Daniel Lager

Simulation and optimisation for thermal debinding of copper MIM parts using thermokinetic analysis

Abstract The thermal debinding behaviour, i.e. the removal of the backbone binder component, of a metal injection moulded copper part was investigated at four different heating rates using a NETZSCH TG 449 F1 Jupiter Thermo-Nanobalance up to 500°C. The derivative thermogravimetry signals corresponding to mass change indicated that thermal debinding decomposition occurred in multiple steps. Using the calculated kinetic parameters through Friedman analysis, such as pre-exponent factors and kinetic energies, a non-linear regression model was established. The prediction was made for the behaviour under rate controlled mass loss (RCM) condition for predefined linear mass loss. The resulting temperature–time profiles were compared with the results of RCM experimental runs. The agreement between the experimental data and the thermokinetic data under RCM was found to be very satisfactory.

Durability of a fin-tube latent heat storage using high density polyethylene as PCM

Polymers have rarely been used as storage materials in latent heat storages up to now. Thus, we systematically screened all polymers available on a large-scale, selected promising ones based on their theoretical properties and experimentally tested more than 50 candidates. We found that polyethylene, polyoxymethylene and polyamides are promising even as recycled material. Especially high density polyethylene (HDPE) turned out to be suitable as was shown by detailed thermophysical characterization including more than 1000 heating and cooling cycles for INEOS Rigidex HD6070EA. We built a storage with 170 kg HDPE and a total mass of 600 kg based on a fin-tube heat exchanger and characterized its energy capacity, power characteristics and temperature profiles using a thermal oil test rig. In total we performed 30 melting and crystallization cycles where the whole storage was above 100 °C for more than 140 hours. After usage we examined the interior of the storage by cutting it into various pieces. A thin layer of degradation was observed on the surfaces of the PCM which is most likely related to thermo-oxidative degeneration of HDPE. However, the bulk of the PCM is still intact as well as the heat exchanger itself.

Methodology to determine the apparent specific heat capacity of metal hydroxides for thermochemical energy storage

Thermochemical energy storage uses reversible thermochemical reactions to store and release heat, representing a promising technology for energy conservation and utilizing fluctuating renewable energy sources and waste heat. Many recent studies have focused on determination of the enthalpy of reaction of possible thermochemical materials (TCM) based on thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). So far, comparatively few attempts have been made to characterize the apparent specific heat capacity at constant pressure

Experimental characterization and simulation of a fin-tube latent heat storage using high density polyethylene as PCM

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High-Temperature Energy Storage: Kinetic Investigations of the CuO/Cu2O Reaction Cycle

cpappT of the investigated TCM. The purpose of this study is to outline a measurement and analysis procedure to evaluate

Fluid dynamics simulations for an open-sorption heat storage drum reactor based on thermophysical kinetics and experimental observations

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