Energy Saving Calculator Software for Motor (Pump & Fans) Application

I had got it from Schneider Electric. Please click here for download.

Please use it wisely. This software has more powerful tools for energy saving calculation in motor and pump application, usually called HVAC Application.

Please don't hesitate to contact me if you have any questions.

Energy Saving Calculator for Motor (Pump & Fans) Application

I have some reference for saving Calculation for Motor (Pump & Fans). Usually, this called HVAC Application. I had this calculation from Schneider Electric

Reference curves

Active power consumed by a frequency converter associated with a variable load torque (quadratic) load can be calculated as shown below.

The load torque can be defined

in the following way (mechanical friction is ignored):

C = k1 x n^2 (1)

with n = Motor rot

ation speed
k1 = Constant (varies as a function of application type)

Mechanical power of this drive is:

P = C x n
...using here expressi

on (1), we obtain:

P = k1 x n^3

In addition, the frequency converter supplies electrical power to the motor at efficiency of around 97%:

P SPEED DRIVE = P / 0.97

Mechanical power required to obtain a given flow is extracted from the following POWER-FLOW curves:

Fans

Flow	Downstream	Upstream	Variable speed drive
10	0.18	0.34	0.1
20	0.36	0.36	0.1
30	0.55	0.39	0.1
40	0.71	0.42	0.13
50	0.85	0.46	0.18
60	0.92	0.51	0.24
70	0.98	0.57	0.37
80	1	0.64	0.54
90	1	0.76	0.77
100	1	1	1

Pumping

Flow	Recirculation	With valve	Variable speed drive
10	0.71	0.39	0.1
20	0.79	0.49	0.1
30	0.86	0.58	0.1
40	0.9	0.68	0.13
50	0.94	0.75	0.18
60	0.97	0.82	0.24
70	0.98	0.89	0.37
80	0.99	0.94	0.54
90	1	1	0.77
100	1	1	1

For a valve according to manometric height H (with variable speed drive) :

Flow	H=0	H=0.5	H=0.85
10	0.06	0.15	0.35
20	0.08	0.18	0.37
30	0.1	0.22	0.41
40	0.11	0.27	0.45
50	0.13	0.35	0.52
60	0.22	0.43	0.58
70	0.34	0.53	0.66
80	0.51	0.66	0.78
90	0.73	0.82	0.9
100	1	1	1

The inclusion of a variable speed drive can satisfy these requirements by eliminating the use of control valves, which operate by reducing the effective cross-section of the pipe.

In addition, variation in motor efficiency as a function of its speed must be taken into account. To determine motor efficiency at a given speed, the following EFFICIENCY-SPEED curve is used:

Speed	Efficiency
10	0.7
20	0.78
30	0.85
40	0.89
50	0.93
60	0.96
70	0.97
80	0.98
90	0.99
100	1

Formulas

Without variable speed drive, active power consumed by a motor driving a pump or fan will therefore be:

P WITHOUT SPEED DRIVE = P RATED MOTOR x (1/s) x (I / In) x f1(Q)

... with s = Rated efficiency of motor according to speed

I / In = Current absorbed by the motor at 100% load / rated current

f1(Q) = Power as a function of flow for a fan or pump (see curves above for precise values)

The reactive power is obtained as follows:

Q = P WITHOUT SPEED DRIVE x (sin phi/cos phi)

With variable speed drive, active power consumed by a motor driving a pump or fan for a given flow will therefore be:

P WITH SPEED DRIVE = P RATED MOTOR x 1/s x (I / In) x f2(Q) x 1/v x f3(Q)

... with f2(Q) = Power as a function of flow with variable speed drive (see curves above for precise values)

f3(Q) = Efficiency as a function of speed (see curves above for precise values)

w = Motor efficiency correction factor as a function of speed
v = Variable speed drive efficiency

Reactive power consumption of the motor-variable speed drive assembly is zero.

When calculation of power consumed for a given flow has been completed, just multiply this by the number of hours of operation at this flow to obtain the energy consumption. The final result is obtained by adding together all the energy consumptions obtained for the various flows.

How To Achieve Energy Saving???

30% savings are available through existing EE solutions, but to really understand where these opportunities are, let’s understand first the main differences between Passive and Active EE.

Passive EE is regarded as the installation of countermeasures against thermal losses, the use of low consumption equipment and so forth. Active Energy Efficiency is defined as effecting permanent change through measurement, monitoring and control of energy usage. It is vital, but insufficient, to make use of energy saving equipment and devices such as low energy lighting. Without proper control, these measures often merely militate against energy losses rather than make a real reduction in energy consumed and in the way it is used.

Everything that consumes power – from direct electricity consumption through lighting, heating and most significantly electric motors, but also in HVAC control, boiler control and so forth – must be addressed actively if sustained gains are to be made. This includes changing the culture and mindsets of groups of individuals, resulting in behavioural shifts at work and at home, but clearly, this need is reduced by greater use of technical controls.
- 10 to 15% savings are achievable through passive EE measures such as installing low consumption devices, insulating building, etc.
- 5 to 15% can be achieved through such as optimizing usage of installation and devices, turn off devices when not needed, regulating motors or heating at the optimized level…
- Up to 40% of the potential savings for a motor system are realized by the Drive & Automation
- Up to 30% of the potential for savings in a building lighting system can be realized via the lighting control system
- And a further 2 to 8% can also be achieved through active EE measures such as putting in place a permanent monitoring and improvement program

But savings can be lost quickly if there is:
- Unplanned, unmanaged shutdowns of equipment and processes
- Lack of automation and regulation (motors, heating)
- No continuity of behaviors

Energy Efficiency is not different form other disciplines and we take a very rational approach to it, very similar to the 6Sigma DMAIC (Define, Measure, Analyze, Improve and Control) approach.

As always, the first thing that we need to do is to measure in order to understand where are the main consumptions, what is the consumption pattern, etc. This initial measurement, together with some benchmarking information, will allow us see howgood or bad we are doing, to define the main improvement axis and an estimation of what can be expected in terms of gains. We can not improve what we can not measure.

Then, we need to fix the basics or what is called passive EE. Change old enduse devices by Low consumption ones (bulbs, motors, etc), Improve the Insulation of your installations, and assure power quality reliability in order to be able to work in a stable environment where the gains are going to sustainable over time. After that, we are ready to enter into the automation phase or Active Energy efficiency. As already highlighted, everything that consumes power must be addressed actively if sustained gains are to be made.

Active Energy Efficiency can be achieved not only when energy saving devices and equipment are installed, but with all kind of end-use devices. It is this aspect of control that is critical to achieving the maximum efficiency. As an example, consider a low consumption bulb that is left on in an empty room. All that is achieved is that less energy is wasted compared to using an ordinary bulb, but energy is still wasted!

Responsible equipment manufacturers are continually developing more efficient products. However, while for the most part the efficiency of the equipment is a fair representation of its energy saving potential - say, in the example of a domestic washing machine or refrigerator - it is not always the case in industrial and commercial equipment. In many cases the overall energy performance of the system is what really counts. Put simply, if an energy saving device is left permanently on stand-by it can be less efficient than a higher consuming device that is always switched off when not in use.

Summarizing, managing energy is the key to maximizing its usefulness and economizing on its waste. While there are increasing numbers of products that are now more energy efficient than their predecessors, controlling switching or reducing settings of variables such as temperature or speed, makes the greatest impact.