ABB KUC711AE 3BHB004661R0001 ACS1000 Accessories

ABB KUC711AE 3BHB004661R0001 ACS1000 Accessories

Comparison project: Hydraulic coupling frequency converter

Efficiency ranges from medium to low (depending on the load) to high (across the entire load range)

Cooling requirements high or low

Low to medium initial investment cost

High or low maintenance costs

Medium to high availability

Overall lifecycle cost is high and very low

The impact on the power supply network cannot be minimized by adopting an appropriate topology structure

The starting current from the power supply network reaches 600% of the rated current, which is lower than the rated current

Dynamic response low high

Environmental impact, high oil content, no harm

The space requirement for the motor is no extension of the shaft length

Extremely large in weight

The speed control range is limited, wide, and easy to adjust

The average repair time is several days and hours

Compared with hydraulic couplings, frequency converters can achieve much higher efficiency, which greatly reduces the overall cost

Life cycle cost of the body. The high starting current of constant speed motors can lead to fragile power systems

Causing serious problems. Limited speed control range, lack of ultra synchronous speed operation, dynamic response

Response and higher maintenance costs are other limiting factors for the application of hydraulic couplings.

Taking into account all the factors mentioned above and the overall lifecycle cost, we will find that electric variable frequency drives

The device is the best solution.

The above calculation is based on the following data:

Power: 9 MW; Service life: 15 years; Cost per kilowatt hour: 0.07 US dollars;

Annual operating time: 8000 hours

Fan

Water supply pump

The performance of centrifugal fans is controlled by a set of rules called fan laws, which are:

The characteristics of the feedwater pump are high reliability requirements and significant changes in load during power plant periods

Dynamic changes. Feedwater pumps typically account for the largest proportion of energy consumption in power plants.

-The air volume is proportional to the rotational speed

The wind pressure is proportional to the square of the rotational speed

With the help of current frequency converter technology, these pumps can be controlled to achieve optimal energy efficiency,

The power is proportional to the cube of the rotational speed

And it will not affect reliability. In addition, by using a frequency converter instead of a throttle valve or hydraulic system

Using couplers to control water flow can effectively reduce mechanical maintenance costs.

The following figure shows typical fan characteristics as a function of wind pressure and air volume. The figure also shows

Typical system characteristics; The working point of the system is located at the intersection of two curves, if required

Energy efficiency control of fans and pumps

If the air volume deviates from this point, it is necessary to make changes to the characteristics of the fan or system.

The control methods used have a significant impact on operating costs. For all wind generated during the power generation process

Machines and pumps: main fan and flue gas fan, feedwater pump, condenser pump, cooling water pump, and centralized supply

Traditionally, the most common way to change the working point is to use dampers that can alter system characteristics

Heat pumps and other devices can achieve high-precision control and excellent energy-saving effects through the use of frequency converters

Moving the working point from position 1 to position 2, as shown in Figure 1, will increase system losses. but

Effectively reduce maintenance costs.

Yes, using a frequency converter to increase or decrease the fan speed will automatically change the fan characteristics

Moving the operating point from position 1 to position 3 (as shown in Figure 1) will not increase any additional losses. This can greatly reduce

Low energy consumption.