Brief Discussion on the Application of Frequency Converter and Energy Saving Analysis

1 control the starting current of the motor

When the motor is directly started by the power frequency, it will generate 7~8 times of the rated current of the motor. This current will greatly increase the electrical stress of the motor winding and generate heat, thus reducing the life of the motor.

The inverter speed regulation can be used under the condition of zero speed and zero voltage. Once the relationship between frequency and voltage is established, the inverter can work according to v/f or vector control to drive the load. Using the frequency conversion speed regulation can fully reduce the starting current and improve The winding bearing capacity has the direct benefit to the heating enterprise that the maintenance cost of the motor is further reduced and the service life of the motor is increased.

2 Reduce voltage fluctuations in power lines and improve power quality

When the motor power frequency starts, the current will increase dramatically and the voltage will fluctuate greatly. The magnitude of the voltage drop will depend on the power of the starting motor and the capacity of the distribution network. Voltage drops can cause voltage sensitive devices in the same power supply network to trip or operate abnormally, such as DCS systems, PCs and contactors, etc. After adopting the frequency conversion speed regulation, the voltage drop can be eliminated to the greatest extent due to the stepwise start of the zero frequency zero voltage.

3 requires less power to start up

The motor power is proportional to the product of current and voltage. The power consumed by the direct start motor of the workpiece will be much higher than the power required for the inverter to start. The direct start of the 315kw circulating pump will cause the surge generated by the motor to be The equipment has a serious impact, even causing the transformer to over-current trip, and thus is warned by the electric industry department, and using the frequency converter to start and stop the motor will not cause similar problems.

4 adjustable acceleration and deceleration function, running speed and torque limit The inverter speed adjustment can freely set the acceleration and deceleration time according to the user's needs. The acceleration and deceleration modes can also be selected, for example, straight type, S type and so on. In this way, the motor or the connected mechanical part shaft or gear does not generate severe vibration, further reducing mechanical wear and loss. At the same time, the potentiometer or hand-operator can be used to adjust the running speed conveniently and smoothly. After adjusting the frequency converter, the corresponding torque limit can be set to protect the machine from damage, thus ensuring the continuity of the production process and the product. Reliability, the current frequency conversion technology makes the torque limit adjustable, and even the torque control accuracy can reach 3%~5%.

5 energy saving

Pumps and fans are the most powerful power equipment in heating enterprises. After using the inverter, the energy consumption can be greatly reduced. For example, the data of the blower motor of the 10T furnace is Pmn=55KW, Nmn=980r/min, and the output air volume. Under the same premise, the measured data before and after the inverter is used is:

Before the 511 is equipped with the inverter (adjust with the damper)

U1=380vI1=82AP1=48KW

512 after using the inverter

U1c=380vI1c=42AP1c=27KW The measured data is the power measurement data. Today, the energy saving effect is calculated as follows:

51211 motor energy saving calculation

(1) Annual energy consumption before using the inverter (12 hours per day, 170 days per year)

W1=48@12@170kw#h=97920kw#h(2) Annual consumption power after using the inverter W2=27@12@170kw#h=55080kw#h(3) Annual energy saving vW=97920-55080= 42840kw#h

51212 line loss energy saving

The blower electric lock has a length of 115km, and the copper conductor cross-sectional area is S = 100m2. The line loss before and after the inverter is calculated as follows:

(1) Single wire resistance

R=01017@1500/100=012558 (wherein 01017 is the resistivity of copper, the unit is 8.mm2 / m)

(2) Line loss before using the inverter

Pl1=3@822 @01255/1000kw=5114kw Wh1=5114@12@170kw#h=10486kw#h(3) Line loss after using the inverter

Pl1c=3@42 2 @01255/1000kw=1135kw Wl1c=1135@12@170=2754kw#h(4) Annual line loss

vW=10486-2754=7732kw#h 51213 energy saving total vW=42840+7732=50572kw#h If the electricity bill is calculated per dollar, then the annual electricity saving fee vá=1@50572=50572 yuan will save more than one year. The price of a 55kw inverter itself. That is, a heating operation period cannot be used, and the cost required by the frequency conversion speed regulation technology can be recovered.

6 frequency control for pump water pipeline

The use rate of water pumps is the highest in heating companies, and the water hammer effect is the most prominent and most problematic problem for heating pipes.

When the electric water pump is started under full pressure, the starting time is less than 1 second. In less than 1 second, the flow rate of the pipeline increases from zero to the rated flow. The sharp change of the fluid flow will generate pressure in the pipeline. Excessive or too low impact force, and may appear / cavitation 0 effect phenomenon.

The pressure impact on the pipe wall will produce noise, just like a hammer hitting a pipe, called the / water hammer effect. 0. The water hammer effect not only produces noise, but more seriously it will also cause physical damage. At the moment when the pressure is too high, the tube may be broken. When the pressure is too low, it will cause the tube to collapse. The cavitation effect causes a strong agitation of the liquid which causes erosion of the inner wall of the pipe and vaporization of the liquid, and the water hammer effect can also damage the valve and the fastener. In the case of direct shutdown, the potential energy of the liquid will overcome the inertia of the motor, causing the system to stop sharply, which will also cause pressure shock and water hammer effect.

After adopting the frequency conversion speed regulation, the lifting and reducing time can be set according to the needs, so that the flow rate change rate in the pipeline system can be reduced to the allowable range, thereby achieving the purpose of completely and completely eliminating the water hammer effect, and the method is very simple. And the effect is the most ideal.

Copper Cooling Tube

Copper Cooling Tube

[HIGH REFRIGERATION EFFICIENCY]Good heat dissipation and refrigeration capability,high strength at low temperature.Copper tubes are hollow,so has strong heat transfer capability.If you need refrigeration for refrigerators, freezers, air conditioners, this is a good choice

[COPPER MATERIAL]Copper refrigerator tube has the features of high temperature resistance, corrosion resistance, oxidation resistance, durability, long service life
[SOFT & SHAPE CHANGEABLE]Because refrigeration copper pipe can bend and deform, they can often be made into elbows and joints. Smooth bending allows copper tubes to bend at any angle
[WIDELY APPLICATION]Refrigerator Tubing is not only used for refrigerator, freezer and air conditioner as refrigeration tubing coil, but also used as a HVAC system pipe.

Condenser Copper Tube,Copper Cooling Tube,Copper Tube Air Cooling,Copper Cooling Fin Tube

FOSHAN SHUNDE JUNSHENG ELECTRICAL APPLIANCES CO.,LTD. , https://www.junshengcondenser.com