Common sense of life: How to add refrigerant in central air conditioning

How to add refrigerant to the central air conditioner, everyone knows which operation method? Let's take a look at it with Xiaobian today!

1. Quantitative fluoride

Connect the three-way valve, pressure gauge, fluorinated hose, fluorine bottle or vacuum pump in the process port of the three-way stop valve. After the fluorine is pumped, the fluorine is slowly added. Weighing with a more accurate measuring tool such as a platform scale, When the amount of fluorine in the fluorine bottle is the scale plus fluorine on the nameplate of the air conditioner, the fluorine bottle valve is closed.

2, measuring current

Set the air conditioner to operate in the state of cooling or heating high-speed wind (the inverter air conditioner is set in the test running state). At the process port of the low-pressure shut-off valve, observe the clamp-type ammeter change while adding fluorine, and approach the rated working current of the air conditioner nameplate. When the value is closed, the fluorine bottle valve is closed. At this time, let the air conditioner inherit the operation for a period of time. When the room temperature is close to 27 ° C in the cooling state or the room temperature is close to 20 ° C in the heating state, consider the influence of the outdoor unit air temperature and the grid voltage level. The working current factor, while fine-tuning the amount of fluoride to reach the rated working current value, to achieve correct fluoride. The reason for fine-tuning is because the rated working current value of the air conditioner nameplate is tested by the air-conditioner manufacturer under the following conditions. Data: cooling state, fan high speed wind at 220V or 380V, indoor air temperature 27°C, outdoor air temperature 35°C; heating state, fan high speed wind at 220V or 380V, indoor air temperature 20°C, outdoor unit The air temperature is 7 ° C. The fine-tuned data of the practice summary is: in the cooling state, the outdoor air temperature is 35 ° C as the scale, and the outdoor temperature is increased or decreased by 1 ° C, increasing or decreasing. 1.4% of the working current value; in the heating state, the outdoor air temperature is 7 °C as the scale, and the outdoor temperature increases or decreases by 1 °C, increasing or decreasing the rated working current value by 1%; in the cooling or heating state, With the rated power supply voltage of 220V or 380V as the scale, the power supply voltage is increased or decreased by 1V, reducing or increasing the rated operating current value.

3, measuring pressure method

The air conditioner is placed in a high-speed cooling state (in winter, when heating is required to add fluorine, the air conditioner is placed in a forced cooling state or the room temperature sensor is placed in warm water of about 27 ° C, and the summer temperature is allowed to cool the air conditioner). In the process port of the low-pressure shut-off valve, observe the low pressure of the vacuum pressure gauge while adding fluorine. When the low pressure is 0.49MPa (summer) or 0.25MPa (winter), close the fluorine bottle valve. Consider the outdoor air temperature and the indoor cooling load. Factors such as size affecting low pressure, fine-tuning the amount of Freon and gauge pressure to achieve correct fluoride. The reason for fine adjustment is that the low pressure is proportional to the indoor cooling load, that is, the greater the cooling load, the higher the pressure, and vice versa. The fluorine-added process port and surrounding pipelines are affected by the outside air temperature due to installation outdoors. The actual pressure and evaporation temperature of the indoor heat exchanger are higher in summer and lower in winter. In the case of high speed wind fan and indoor temperature of 27 ° C, the low pressure pressure data is shown in the attached table.

4, observation method

The air conditioner is set to operate under the condition of cooling or heating high-speed wind. When the amount of fluoride is correct, the temperature difference between the inlet and outlet of the indoor heat exchanger is 10cm: when cooling is greater than 12°C, when heating is greater than 16°C; when cooling, indoor The heat exchanger is totally dew condensation, the average sound of evaporation is low, the condensation at the outdoor stop valve is continuous, the condensation in the summer is continuous, the connection between the indoor heat exchanger and the capillary is frost-free, etc.; when heating, the wall temperature of the indoor heat exchanger More than 40 ° C.

In the actual maintenance, the inverter air conditioner has a high requirement for the correctness of the amount of fluoride added, or the fixed frequency air conditioner should adopt the quantitative fluorine addition method when the refrigeration pipeline system needs to be vacuumed. If the pipeline system needs to add fluorine, it is better. The method of taking the current as the main measurement and the measurement of the gauge pressure as the supplement, taking into account the observation method.