1.
M Koehl; S Saile; K-A Weiß; S Fischer; M Meir; G Wallner; Y Louvet; F Giovannetti; F Veynandt; D Mugnier; D Philippen; A Thür
Price reduction of solar thermal system – Results of IEA SHC Task 54 Proceedings Article
In: AEE, (Hrsg.): Proceedings 1st International Sustainable Energy Conference (ISEC), S. 429-436, Graz, Austria, 2018.
@inproceedings{Koehl2018,
title = {Price reduction of solar thermal system – Results of IEA SHC Task 54},
author = {M Koehl and S Saile and K-A Weiß and S Fischer and M Meir and G Wallner and Y Louvet and F Giovannetti and F Veynandt and D Mugnier and D Philippen and A Thür},
editor = {AEE},
year = {2018},
date = {2018-10-05},
booktitle = {Proceedings 1st International Sustainable Energy Conference (ISEC)},
pages = {429-436},
address = {Graz, Austria},
keywords = {},
pubstate = {published},
tppubtype = {inproceedings}
}
2.
J Glembin; C Büttner; J Steinweg; G Rockendorf; A Klingenschmidt
New Control Strategy for Solar Thermal Systems with Several Heat Sinks Proceedings Article
In: ISES, (Hrsg.): Conference Proceedings EuroSun 2014, Aix-les-Bains, France, 2014.
@inproceedings{Glembin2014bb,
title = {New Control Strategy for Solar Thermal Systems with Several Heat Sinks},
author = {J Glembin and C Büttner and J Steinweg and G Rockendorf and A Klingenschmidt},
editor = {ISES},
doi = {10.18086/eurosun.2014.03.09},
year = {2014},
date = {2014-09-19},
booktitle = {Conference Proceedings EuroSun 2014},
address = {Aix-les-Bains, France},
abstract = {Most solar thermal systems have only one heat sink, usually a storage tank. In most cases such systems are equipped with a controller, which compares the current collector temperature with a sensor representing the heat sink conditions, e.g. a temperature sensor in the lower part of the storage tank. However, solar thermal systems may have more than one heat sink to use the solar heat on different temperature levels, thus in- creasing the solar benefit. The control of such a system needs to permanently determine an independent de- mand signal for the different heat sinks. The paper introduces control variants for a solar thermal system operating on different heat sinks. A more theoretical control approach uses the ambient and operating conditions to determine the potential collector temperatures of each heat sink. In a second approach, the collector pump of one defined heat sink is switched on periodically to get the current collector status. The controller uses this information to determine the po- tential temperatures for all other heat sinks. A detailed simulation study shows that the second, less complex and lower-priced variant leads to a slightly lower system performance than the theoretic approach which can be defined as the benchmark. Apart from the collector temperature the control has to decide which heat sink should be used in case of more than one positive demand signal. Simulations show that the best results occur if this decision is based on the potential thermal power, taking into account an optimized predefined weighting factor.},
keywords = {},
pubstate = {published},
tppubtype = {inproceedings}
}
Most solar thermal systems have only one heat sink, usually a storage tank. In most cases such systems are equipped with a controller, which compares the current collector temperature with a sensor representing the heat sink conditions, e.g. a temperature sensor in the lower part of the storage tank. However, solar thermal systems may have more than one heat sink to use the solar heat on different temperature levels, thus in- creasing the solar benefit. The control of such a system needs to permanently determine an independent de- mand signal for the different heat sinks. The paper introduces control variants for a solar thermal system operating on different heat sinks. A more theoretical control approach uses the ambient and operating conditions to determine the potential collector temperatures of each heat sink. In a second approach, the collector pump of one defined heat sink is switched on periodically to get the current collector status. The controller uses this information to determine the po- tential temperatures for all other heat sinks. A detailed simulation study shows that the second, less complex and lower-priced variant leads to a slightly lower system performance than the theoretic approach which can be defined as the benchmark. Apart from the collector temperature the control has to decide which heat sink should be used in case of more than one positive demand signal. Simulations show that the best results occur if this decision is based on the potential thermal power, taking into account an optimized predefined weighting factor.
3.
J Glembin; G Rockendorf
Simulation and Evaluation of Stratified Discharging and Charging Devices in Combined Solar Thermal Systems Proceedings Article
In: ISES, (Hrsg.): Proceedings of the ISES Solar World Congress 2011, Kassel, Germany, 2011.
@inproceedings{Glembin2011b,
title = {Simulation and Evaluation of Stratified Discharging and Charging Devices in Combined Solar Thermal Systems},
author = {J Glembin and G Rockendorf},
editor = {ISES},
doi = {10.18086/swc.2011.22.06},
year = {2011},
date = {2011-09-02},
booktitle = {Proceedings of the ISES Solar World Congress 2011},
address = {Kassel, Germany},
abstract = {Combined solar thermal systems for domestic hot water preparation and space heating are usually equipped with water storage tanks. The stratification behavior of the tank including its external connections is significant for the collector yield and the saving of conventional backup energy. The charging and discharging units take a decisive role for the development of the stratification. While many studies analyzed the stratified charging process in detail, investigations about stratified discharging units are rare. Stratified discharging means, that the fluid is leaving the tank from at least two different heights, which are nearest to the demand temperature, using a mixing device, in order to consume the smallest possible amount of the hottest water. It could more clearly be called “layer related discharging”. This simulation study analyzes the effects of different discharging and charging strategies on the performance of a combined solar thermal system in a single-family house. Based on the system according to Task 32 of the Solar heating and Cooling Program of the International Energy Agency (IEA SHC) the system layout and in specific the storage connections are modified to investigate different stratified charging and discharging concepts realized by external valves or devices within the storage tank.},
keywords = {},
pubstate = {published},
tppubtype = {inproceedings}
}
Combined solar thermal systems for domestic hot water preparation and space heating are usually equipped with water storage tanks. The stratification behavior of the tank including its external connections is significant for the collector yield and the saving of conventional backup energy. The charging and discharging units take a decisive role for the development of the stratification. While many studies analyzed the stratified charging process in detail, investigations about stratified discharging units are rare. Stratified discharging means, that the fluid is leaving the tank from at least two different heights, which are nearest to the demand temperature, using a mixing device, in order to consume the smallest possible amount of the hottest water. It could more clearly be called “layer related discharging”. This simulation study analyzes the effects of different discharging and charging strategies on the performance of a combined solar thermal system in a single-family house. Based on the system according to Task 32 of the Solar heating and Cooling Program of the International Energy Agency (IEA SHC) the system layout and in specific the storage connections are modified to investigate different stratified charging and discharging concepts realized by external valves or devices within the storage tank.