides refrigerant reversal for air conditioner operation in heating mode
Strainer- filter, in this diagram it is a filter-drier, as it is installed before the expansion valve (and after, since the system can operate in reverse mode and the refrigerant changes its direction of movement).
Its task is to prevent moisture from entering the thin channel of the expansion valve - as moisture will clog it, preventing the refrigerant from passing through.
Muffler- muffler
The arrows indicate the direction of freon movement along the contour:
- solid arrow - in cooling mode
- dotted arrow - in heating mode
Also, in more complex and advanced air conditioners, they install:
- Pressure Sensors
- liquid refrigerant separators
- bypass lines
- injection systems (injection) into the compressor
- oil separators
Scheme of a multi split system
Multi split system- this air conditioner has one outdoor unit and several indoor
In this case, a few more internal blocks are added, as well as:
distributor- a distributor that splits the refrigerant flow and directs it to several indoor units.
The scheme also contains elements that are used not only in multi systems:
receiver tank- receiver.
The receiver has several purposes - protection against compressor water hammer, freon drain during repairs, etc.
In this case, this is a linear receiver that prevents freon gas from entering the expansion valve
Scheme electrical connections outdoor unit split system:
Terminal- terminal block for connecting an interconnect cable for connection with the indoor unit.
N- electric neutral
2 - power supply to the compressor from the control board of the indoor unit
3 - supply power to the fan motor for operation at 1st speed
4 -
supply power to the fan motor for 2nd speed operation
5 - power supply to the drive four directional valve to switch to heating mode
Compressor
C- common - common output of the compressor windings
R- running - working winding of the compressor
S- starting - phase-shifting winding of the compressor motor, starting
Internal overload protector- internal overload protection
Compressor Capacitor- an electric capacitor, in this case a working one (there are also starting ones, currently they are not used in air conditioners)
fan motor- engine, fan motor
thermal protector- protection against overheating, usually placed directly on the motor windings and breaks the circuit when the temperature is exceeded.
Fan Motor Capacitor- fan motor run capacitor
SV- solenoid valve - an electromagnetic valve that drives the four-way valve mechanism.
Scheme of the indoor unit of the air conditioner
Terminal block
On the terminal block, in addition to interconnections, there are also clamps for connecting power (power can be supplied and vice versa - to the external unit)
L, N - electrical line and single-phase power neutral
Filter Board- filter board, reduces the level of interference in the power supply
Control Board- control board - controls all devices, receives data from all sensors, performs thermoregulation, displays information for the user on the display, performs self-diagnosis.
main relay- the main relay is a power relay that supplies voltage to the compressor.
display board - the display module can be a line of LEDs that show the presence of power, the selected mode, an error code, or a display that also displays the temperature.
Thermistor- thermistor, thermistor, temperature sensor
Room temp. - room temperature sensor
pipe temp. - heat exchanger tube temperature sensor, evaporator
Temperature sensors can also be located in:
- control panel - to maintain the temperature at the point where the remote control is located (for example, the "I Feel" mode).
- at the inlet, outlet and midpoint of the evaporator
step motor- stepper motor,
It is used to open louvre grilles, curtains covering the fan
Content:AT modern premises for a long time with the help of air conditioners create the most comfortable climatic conditions. AT hot weather the temperature drops to the desired value, and in cold weather a warm microclimate is created in the room. The electrical circuit of the air conditioner is applied in various types and models. They are installed on walls, on the floor and under the ceiling. Thanks to modern design, conditioners organically fit into an interior of any room.
Main types of air conditioners
A variety of designs of air conditioning devices allows them to be used in the most different places. For example, models mobile air conditioners do not require installation work. Moves out of the room to the street special block or hose to remove warm air.
Very simple installation and further maintenance of monoblock devices. There are no connectors in the freon lines, so its leakage is completely excluded. These air conditioners are quiet, high efficiency, however, are quite expensive.
Mounting window air conditioners carried out in wall openings or windows. During operation, they produce a lot of noise, but due to their low price, ease of installation and maintenance, they are widely popular with consumers.
Split systems are one of the types of air conditioners. Their design includes an outdoor and indoor unit. Both parts are connected with copper pipes. Freon circulates through these pipes. The outdoor unit consists of a compressor, condenser, fan and throttle. The indoor unit has an evaporator and a fan. There are many modifications of split systems, which allows them to be installed in many places.
General scheme of the air conditioner
Each capacitor contains basic elements that perform certain functions. Inside the outdoor unit is a condenser that converts the gaseous refrigerant into liquid form. Another important element is the throttle or expansion valve. With its help, the pressure of the refrigerant decreases when approaching the evaporator. The evaporator itself is made in the form of a radiator installed in the indoor unit.
During pressure reduction, it is here that the transition of the refrigerant from liquid to gaseous form takes place. The compressor compresses the refrigerant and circulates it around. The fans create the air flows needed to blow around the evaporator and condenser. The connection of all the main elements is carried out using copper tubes. As a result, a closed circuit is formed, through which the refrigerant circulates.
Air conditioner electrical equipment
All the main elements of air conditioning systems cannot work by themselves. All work is provided by the electrical circuit of the air conditioner. General scheme includes several main parts. to the indoor unit is carried out using the terminal block Terminal. There are several terminals in the block itself. N is electrical neutral, #2 supplies power from the control board to the compressor, #3 runs the fan at speed one, and #4 at speed two. Terminal 5 supplies power to the 4-way valve actuator when entering heating mode.
There are three outputs in the compressor itself: C, R and S, denoting, respectively, the common output of the windings, the working winding and the starting winding of the compressor motor for phase shift. In addition, the circuit includes protection against overloads and overheating, as well as terminals for connecting a fan, capacitor, solenoid valve and other elements.
How air conditioner works
And where does the refreshing coolness come from on a hot summer day, it is necessary to consider in detail the main principles of air conditioning systems. To do this, it is worth recalling school physics lessons, which dealt with the absorption of heat by a liquid, and a simple experiment: cologne or alcohol was poured onto the hand, which in the process created a pleasant chill. It is this simple principle that is used in modern air conditioners.
What does a standard split system consist of? As a rule, inside it there is a closed circuit along which the liquid moves -. Flowing within the circuit, the refrigerant absorbs heat in one place in order to release it in another. This process takes place in special tubes - which are made of copper and contain transverse aluminum partitions. For faster processes, air is injected into the heat exchangers, doing this with the help of special fans.
Based on the name of the processes occurring in the heat exchanger, one of them is usually called, and the other -. When the air conditioner works "for heat" it acts as internal evaporator(the part of the air conditioner located in the room), and when working "in the cold" - everything happens the other way around. Such air conditioner working principle but what's the point?
Cold itself is not a finished product, but only a derivative of the transfer of heat with the help of a refrigerant. This process is referred to in the literature as "". Thanks to him, the performance of the air conditioner is obtained in three times higher than its power consumption. At first glance, this may cause bewilderment: 300% efficiency - is this really possible? What is a refrigerant and how can it be transferred from a room where the temperature is about 20 degrees to outside where the temperature is twice as high?
It turns out that everything is much simpler than you might think. Temperature transfer directly depends on pressure, and it does not occur linearly, but monotonously. Thus, during the transportation process, the pressure value becomes higher than the phase transition temperature. The boiled refrigerant changes its state from liquid to vapor and begins to absorb heat from the surrounding air, while creating in the heat exchanger required pressure, at which the phase transition temperature becomes lower than the ambient temperature. AT reverse process the refrigerant gives up its heat to the air and the junction temperature rises.
One more important detail in the operation of the air conditioner is closed loop, for the creation of which at least two elements are needed: - to increase the pressure and a throttle device - to lower it. The first of them is installed directly in front of the capacitor, and the second in front of.
In general, there are five elements that are indispensable in air conditioners of any type: a closed circuit, an external and internal heat exchanger, a compressor and a throttling device. They are the main component of both the simplest and the most complex split system.
Nowadays, for full-functional operation of the air conditioner, a four-way valve is added to the circuit, thanks to which it can produce both heat and cold. Such a split system is called " reverse cycle air conditioner», additional function which was the transfer of heat from the room to the street and vice versa.
- 3. Compressor- compresses freon and keeps it moving along the refrigeration circuit. The compressor can be piston or scroll (scroll) type. Reciprocating compressors are cheaper but less reliable than scroll compressors, especially in low outdoor temperatures.
- 5. four way valve- is established in reversible (heat - cold) conditioners. In heating mode, this valve changes the direction of freon movement. In this case, the indoor and outdoor units seem to change places: the indoor unit works for heating, and the outdoor unit for cooling.
- 4. Control board- Usually installed on inverter air conditioners. In non-inverter models, they try to place all electronics in the indoor unit, since
- Large fluctuations in temperature and humidity reduce the reliability of electronic components.
- 1. Fan- creates a stream of air blowing around the condenser.
- In inexpensive models, it has only one rotation speed.
- Such an air conditioner can work stably in a small range of outdoor temperatures. More than high class designed for a wide temperature Range, as well as in all semi-industrial air conditioners, the fan has 2 - 3 fixed rotation speeds or smooth adjustment.
- 2. Capacitor- a radiator in which freon is cooled and condensed. The air blown through the condenser is heated accordingly.
- 7. Freon system filter- is installed in front of the compressor inlet and protects it from copper chips and other small particles that may enter the system during the installation of the air conditioner. Of course, if the installation was performed in violation of the technology and a large amount of debris got into the system, then the filter will not help.
- 6. Union connections- connect to them copper pipes connecting the outdoor and indoor units.
- 8. Protective quick-release cover- closes the fittings and the terminal block used for connection electrical cables. In some models, the protective cover covers only the terminal block, and the fittings remain outside.
Air conditioner indoor unit
- 1. Front panel- is a plastic grate through which air enters the unit. The panel can be easily removed for maintenance of the air conditioner (cleaning filters, etc.)
- 2. Coarse filter- represents plastic mesh and is designed to trap coarse dust, animal hair, etc. For normal operation The air conditioner filter must be cleaned at least twice a month.
- 5. Evaporator- a radiator in which cold freon is heated and evaporated. The air blown through the radiator is cooled accordingly.
- 6. Horizontal blinds - adjust the direction of the air flow vertically. These blinds are electrically operated and their position can be adjusted from the remote control. remote control. In addition, the blinds can automatically make oscillatory movements to evenly distribute the air flow throughout the room.
- 7. Display panel- indicators (light-emitting diodes) are installed on the front panel of the air conditioner, showing the operating mode of the air conditioner and signaling about possible malfunctions.
- 3. Fine filter- it happens various types: charcoal (removes unpleasant
- odors), electrostatic (detains fine dust), etc. The presence or absence of fine filters has no effect on the operation of the air conditioner.
- 4. Fan- has 3 - 4 speeds of rotation.
- 8. Vertical blinds - serve to adjust the direction of the air flow horizontally. In domestic air conditioners, the position of these shutters can only be adjusted manually. The ability to control from the remote control is only in some models of premium air conditioners.
- Condensate tray(not shown in the figure) - located under the evaporator and serves to collect condensate (water that forms on the surface of a cold evaporator). Water is drained from the sump through a drain hose.
- Control board
- (not shown in the figure) - usually located on the right side of the indoor unit. This board contains an electronics unit with a central microprocessor.
- Union connections
- (not shown in the picture) -
- located at the bottom rear of the indoor unit. Copper pipes connecting the outdoor and indoor units are connected to them.
