Projects-Archive
Migration of heavy metals from devices of drinking water heating systems
| Colleague: | Dr. Ing. Karin Rühling, Dipl.- Ing.(FH) Knut Gietzelt |
| Co-operation: | IKS Dresden |
| Financing: | DVGW; AGFW; Industry |
| Duration: | 12/05 - 03/2009 |
Abstract
The new Drinking Water Ordinance is coming into effect in 2003. Since that time the regulations and threshold values are valid likewise for cold and hot drinking water.
Therefore the modification of the drinking water quality, especially the migration of heavy metals, during the path through the domestic installation
and the drinking water heating system respectively) is important.
Currently secured technical expertises are only available for materials and alloys which are certified via DIN 50931-1 under cold drinking water conditions.
During the construction of the novel testrig was finished, so that the migration of the heavy metals cooper, nickel and lead is possible for several kinds
of devices of drinking water heating systems could have been assessed.
The plant testrig consists of three parallel drink water test tracks:
• Test track 1 – reference track for migration in domestic water (cold)
• Test track 2 – drinking water heating system without circulation
• Test track 3 – drinking water heating system with circulation
The results are available for two 26-weeks-test runs. Plate heat exchangers (stainless steel) and warm water meters were tested.
The comparative field tests were carried out as a complete S0, S1 and S2-sample at the last tapping point at customer side.
The sampling was carried out according to the recommendations of the German Federal Environmental Agency (UBA) and was likewise carried out separately
for cold and hot drinking water conditions. The analysed heavy metal migration values from the hot water side partly exceed the values for the cold water condition significantly.
Railway switch heater system by means of renewable energy sources
| Colleague: | Dr.-Ing. Bernd Müller, Dipl.-Ing. Lutz Dittmann |
| Co-operation: | HERMOS Systems GmbH, Dresden; Rochhausen Kältesysteme GmbH, Scharfenstein |
| Financing: | BMWA, (AiF-ProInno) |
| Uptime: | 01/07 - 02/2009 |
Abstract
During report period TUD’s activities on the project had been finished according to plan. Involved companies now are able to complete
the reconstructed railway switch heater system at the Hermos company area as a test rig and illustrative model to carry out tests during winter 2009/2010.
The delay in the extensive project depended on difficulties mentioned in last year’s report.
The results of the project were honoured and the activities within the project supported by leading employees of DB, the potential user of the developed system.
Decrease of losses from circulation in central heating installations for drinking water
| Colleague: | Dipl.-Ing. Robert Huhn, Dipl.-Ing. (FH) Knut Gietzelt |
| Co-operation: | ILK Dresden |
| Financing: | BMWA, (AiF-ProInno) |
| Uptime: | 06/05 - 08/2007 |
Abstract
The heating demand for buildings decreases due to official laws (i.e. EnEV) requiring im-proved insulation and efficient heat generation devices.
Thus the share of energy used for preparation of domestic hot water (DHW) and especially for covering the circulation losses receives increased importance.
Measurements at three residential buildings in Dresden show a very low demand of DHW and therefore very high relative circulation losses.
This project contains complex analyses of different hot water circulation systems and there integration in local or district heating systems or in
decentralized thermal supply systems (heating boilers, heat pumps, CHP, solar systems). The primary energy demand of the supply chains is to evaluate.
Thermal, hydraulic and energetic data are continuously measured in the three buildings. A test rig for examination of dynamic processes in
hot water circulation systems and for testing new hydraulic configuration and devices for covering the circulation losses is installed at TU Dresden.
The practical results will help to derive new specifications for improved circulation systems and its operation.
air/water – heat pump with alternative heat source at lowly outside temperature; Theoretical research into peak-load-heat-sources
| Colleague: | Dipl.-Ing. Klaus Ramming |
| Co-operation: | Lattermann Haustechnik GmbH |
| Financing: | BMWA, (AiF-ProInno) |
| Uptime: | 09/05 - 08/2007 |
Abstract
The aim of the project is the development of a peak load heat source for heat pump applications as well as a
numerical simulation program and an analytical dimensioning tool for horizontal heat collectors in general.
The results of the experiment to support the peak load heat collector with short heat pipes, which should transport
heat from deeper layer of earth up to the collector, were not satisfactory. The efforts were much higher than the effects.
Despite of that, the experiment shows that it is possible to use the soil as peak load heat source also without
short heap pipes by optimizing the pipe distance and diameter of the collector.
With the developed analytical and numerical programs it is possible to simulate extreme situations and design
the collector economical or area oriented optimized, depending on the clime and the soil properties. (Wärmepumpen-Info)
EDUAR&D - Multidimensional evaluation of technology
| Colleague: | Dipl.-Ing. Lutz Dittmann |
| Co-operation: | AGFW, FhG-Institut für Systemtechnik und Innovationsforschung Karlsruhe, Institut für Sozialforschung an der Universität Frankfurt, Energiewissenschaftliches Institut der Universität Köln |
| Financing: | BMWA, Arbeitsgemeinschaft Fernwärme e.V. (AGFW) |
| Uptime: | 07/05 - 03/2007 |
Abstract
The research project EduarR&D of the Federal Ministry of Economics and Labour (BMWA) aims at the creation of efficient tools for the assessment
of activities of federal technology promotion. In this context the project "Multi-dimensional evaluation of technology" on the one hand should illustrate
the development direction in the field of production and storage of heat and electric energy. On the other hand a sociological approach is followed up
which tries to comprehend and value the decision-making processes of substantial innovation carriers of this line of business.
The share of the professorship of energy system engineering and heat economy of the TU Dresden in the processing concerns the creation of the base
of the examinations at the technical level. For this purpose a comprehensive data collection was carried out basing on a extensive database created
by the project team which takes into account all relevant technologies at present or in foreseeable future. As a result a reliable matrix was created
which could be augmented with reflection on the comparative evaluation of electric energy and heat and on the consideration of part load condition cases and supply energies.
The work of the institute of power engineering of the TU Dresden for this project therewith is completed largely. Since the processing time period will expand,
however, by delays in the construction of the simulation models until the middle of 2007, further work will be carried out to the completion of the database.
Research into optimisation of interaction of technologies of distributed energy generation based on fuel gases from renewable energy sources
| Colleague: | Dr.-Ing. Karin Rühling Dr.-Ing. Bernd Müller Dipl.-Ing. Lutz Dittmann |
| Co-operation: | DBI-Gastechnologisches Institut gGmbH Freiberg (Netzwerksmanagement) University of Chemistry and Technology Prague, Czech Republic University Miskolc, Hungary Institute of Oil and Gas Krakow, Poland Technische Universität Bergakademie Freiberg Fraunhofer Institut Fertigungstechnik und Angewandte Materialforschung Dresden Institut für Polymerforschung Dresden Institut für Agrartechnik Bornim e.V. Fördergesellschaft Erneuerbare Energien e.V. Berlin MITGAS Mitteldeutsche Gasversorgung GmbH |
| Financing: | BMBF |
| Uptime: | 11/03 - 08/06 |
Abstract
The appropriately utilizable reserves of fossil fuels are restricted. The energy mix of the future depends on an efficient use of biomass and waste
for supply with electricity, heat and cold. Since 2004 a network has been operating on the branch of gaseous fuels which are producible from renewable sources of energy.
Eleven research institutes and universities of 4 countries are working together. An analysis of the state of the art was made regarding the generation
and respectively the extraction of methane-rich gases like digester gas, sewage gas, landfill gas, mine gas and hydrogen-rich gas produced by gasification (gasification gas).
The conditioning of the gas to a quality which allows the feeding into existing natural gas networks is technically possible, but it is also associated with high costs.
Alternatively, the material and energetic use was investigated at locations close to the production of biomass and waste.
Comparative statements concerning the complete chain from gas production over necessary refining steps until the use in CHP-technologies
(gas turbines, gas engines, fuel cells) are focussed. The new quality is achieved by the consideration of the local consumption and net structures of heat and cold supply.
With the ENERGY-database a new tool was created. This tool allows the comparison of possible process chains depending on local available resources.
The database can take into account useful solutions either from the energetic or economic point of view.
The database is enlargeable and can achieve a high degree of benefit by the continuous update of the data and the implementation of new algorithms of analysis.
Advanced modelling of losses in heat storages and development of a calculation method for an optimised construction design of storages
| Colleague: | Dipl-Ing. Robert Huhn |
| Co-operation: | FFI in Hannover e.V. |
| Financing: | AiF |
| Uptime: | 08/03 - 01/06 |
Abstract
Hot water storage tanks (HWST), integrated in heat or cold supply systems in an optimal way, contribute to the reduction of installed capacity,
fuel and operation costs. By smoothing peak loads and equalising the throughput in pipeline systems they increase the lifetime of the components.
Furthermore, storage tanks help to reduce return pipe temperatures and thus energy consumption of circulation pumps and heat losses in district heating networks
while the power output of combined heat and power generation (CHP) plants is increased at the same time.
Already in the AiF-Project 12588 BG key numbers and a test procedure had been developed for evaluating internal and external losses of HWST.
This test procedure has now been extended for horizontal tanks. Experimental investigations were carried out at Fernwärmeforschungsinstitut in Hannover e.V.,
the research partner of this project.
Internal exergetic losses in HWST are caused by temperature equalization processes within the tank without any heat loss to the ambience.
The extension of these losses is influenced by the design and material properties of the tank as well as operation parameter like temperature levels and flow rates.
Aim of the examination is to quantitatively and qualitatively describe these influences. For that reason dimensionless key numbers have been developed to deliver
information about tank design and intended operation conditions.
Comprehensive numerical computations with the CFD-Code Fluent and experimental tests yielded in empirical correlations for determination of internal losses in hot water storage tanks.
An improvement of guidelines for optimized storage tank design is achieved by coupling the losses to details of tank design and operation conditions.
Calculation of storage tank losses already during tank design contributes to cost reductions and reduces tests on prototype tanks.
The design engineer can easier determine, if a given storage tank is appropriate for an application with given boundary conditions, or if the tank needs to be modified to guarantee an efficient operation.
Thermal disinfection in central heating installations for drinking water
| Colleague: | Dr.-Ing. Bernd Müller, Dipl.-Ing. Matthias Mischke |
| Co-operation: | STS Energietechnik GmbH, TUD- Institut für Medizinische Mikrobiologie und Hygiene |
| Financing: | BMWA, (AiF-ProInno) |
| Uptime: | 05/04 - 07/06 |
Abstract
Thermal disinfection in central heating installations for drinking water
The aim of the project is the development of a prototype installation for thermal disinfection of DHW by use of high disinfection temperatures,
reduced reaction volume and of high energy efficiency. The thermal disinfection of DHW is carried out in principle like a flow heater.
Due to the short staying time of the water within the reactor disinfection needs considerably higher temperatures as usual.
To increase the energy efficiency of the installation intensive heat recovery between disinfection temperature and DHW temperature (60 °C) was necessary.
To reduce the required heat energy the application of compression-type and Peltier-type of heat pumps were considered.
The heat source of the heat pump is the DHW at a required temperature of 60 °C as heat sink the disinfection part at temperatures of about 80 °C is used.
The prototype installation was tested under real conditions at the Institute for Medical Micro-biology and Hygiene of the TU Dresden.
The extracellular and intracellular legionellae were exposed to different disinfection temperatures and varying time of exposure to determine the inactivation kinetics.
The inactivation of legionellae occurs within 200 sec. at a temperature of 65 °C, inactivation time is shortened to 60 sec. at a disinfection temperature of 80 °C.
There is a marginal difference between extracellular and intracellular legionellae in their in-activation kinetics.
Intracellular legionellae are marginal more heat-resistant than extracellular legionellae.
There are comprehensive construction plans and an instruction manual for the prototype installation.
Development, construction and test of a measuring system for determination of steam moisture
| Colleague: | Dipl.-Ing. Matthias Mischke |
| Co-operation: | Ingenieurbüro Hoffmann, PCE - Ingenieurbüro für Mess-, Steuer- und Regelungstechnik GmbH |
| Financing: | BMWA, (AiF -ProInno) |
| Uptime: | 03/05 - 12/2006 |
Abstract
The aim of the project is the development of a measuring device for continuous measurement of steam moisture and therefore of the moist steam enthalpy.
The measuring device shall be compact, offer the highest possible precision and be insensitive against fluctuations of the operating parameters.
The built device has to be tested and optimised extensively at different experimental setups.
After assembly of the device first component tests as well as examinations of the pressure losses have been carried out.
They are followed by tests for the determination of heat losses.
After that the measuring device has been tested up to now in two different plants.
Migration of heavy metals from devices of drinking water heating systems
| Colleague: | Dr.-Ing. Karin Rühling |
| Co-operation: | Institut für Korrosionsschutz Dresden GmbH (IKS) |
| Financing: | DVGW, AGFW |
| Uptime: | 12/05 - 05/2008 |
Abstract
The new Drinking Water Ordinance is coming into effect in 2003. Since that time the regulations and threshold values are available
for cold and hot drinking water similarly. Therefore the modification of the drinking water quality, especially the migration of heavy metals,
is important during the path through the domestic installation and the drinking water heating system also.
Until today secured technical expertises are only available for materials and alloys which are certified via DIN 50931-1 under a cold drinking water situation.
Comparable awareness for complete devices like fittings, tap water meters, heat exchangers e.g. are not available.
There are two main aims of the project. At first the conception, construction, instal-lation and operation of a testrig for several kinds of complete devices
for the assessment of the migration of the heavy metals cooper, nickel and lead. A comparative study will take place under cold and hot drinking water conditions.
At second a comparative field test are carried out in interaction with housing societies as well as water and district heating suppliers.
DemoCell – Practical test from small fuel cells (Projectinfo IMSA)
| Colleague: | Dipl.-Ing. Thomas Pfeifer, Dr.-Ing. Karin Rühling |
| Financing: | DBI Gas- und Umwelttechnik GmbH , NL Freiberg |
| Uptime: | 12/01 – 12/06 |