Project No.:MC-IND ISR
Report No.: 20100428
PEDS
PRO ELECTRONIC DESIGN SYSTEMS
Registration Number: 2003/071737/23
PRELIMINARY REPORT ON ENRGY CONSUMPTION COMPARISON
BETWEEN INDUCTIVE AND RESISTIVE STOVE PLATE
by
Dr.P.J.L.Smit
Submitted to:
M.C.Botha
EXECUTIVE SUMMARY
A Complete Inductive Stove Plate was supplied by MC Botha for energy consumption and energy saving analyses. Results were repeatable within a 5% variation including a 3% uncertainty. A saving of up to 50% can be achieved with the Inductive Stove Plate compared to a Resistive Stove Plate and a 64% saving on time will reduce the time that the kitchen will be in operation.
Keyword: kWh, Current energy.
This graph indicates the non-linear heating of the resistive type heating plate.
The Induction plate shows a near perfect linear heating line.
This graph can be used to indicate the losses of the resistive plate.
1. INTRODUCTION
PEDS was requested to do various tests within his own discretion to test the energy saving capability of the Induction stove plate. These tests included comparison with a resistive plate, energy consumption and time.
2. BACKGROUND
Induction heating has been used in the Industry for a very long time because of its ability to generate heat in a magnetic material without touching it and with minimum losses. The introduction of induction stove plates were forced by the need for more efficient use of electrical energy and to minimize the losses.
Induction heating is the process of heating an electrically conducting object (usually a metal) by electromagnetic induction, where eddy currents are generated within the metal and resistance leads to Joule heating of the metal. An induction heater (for any process) consists of an electromagnet, through which a high-frequency alternating current (AC) is passed. Heat may also be generated by magnetic hysteresis losses in materials that have significant relative permeability. The frequency of AC used depends on the object size, material type, coupling (between the work coil and the object to be heated) and the penetration depth.(Wikipidea definition)
Induction cooking
In induction cooking, an induction coil in the cook-top heats the iron base of cookware. Copper bottomed pans, aluminum pans and most stainless steel pans are generally unsuitable.
The heat induced in the base is transferred to the food via conduction. Benefits of induction cookers include efficiency, safety (the induction cook-top is not heated itself) and speed. Drawbacks include the fact that non-metallic cookware such as glass and ceramic cannot be used on an induction cook-top.
3. METHOD
A very simple practical method was used to demonstrate and test the
efficiency of the ISP. A similar dual stove plate was installed with a
1kW and a 1.5 kW plate to be compared. A combination of current,
potential, temperature and timing instruments were used to collect
information for the results. Two identical pots with a measured 750ml
of water were placed on the plates, the current, voltage, time to
94 Deg C, frequency, kWh and temperature were measured, before
and during the heating process.
4. RESULTS
Results are based on a series of tests which were done with the same
environmental conditions to minimize the uncertainties. The results as
on the Graphs 1 and 2 show a clear indication of a much higher
efficiency by the ISP then the RSP. If the tests are to be explained
in a scientific format, then it is clear that the same amount of energy
is used to heat the same volume of water, for both heating
devices, but the RSP has a very low efficiency, while the ISP has a
much higher efficiency and hence the saving of energy.
5. CONCLUSIONS
5. CONCLUSIONS
The induction cooking plate has a much higher efficiency then
any of the solid plates on the market.
It meets the speed and capabilities of a high speed kettle.
Energy is transferred directly to the container and not by heating
insulation, metal or ceramic and then the container.
4200 Joules of energy is needed to raise the temperature of one litre
of water by one degree C. From this scientific rule, the losses can be
calculated.
The saving based on these tests will be of a much greater magnitude
when done in real life situation. It is then possible to repay the total
value of the stove plate over a period of less than twelve months
from the savings only.
It is a fact that the savings in rands will increase as the price of
electricity increases by 25% per year.
The intense heat , for example a solid plate reaches a temperature
of over 400 Deg C in just 10 minutes, generated will have a negative
effect on the cooling system of the area around it.
6. SAMPLE CALCULATIONS:
6. SAMPLE CALCULATIONS:
Calculating the monthly saving by cooking 3 small pots of 750 ml
of water per day.
Standard Solid Plate Calculation: (1500 Watt)
Time to cook 1 pot: 11 Min
Current: 5.4 Amp
AC Volts: 211.6 V
Energy Consumed: Hours x Amps x Volts
( 11/60 )x 5.4x211.6 = 209 Watt
Energy Consumed per Day = Energy Consumed x3
= 209 x 3
= 627 Watt
Monthly Energy Consumption = Daily Consumption x 30
= 627 x 30
= 18 810 Watt
= (18810/1000) x R0.73
= R13.73
Induction Plate Calculation: (2000 Watt)
Time to cook 1 pot: 4 Min
Current: 7.1 Amp
AC Volts: 211.6 V
Energy Consumed: Hours x Amps x Volts
( 4/60 )x 7.1 x 211 = 100 Watt
Energy Consumed per Day = Energy Consumed x3
= 100 x 3
= 300 Watt
Monthly Energy Consumption = Daily Consumption x 30
= 300 x 30
= 9000 Watt
= (9000/1000) x R0.73
= R 6.57
SAVING of 52% on energy and a 64% saving on valuable time.
You could save up to R1 277.00 a year based on an average of 2 plates running 1 hour per day.
Graph 1
Demonstrate the difference in energy consume
Graph 2
Graph 3
