The air conditioning and refrigeration system is mainly composed of four basic components: refrigeration compressor, condenser, evaporator, and throttle expansion valve. They are connected by pipes to form a closed system, in which the refrigerant is constantly circulating and changing, and the state changes and exchanges heat with the outside world.
In the refrigeration system, the evaporator is the equipment that transports cold energy;The refrigerant absorbs the heat of the water in it, making it chilled water to achieve refrigeration;The compressor is the heart and plays the role of inhaling, compressing and transporting refrigerant vapor;A condenser is a device that emits heat and transfers the heat of the refrigerant to the cooling water or air to take it awayThe throttle valve acts as a throttle and depressurized refrigerant, controls and regulates the amount of refrigerant liquid flowing into the evaporator, and divides the system into two parts: the high-pressure side and the low-pressure side. *Air conditioning principle includes:
1. The principle of air conditioning and refrigeration: there are compression, absorption, etc., which will not be described in detail here
Second, the principle of air conditioning system:
The working principle of the wind system, the working principle of the water system, the working principle of the coil system, etc., are briefly introduced as follows:
1. The fresh air system of the air conditioning principle works
The fresh air outside is attracted by the air handler into the wind cabinet, and after filtering, cooling and dehumidification, it is sent to each room by the air duct, the fresh air at this time can not meet the indoor heat and humidity load, and can only meet the indoor fresh air volume, with the indoor fan coil unit processing the indoor air heat and humidity load at the same time, the excess air is discharged out of the outdoor part through the return fan according to the opening ratio of the valve, and a part is returned to the air inlet for recycling again.
2. The coil system of the air conditioning principle works
When the indoor fan coil unit is working, a part of the fresh air treated by the wind cabinet is inhaled, and then a part of the indoor untreated air is inhaled after process treatment, and the cold air that can absorb the indoor waste heat and humidity is sent out by the tuyere, so that the indoor temperature and humidity reach the required standard, and so on.
The so-called ** type air conditioning (centralized air conditioning) is suitable for high-rise buildings, tourist hotels, factory workshops, gymnasiums, theaters and other large area of air conditioning equipment, its air conditioning equipment is relatively large capacity, large volume, need to configure refrigeration equipment and heating equipment, generally have air conditioning room, refrigeration station, control room ......Wait a minute.
* Air handling equipment is generally located in the air conditioning room, after the air is treated, sent to each room by the air duct, the current more widely used ** air handling equipment can be divided into a return air spray system and a return air cold water surface cooling system. Water spray air handler: At present, the prefabricated air conditioner is mostly used, which is composed of a modular grid. The box is a frame type, which is composed of standard elements, such as fresh air, return air combination section, air filtration section, surface cooling section, secondary return air combination section, heating section, steam humidification section, etc., and any combination according to the needs to meet the requirements of different air conditioning systems to deal with air. There are too many specific contents, I type too slowly, and I can't draw on the computer, so I don't have time to talk about it. *Air conditioners can be divided into residential**air conditioners and commercial** air conditioners.
Household air conditioner: Household air conditioner uses a host to drag multiple terminal devices (indoor units) through a fluorine pipeline to form a cooling and heating system.
Commercial** air conditioner: It is an air conditioner that controls different rooms by one or more hosts through air ducts or connecting multiple terminal devices (fan coil units) with hot and cold water pipes to achieve the purpose of indoor air conditioning. The air duct air supply mode is adopted, and one or more hosts are used to control multiple non-air rooms and introduce fresh air, which effectively improves the quality of indoor air and prevents the occurrence of air conditioning diseases. * Working principle of air conditioner: Air conditioning refrigeration: The air conditioning system has a built-in heat-absorbing medium - refrigerant (refrigerant), refrigeration.
After throttling through the expansion valve, the agent is evaporated and vaporized inside the indoor unit (evaporator), the indoor unit fan blows the cold air to the room to absorb the heat energy in the indoor air, the refrigerant returns to the suction end of the compressor through the pipeline, and the temperature of the refrigerant is increased through the compression of the compressor, and the refrigerant is converted from the vaporization state to the liquefied state through the outdoor unit (condenser), and in the conversion process, a large amount of heat is released, and the heat is discharged through the outdoor unit fan, and the purpose of refrigeration is achieved through repeated circulation. Air conditioning heating: Through the conversion of the electric four-way valve, the system directly enters the indoor unit condenser (the indoor unit is converted from refrigeration to heating, and the function is changed from evaporator to condenser), and a large amount of heat is discharged into the room by the fan to absorb the cold air in the roomAfter the refrigerant of the system is throttled by the expansion valve, it is converted from liquid to gas through the evaporator of the outdoor unit, and the cold air absorbed by the indoor unit is discharged to the outside through the evaporator and fan of the outdoor unit, and the refrigerant is returned to the suction end of the compressor through the pipeline. Through the cycle of repetition, the purpose of heating is achieved.
Air conditioning maintenance. The maintenance of air-conditioning system equipment mainly includes:Maintenance of chillers, air conditioning treatment equipment, cooling water systems, electrical controls and other parts.
Daily maintenance is to deal with faults found in a timely manner during patrol inspections and clean the equipment.
1. Maintenance of chiller part.
1) Remove the dust on the surface of the unit, remove rust from the metal surface and add anti-rust oil.
2) Check whether the bolts are loose, whether there is abnormal vibration and noise in the unit, and deal with it immediately.
3) Use Freon electronic leak detector to detect whether there is Freon leakage in the unit, and when it indicates that there is leakage, it should be repaired immediately to stop the leakage.
4) Check whether the oil level and oil pressure are normal, and replenish the refrigeration oil immediately if the oil level is low.
2. Maintenance of fan coil unit and fresh air conditioner.
1) Check whether the air volume and temperature of the air outlet of the fan coil unit are normal, and clean the dust of the air outlet and return air outlet.
2) Clean the dust on the surface of the fresh air conditioning cabinet, check whether the bolts on the feet and connecting bolts are loose, and whether the metal surface of the bolts and fire damper is corroded, and deal with the fault immediately.
3. Maintenance of cooling water and chilled water systems.
1) Check whether the lubricating oil in the oil tank of the water pump oil cup is normal, whether the bearing is worn, and replace the lubricating oil or bearing in time if there is a problem.
2) Check whether the shaft seal of the pump is leaking, whether the operation is normal, whether the foot bolts are loose, and whether there is water leakage in the inlet and outlet gate valves of the check valve.
3) Check whether the cooling tower is working normally, whether the connecting bolts, the pin screws are loose and corroded, and whether there are any problems in the operation of the pipeline and automatic electric valves.
4. Maintenance of electrical control parts.
1) Check whether all kinds of temperature sensors, pressure sensor controllers, water flow controllers, thermometers, and pressure gauges are loose. Problems are identified and dealt with immediately.
2) First cut off the power supply, clean the dust inside and outside the electric control cabinet, check the electronic control rejection, and start the internal components, wires and wire heads.
If there is any loose or abnormal heating, deal with the problem immediately.
Knowledge of air conditioner breakdown maintenance.
1. Air conditioner related knowledge 1. Air conditioner: The full name is air conditioner, which is a kind of equipment that directly provides treated air to rooms or other confined areas. It mainly includes refrigeration and dehumidification refrigeration systems, air circulation and purification devices, heating and ventilation devices, etc. The main function of an air conditioner is to filter, cool, and dehumidify indoor air. (Some also have heating and.)
1. Air conditioning related knowledge.
1. Air conditioner:
An air conditioner is a device that delivers treated air directly to a room or other confined area. It mainly includes refrigeration and dehumidification refrigeration systems, air circulation and purification devices, heating and ventilation devices, etc. The main function of an air conditioner is to filter, cool, and dehumidify indoor air. (Some also have the function of heating and replacing fresh air) to achieve automatic adjustment of indoor temperature. According to different functions, air conditioners can be divided into single cooling type, heat pump type and electric auxiliary heating type.
2. Inverter air conditioner:
This is a new type of air conditioner that can continuously adjust the frequency or speed of the compressor within a certain range to change the flow rate of refrigerant, and automatically adjust the output to best match the environmental conditions. Inverter air conditioners use digital signal processing and analog control combined with artificial intelligence control. Compared with ordinary air conditioners, inverter air conditioners have the advantages of fast and strong refrigeration and heating, high efficiency and energy saving, comfort and reliability, intelligent defrosting, large dehumidification capacity, ultra-quiet, and wide voltage work.
The difference between inverter air conditioner and fixed frequency air conditioner:
1) The inverter air conditioner starts to run with high power, quickly reaches the set temperature, maintains low power, and balances the room temperature, so that the refrigeration and heating are rapid, the power is saved, and the room temperature fluctuation is small.
2) Fixed-frequency air conditioners run at a fixed power and maintain the indoor temperature by frequently switching on and off, so the cooling and heating speed is slow, which has a large impact on the home power grid and large fluctuations in room temperature.
Difference Between Digital DC Air Conditioner and AC Air Conditioner:
The AC air conditioner changes the power supply frequency of the compressor, thereby changing the working speed of the compressor and the power supply frequency of 10Hz150hz；
The DC air conditioner changes the power supply voltage of the compressor, thereby changing the working speed of the compressor and the power supply voltage is 150V?260v。
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QY-JDW03** air conditioning training assessment device (network type) system using water cooling unit, stainless steel frame structure, terminal to establish a special room for customer simulation, the simulation of the hall directly use the original space of the classroom, the use of water separator and water collector to distribute and adjust the cooling or heat, the whole ** air conditioning using Mitsubishi FX2N-48MR PLC programmable controller and industrial bus control, by the computer through the communication bus and PLC communication, control the operation of the entire ** air conditioner. The operating parameters of the air conditioner are collected by various sensors, sent to the computer through the communication bus, and monitored in real time by the special air conditioning configuration control software. The configuration software can synchronously display the system structure, control principles and processes in the form of animations.
Practical training projects
1. Cognition and use of air conditioning system.
2. Refrigeration principle and heat exchange technology.
3. Identification and application of commonly used sensors in air conditioning systems.
4. PLC programming and control application of air conditioner.
5. Operation and assessment of air conditioning.
6. **Air conditioning operation protection and daily maintenance operation assessment.
7. **Air conditioning fault maintenance and assessment.
8. Inverter application.
9. Touch screen application.
10. Application of computer data acquisition and configuration control technology.
11. Network communication technology and its application.
12. It has an automatic overflow protection system.