Alexander Morgenstern - Academia.edu (original) (raw)
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Papers by Alexander Morgenstern
Fraunhofer IRB Verlag eBooks, 2015
Solar Energy, Jun 1, 2014
An enhanced evaporatively cooled open sorption cycle which can be driven by solar thermal heat is... more An enhanced evaporatively cooled open sorption cycle which can be driven by solar thermal heat is presented as an environmentally benign alternative to conventional air conditioning cycles. Experimental data of the core component – the desiccant coated heat exchanger – cooled by water evaporation are given. This evaporation of water in the heat exchanger leads to an increase in adsorbed water mass by 46% and an enhancement of the cooling capacity by factor 4.1 when compared to a solely air cooled process. By simulation analysis, the recently designed heat exchanger is then compared to data of an air cooled open sorption process published in earlier research. Measurement data of this earlier research are analysed with a dynamic model. It is demonstrated that only a fraction of the dry desiccant mass was actively cycled in the earlier prototype. Simulation of the evaporatively cooled current prototype underlines the enhanced performance that can be achieved with the new concept and prototype design.
Fraunhofer IRB Verlag eBooks, 2015
Fraunhofer IRB Verlag eBooks, 2015
Kühlen und Klimatisieren mit Wärme., 2015
Kühlen und Klimatisieren mit Wärme., 2015
Kühlen und Klimatisieren mit Wärme., 2015
Fraunhofer IRB Verlag eBooks, 2015
Fraunhofer IRB Verlag eBooks, 2015
World Academy of Science, Engineering and Technology, International Journal of Environmental and Ecological Engineering, Jan 25, 2016
BTU Cottbus - Senftenberg, 2005
Kühlen und Klimatisieren mit Wärme., 2015
In this paper, a desiccant solar unit for air<br> conditioning and desalination is presente... more In this paper, a desiccant solar unit for air<br> conditioning and desalination is presented first. Secondly, a dynamic<br> modelling study of the desiccant wheel is developed. After that, a<br> simulation study and an experimental investigation of the behaviour<br> of desiccant wheel are developed. The experimental investigation is<br> done in the chamber of commerce in Freiburg-Germany. Indeed, the<br> variations of calculated and measured temperatures and specific<br> humidity of dehumidified and rejected air are presented where a good<br> agreement is found when comparing the model predictions with<br> experimental data under the considered range of operating conditions.<br> Finally, the study of the compartments of desalination and water<br> condensation shows that the unit can produce an acceptable quantity<br> of water at the same time of the air conditioning operation.
Device for the controlled, representative taking water samples, consisting of a) a control module... more Device for the controlled, representative taking water samples, consisting of a) a control module (1) with an upper packer (3) and a sensor unit (4) with sensors (5) for measuring flow (5.1), temperature (5.2), conductivity (5.3), pH (5.4) and redox potential (5.5) at the measuring point , in which a plurality of flow sensors (5.1) are arranged distributed on the circumference and probe b) a sampling module (2) with a lower packer (6) and a specimen chamber (7) and in this integrated sensors (5) for measuring temperature (5.2), conductivity (5.3) and pressure (5.6) and a data logger module (8) for recording the sensor data, c) wherein the control module (1) and the sampling module (2) via a connection unit (9) are detachably connected together.
L’invention concerne un dispositif et un procede de sechage de l’interieur de modules solaires. L... more L’invention concerne un dispositif et un procede de sechage de l’interieur de modules solaires. Le dispositif et le procede sont en particulier appropries pour des concentrateurs photovoltaiques (CPV). Le dispositif de sechage presente a cet effet un adsorbant destine au sechage et un element chauffant destine a chauffer un gaz en circulation et il est relie par branchement a une cellule solaire, de sorte que le gaz seche soit conduit dans la cellule solaire.
Solar Energy, 2017
Abstract A design of a box-type solar cooker was modeled and tested in the region of Sfax-Tunisia... more Abstract A design of a box-type solar cooker was modeled and tested in the region of Sfax-Tunisia. This solar cooker was designed to allow reaching relatively high temperatures during days with low solar radiation owing to four outer reflectors. A mathematical model, which is based on thermal balances, was developed and implemented in a Matlab program to predict the thermal performances of the solar cooker. Several tests were effectuated in order to validate the robustness of the mathematical model and to determine the thermal performance of the solar cooker. The obtained results showed an acceptable matching between the experimental temperature values and the computed temperature values with a maximum error inferior to 4%. It was also proven that the use of four outer reflectors improved the optical efficiency of the solar cooker. Indeed, the first figure of merit passed from 0.07 to 0.14 and the maximum temperature of the absorber plate passed from 81.3 °C to 133.6 °C. The sensible loading test revealed that the calculated second figures of merit for different water loads were in the range of 0.34–0.39. Finally, two real cooking process were carried out where 72 min and 107 min were required to fully cook rice and beans respectively.
Fraunhofer IRB Verlag eBooks, 2015
Solar Energy, Jun 1, 2014
An enhanced evaporatively cooled open sorption cycle which can be driven by solar thermal heat is... more An enhanced evaporatively cooled open sorption cycle which can be driven by solar thermal heat is presented as an environmentally benign alternative to conventional air conditioning cycles. Experimental data of the core component – the desiccant coated heat exchanger – cooled by water evaporation are given. This evaporation of water in the heat exchanger leads to an increase in adsorbed water mass by 46% and an enhancement of the cooling capacity by factor 4.1 when compared to a solely air cooled process. By simulation analysis, the recently designed heat exchanger is then compared to data of an air cooled open sorption process published in earlier research. Measurement data of this earlier research are analysed with a dynamic model. It is demonstrated that only a fraction of the dry desiccant mass was actively cycled in the earlier prototype. Simulation of the evaporatively cooled current prototype underlines the enhanced performance that can be achieved with the new concept and prototype design.
Fraunhofer IRB Verlag eBooks, 2015
Fraunhofer IRB Verlag eBooks, 2015
Kühlen und Klimatisieren mit Wärme., 2015
Kühlen und Klimatisieren mit Wärme., 2015
Kühlen und Klimatisieren mit Wärme., 2015
Fraunhofer IRB Verlag eBooks, 2015
Fraunhofer IRB Verlag eBooks, 2015
World Academy of Science, Engineering and Technology, International Journal of Environmental and Ecological Engineering, Jan 25, 2016
BTU Cottbus - Senftenberg, 2005
Kühlen und Klimatisieren mit Wärme., 2015
In this paper, a desiccant solar unit for air<br> conditioning and desalination is presente... more In this paper, a desiccant solar unit for air<br> conditioning and desalination is presented first. Secondly, a dynamic<br> modelling study of the desiccant wheel is developed. After that, a<br> simulation study and an experimental investigation of the behaviour<br> of desiccant wheel are developed. The experimental investigation is<br> done in the chamber of commerce in Freiburg-Germany. Indeed, the<br> variations of calculated and measured temperatures and specific<br> humidity of dehumidified and rejected air are presented where a good<br> agreement is found when comparing the model predictions with<br> experimental data under the considered range of operating conditions.<br> Finally, the study of the compartments of desalination and water<br> condensation shows that the unit can produce an acceptable quantity<br> of water at the same time of the air conditioning operation.
Device for the controlled, representative taking water samples, consisting of a) a control module... more Device for the controlled, representative taking water samples, consisting of a) a control module (1) with an upper packer (3) and a sensor unit (4) with sensors (5) for measuring flow (5.1), temperature (5.2), conductivity (5.3), pH (5.4) and redox potential (5.5) at the measuring point , in which a plurality of flow sensors (5.1) are arranged distributed on the circumference and probe b) a sampling module (2) with a lower packer (6) and a specimen chamber (7) and in this integrated sensors (5) for measuring temperature (5.2), conductivity (5.3) and pressure (5.6) and a data logger module (8) for recording the sensor data, c) wherein the control module (1) and the sampling module (2) via a connection unit (9) are detachably connected together.
L’invention concerne un dispositif et un procede de sechage de l’interieur de modules solaires. L... more L’invention concerne un dispositif et un procede de sechage de l’interieur de modules solaires. Le dispositif et le procede sont en particulier appropries pour des concentrateurs photovoltaiques (CPV). Le dispositif de sechage presente a cet effet un adsorbant destine au sechage et un element chauffant destine a chauffer un gaz en circulation et il est relie par branchement a une cellule solaire, de sorte que le gaz seche soit conduit dans la cellule solaire.
Solar Energy, 2017
Abstract A design of a box-type solar cooker was modeled and tested in the region of Sfax-Tunisia... more Abstract A design of a box-type solar cooker was modeled and tested in the region of Sfax-Tunisia. This solar cooker was designed to allow reaching relatively high temperatures during days with low solar radiation owing to four outer reflectors. A mathematical model, which is based on thermal balances, was developed and implemented in a Matlab program to predict the thermal performances of the solar cooker. Several tests were effectuated in order to validate the robustness of the mathematical model and to determine the thermal performance of the solar cooker. The obtained results showed an acceptable matching between the experimental temperature values and the computed temperature values with a maximum error inferior to 4%. It was also proven that the use of four outer reflectors improved the optical efficiency of the solar cooker. Indeed, the first figure of merit passed from 0.07 to 0.14 and the maximum temperature of the absorber plate passed from 81.3 °C to 133.6 °C. The sensible loading test revealed that the calculated second figures of merit for different water loads were in the range of 0.34–0.39. Finally, two real cooking process were carried out where 72 min and 107 min were required to fully cook rice and beans respectively.