Air conditioning energy meterIt mainly consists of two parts: sensors and converters. The sensors include flanges, liners, motors, measuring tubes, excitation coils, sensor housings, and other parts; The converter includes internal circuit board and converter housing.

(1) Converter: Provides stable excitation current for sensors, amplifies the induced electromotive force obtained through sensors, converts it into standard electrical or frequency signals, and displays real-time flow and parameters for flow display, control, and regulation.

(2) Flange: used to connect with process pipelines.

(3) Lining: A complete layer of electrically insulating and corrosion-resistant material on the inner side of the measuring tube and the sealing surface of the flange.

(4) Electrode: A pair of electrodes are installed on the wall of the measuring tube perpendicular to the magnetic field lines to detect flow signals. The electrode material can be selected according to the corrosion performance of the measured medium. Also equipped with 1-2 grounding electrodes for grounding and anti-interference in flow signal measurement.

(5) Measuring tube: The measured medium flows through the measuring tube. The measuring tube is made of non-magnetic stainless steel and flange welded together, lined with insulation lining.

(6) Excitation coil: A set of coils are installed on the upper and lower sides of the measuring tube to generate a working magnetic field.

Air conditioning energy meterBased on Faraday's law of electromagnetic induction. The two electromagnetic coils at the upper and lower ends in Figure 3 generate a constant or alternating magnetic field. When a conductive medium flows through the electromagnetic flowmeter, an induced electromotive force can be detected between the left and right electrodes on the flowmeter tube wall. The magnitude of this induced electromotive force is proportional to the flow velocity of the conductive medium, the magnetic induction intensity of the magnetic field, and the conductor width (the inner diameter of the flowmeter measuring tube). The medium flow rate can be obtained through calculation. The equation for induced electromotive force is:

E=K×B×V×D

Among them: E - induced electromotive force;

K - Instrument constant;

B - Magnetic induction intensity;

V - Average flow velocity within the cross-section of the measuring tube;

D - Measure the inner diameter of the tube.

When measuring flow rate, the fluid flows through a magnetic field perpendicular to the flow direction, and the flow of conductive fluid induces an induced potential proportional to the average flow velocity. Therefore, it is required that the conductivity of the flowing liquid being measured be higher than the minimum conductivity of 5 us/cm (electromagnetic flow meters can theoretically measure conductive media with conductivity greater than 5 μ s/cm, but in actual measurement, it should be ensured that the electromagnetic flow meter is used in environments where the conductivity of the measured medium is 50 μ s/cm or more (one to two orders of magnitude greater than the theoretical value), and the conductivity value obtained online must be used as a reference). The induced voltage signal is detected through two electrodes and transmitted to the converter through a cable. After a series of analog and digital signal processing, the cumulative flow rate and instantaneous flow rate are displayed on the converter's display screen.