The Institute for Energy Systems and Thermodynamics at TU Wien getting ready for the testing campaign

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During the last months, IET concentrated on design tasks according to work package 4, where pre-tests for the design of the air-cooled condenser (ACC) and the recuperator (printed circuit heat exchanger) are planned. Therefor several modifications of the test rig are necessary, see Figure 1:

 

 

Figure 1: Modifications of test rig at IET. Grey: additional heat exchangers (precooler and test tube). Blue: cooling water lines.

 

With the combination precooler and test-test-tubes, desuperheating and condensation experiments at a pressure level of p = 66 bar are planned. For pure CO2 the corresponding condensation temperature is 26,11 °C. Maximum CO2-temperature will be 180 °C, so different desuperheating / condensation tests are possible depending on entrance temperature of CO2 and cooling load of the precooler. In the first step, experiments with pure CO2 will be done, then testing with blended CO2 by adding a refrigerant (R1234ze) will follow. Adding a blend will give a first impression of about the behaviour of a mixture instead of pure CO2 and will help to train the handling of harmless mixtures on the rig, in the perspective of the future planned tests with other blends being developed and tested at UBS and POLIMI.

 

 

Figure 2: Left: Precooler delivered from KELVION. Right: test rig under modification.

 

 

The SCARABEUS team keeps growing at University of Seville

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The SCARABEUS team at University of Seville keeps growing. USE is very happy to welcome Pablo Rodríguez to support the optimization and integration tasks. Find some more information about him below and follow his activities through LinkedIn here: https://www.linkedin.com/in/pablo-enrique-rodr%C3%ADguez-de-arriba-9088b91b7/

 

 

 

Pablo Rodríguez standing in front of a Ljungström turbine at the lab

 

I’m Pablo Rodríguez, a Sevillian engineer recently graduated from the master’s degree in Industrial Engineering at the Escuela Técnica Superior de Ingeniería (University of Seville). Specialised in Energy Engineering, I’m keen on topics such as energy efficiency, process optimization, power generation, renewable energies, SWRO plants or refrigeration. It’s in the latter of these subjects that I wrote my BSc and MSc theses: performing an analysis about the international regulations of refrigerants (anybody sees the link to some of the dopants used in SCARABEUS?).

 

I just joined the Thermal Power Group (Department of Energy Engineering, University of Seville) as a researcher. I’m sincerely enthusiastic about being part of the SCARABEUS project, in which I promised to put all my commitment and energy to achieve the best results.

 

Recuperator Model with design process using pure CO2

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The SCARABEUS concept relies on a recuperative cycle using supercritical carbon dioxide as working fluid. Being supercritical and in order to achieve high efficiency, very high pressures and temperatures are involved and a recuperator becomes mandatory. This is a device which can improve the thermodynamic cycle efficiency by cooling the sCO2 after its expansion and heating it after its compression, without any additional heat exchange with the environment.

 

3D model of the recuperator to be installed in the test rig at TUW

 

The advantage to use printed circuit heat exchanger technology in the recuperator is to withstand high pressure and high temperature with reduced footprint (large area-to-volume ratio). This is why PCHE is the technology of choice in SCARABEUS. The 3D model above represents the recuperator which will be installed in the test rig at TUW. It is designed for a pressure of 220 bar and a temperature of 650°C and the geometry of the internal channel configuration is shown below.

 

 

Internal channels of the PCHE developed by KELVION for SCARABEUS

 

Some CFD calculations will be performed to study new types of internal geometries in order to optimize the thermal-hydraulical performances and to decrease heat exchange area. While this technology is already very compact, the Company is pursuing further reductions of footprint.

Researchers from City pass milestone on the route to PhD

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Researchers from City pass milestone on the route to PhD

 

This week two researchers from the SCARABEUS research team at City, University of London, successfully completed their transfer from MPhil to PhD. This milestone, which has been completed just over a year since beginning at City, marks the successful transition from registration as a Master of Philosophy (MPhil) student to a full PhD candidate.

 

For the transfer, Mr Omar Aqel and Ms Salma Salah both prepared a technical report containing a literature review and an update on their work to date, and presented a 30-minute presentation over Microsoft Teams, followed by Q&A, to an internal audience of academics and researchers from City.

 

Mr Omar Aqel presented his report entitled “Optimization of cycle and turbine design for small-scale solar power plants employing CO2-based working fluids”. Within Omar’s work he has investigated the effect of candidate dopants on optimal cycle conditions within CSP applications, with a particular focus on the expansion process. Results highlighted the change in working fluid properties such as molecular weight, speed of sound, density, and the adiabatic coefficient. Having also explored the sensitivity of turbine design to dopant type and amount, Omar will now focus on the application of CO2-based working fluids in small-scale power plants. He aims to investigate their feasibility using an integrated system approach which accounts for turbomachinery design restrictions that are unique to small-scale installations.

 

 

 

Ms Salma Salah presented her report entitled “Advanced design optimisation methods for supercritical CO2 multi-stage axial turbines”. Within Salma’s work she discussed the various aspects of axial turbine design including design methodology, previous preliminary and computational fluid dynamic (CFD) studies on sCO2 turbines, in addition to existing prototypes and conceptual designs for sCO2 turbomachinery. In this work, 100 kW and 100 MW design models have been developed and a parametric study has been conducted to examine the effect of various design parameters on the performance of a small-scale sCO2 turbine. This work was concluded by detailing the future steps for her research.