Periodic Reporting for period 2 - CRCP (First liquid tolerant Centric Reciprocating Compressor enabled to Pump (CRCP))
Período documentado: 2021-10-01 hasta 2023-02-28
Compression of air in industrial applications accounts for as much as 10% of total electricity consumption in Europe (Fraunhofer Institute). The CRCP addresses specifically compression of ammonia in Waste Heat Recovery (WHR) systems and compression of hydrogen gas from electrolysis. These areas of application respond to the Green Deal call for energy savings and non-fossil mobility. In collaboration with pilot partners, we will demonstrate the efficiency of the CRCP in several ways.
In a heat pump system, the compressor and solution pump are the active (and energy consuming) components. Currently, we are pursuing two specific heat pump applications of the CRCP: Compression-Absorption Heat Pump (CAHP) systems with ammonia and water as working fluids, and water/steam heat pumps for steam generation. Both are relevant and important to a growing European market for industrial WHR and energy storage. The CRCP eliminates the need for liquid separation and solution pumping, oil removal etc, thus enabling significant cost savings for an industrial heat pump.
The role of the CRCP in hydrogen production applies in particular to the initial compression stages after electrolysis, where its liquid tolerant properties and robust design enables system simplifications providing competitive edge against existing compressor technologies.
Work performed in this period pertains to task 1. The point of departure for design and operation of the CRCP is our previous Horizon 2020 project no. 767272 (development of the Centric Reciprocating Compressor), along with parallel internal projects to develop a heavy-duty multi-phase pump. Suitable functional requirements and design specifications for the CRCP were obtained from potential pilot partners for ammonia and hydrogen.
At the outset, we carried out a fundamental design review to identify pros and cons of various configurations where mechanical stability, stroke, timing etc were considered, eventually concluding on an arrangement combining robustness, simplicity and volumetric efficiency. Advanced mathematical modelling and Computational Fluid Dynamics (CFD) analysis have been applied to support all engineering decisions especially related to key features such as mechanical tolerances, crevice (gap) openings, and ports for suction and exhaust. A system of channels and conduits has been designed to lead injection water to suitable locations for lubrication, sealing and cooling. All elements of the compressor including the control unit (CU) with elliptic gear arrangement as well as process unit (PU) were re-designed from the bottom up to reflect learning points from previous projects and considerations for improved efficiency and manufacturability. Manufacturing of compressor housing, vanes, axles, shafts etc has been sublet to high precision machine shops according to our established supply chain strategy.
The redesigned compressor parts were assembled in-house and lined up with motor, power supply, controls, and data acquisition. Testing was done commenced according to our test procedure. Results show excellent mechanical performance. Testing with air and injection water has produced very good results with respect to key functional requirements (pressure increase and fluid flow). Mechanical adjustments have been carried out to achieve even better performance, e.g. decrease of clearance gaps to reduce slip and adjustment of port positions for optimal timing.
Test procedures were developed based on Pilot partners specification and other input. The test methods were validated by external experts. Particular focus was on health and safety aspects as the gas used for testing were toxic and represented explosion risks.
CRCP compressors were rebuilt or refurbished to suite the test requirement of the pilot applications hydrogen gas and CO2 gas compression. This included applicable safety features related to explosion risks.
The CRCP compressors were tested compressing CO2 gas with very good results, i.e. very good efficiency and no failure or irregularities during testing.
The CRCP compressor was also tested with Hydrogen gas. The compression efficiency at the stated pilot inlet and outlet pressures were extremely good, showing an energy consumption of only 35% of existing technology used today. The test results have been evaluated by potential clients and by independent hydrogen and compressor experts.
After the above testing a final adjustment and optimisation has been carried out, and the compressor made ready for market.
Regarding dissemination, we have attended 3 events, produced a video and established contact with 30 partners. In terms of exploitation, at the end of the project period Otechos received the first order for the delivery of a CO2 compressor, as well as interest in the hydrogen compressor technology.
Tests have proven that the compressor is liquid tolerant and take a large liquid volume fraction in the inlet gas stream. The Otechos CR technology has proven to be able to handle all volume fraction of liquid to gas from 0% to 100% in the inlet stream.