No Longer Worry About The Air Conditioning Malfunction Of The Tractor

Nowadays, more and more tractors and harvesters are using air conditioning, and the working environment for drivers is also getting better. However, with the increasing use of air conditioning on agricultural machinery, there are also more and more faults in the use of air conditioning. The overall manifestation of air conditioning faults is not cooling, but there are many reasons that cause non cooling. The most common ones are non cooling caused by blocked circuits and poor plug contact, non cooling caused by refrigerant leakage in pipelines, non cooling caused by relay and temperature controller faults, non cooling caused by compressor faults, non cooling caused by compressor belt damage, and non cooling caused by compressor electromagnetic clutch faults. Due to the general unfamiliarity of tractor drivers and service personnel with the structure and principle of vehicle air conditioners, the maintenance and repair of air conditioners on tractors now mostly rely on professional personnel from air conditioning manufacturers, or are carried out by professional air conditioning maintenance personnel in society, resulting in untimely and high costs of air conditioning maintenance services, which makes users and dealers dissatisfied. It is recommended that agricultural machinery manufacturers increase the skill training of air conditioning installation and debugging personnel to reduce the occurrence of later use failures caused by improper installation and debugging during production; Secondly, we need to increase the training of air conditioning repair and maintenance skills for users, dealers, and our own service personnel to improve the timeliness of air conditioning services; Thirdly, agricultural machinery manufacturers should match products from well-known air conditioning manufacturers, and should not match low-quality air conditioners produced by small factories. Air conditioners are designed to increase driver comfort, not to cause inconvenience. Please pay attention to the quality of the matching air conditioners.

|Agricultural Machinery Classroom | Tractor Air Conditioning

Below we will introduce the basic principle and structure of tractor air conditioning, so that you can have a quick understanding of tractor air conditioning.

1, The basic principle of tractor air conditioning refrigeration

The refrigeration principle of air conditioning for tractors, cars, and homes is the same. In daily life, everyone knows that when wiping the body with alcohol cotton balls, there will be a cool feeling, which indicates that when the liquid becomes a gas, it absorbs heat, thereby lowering the temperature. Tractor air conditioning refrigeration uses this basic principle. In practical use, the refrigeration of tractor air conditioning is mainly divided into four processes based on the flow order of refrigerant (refrigerant): compression process, condensation process, throttling process, evaporation process, etc. These four processes cycle back and forth, using refrigerant as the medium to continuously "transport" the heat inside the tractor cab to the outside of the vehicle, achieving a decrease in the air temperature in the cab and achieving refrigeration.

2, The main components and functions of tractor air conditioning refrigeration system

The tractor air conditioning refrigeration system mainly includes five components: compressor, condenser, drying reservoir, expansion valve, evaporator, etc. Each component is connected with copper pipes or high-pressure rubber hoses to form a closed system. The refrigerant circulates in different states of gas liquid gas within this closed system. The following diagram shows the main components and composition of the tractor air conditioning refrigeration system, with evaporator 1 being the main component; 2 is the expansion valve; 3 is the inspection window; 4 is a drying reservoir; 5 is the condenser; 6 is a compressor.

1. The main functions of compressors

The compressor is the power source that drives the refrigerant to circulate continuously in the system, and also the power source of the entire refrigeration system. The power of the compressor is transmitted by the engine through the belt, and the compressor is generally installed at the front of the engine.

2. The main functions of the condenser

The condenser is similar to the radiator of the engine, and its main function is to discharge the heat of the refrigerant. Usually installed in front of the water tank of a diesel engine on a tractor, using a diesel engine fan for strong heat dissipation and cooling.

3. The main functions of the drying storage tank

The drying reservoir is connected in series behind the condenser, mainly for drying and filtering, to ensure the normal operation of the system. It is generally installed on the front side of the condenser.

4. The main functions of expansion valves

Expansion valve, also known as throttle valve, is installed before the inlet of the evaporator. Its main function is to control the change in refrigerant flow rate, throttle and reduce the pressure of refrigerant liquid, and reduce it from condensation pressure to evaporation pressure.

5. The main functions of evaporators

The function of the evaporator is to evaporate the liquid refrigerant and absorb the heat inside the cab, thereby achieving the cooling of the air inside the cab. It is generally installed at the rear of the top of the cab. There is a blower inside the evaporator, and the volume can be adjusted to continuously blow the cooled air into the cab.

3, The refrigeration process of tractor air conditioning

The low-temperature and low-pressure gaseous refrigerant (refrigerant pressure of about 0.3MPa, temperature of about 0 ℃) passing through the evaporator becomes high-pressure and high-temperature refrigerant gas (when the external temperature is 30 ℃, the refrigerant pressure is about 1.7MPa, about 70 ℃) after passing through the compressor. The compressed refrigerant enters the condenser through the exhaust pipe, and the high-pressure and high-temperature refrigerant gas enters the condenser. Under the forced cooling effect of the engine cooling fan, the refrigerant dissipates a large amount of heat through the condenser to the air, causing the gaseous refrigerant to condense and form a high-pressure and medium temperature refrigerant liquid (at this time, the temperature of the liquid refrigerant is about 60 ℃, and the pressure is about 1.6MPa), which then enters the drying storage tank. The refrigerant, after being absorbed and filtered by the drying storage tank, then reaches the evaporator through the expansion valve. The small hole function of the expansion valve (with a diameter of only about 1mm), The pressure and temperature of the liquid refrigerant decrease sharply (refrigerant pressure is about 0.3MPa, temperature is about 0 ℃), and a small amount of liquid refrigerant (about 15-20%) flashes into a gas state, then enters the evaporator and exchanges heat with the air inside the cab (about 0.1MPa, 30 ℃), absorbing heat inside the cab (transmitted through air). After absorbing heat, the refrigerant becomes gaseous (refrigerant gas pressure is 0.2MPa, temperature is about 5 ℃), and then the low-temperature and low-pressure gaseous refrigerant returns to the compressor. In this way, it is circulated in the sealed system, continuously absorbing the heat inside the car to achieve cooling until the required set temperature inside the carriage is reached.