ACT Offers a Variety of Pumped Two-Phase Cooling Options

In 2018, ACT acquired Parker Hannifin Corporation’s Precision Cooling Business which designs and manufactures Pumped Two-Phase Cooling products for industrial and defense power electronics applications. This acquisition also enhanced ACT’s experiences in pump reliability and field installation and service for this technology.

ACT’s Pumped Two-Phase (P2P) Cooling Products and Solutions are based on patented technologies and use a non-corrosive and non-electrically-conductive fluid that vaporizes and cools hot surfaces on contact. These products are ideal for cooling of high-power electronics where heat loads have increased to a level beyond what traditional air and water cooling systems can effectively manage.

By combining a non-conductive dielectric refrigerant with the science of heat dissipation through vaporization, our Pumped Two Phase Cooling Products can increase power densities for high-power electronics by more than 2x over traditional water/glycol systems, while eliminating the dangerous consequences of a fluid leak. Although the systems are leak-tight, should an accidental leak occur, the non-conductive fluid is inherently safe even when in direct contact with sensitive electronics.

Combining the high heat removal of the two-phase heat transfer technology with the high reliability of low-flow liquid pumping, ACT’s P2P system is highly modular (hot-swappable) and scalable. With such high efficiency, it simplifies the plumbing and reduces the overall size and weight, providing an excellent thermal performance/cost ratio. And, due to the inherent non-corrosive properties of the fluid, no regular end-user maintenance is required.

how Pumped Two-Phase Cooling Compares

The test results shown in the graphic below clearly demonstrate the benefits of ACT’s P2P products.  The data compares the maximum power and thermal resistances of various cooling solutions.  The maximum power dissipation was determined through testing by increasing the module power until the junction temperature reached a common limit of 120°C.

Fielded Systems for Power Electronics show advantages versus traditional cooling systems:

Pumped Two Phase Cooling Systems can enable higher-density electronics in your current or new rack systems. A 2-3X greater density benefit is realized simply by integrating ACT’s unique two-phase evaporative cooling system. Alternatively, where rack redesign is not practical, P2P solutions are also available in a stand-alone drop-in replacement for legacy air- or water-cooling systems. This consists of a stand-alone cooling unit, complemented by cold plate kits added at the sub-system level.

ACT’s Pumped Two-Phase Cooling Systems leverage common components and have been designed for 8kW, 30kW, and 50kW capacities. To meet specific customer performance needs, some level of customization is required.

Using non-corrosive, non-conductive fluid to vaporize and cool hot surfaces on contact, ACT’s Pumped Two Phase Cooling Systems is ideal for high-power electronics systems with heat loads above those that traditional air- and water-cooling systems cannot support.

How Does Pumped Two-Phase Cooling Work?

A basic Pumped Two-Phase cooling system, as shown in the video below, has a pump, one or more cold plates to remove heat, a condenser to condense the two-phase mixtures, and an accumulator.

1. The liquid flows through hard tubing or hose to a low-flow pump
2. The pump moves saturated liquid across a cold plate directly attached to a heat source. With the latent heat transfer, the liquid immediately starts to vaporize
3. Heat is carried away by the vapor
4. Vapor moves to an air- or water-cooled condenser where it re-condenses into liquid and the heat is dissipated
5. Excess liquid is stored in the accumulator ready to be pumped back into the system

Fully Customized Pumped Two-Phase Systems

The Thermal Experts at ACT have been providing custom solutions since 2003.  Anywhere from design and analysis, and prototyping, to full-scale manufacturing, ACT is an industry leader in custom thermal solutions for the most challenging applications.  Full-scale custom P2P systems can be designed to meet the unique specifications of each customer’s application.  Read our case study that details our work with Intel, Pumped Two Phase Cooling for High-Performance Computing Applications.  No matter where you are in your project, ACT is your trusted thermal partner.

Consider Pumped Two-Phase Cooling for Applications that:

• Have critical packaging constraints
• Have a propensity for high cyclical loads
• Call for more power output from a given device package (e.g., increased switching frequency or difficulty in paralleling devices)
• Need modular and easy field service (quick-dry break connectors)
• Involve high-voltage and use de-ionized water
• Require elimination of the chiller

Industries Benefiting from Pumped Two-Phase Products:

• Industrial Power Electronics
• Power Transmission and Distribution
• Alternative Power Generation
• Hybrid and Industrial Vehicles
• Marine and Rail Propulsion
• Medical Equipment
• Telecommunications and Data Centers
• Military

Industrial Power Solutions – Medium Voltage Motor Drives and Electronic Stability Programs

The high dielectric strength properties of our coolant make ACT’s Pumped Two Phase Cooling Systems ideally suited for medium voltage motor drive applications, especially considering the reluctance to use water around high voltage electronics. In addition, our electrically isolated fluid interconnect system allows for modular cold plate designs that more easily isolate high-voltage circuits.

• Supports motor drives 1 MW to 4 MW
• Increased power throughput of 40% or more
• Higher reliability
• Field Serviceable – Highly modular IGBT cold plate design

Pumped Two-Phase Cooling for Renewable Energy Solutions

Example of a Pumped Two-Phase system layout for an Industrial Power application

The less weight in the nacelle or power conversion container, the better. ACT’s Pumped Two Phase Cooling Systems have been designed in a rack-ready design or can be configured as a drop-in replacement solution to easily retrofit legacy water- or air-cooling systems. ACT can cool the full range of wind turbine/power generation systems, including the converter/inverter, reactor, transformer, and generator with compelling benefits, including:

• Scalability: 20 – 300 Kw of cooling
• Improved system efficiency due to low parasitic pumping power requirements
• Cost: up to 20% system-level cost savings
• Power Density: 2x or more increase in power density
• Size and Weight: up to 50% smaller/lighter
• Safety: The fluid used is non-corrosive, does not conduct electricity, and needs no freeze protection
• Service: Hermetically sealed system with 50,000 hr L10 life. No regular service is required.
• Extended Temperature Rating: No de-rating in hot climates

Grid-Scale Energy Storage & Power Conversion – Container Solutions (Wind and Solar)

ACT delivers thermal systems for grid energy storage for wind and solar farms, configured to customer requirements for battery and power conversion:

• 20’ and 40’ ISO container configurations
• Adaptive thermal management, to meet individual configuration demands:
  • Air cooling (HVAC)
  • Pumped Two-Phase Cooling
  • Hybrid- a mix of both cooling technologies (Air Cooling and Pumped Two-Phase)

Pumped Two-Phase Cooling for Hybrid/Electric Industrial Vehicles

Agricultural and construction equipment continues to strive for more ways to increase power and fuel economy through electrification and energy storage of key motor functions. These high-energy (HE) motor drives require aggressive thermal management solutions, and ACT is pleased to deliver these benefits:

• Smaller, more robust cooling systems
• Up to 40% power higher throughput than traditional cooling methods
• Safety: Nonconductive fluid is inherently safer for:
  • Ultracapacitors
  • Battery modules
  • IGBT modules
• Greater IGBT reliability and overload protection
• Fluid requires no freeze protection
• Ability to cool all electronics on one loop

Pumped Two-Phase Cooling for Data Center and Edge Computing Solutions

ACT’s Pumped Two-Phase (P2P) Cooling Systems provide stationary and portable data centers with increased processing performance density while reducing overall life cycle costs. Both are achieved through much greater cooling efficiency than that of air or water cooling.

• Enabling over two times rack performance density
• Higher reliability
• Reduced energy consumption – no chiller or dedicated HVAC required
• Space savings – up to 50% smaller cooling system footprint
• 20’ and 40’ container options (up to 350KW per container)

Pumped Two-Phase Cooling for DEWs, Directed Energy Weapons Systems

DEW systems harnessing the output of an array of laser diodes often find that the effectiveness and accuracy of the laser is influenced by the thermal management of these laser diode arrays. Pumped Two-Phase (P2P) cooling offers the needed temperature uniformity and thermal responsiveness that traditional single-phase cooling cannot provide for these high heat loads across multiple diodes within reasonable packaging constraints.

• Maintains temperature uniformity across dozens of laser diodes
• Prevents temperature spikes during “fire” or on/off mode
  • Auxiliary (standby) electronics cooled using single-phase flow
  • Boiling initiates once primary components are turned on
  • Two-phase heat transfer allows for a rapid transient response
• Added reliability and system benefits
  • Non-corrosive fluid avoids catastrophic failure if ruptured
  • No freeze concerns
  • Smaller pumps / low flow rate requirement

Is space the next frontier for this advanced technology? Our R&D team has been investigating for some time.

Pumped Two-Phase Cooling Summary