THERMAL SOLUTIONS FOR A VARIETY OF ENERGY-RELATED INDUSTRIES
ACT is a leading provider of proven, fielded hardware for the energy sector. In addition to our commercial customers, ACT’s engineering teams have worked on large impactful energy-related programs for NASA and the Department of Energy (DOE) organizations including NREL (Nuclear Renewable Energy Lab), ARPA-E (Advanced Research Program Agency-Energy), and INEL (Idaho National Engineering Lab). These projects span a wide range, including Wind Energy, Solar, Fossil Fuel Power Plants, and Nuclear Fission for Terrestrial and Lunar/Martian power.
WIND ENERGY
Since 2000, electricity generation from wind energy has increased nearly 100-fold as nations across the globe invest in technology and implementation. Wind energy is critically important technology in the fight to eliminate CO2 emissions and as technology and supply chain continue to innovate, it should continue to drive down the levelized cost of electricity. On-shore and off-shore wind turbines have continuously evolved, scaling physical size, creating higher efficiency, and generating more usable energy. These trends are driving a need for higher-performance thermal management solutions. Wind turbines operate very similarly to a traditional fan in your house, except in reverse. Where fans use electricity to turn the blades and create airflow, wind turbines harness the wind to turn the turbine blades around a rotor, spinning a generator that can create electricity. From a thermal perspective, there are a lot of moving parts, friction forces, and control electronics that create heat in the system and must be properly and efficiently managed.
Understanding the heat sources is the first step in developing an appropriate thermal management architecture for wind turbines. With many different sources and physical locations of heat generating components, it’s important to study the entire architecture and take a system level thermal approach to drive out inefficiencies and provide an optimized performance for the wind turbine manufacturer and end users. Critical areas in designing a full thermal management system that ACT has seen from our customers include:
- Gear and hydraulic oil cooling
- Generator waste heat
- Power Electronics cooling
- Energy storage thermal management
Like most industries, the waste heat levels, form factors, etc. will drive the thermal technology selection; however, in the energy sector and especially upscale wind turbine applications there is a premium for high reliability, maintenance free, and low energy consumption solutions. This desire tends to drive designers to passive thermal management solutions. ACT’s Loop Thermosyphon Technology is 100% passive operation and highly scalable with fielded solutions ranging from 100 Watts to 100,000 Watts of waste heat rejection. The maintenance free technology extends the life of the turbine by reducing thermal wear and reduces the parasitic energy losses by removing pumps and fans in the system.
RELATED TECHNOLOGIES
Application Spotlight: Direct IGBT Cooling
A traditional enclosure cooler circulates air inside the cabinet to collect heat to the internal fin stack and transfer heat to the external heat sink for rejection to ambient air. In a scenario where a small number of components are generating the heat, it makes more sense to mount those components directly to an external heat sink. This can be achieved very easily by removing the internal heat sink and fan on one of our off the shelf Sealed Enclosure Cooling units and adding simple mounting features to the base plate. No changes are required that will impact the seal, the easy mounting, or the external heatsink performance. Thermally, the solution is significantly better by eliminating the internal, air-side delta T and shortening the conduction path. This solution also still allows ACT to maintain the cost efficiencies on common components; primarily the mounting plate, external heat sink, and fan which are used across many types of coolers.
POWER STORAGE AND CONVERSION
One of the greatest challenges within the energy industry is power storage yet it is critical in providing energy to locations in demand. Likewise converting the harvested energy into usable electricity distributed into the Grid requires sophisticated power conversion through power electronics such as inverters. These energy storage and power electronic systems require enhanced thermal management to optimize the efficiency and life while reducing the thermal energy losses. As technology advances, the power systems increase in size, speed, intelligence, complexity, and relatively: waste heat. The passive and hybrid thermal management technologies developed by ACT offer efficient thermal control with minimal energy consumption.
Grid-Tie Power Conversion Cooling: Cooling Power Electronics
ACT’s Pumped Two-Phase (P2P) Cooling products and solutions use a non-corrosive and non-electrically-conductive fluid that vaporizes and cools hot surfaces on contact. These products are ideal for cooling high-power electronics where heat loads have increased to a level beyond what traditional air and water cooling systems can effectively manage. Since the pumped two-phase technology leverages the latent heat of vaporization, it can pull more heat per molecule of fluid than typical single-phase cooling. This means it can handle the high heat flux from IGBTs and Inverters without increasing fluid flow and therefore minimalizing pump size and parasitic energy losses.
Pumped Two-phase Cooling Benefits
- Up to 85% reduction in pumping power consumption compared to single phase cooling
- Dielectric working fluid to avoid catastrophic failure in the event of a leak
- Hot Swappable connections to reduce service down time
Battery Energy Storage Systems (BESS)
ACT’s sub-ambient product line out of York Pennsylvania is ideal for battery thermal management. Batteries require a tight temperature range to operate efficiently. ACT’s hybrid environmental control unit, Vaphtek™ leverages vapor compression to operate below the ambient temperature and semi-passive two-phase heat transfer for above ambient support. This provides cooling for the BESS in hot ambient environments and an energy efficient two-phase operation in a low ambient environment. When coupled with a well-designed thermal management system the ECU will provide thermal stability to the BESS which will reduce the degradation of an under performing cell and enhance the energy storage efficiency. The key benefits of the Vaphtek™ environmental control unit system includes:
- Cooling in hot ambient environments
- Temperature stability
- Energy efficiency in mild-ambient environments
- Full thermal control
Battery Management System (BMS)
Battery Management Systems (BMS) are essential in the renewable energy sector, enhancing grid stability and enabling the integration of solar and wind energy. Lithium-ion batteries, known for their high energy density and efficiency, are the most commonly used in energy storage. Effective thermal management is crucial for the safety and efficiency of these systems. Advanced thermal management solutions such as passive two-phase thermal control, Pumped Two-Phase Cooling, Environmental Control Units (ECUs) and chillers provide precise temperature control, ensuring optimal performance even in extreme conditions. Additionally, advanced temperature monitoring and control systems leverage real-time data analytics to maintain safe operating temperatures, ensuring the longevity and reliability of battery energy storage systems.
RELATED TECHNOLOGIES
Phase change material (PCM) heat sinks can improve the thermal performance of power plants by storing thermal energy. This works by storing the low-grade heat during the day and rejecting the heat at night when the ambient temperature is cooler. ACT’s engineers explored the use of salt hydrate Phase Change Material (PCM) with ARPA-E.
NUCLEAR ENERGY AND ADVANCED THERMAL TECHNOLOGIES
Nuclear – Space
ACT is developing thermal solutions for surface-based power and both nuclear electric and nuclear thermal propulsion (NEP, NTP). The space applications require high temperature heat pipe with wicks for micro-gravity liquid return. ACT has been working with NASA to qualify and enhance our high-temperature wicked heat pipes. Once the heat has been removed from the reactor core and converted to electric energy the waste heat must also be managed. Here ACT has developed both passive and active solutions to remove heat from the cold end. This technology is highlighted in our application spotlight below.
APPLICATION SPOTLIGHT
In collaboration with the NASA Glenn Research Center on the Kilopower Project, Advanced Cooling Technologies, Inc. (ACT) designed and fabricated hybrid screen-groove titanium water heat pipes to dissipate waste heat from nuclear power systems to the radiators, as solely grooved wicks are insufficient for the varied operating environments seen in space.
Nuclear – Terrestrial
Terrestrial applications require strict safety regulations. The passive nature of the heat pipe makes it ideal for the previously mentioned micro-reactors. Heat pipes allow nuclear reactors to adapt to changing temperatures dynamically. These high temperature heat pipes are used to pull heat from the reactor core and distribute to the heat exchanger/generator. ACT has delivered high temperature thermosyphons with wicked evaporators that leverage gravity for the liquid return to the nuclear industry. Like space, work is being done to develop fully wicked heat pipes to support horizontally oriented micro-reactors.
Cold end reactor thermal management technologies are being developed to offer redundant cooling and passive thermal control. ACT has experience working and delivering thermal management solutions for the cold end temperature range.
TECHNOLOGY SPOTLIGHT
High-temperature heat pipes are used to passively and safely transfer the heat (fission power generated) from the reactor core to the intermediate coolant.
ACT’s Alkaline Metal Heat Pipes have the capability to operate up to 1100̊C. They are, therefore; ideal for removing the heat from the reactor core – typically measured around 600̊C – at the highest temperature possible in the most efficient manner.
OIL & GAS
Technology Spotlight
Funded by DOE and ARPA-E, Swiss-roll combustor is an innovative, enclosed combustion control device (ECD) that can achieve > 99.5% methane destruction and removal efficiency (DRE) for small and low-pressure emission sources (e.g. tank vent, pipeline blow down). The technology provides a perfect solution for the recently updated EPA regulatory (e.g. OOOOb/c, Subpart W).
Swiss-roll Features
- Wide flow range (from < 1 MSCFD to > 10 MSCFD)
- Made by high temperature ceramic composite material (operation temperature > 1350C) with advanced low-cost manufacturing process
- Ultra-high methane and VOCs DRE (> 99.5%)
- Ultra-compact (combustor size: 1’ cube), whole system is trailer transportable
- Scalable via modular design
- No visible flame, low NOx, no soot/ smoke
Unlike commercial air conditioners, Environmental Control Units (ECUs) are designed to be rugged. They must survive rough terrain and remain operational at the extreme temperatures and conditions to which they will be exposed. ECUs are mobile, capable, durable solutions for environmental control needs.
SOLAR ENERGY COLLECTION AND CONVERSION
APPLICATION SPOTLIGHT
TECHNOLOGY SPOTLIGHT
A loop thermosyphon is a type of high-power heat pipe that works in many cooling applications (computers, HVAC, electronics, etc.).
RELATED TECHNOLOGIES
ACT has experience designing heat pipe heat sinks to spread the heat from the solar cell and dissipate the heat through finned heat sinks. The benefit of this solution is no moving parts, resulting in the high reliability typical of traditional solar panels.
Heat engines, such as Stirling engines, thermoacoustic generators, and thermionic converters, are often used to generate electricity from solar energy. In these processes, solar energy is concentrated onto a solar receiver which absorbs the solar energy as heat. Performance is improved by using ACT’s high-temperature heat pipes to acquire the high-temperature heat from the receiver and transfer the heat isothermally to the hot side of the engine with minimal losses.
ENERGY RECOVERY FOR COMMERCIAL BUILDINGS
APPLICATION SPOTLIGHT
When 3M Korea encountered costly cleanroom issues due to inconsistent cooling and humidity levels, they were concerned with reducing energy costs to lower their carbon emissions. ACT configured multiple Wrap-Around Heat Pipe Heat Exchangers for both the DX and chiller-water systems, with post-installation data showing approximately $320,000 in saving for 2023, and projecting $440,000 in savings for 2024. In addition, 3M reduced their carbon output by over 1,100 metric tons.
TECHNOLOGY SPOTLIGHT
Wrap-Around Heat Pipe Heat Exchanger (WAHX) systems can be designed for all major air handler units (AHU) OEMs. Control options, corrosion-resistant coatings, and enhanced dehumidification are all benefits of the Wrap-Around HVAC system. When retrofitting existing HVAC systems, ACT can ship a pre-engineered unit, fully charged and ready to install. ACT offers onsite installation of HVAC systems or units can be factory installed. Typical HVAC design-build/install costs are recouped in a 1-2 year payback period.
RELATED TECHNOLOGIES
Air-to-Air Energy Recovery Heat Pipe Heat Exchanger (AAHX) is a counter-flow heat exchanger-energy recovery system that features ACT’s high-performance, highly-reliable copper-water heat pipes. These systems save energy by pre-cooling or pre-heating your incoming building supply air and save you money on utility and energy costs.
