e-Transformers
Background
The primary
driver of rising CO₂ levels in the atmosphere is the burning of fossil
fuels. To combat this, we aim to transition towards electrification, which has
the potential to significantly reduce CO₂ emissions. Electricity can be
generated from renewable sources such as solar cells or wind turbines, enabling
a cleaner and more sustainable energy system.
State of the art
Fossil
fuels are widely used for heating in various industrial processes, including
the melting of metals and ceramic materials. In the chemical industry, heat is
often generated through combustion, which contributes heavily to CO₂
emissions.
Example cement production
Today,
nearly all cement is produced using a high-temperature
burning process that relies on fossil fuels such as coal, oil, or gas. This
method is energy-intensive and one of the largest contributors to industrial
carbon emissions worldwide beside from pollution from SOx
and NOx.
Traditional electrical
heating methods
While electrical
heating methods have been explored, several challenges hinder their widespread
adoption in high-temperature industrial applications:
Material Constraints
- Cables made from materials
like aluminum or copper cannot withstand the extreme temperatures in
heating zones, where they would melt.
- Heating elements are made from
materials such as FeCrAl
(iron-chromium-aluminum alloys), which are capable of withstanding high
temperatures but cannot be used as cables extending to the power supply
due to their high electrical resistivity and brittle mechanical
properties.
Connection Issues
- Achieving robust mechanical
and electrical connections to heating elements is critical.
- Oxides, which form on metal
surfaces, have low electrical conductivity and impair connections over
time.
- Different metals used in the
connection points have varying thermal expansion coefficients. These
differences lead to mechanical instability, causing connections to loosen
during thermal cycling in the system's operation. If welded, they tend to
develop cracks, which can increase electrical resistivity or even cause
the heating element to disconnect entirely.
- The current feedthroughs from
the cables to the heating elements can be completely
eliminated, allowing for the creation of an efficient pressure
chamber around the heating elements.
Description of
e-Transformers
The
e-Transformers concept introduces a novel approach to high-temperature
electrical heating. By addressing the limitations of traditional methods, this
solution ensures reliable performance under extreme conditions.
Key features include:
- Heating elements capable of
maintaining integrity at high temperatures.
- The heating elements are energized
by magnetic induction technology, directly supplied from a grid connected
transformer. This design eliminates the need for terminals, cables, or
connections, consisting solely of the heating element material.
- A transformer is also required
in traditional electrical heating systems, as the voltage needed for the
heating elements is significantly lower than the voltage supplied by power
lines. This requirement adds a competitive advantage to the overall cost
of the heating system, because the transformer is needed anyway for all high power installations.
- A modular system that can be
adapted to different industrial processes. I.e. different levels of
temperature, dust and fluids.
- It is possible to loop back the
fluid from the process to the e-Transformer, at a very high temperature
(i.e. more than 600°C), which increases the process efficiency
considerably, because the temperature only needs to be increased by i.e.
300°C.
Possibilities and
advantages
Reduced
CO₂ Emissions: Transitioning from fossil-fuel-based systems to electrical
heating directly reduces carbon footprints.
Integration
with Renewable Energy: The system is compatible with renewable electricity
sources, enabling sustainable industrial processes.
Prototype
A 1-phased 3kW
prototype has been developed to validate the concept. It is currently being build to verify the simulation software, which makes it
possible to upscale the machine to a much higher power level. The next
prototype is expected to be around 1MW and has a 3-phased connection to the
power grid.
The
e-Transformers prototype represents a step towards electrifying industrial
heating processes, offering a cleaner and more sustainable alternative to
fossil fuels.
Solving
hard-to-abate Industries with electrical heating
e-Transformers
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Replacing fossil burners with
electrical heating at very high temperature using a robust electrical heater |
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Reliable: No terminals/cables required for
hot connection Inductive heating of Simple
elements |
Advantages: Use necessary transformer
directly Local use and production of
electricity |
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Present |
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Future options |
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Executed till now: 1. Prototype 2. 3 kW in, collaboration w. Aalborg
University, Denmark |
Future short
term prospect: Partner for industrial application
to substitute part of fossil fuel as a simple low risk add on to existing
operation Operate 1 MW e-Transformer to
substitute fuel when operation is beneficial. |
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Mogens Føns M. Sc. Mech. Eng. +45 40845804 |
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Flemming Buus Bendixen M. Sc. E. E., Ph.D. +45 61631717 |
