air conditioner

Common types

air conditioner

There are many kinds of household air conditioners, including wall mounted air conditioners, cabinet mounted air conditioners, window mounted air conditioners and ceiling mounted air conditioners. However, these products have different characteristics and prices, so they should be selected according to their own needs.

According to the Forecast and Analysis Report on Production and Marketing Demand and Smart Selection of China's Refrigeration and Air Conditioning Equipment Industry from 2013 to 2017, household air conditioners are divided into the following four categories:

wall air conditioner

Wall mounted air conditioners are widely welcomed, and the technology is also constantly innovating. You should pay attention to comparing the functional differences of different brands.

The ventilation function is a new technology used in wall mounted air conditioners to improve/increase the fresh air in the home, prevent the occurrence of air conditioning diseases, and make the use more comfortable and reasonable.

In addition, silence and energy-saving design are also important to let you sleep until dawn. Some wall mounted air conditioners have ultra small outdoor units. If you plan to put the outdoor units on the balcony, this is also a good choice.

As for the wall mounted air conditioners of cold and warm type, attention should be paid to the selection of air conditioners whose heating capacity is greater than the cooling capacity to ensure the heating effect. If the electric auxiliary heating function is available, it can improve/increase the ability of heating in ultra-low temperature environment (lower - 10 ℃) (outlet temperature above 40 ℃).

vertical chamber air-conditioner

To adjust the temperature of a wide range of spaces, such as large living rooms or commercial places, the vertical cabinet type air conditioner is suitable. When selecting, pay attention to whether there is a negative ion sending function, because it can clean the air and improve/increase health. However, some cabinet type air conditioners have the mode locking function, and the operation status is controlled by the owner, which is more useful for commercial places or families with children at home, and can avoid unnecessary damage.

In addition, whether the air supply range is far enough and wide enough is also important. At present, the distance of the vertical cabinet type air conditioner can be more than 15 meters. With wide angle air supply, a larger area can be considered.

Window type air conditioner

Convenient installation, low price, suitable for small rooms. When selecting, pay attention to its mute design. Because the window unit is usually more noisy than the split air conditioner, it is better to select a window unit that is close to the noise standard of the split air conditioner. In addition to the traditional window type air conditioner, there are also new styles, such as the color panel children's machine designed for children, with voice prompts, which is lively, practical and safe, and also a good choice.

Ceiling type air conditioner

Innovative air conditioning design concept: the indoor unit is hoisted on the ceiling, and the air is supplied from all sides at wide angles. The temperature is adjusted quickly, and the indoor decoration will not be affected.

According to the air conditioning function, air conditioners can be divided into single cooling air conditioners and cold and warm air conditioners. Single cooling air conditioner: It has no heating function, and is suitable for areas with hot summer or sufficient heating supply in winter. Cooling and heating air conditioner: it has heating function.

According to its heating mode, it can be divided into heat pump type and electric auxiliary heating type. The heat pump type is suitable for hot summer and cold winter areas; The electric auxiliary heating type is suitable for hot summer and cold winter regions because of its strong heating capacity due to the addition of electric auxiliary heating components.

The above air conditioners can also be divided into: single cooling type: only used for refrigeration, suitable for areas with warmer summer or sufficient heat supply in winter. Cold and warm type: with heating and cooling functions, it is suitable for hot summer and cold winter areas. Electric auxiliary heating type: the electric auxiliary heating function is generally only used for high-power cabinet air conditioners. The body is equipped with electric auxiliary heating components to ensure strong heating in winter. However, it does not seem necessary in northern areas where there is sufficient heating in winter.

Composition

The structure of the air conditioner includes: compressor, condenser, evaporator, four-way valve, one-way valve capillary components.

compressor

The working process of an interdental volume pair specified in the air conditioning compressor. The gas on the side where the female screw and the male screw turn to meet each other is compressed, and this side is called the high-pressure zone; On the contrary, the screw turns to the side away from each other, and the volume between teeth is expanding and in the suction stage, which is called the low-pressure area. These two areas are separated by the contact line between the tooth surface of the male screw and the female screw. It can be approximately considered that the plane where the two screw axes are located is the interface between the high and low pressure areas.

The compressed refrigerant (e.g. Freon) becomes liquid. Then use the heat absorption phenomenon when the liquid changes to the gas state under normal pressure to cool.

The air density is very small. Take a needle for injection. Fill a needle tube with air, block the air outlet with your hand, and push the needle tube to compress the air. A needle can compress the gas by one-third of its volume.

condenser

The compressor sucks in the working medium steam with lower pressure from the evaporator, and sends it to the condenser after the pressure rises. The liquid with higher pressure is condensed in the condenser. After being throttled by the throttle valve, the liquid with lower pressure is sent to the evaporator, where it absorbs heat and evaporates to become the steam with lower pressure, thus completing the refrigeration cycle. For some applications, the gas must be a long pipe (usually coiled into a solenoid) so that heat can be lost to the surrounding air. Heat conducting metals such as copper are often used to transport steam. In order to improve the efficiency of the condenser, fins are often attached to the pipes to accelerate heat dissipation. The heat sink is a flat plate made of good heat conducting metal.

evaporator

The evaporator is an indoor unit, composed of tubes and covered with fins. Equipment for heating to concentrate the solution or precipitate grains from the solution. It is mainly composed of heating chamber and evaporation chamber. The heating chamber provides the heat required for evaporation of the liquid to promote the boiling vaporization of the liquid; The evaporation chamber completely separates the gas and liquid phases. The vapor generated in the heating chamber contains a large amount of liquid foam. After reaching the evaporation chamber in a larger space, these liquids can be separated from the vapor by their own condensation or demister.

Four-way valve

Four way valve, hydraulic valve term, is a control valve with four ports. The four-way valve is an indispensable part in the refrigeration equipment. Its working principle is that when the solenoid valve coil is in the power off state, the pilot slide valve moves to the left under the drive of the right compression spring, and the high-pressure gas enters the capillary ① and then enters the right piston chamber. On the other hand, the gas in the left piston chamber is discharged. Due to the pressure difference at both ends of the piston, the piston and the main slide valve move to the left, The exhaust pipe is connected to the connecting pipe of the outdoor unit, and the other two connecting pipes are connected to form a refrigeration cycle.

Capillary assembly

The capillary assembly includes capillary and check valve. One way valve is widely used in outdoor units of air conditioners, which is composed of auxiliary capillary and one way valve. The one way valve components of different models of air conditioners are similar with little difference. There is an arrow on the check valve, which means that the air flow can only flow in the direction of the arrow, and the reverse direction will stop, only from the auxiliary capillary. The one-way valve assembly is installed at the lower rear of the outdoor unit, and is usually wrapped with a black damping block. Asphalt coating is used for sound attenuation.

The check valve assembly is only used in the heating process of the air conditioner, and the check valve assembly does not work in refrigeration. The function of the check valve assembly in heating is to increase the flow resistance of refrigerant, reduce the flow speed of refrigerant, make the refrigerant fully evaporate in the outdoor unit, change the refrigerant gas discharged from the compressor into refrigerant liquid, and improve the heating effect of the air conditioner.

Household air conditioner

Air conditioners are divided into single cooling air conditioners and dual-use air conditioners. The working principle is the same. Most of the refrigerants used in air conditioners before were Freon. Freon is characterized by releasing a lot of heat when it changes from a gaseous state to a liquid state. When the liquid state changes to the gas state, it will absorb a lot of heat. (i.e. endothermic gasification before liquefaction and exothermic) Air conditioning is designed according to this principle.

The compressor compresses the gaseous refrigerant into high-temperature and high-pressure gaseous refrigerant, which is then sent to the condenser (outdoor unit) for heat dissipation and becomes the liquid refrigerant with normal temperature and high pressure, so the outdoor unit blows hot air.

Then it goes to the capillary tube and enters the evaporator (indoor unit). Since the space suddenly increases after the refrigerant reaches the evaporator from the capillary tube and the pressure decreases, the liquid refrigerant will vaporize and become a gaseous cryogenic refrigerant, thus absorbing a lot of heat, and the evaporator will become cold. The fan of the indoor unit will blow the indoor air through the evaporator, So the indoor unit is blowing cold air; The water vapor in the air will condense into water drops after encountering the cold evaporator and flow out along the water pipe, which is the reason why the air conditioner will produce water.

During heating, there is a component called four-way valve, which makes the flow direction of refrigerant in the condenser and evaporator opposite to that during cooling. Therefore, during heating, cold air is blowing outdoors, and hot air is blowing indoors.

In fact, it is based on the principle learned in junior high school physics that heat should be discharged when liquefying (from gas to liquid) and heat should be absorbed when vaporizing (from liquid to gas).

Operating principle of environment-friendly air conditioner:

The circulating water pump is used to draw out the water in the water tank without interruption, and the water distribution system is used to spray the water evenly on the evaporation filter layer. The outdoor hot air enters the evaporation cooling medium, and the heat exchange with the water is fully carried out in the evaporation cooling medium CELdek (honeycomb filter layer made of special materials, making the cooling effect more ideal, Sweden's high-tech patented product), Cool and clean air cooled by water evaporation and heat absorption is pressurized into the room by low-noise fan, so that the indoor hot air is discharged to the outside, so as to achieve the purpose of indoor cooling.

central air-conditioning

1、 Refrigeration principle of central air conditioning: compression type, absorption type, etc.   

 

2、 Heating principle of central air conditioning.

3、 Principle of central air conditioning system: working principle of air system, working principle of water system, working principle of coil system, etc.

1. Refrigeration principle

Liquid vaporization refrigeration is realized by the heat absorption effect of liquid vaporization and the heat release effect of liquid condensation. The liquid vaporizes to form vapor. When the liquid (refrigerant) is in a closed container, there is no other gas in the container except the liquid and the vapor generated by the liquid itself. The liquid and vapor will reach equilibrium at a certain pressure. At this time, the vapor is called saturated vapor, the pressure is called saturated pressure, and the temperature is called saturated temperature. When the liquid is in equilibrium, it will no longer vaporize. At this time, if some steam is pumped from the container, the liquid must continue to vaporize to generate some steam to maintain this equilibrium. When liquid vaporizes, it shall absorb heat, which is called latent heat of vaporization.

The latent heat of vaporization comes from the cooled object, which makes the cooled object cool. In order to make this process continuous, it is necessary to continuously extract steam from the container, and make it condense into liquid before returning to the container. If the steam extracted from the container is directly condensed into steam, the temperature of the cooling medium required is lower than the evaporation temperature of the liquid. It is hoped that the condensation of the steam is carried out at normal temperature, so the pressure of the steam needs to be increased to the saturation pressure at normal temperature.

The refrigerant will evaporate at low temperature and pressure, resulting in cold effect; And condense under normal temperature and high pressure to release heat to the surrounding environment or cooling medium. Steam becomes high-pressure liquid after condensation at normal temperature and high pressure, and its pressure must be reduced to evaporation pressure before entering the container.

Liquid vaporization refrigeration cycle is composed of four processes: working medium vaporization, steam pressure rise, high-pressure steam condensation and high-pressure liquid pressure drop.

2. Heating principle

The low-pressure gas inhaled by the compressor is compressed into high-temperature high-pressure gas by the compressor. The high-temperature gas heat exchanger increases the water temperature, and the high-temperature gas will condense into liquid. The liquid enters the evaporator for evaporation. (The evaporator also needs heat exchange media. According to the heat exchange media, the model and structure of different machines are different, and the commonly used ones are air cooling and ground source.) After the liquid passes through the evaporator, it becomes a low-pressure and low-temperature gas, which is sucked into the compressor again for compression.

In this way, the circulating water on the air conditioning side will become hot water of about 45-55 degrees. The hot water is sent to the room that needs heating through pipes, and the room is equipped with fan coil units to heat exchange the hot water and air for heating purposes.

3. System principle

 

Working principle of water system

The water-cooled central air conditioner consists of four parts: compressor, condenser, throttling device and evaporator. The refrigerant circulates in the above four parts in turn. The refrigerant (refrigerant) gas with high temperature and pressure from the compressor flows through the condenser to cool and depressurize. The condenser cooling water system brings heat to the cooling tower for discharge, and the refrigerant continues to flow through the throttling device, It becomes a liquid with low temperature and pressure, flows through the evaporator, absorbs heat, and then is compressed.

The two ends of the evaporator are connected with a chilled water circulation system. The heat absorbed by the refrigerant this time lowers the temperature of the chilled water, making the low-temperature water flow to the user end, and then heat exchange through the fan coil to blow out the cold air.

Working principle of air system

The transmission mode of fresh air is displacement, instead of the internal circulation principle of air conditioning gas and the unhealthy practice of mixing new and old gas, the outdoor fresh air will be automatically sucked into the room through the negative pressure mode, and when it enters the room through the new air outlet installed on the window of the bedroom, living room or living room, it will automatically remove dust and filter. At the same time, the corresponding indoor pipeline is connected to the exhaust outlets in several functional rooms, and the formed circulation system will take away the indoor waste gas and concentrate it on the exhaust outlet for "exhalation", while the exhaust gas will not be recycled any more, and the old and new wind will circulate well.

Operating principle of coil system

The working principle of the fan coil unit air conditioning system is to continuously circulate the indoor air with the help of the fan coil unit, so that the coil unit can be cooled or heated to maintain the required temperature and certain relative humidity of the room.

The cold or hot water used by the coil is supplied by the centralized cold source and heat source. At the same time, the fresh air, which is centrally processed by the fresh air air-conditioning room, is sent to each air-conditioning room through special fresh air ducts to meet the sanitary requirements of the air-conditioning room.

Compared with the centralized system, the fan coil unit air conditioning system has no large air duct, only water pipes and small fresh air ducts. It has the advantages of convenient layout and installation, small occupation of building space, good independent adjustment, etc. It is widely used in comfort air conditioning that requires independent control due to low temperature and humidity accuracy requirements, large number of rooms, small rooms, and small number of rooms.

Relocation and disassembly

Air conditioner relocation is a professional air conditioning technology work. It seems that the simple air conditioner relocation work has different operation results in the hands of different air conditioner relocation personnel. When it is necessary to move the air conditioner, try to choose a company authorized by the manufacturer to move the air conditioner. Otherwise, it will cause damage to the air conditioner. Air conditioner relocation is divided into two parts: disassembly and installation.

Setup Installation

Cooling settings

According to the startup index of air conditioners in summer, 30-33 ℃ belongs to level 4, and 70% of people need to start up; 33-35 ℃ belongs to Level 5, and 90% of people need to start the machine. After the air conditioner is turned on, pay attention to adjusting the indoor and outdoor temperature difference. The room temperature should be set at about 24 ℃ - 18 ℃, and the indoor and outdoor temperature difference should not exceed 7 ℃.

If the outdoor temperature is 32 ℃, the indoor air conditioner is generally 25 ℃.

When the air conditioner is cooling, the setting temperature is about 26-28 ℃. In this case, not only the human body feels comfortable, but also it is conducive to energy conservation. When the air conditioner is cooling, do not set the temperature too low. When the room temperature is adjusted to 26-27 degrees, its cooling load can be reduced by more than 8%. The experiment shows that under normal circumstances, the room temperature is kept at 28-29 degrees, and the humidity is kept at 50-60%. People do not feel stuffy or sweaty, which belongs to the comfort range. When people sleep, their metabolic capacity decreases by 30-50%. The air conditioner can be set at the sleep switch, and the temperature can be set 1 ℃ higher, which can save 10% electricity;

Heating setting

The good temperature set for air conditioning in winter is 20 ℃. Moderate indoor temperature is not only conducive to health, but also can avoid overload of air conditioning. When heating, just start the machine and use the low windshield. After half an hour, use the stroke windshield. For those who like to increase the indoor temperature, please be careful not to set the temperature at the extreme 30 ℃ that the air conditioner can withstand in winter, otherwise the air conditioner will start or stop frequently, increase the power consumption, and even damage the air conditioner compressor in serious cases. Since the heating air flow is lighter than the air, it is easy to float above the whole enclosed room. When using the wall mounted air conditioner, it is better to adjust the air outlet to the downward angle, which can save electricity.

Careful setting

The air conditioning temperature must be set within a reasonable temperature range, that is, 26 ℃~28 ℃ in summer and 18 ℃~20 ℃ in winter. The difference between indoor and outdoor air conditioning temperature shall not be too large, generally 5 ℃~10 ℃ is appropriate. If the temperature difference is too large, it is easy to suffer from colds and other physical problems after the sudden change of temperature when entering and leaving.

Installation position

The installation position of general air conditioners should avoid heat sources, and the hot air removal and noise interference should not affect the neighbors.

The installation height of outdoor unit shall be lower than that of indoor unit, which is conducive to the circulation of refrigeration oil. The outdoor unit shall be installed without hot air short circuit circulation, so as not to affect heat dissipation: the installation position shall be convenient for maintenance, easy for drainage and not to affect passers-by, and shall avoid or be far away from high-voltage lines, places with radiation and flammable and explosive places. There should be no obstructions in front of the indoor unit installation, and the jet distance of cold air (or hot air) should be increased/increased to make the indoor temperature more uniform.