Month: October 2021

October 25, 2021

Fuel Cell Thermal Management by CPI

As we all look forward to a greener, more sustainable energy future, the promise of hydrogen based fuel cells is certainly one of the most exciting energy technologies on the cusp of mainstream acceptance.  Fuel cells were a 10 billion dollar industry in 2019 and that is only growing as the technology continues to become more affordable and more efficient.  CPI is excited about this promising technology and even more excited that fuel cell manufacturers are choosing CPI thermal switches as key components in their evolving solutions.

What is a Fuel Cell and How does it Work?

Fuel Cell DiagramA fuel cell is an electrochemical device that combines hydrogen fuel and oxygen to produce electricity, heat and water. Fuel cells operate without combustion, so they are virtually pollution free literally producing water as a by-product. Since the fuel is converted directly to electricity and heat, a fuel cell’s total system efficiency can be much higher than internal combustion engines, extracting much more energy from the same amount of fuel. Some modern fuel cells have an overall efficiency of almost 65% compared only 20% of a gas engine. The fuel cell itself has no moving parts, making it a quiet and reliable source of power.

Of course challenges exist with fuel cells because hydrogen is not a naturally occurring element. Hydrogen must be separated from other compounds that contain hydrogen, and breaking these chemical bonds requires energy that is mostly coming from fossil fuel sources.  Until renewables provide a much higher percentage of the energy grid, it is fair to say that fuel cells aren’t entirely emissions-free. And of course, in this electrochemical reaction heat is produced along with electricity and water. This heat must be managed carefully as the temperature of the fuel cell is a significant performance changing factor. That’s where CPI comes in.

Managing Thermal Performance of Fuel Cells.

One CPI thermal switch already seeing use in fuel cells is our AD173 bimetallic thermal switch. This switch is a small form factor switch that can detect temperatures from –18C to 148C with tolerances as tight as 2.8C. The under-clamp mounting tab makes this switch perfect for pipe or exhaust mounting and the small size and custom lead lengths mean it can fit into a tight space.  Another feature of the AD series appropriate for fuel cells is the fact that it is hermetically sealed and can be deployed inside or exposed to the elements without issue. The switch is also impervious to shock and vibration for vehicle mounted cells and will not fail even under highly challenging environmental conditions.

Controlling the temperature of fuel cell reactions is critical to the overall efficiency of its operation and the AD series of thermal switches has been used for both high and low temperature detection in fuel cells for different monitoring applications.

Low Temperature Fuel Cell Detection & Prevention

Given that water is such an important part of fuel cell operation, careful precautions must be take to ensure that the water in a cell is not allowed to freeze. For this our AD series turns out to be a perfect solution as well. Deployed at a 35F set point, our AD series switches have been used to initiate anti-freeze protection extending the useful temperature range of outdoor fuel cells. 

Our AD series also offers flexible off the shelf mounting options as well as customizable lead lengths. And for those who need something more, our engineering team is able to handle custom features.

Please call our team today for a consultation on your Fuel Cell Application.

Original content published: https://www.cpi-nj.com/fuel-cell-thermal-management-by-cpi/

Fuel Cell Bus CPI Thermal Switches

October 12, 2021

CPI Helps Keep Windmills Warm

CPI Thermal Switches for Windmills

Earlier this year the state of Texas saw one of its most devastating statewide power outages when winter storms rolled through the state and left freezing temperatures behind for weeks.  While the vast majority of power was lost due to the failure of so-called thermal sources including coal, natural gas and gas power plants, and nuclear (87% of Texas’ outages were from these sources only %13 from the failure of renewable sources*) , much was made of the failure of renewable sources like solar and wind which in normal circumstances, generate about ¼ of the state’s power.

It turns out that CPI thermal switches can be part of the solution for Texas’ infrastructure improvements, particularly in the area of wind turbines. Wind turbines can be made to work reliably even in extreme weather as they do routinely in Greenland or the Artic regions of Sweden and Finland. Here’s one of the ways we help do that.

* Electric Reliability Council of Texas (ERCOT)

Thermal Switches for cold detection in Windmills

In the great Texas freeze of 2021, it was clear that winterization techniques are now a reality to deal with a rapidly changing global climate. In the case of wind turbines, many systems can be protected from cold related failure by used of special anti-freeze fluids, more weatherproof or heated gearboxes not to mention internally heated electronics which can also fail in extreme cold.

This is a proven application for CPI thermal switches which have been used in power grid applications, windmills, and shipboard military equipment to do exactly this: accurately detect cold conditions to turn on systems that heat things up!

CPI M1 thermal Switch
CPI’s hermetically sealed M1 Thermal Switch

Commonly used in these applications is our M1001 Plugstat Thermal Switch.  This switch is a hermetically sealed, bimetal thermal detector rated for accurate switching down to -17 degrees C.  It is slow make and break, providing natural hysteresis against chatter. The technology is a carefully engineered and manufactured thermocouple that has decades of proven operation in the field and in applications all over the world, both hot and cold.

In windmill applications there are actually many ways to use this switch to activate heater systems or other fail prevention systems.  For example, windmills depend on critical voltage converters to translate the mechanical energy of the turbine to electrical energy. But these converters have a lower limit on the temperature under which they can safely operate. Our switch is used as a cold temperature indicator that the converter controller software reads. If the temperature hits the low temperature set point (in this case -3C) it is a signal that the internal heating system for the voltage converter has failed to turn on. To prevent a failure, our switch sends a signal to raise a fault and shut down the converter.

In other applications the same switch closure is used to turn on local heating elements which prevent the gearbox and associated electronics from reaching  freezing temperatures which may exceed their ratings.

The switch closure can also be used in windmills to enable the flow of antifreeze by turning on pumps and generating alarms when various temperature thresholds are reached.

For Hardening the Power Grid – Think CPI Thermal Sensors and Switches.

CPI has been evolving its thermal switches for over 50 years until now, where they are arguably the most robust, fool-proof, thermal detectors in the world. When you’re protecting something as important as the power grid, your best choice is to design-in CPI.

Call us today for a free engineering consultation on your Thermal Switch Application.

SnapStat Thermal Switch wiring diagram

Original content published: https://www.cpi-nj.com/windmills-cpi-thermal-switches/