What is specific power consumption of compressor?

What is specific power consumption of compressor?

Specific power is how much energy is used (kW) per 100 cfm of compressed air produced. In order to develop this metric, measurements must be taken. Our lead article is a case study about a UniFirst plant in Kentucky, where Kaeser Compressors performed, what they call, an Air Demand Analysis (ADA).

What is surge in a centrifugal compressor?

Surge is defined as the operating point at which centrifugal compressor peak head capability and minimum flow limits are reached. A collection of surge points during varying compressor speed or varying inlet gas angle is fitted as surge line.

How do you calculate the power consumption of a compressor?

This trim compressor would be 45% loaded (186/414= 45%). At the 600 cfm level the kWh for the fully loaded base compressor is calculated as follows: For the trim: Specific power at 45% load would be 33.6 kW/100 cfm (from Figure 3 the unit consumes 72% of full load power at 45% which is 1.6 times the full load sp).

How do you calculate the power of a centrifugal compressor?

Centrifugal Compressor Power Calculation

1. Compressibility factor (Z) = 0.9972.
2. Molecular weight (MW) = 18.15.
3. Gas constant (R) = 1544/molecular weight.
4. Inlet temperature (T1) = 546 deg R.
5. Inlet pressure (P1) = 15 psia (don’t forget to use absolute pressure)
6. Outlet pressure (P2) = 60 psia.
7. K (Cp/Cv) = 1,274.

What is specific power consumption?

Specific Power Consumption (kcal/ Tonne) (AY) = Electrical Energy Consumption (kWh/Tonne) * Heat Rate (kcal/kWh)

What are the typical units for specific energy?

The SI unit for specific energy is the joule per kilogram (J/kg).

Why do centrifugal compressors surge?

Centrifugal compressor surge is a characteristic behavior of the compressor that occurs in situations when inlet flow is reduced and the compressor head developed is so low that it can not overcome the pressure at the compressor discharge. Compressor surge normally occurs in centrifugal and axial compressors.

How do you control the surge on a centrifugal compressor?

6 Ways to to Avoid Centrifugal Compressor Surge

1. Larger Anti-surge Valve (ASV) Size with a Quick Opening Valve.
2. Suction and Discharge Pipe Re-Routing.
3. Re-Positioning Anti-surge Tap off- Point.
4. Slowing Compressor Speed during Coast down.
5. Discharge Side Gas Flaring.
6. Hot Gas Recycle Valve Installation.

How do you calculate specific power consumption?

SEC is perhaps used due its convenience, i.e., the amount of energy can be directly reported per amount of product. Generally, SEC is calculated by dividing the amount of energy used with the amount of products.

How can I reduce the power consumption of my compressor?

Methods of Reducing Air Compressor Energy Use

1. Create and manage an air compressor operating schedule.
2. Fix existing system leaks.
3. Examine whether spray pressure can be reduced.
4. Use cooler supply air.
5. Clean air filters regularly.

How do you calculate the kW of a compressor?

kW = (A x V x 1.732 x pf)/1,000 Eqn 1 But, you can calculate kW from measured amperage accurately only if you simultaneously measure the voltage and power factor. Or use a kW meter or motor analyzer, which gives a direct kW reading.

How do you measure the shaft power of a compressor?

Calculate shaft power with C = 0.013, F = 1.08, R = 2.98, N = 2, and Q = 506.5. Assume 10% additional because this is a small compressor operating at speed above 500 rpm. Answer: Shaft Power = 47 kW.

How is the power of a centrifugal compressor calculated?

Centrifugal compressors : η is calculated from the polytropic efficiency given by the manufacturer. A chart is then used to calculate the polytropic coefficient of the gas, then the discharge temperature calculated and then the actual power needed thanks to the formula 1 above.

What is the ASV on a centrifugal compressor?

Compressor Surge Control using Anti-surge Valve (ASV)-Cold Gas Recycle The chief protecting agent of a centrifugal compressor is the anti-surge line/valve that recycles cold gas from the discharge side cooler back to the suction scrubber to keep the operating point away from the surge line. Compressor Surge Control: Hot Gas Recycle Valve

Is the centrifugal compressor the heart of any oil and gas facility?

The centrifugal compressor is the heart of any oil & gas facility and since the last 100 years has been subjected to scrutiny as to what is the perfect control mechanism.

When to avoid a surge in a compressor?

The power of a compressor surge is also proportional to the capacities (flow, power, pressure ratio) and even in the case of small turbo compressors, the gear teeth wear out when the impeller rotates in the opposite direction during a surge. The bottom line is: Always avoid a surge in compressors and other rotating equipment.