VP 2.0 compressor test rig

The decarbonisation of industrial process heat is one of the key challenges of the energy transition. In many industrial sectors – such as the paper, food and chemical industries – a significant proportion of the energy required is used in the form of process heat at temperatures ranging from 100 to 500 °C. To date, this heat has predominantly been generated through the combustion of fossil fuels. New technological solutions are therefore required to enable industrial processes to be operated in a climate-compatible, efficient and cost-effective manner in the long term.

One promising approach is the use of high-temperature heat pumps (HTHPs), which upgrade waste heat to a higher temperature level and can thus replace fossil fuels in the supply of process heat. To this end, the Institute for Low-Carbon Industrial Processes develops and operates its own HTHP demonstration plants – the ZiRa and CoBra plants – where new system and operational concepts are tested under real-world conditions. However, a key prerequisite for high-performance HTHPs is the availability of suitable radial steam compressors. This is where the VP 2.0 compressor test rig plays a key role.

Steam Compressors as a Key Technology for High-Temperature Heat Pumps

In many industrial applications, waste heat is generated at temperatures between approximately 40 and 70°C, while central steam networks are operated at pressures of 6 to 16 bar. Commercial heat pumps can already generate usable process steam from this waste heat, but typically only at comparatively low pressures and temperatures. In order to feed this steam into existing steam networks or reuse it within industrial processes, high-performance steam compressors are required to significantly increase both pressure and temperature.

Particularly in the industrially relevant power range of approximately 0.1 to 1 MW, there is currently a lack of commercially available compressor solutions that reliably support operation with steam at high temperatures and pressures. While major manufacturers primarily focus on very large systems for the district heating market, a technological gap remains for industrial applications. At the same time, there are currently few realistic test environments available for the systematic development, testing and optimisation of such compressors.

The VP 2.0 Compressor Test Rig

The new VP 2.0 compressor test rig is being developed at the Zittau site of the Institute for Low-Carbon Industrial Processes. The aim is to establish a high-performance, application-oriented test infrastructure for the development and testing of industrial turbo-radial steam compressors. The VP 2.0 compressor test rig simulates operating conditions at a technology readiness level (TRL) of approximately 5 and enables investigations within the industrially relevant performance range.

The VP 2.0 compressor test rig provides the basis for interdisciplinary research and development on industrial steam compressors. Expertise in fluid mechanics, thermodynamics, design, electrical engineering, measurement and control engineering is incorporated into the design, optimisation and testing of the systems. By conducting tests under conditions that closely resemble real-world applications, the technological maturity of new compressor concepts can be significantly enhanced.

Particular emphasis is placed on integrating compressor development with the system development of high-temperature heat pumps. The experimental findings obtained from the VP 2.0 project are directly incorporated into the further development of high-temperature heat pump demonstration plants. This means that compressors can be examined and optimised not only in isolation, but specifically in conjunction with real heat pump systems.

Furthermore, the compressor test rig serves as a platform for collaboration with industrial partners. It enables the joint development and testing of application-oriented compressor solutions, from initial development and testing through to functional demonstrations, and supports the transfer of research results into industrial applications.

The DLR Institute for Low-Carbon Industrial Processes

At the Institute for Low-Carbon Industrial Processes, DLR conducts application-oriented research into industrial heat supply. A key focus is on the development, construction and operation of high-temperature heat pumps for industrial applications, including at the institute’s own demonstration plants, ZiRa and CoBra.

With the VP 2.0 compressor test rig, the institute is specifically expanding its research infrastructure to include the field of industrial steam compressor technology. The institute bears full responsibility for the construction, operation and scientific use of the compressor test rig. The experimental findings obtained from VP 2.0 are directly incorporated into the further development of high-temperature heat pumps and into application-oriented research and development activities.

Funding