Temperature control for material tests

Precise, responsive and stable temperature control for material tests and test benches.

Temperature control is a critical factor during stress and load testing during the development of alternative drive solutions, batteries, materials and other vehicle components. This testing often dictates that the heat transfer fluid used is a water-ethylene glycol mixture.

To address these applications, Huber has expanded their portfolio to include temperature control systems designed and tested specifically for use with water-ethylene glycol over the temperature range of -45 °C to 95 °C for the automotive industry.

Based on the proven Unistat technology, developed by Huber over 40-years ago, this technology operates with a very low volume of HTF, uses plate heat exchangers for efficient thermal transfer and has a sealed fluid system. This results in very short "time to temperature" times, extremely responsive, stable, accurate and repeatable temperature control.

The Unimotive series comprises of five units with up to 35 kW cooling capacity and 24 kW heating capacity. The models are fitted with a magnetically coupled, speed-controlled pump with a maximum flow of 145 l/min and pressure up to 5.5 bar. The devices can be individually configured and adapted to various test situations or integrated into existing test benches. Various sensors, expansion vessels, pumps and data interfaces are available as accessories to adapt to every application complexity.

All Unimotive models are operated using a touchscreen controller which supports the most common data communication protocols (including Profibus, Modbus, TCP, Ethernet, OPC-UA, RS232, USB) enabling easy integration into automated industrial environments.

The Unimotive devices can also be used as an alternative to, or to supplement/widen the temperature range of environmental chambers. One advantage here is the increased responsiveness of the temperature control, meaning the target temperature can be quickly and precisely achieved under varying thermal conditions in the test specimen. A combination of the Huber temperature control system plus an environmental chamber also enables simultaneous control of the test specimen temperature as a function of the ambient temperature.

The new Unimotive XT models are designed for working temperatures up to +150 °C, operating with water-glycol. The high-temperature models set new standards working with a unique, fully integrated and variable system pressure.

The overpressure in the liquid circuit can be set to a fixed value or as a ramp for the ranges above the boiling point. The variable system pressure provides better protection for the application at low temperatures. Another advantage: No external pressure is necessary for operation, i.e. the use of Unimotive does not require any special infrastructure (e.g. nitrogen gas tanks or similar). Also, the Unimotive expansion tank remains pressureless, which simplifies the risk assessment.

The Flow Control Cube (FCC) was developed for flow rate measurement and control. This optional addition to the Unimotive devices is available in two options: either as a space-saving version being mounted on top of the temperature control system or fitted with castors and placed directly on the floor. In both variants, the bypass, flow meter, interfaces etc. are housed in a compact stainless-steel module.

Flow measurement is carried out with magnetic-inductive flow meters or via a turbine flow sensor and operates over the range of 0.2 l/min to 95 l/min depending on the model.