| 1. |
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| 2. |
- Sandström, Maria, et al.
(författare)
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Hosting capacity of the power grid for electric vehicles - A case study on a Swedish low voltage grid
- 2022
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Ingår i: IOP Conference Series: Earth and Environmental Science. - : IOP Press. - 1755-1307 .- 1755-1315.
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Konferensbidrag (refereegranskat)abstract
- Hosting capacity (HC) is described as the maximum amount of new production or consumption that can be added to the grid without causing a violation. In this case study, a deterministic approach is used to investigate the HC of electric vehicle (EV) charging in a low-voltage grid, containing 13 detached single-family houses. It investigates how different parameters affect the HC, and what is causing the violation in the grid. Two different performance indices (PI) are used in the study: power cable overloading and voltage drop. The local grid is simulated for one year for four cases and the HC is derived for these. The cases are distinguished by two different violation thresholds for the voltage drop and two different implementation orders of the location of the charging. The results show that the HC of the grid is 6-11 EVs charging simultaneously. The difference in HC is primarily due to variation in the baseload through the year and location of charging. The cable between the substation and the first cable cabinet was the major contributor to the fault, and the PI causing the violation differed depending on what case was used.
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| 3. |
- Albaric, Michael, et al.
(författare)
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Solar CombiSystems Promotion and Standardisation (COMBISOL project)
- 2008
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Ingår i: Eurosun 2008. - Lisbon.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Solar combisystems (SCS) are solar heating installations providing space heating as well as domestic hot water in buildings. Within a global solar thermal energy strategy, SCS are a key element to decrease the fossil energy demand for heating in existing and new buildings. This project will help to reduce the use of fossil fuels and hence also the emission of greenhouse gases. During 3 years December 2007 – December 2010), experts from research, testing institutes and industry will work in the aim to encourage an accelerated deployment of SCS market – hence a higher share of heat produced by solar energy - and promote an improved quality of the installed systems.
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| 4. |
- Andersen, Martin, 1985-, et al.
(författare)
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Economic Analysis of Heat Distribution Concepts for a Small Solar District Heating System
- 2022
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Ingår i: Energies. - : MDPI. - 1996-1073. ; 15:13
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Tidskriftsartikel (refereegranskat)abstract
- One challenge in today’s district heating systems is the relatively high distribution heat loss. Lowering distribution temperatures is one way to reduce operational costs resulting from high heat losses, while changing the distribution system from steel pipes to plastic pipes and changing the heat distribution concept can reduce investment costs. The result is that the overall life cycle cost of the district heating system is reduced, leading to the improved cost competitiveness of district heating versus individual heating options. The main aim of this study was to determine the most cost-efficient distribution system for a theoretical solar district heating system, by comparing the marginal life cycle cost of two different distribution systems. A secondary aim was to determine the influence of the employed pipe type and insulation level on the marginal life cycle cost by comparing detailed economic calculations, including differences in pipe installation costs and construction costs, among others. A small solar-assisted district heating system has been modeled in TRNSYS based on a real system, and this “hybrid” model is used as a basis for a second model where a novel distribution system is employed and the heating network operating temperature is changed. Results indicate that a novel distribution concept with lower network temperatures and central domestic hot water preparation is most efficient both from an energy and cost perspective. The total life cycle costs vary less than 2% for a given distribution concept when using different pipe types and insulation classes, indicating that the investment costs are more significant than operational costs in reducing life cycle costs. The largest difference in life cycle cost is observed by changing the distribution concept, the novel concept having approximately 24% lower marginal life cycle cost than the “hybrid” system. © 2022 by the authors. Licensee MDPI, Basel, Switzerland.
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| 5. |
- Andersen, Martin, 1985, et al.
(författare)
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Heat distribution concepts for small solar district heating systems – Techno-economic study for low line heat densities
- 2022
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Ingår i: Energy Conversion and Management: X. - : Elsevier BV. - 2590-1745. ; 15
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Tidskriftsartikel (refereegranskat)abstract
- The high operating temperatures in today's district heating networks combined with the low energy demand of new buildings lead to high relative network heat losses. New networks featuring lower operating temperatures have reduced relative heat losses while enabling an increase in the use of solar heat. The primary aim of this study was to determine if a particular district heating system can be made more effective with respect to heat losses and useful solar energy, by considering different distribution concepts and load densities. A small solar assisted district heating system with a novel hybrid distribution system has been modelled based on a real case study. This model serves as a basis for two other models where the distribution system and heating network operating temperature is changed. A secondary aim of the study was to determine the economic implications of making these changes, by using costs estimates to calculate the contribution of essential system components to total system cost. Results indicate that a novel distribution concept with lower network temperatures and central domestic hot water preparation is most energy efficient in a sparse network with a heat density of 0.2 MWh/m∙a and a performance ratio of 66%, while a conventional district heating system performs worst and has a performance ratio of less than 58% at the same heat density. In an extremely sparse network with heat density of 0.05 MWh/m∙a, the performance ratio is 41% and 30% for these systems, respectively. A simple economic analysis indicates that the novel distribution concept is also best from an economic point of view, reducing the initial investment cost by 1/3 compared to the conventional concept, which is the most costly. However, more detailed calculations are needed to conclude on this.
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| 6. |
- Andersen, Martin, 1985-, et al.
(författare)
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Techno-Economic Analysis of Solar Options for a Block Heating System
- 2016
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Ingår i: Conference Proceedings: Eurosun 2016. - Palma De Mallorca : International Solar Energy Society.
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Konferensbidrag (refereegranskat)abstract
- An innovative small solar district heating system with one central heating plant and four solar substations has been built in Vallda Heberg, Sweden, to supply a new housing area with passive houses. The target solar fraction was 40% and the total system design, including heat distribution in the buildings, was based on previous experience and aimed to be simple and cost-effective. The main aim of this study was to determine whether the system can be designed in a more effective manner by change of distribution system and load density. TRNSYS models were calibrated against measured data and then used to predict the energy performance. Results indicate that lower distribution heat losses can be obtained by change to a distribution concept with lower operating temperatures, while potentially reducing cost. Changes in heat density cause reduced distribution losses and boiler supplied heat demand, with only minor effects on solar system yield.
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| 7. |
- Andersen, Martin, 1985, et al.
(författare)
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Techno-economic analysis of solar options for a block-heating system
- 2018
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Ingår i: Solar Energy. - 0038-092X.
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Tidskriftsartikel (refereegranskat)abstract
- An innovative small solar district heating system with one central heating plant and four solar substations has been built in Vallda Heberg, Sweden, to supply a new housing area with passive houses. The target solar fraction was 40% and the total system design, including heat distribution in the buildings, was based on previous experience and aimed to be simple and cost-effective. The main aim of this study was to determine whether the system can be designed in a more effective manner by change of distribution system and load density. TRNSYS models were calibrated against measured data and then used to predict the energy performance. Results indicate that lower distribution heat losses can be obtained by change to a novel distribution concept with lower operating temperatures, while potentially reducing cost. Increases in heat density cause reduced distribution losses and boiler supplied heat demand, with only minor effects on solar system yield.
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| 8. |
- Bales, Chris, et al.
(författare)
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Advanced Storage Concepts For Solar Houses And Low Energy Buildings - IEA-SHC Task 32
- 2005
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Ingår i: ISES Solar World Congress 2005. - Orlando, Florida, USA.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- This paper presents the current status of the work in Task 32 (Advance Storage Concepts for Solar and Low Energy Buildings) of the International Energy Agency’s Solar Heating and Cooling Programme (IEA-SHC). A methodology for inter-comparison has been established and boundary conditions and reference systems for this have been defined. The current status of the projects range from recently concluded feasibility studies for chemical heat storage, to prototyping, lab testing, modelling and system simulation for advanced water stores, with and without PCM content, as well as for stores based on the sorption principle. Promising new components and solutions for more classical water tanks are also described in order to define market references.
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| 9. |
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| 10. |
- Bales, Chris, et al.
(författare)
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Chapter 12: Sorption and Themo-Chemical Storage
- 2005
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Ingår i: Thermal energy storage for solar and low energy buildings - State of the art. - Lleida, Spain : Lleida University. - 848409877X
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Bokkapitel (övrigt vetenskapligt/konstnärligt)
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| 11. |
- Bales, Chris, et al.
(författare)
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Chemical and Sorption Storage – Results from IEA-SHC Task 32
- 2008
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Ingår i: Eurosun 2008. - Lisbon.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Six main groups have studied chemical and sorption storage within IEA-SHC Task 32 “advanced storage concepts for solar and low energy buildings”. Closed and open adsorption systems, two and three phase absorption as well as chemical storage have been studied. The main results of the work are: identification of potentially suitable materials for long term storage of solar heat and publication of material properties; development of new concepts of short and long term storage of solar heat to prototype stage with lab and field tests; development of models for simulation of chemical and sorption storage; simulation of three systems with long term chemical or sorption storage with the Task 32 boundary conditions; and support in the commercialisation of a chemical heat pump with short term thermal storage for solar heating and cooling applications. The main conclusion from the work is that there are a number of promising technologies and materials for seasonal storage of solar heat for single families but that a lot of research is required before it can be become practical and economical.
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| 12. |
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| 13. |
- Bales, Chris
(författare)
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ClimateWell TDC with District Heat
- 2010
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- The PolySMART demonstration system SP1b has been modeled in TRNSYS and calibrated against monitored data. The system is an example of distributed cooling with centralized CHP, where the driving heat is delivered via the district heating network. The system pre-cools the cooling water for the head office of Borlänge municipality, for which the main cooling is supplied by a 200 kW compression chiller. The SP1b system thus provides pre-cooling. It consists of ClimateWell TDC with nominal capacity of 10 kW together with a dry cooler for recooling and heat exchangers in the cooling and driving circuits. The cooling system is only operated from 06:00 to 17:00 during working days, and the cooling season is generally from mid May to mid September. The nominal operating conditions of the main chiller are 12/15°C.The main aims of this simulation study were to: reduce the electricity consumption, and if possible to improve the thermal COP and capacity at the same time; and to study how the system would perform with different boundary conditions such as climate and load.The calibration of the system model was made in three stages: estimation of parameters based on manufacturer data and dimensions of the system; calibration of each circuit (pipes and heat exchangers) separately using steady state point; and finally calibration of the complete model in terms of thermal and electrical energy as well as running times, for a five day time series of data with one minute average data values. All the performance figures were with 3% of the measured values apart from the running time for the driving circuit that was 4% different. However, the performance figures for this base case system for the complete cooling season of mid-May to midSeptember were significantly better than those for the monitoring data. This was attributed to long periods when the monitored system was not in operation and due to a control parameter that hindered cold delivery at certain times.
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| 14. |
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| 15. |
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| 16. |
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| 17. |
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| 18. |
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| 19. |
- Bales, Chris, et al.
(författare)
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Comparison of Simple EPBD Calculation Tool for Solar Combisystems with TRNSYS
- 2010
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Ingår i: Eurosun 2010. - Graz, Austria.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- An excel based calculation tool has been developed within the EU project Combisol. It implements the standard calculation method EN 15316-4-3 for solar combisystems, as defined for the Energy Performance of Buildings Directive (EPBD). A base case system and building were defined and a number of parametric studies were performed with this EPBD tool as well as TRNSYS for the same systems and boundary conditions. For all the simulations in this study, the EPBD tool predicted a greater solar contribution than detailed TRNSYS simulations predicted. The difference was greater for Stockholm (high latitude) and Madrid (high solar fraction). Other studies showed that the EPBD predicted changes in solar contribution due to changes in system size, orientation and azimuth as well as store size in the same way that TRNSYS does.
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| 20. |
- Bales, Chris, et al.
(författare)
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D2.1c Simulation Results of Reference Buildings
- 2014
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- This report is the third part of the deliverable D2.1, where the other two parts report on the energy consumption in the building stock in Europe based on the available energy statistics (D2.1a) and the energy policies related to buildings (D2.1b).The aim of this report is to give complementary information about the heating and cooling demands of residential and office buildings based on simulations, so that the many gaps in the energy statistics can be filled and the statistics can be critically evaluated. The methodology results in a complete and consistent overview of the heating and cooling demands in residential and office buildings for seven different climate regions covering the whole of the EU and six different periods of construction, covering pre-1945 to post 2000. In addition, the data for the residential building stock is split into single family houses, small and large multifamily houses, while for offices the results are given for low and high rise offices with 6 or 12 office units per floor.The simulation models have been benchmarked (calibrated) against the energy statistics for each of the seven climate regions based on the aggregated data for the whole residential building stock and then for the office building stock in that climate region (in D2.1a). The methodology derives the aggregated average using weighted averages of data split into periods of construction and typology for both energy statistics and simulation results. The weighting is done based on heated and cooled floor area. As nearly all of the energy statistics are given in terms of consumption, while simulation results were calculated as demand, the demand data were converted to consumption data. One fixed conversion factor was used for heating (average efficiency 0.8) and one for cooling (average EER 2.5). Since the calculated demands strongly depend on the imposed heating or cooling set temperatures, this simulation parameter was varied so that the aggregated simulation result was the same as that for the consumption derived from the energy statistics. The calibrated models were then used to derive the average heating and cooling consumptions of the building stock in the seven climate regions.The methodology has a number of uncertainties, both in terms of the energy statistics as well as in terms of the simplifications and assumptions in the simulation models. During the calibration process a number of inconsistencies have been detected for individual countries and climate regions between simulation results and energy use from statistic data. The mismatches are analytically assessed, showing improvements necessary both in terms of statistic data necessary for reliable energy estimations and data to be gathered in order to guarantee consistent simulations outcomes.Beside the building stock survey completion and statistic data quality assessment, the work is also the basis for the definition of suitable Energy Renovation Packages and Products within the iNSPiRe project. The simulation results will be used to identify which building typologies, periods of construction and climate region have the largest potential for impact on the European scenario. Such information will be used within the iNSPiRe project to define reference Target buildings, as virtual demonstration cases to prove the potential improvements and impacts following the renovation process of a given share of the European building stock.
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| 21. |
- Bales, Chris, et al.
(författare)
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Development of the Thermo Chemical Accumulator (TCA)
- 2004
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Ingår i: Proc. Eurosun 2004. - Freiburg, Germany.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The Thermo Chemical Accumulator (TCA) is a chemical heat pump driven by low temperature heat that has integral heat storage with high energy density. This makes the device very suitable for solar cooling. The working pair consists of Lithium Chloride and water, and energy is stored and released by desorption and absorption of water under near vacuum conditions. In contrast to most absorption processes and chemical heat pumps, the TCA works with three phases: solid, solution and vapour. This results in near constant operating conditions during charge and discharge, independent of state of charge. This paper describes the fundamental working principles of the TCA as well as a simple steady state model for the TCA. A temperature difference between theoretical and effective temperature in the reactor during absorption and desorption was required in order to get reasonable agreement with measurement data of a prototype TCA machine. For absorption, this value for subcooling was 15°C, which is significantly higher than has been found for low-temperature absorption chillers, indicating potential for improvement. For desorption the value was 7.5°C. The TCA has desorption temperatures of below 100°C for ambient temperatures below 40°C, which is relatively low. The temperature lift depends on the cooling rate supplied and varies from 15°C for the design cooling rate of 5 kW per TCA unit and 30°C inlet temperature to the reactor, to 20°C for a cooling rate of 2.5 kW. The energy density for storage was 180 kWh/m3 for the tested prototype.
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| 22. |
- Bales, Chris, et al.
(författare)
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Dimensioning of Solar Combisystems
- 2003
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Ingår i: Solar heating systems for houses. - London : James & James. - 1902916468
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Bokkapitel (övrigt vetenskapligt/konstnärligt)
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| 23. |
- Bales, Chris, 1960-
(författare)
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European resarch school on large scale solar thermal - SHINE
- 2014
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Ingår i: Solar District Heating 2014. - Hamburg, Germany.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The Solar HeatIntegration NEtwork (SHINE) is a European research school in which 13 PhDstudents in solar thermal technologies are funded by the EU Marie-Curie program.It has five PhD course modules as well as workshops and seminars dedicated to PhDstudents both within the project as well as outside of it. The SHINE researchactivities focus on large solar heating systems and new applications: ondistrict heating, industrial processes and new storage systems. The scope ofthis paper is on systems for district heating for which there are five PhDstudents, three at universities and two at companies. The PhD students allstarted during the early part of 2014 and their initial work has concentratedon literature studies and on setting up models and data collection to be usedfor validation purposes. The PhD students will complete their studies in2017-18.
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| 24. |
- Bales, Chris, et al.
(författare)
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European Solar Engineering School ESES : Past and Future
- 2006
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Ingår i: Eurosun 2006. - Glasgow, Scotland.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The European Solar Engineering School ESES is a one-year masters program that started in 1999 at the Solar Energy Research Center SERC, Dalarna University College. It has been growing in popularity over the years, with over 20 students in the current year. Approximately half the students come from Europe, the rest coming from all over the globe. This paper described the contents and experiences from seven years of running the programme and the plans for adapting the programme to the Bologna process. The majority of the students from ESES have found work in the solar industry, energy industry or taken up PhD positions. An alumni group has been started that actively gives support to past, present and potential future students.
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| 25. |
- Bales, Chris, et al.
(författare)
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External DHW units for solar combisystems
- 2003
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Ingår i: Solar energy. - 0038-092X. ; 74, s. 193-204
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Tidskriftsartikel (refereegranskat)abstract
- This article compares seven different external DHW units, comprising flat plate heat exchanger and flow control, with a reference method for preparing hot water. These DHW units use different control methods. The objective of the study was to determine which methods are most effective in solar combisystems and to identify other factors that strongly influence the energy savings of the system. Five of the DHW units were judged to be of interest for the study because of their measured performance or the simplicity of their design. Of these, measurement data showed that two had the same control function although of different physical construction. Thus four DHW units were modelled in the simulation environment PRESIM/TRNSYS, parameters were identified from measured data, and annual simulations were performed with a number of parametric variations. Three of the DHW units performed significantly better than the reference system provided that they were sized correctly: microprocessor control with variable-speed pump; proportional controller with regulating valve; and a turbine pump. The most important design factors identified by the study were: the maximum possible primary flow, which needs to be suitable for the design hot water load profile; and ensuring a low temperature is returned to the store. The hot water load profile was also shown to strongly influence the energy savings, assuming that auxiliary heater's thermostat is set so that the system just meets the worst-case discharge.
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| 26. |
- Bales, Chris, et al.
(författare)
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Final Report of Subtask B “Chemical and Sorption Storage” : Report B7 of Subtask B
- 2008
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- This report is the final report of a Subtask of the Task 32 “Advanced Storage Concepts for solar and low energy buildings” of the Solar Heating and Cooling Programme of the International Energy Agency. As a final report of a Subtask it has two aims: 1. it summarizes all the works conducted in the Subtask during the period of the Task (June 2003 – December 2007) highlighting some important results that the participants in the Subtask reached and it refers to all the detailed documents that have been produced by the Subtask and Task 32, 2. it presents some hints on the management of an IEA Subtask in order to improve future collaborative works within this framework In Subtask B, major achievements have been: 1. Identification of potentially suitable materials for long term storage of solar heat and publication of material properties. 2. Documentation of State of the Art in chemical and sorption storage in Task 32 Handbook. 3. Development of new concepts of short and long term storage of solar heat to prototype stage with lab and field tests. 4. Development of models for simulation of chemical and sorption storage. 5. Simulation of three systems with long term chemical or sorption storage with the Task 32 boundary conditions (reports for only two of these were completed). 6. Support in the commercialisation of a chemical heat pump with short term thermal storage for solar heating and cooling applications. 7. Input for the storage part of the strategic research agenda of the European Solar Thermal Technology Platform, further refining the compact heat storage R&D questions that should be tackled on an international level. IEA SHC – Task 32 – Advanced storage concepts
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| 27. |
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| 28. |
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| 29. |
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| 30. |
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| 31. |
- Bales, Chris, et al.
(författare)
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Laboratory Prototypes of Thermo-Chemical and Sorption Storage Units : Report B3 of Subtask B
- 2007
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Four laboratory prototypes are described in this report. Measured results and projected heat storage densities for units of 70 and 1000 kWh storage for single family houses are reported. All four prototypes are closed sorption units and act as thermally driven heat pumps. Two work with absorption: three phase absorption process (TCA) with LiCl-water, and two phase absorption with NaOH-water. Two work with adsorption, one with zeolite and the other with silica gel. The different technologies are at very different stages of development. The TCA technology is in the process of commercialisation by the Swedish company ClimateWell AB, and over 20 storage systems have been installed, mostly in Spain. A further 100-200 are planned for 2007. The other technologies are in the prototype stage with no companies intending to develop and market them. The Modestore store was developed in a European project, and the main company within the project (Sortech) is commercialising the technology as a heat pump with essentially no heat storage. The storage density for cold, when compared to water, is more favourable than for heat. For the ClimateWell 10 commercial prototype the storage density for cold is 4.7 that of water whereas for heat it is only 1.2 times greater. This is due to the fact that the temperature range available for water storage for cold is much smaller (~10°C) than for heat (~60°C). For short term heat storage, none of the technologies have a significant advantage compared to water in terms of storage density. The energy density can only be slightly greater than that for water, mainly due to the space required for heat exchangers and other components. In addition all of the storage systems lose heat during the charge and discharge process due to irreversibilities in the processes themselves. Most of this is due to the different temperature levels of charge/discharge and the related sensible energy between these. For longer term storage (1000 kWh) the energy density for the TCA technology and NaOH storage systems is nearly three times that of water. In addition, once the sensible heat from the solution has been lost, the energy can be stored indefinitely, a significant advantage compared to water. In terms of material cost, all materials are expensive compared to water, with NaOH being by far the least expensive. The cost for the whole storage system has not been estimated here. For the ClimateWell 10, the projected cost is ~8000€ for a heat pump system consisting of two units in parallel, with a total heat storage capacity of 70 kWh.
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| 32. |
- Bales, Chris, et al.
(författare)
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Laboratory Tests of Chemical Reactions and Prototype Sorption Storage Units : Report B4 of Subtask B
- 2008
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Five laboratory prototypes of thermochemical and sorption storage are described in this report as well as the material characterisation of a promising thermochemical reaction with MgSO4.7H2O. Measured results and projected heat storage densities for units of 70 and 1000 kWh storage for single family houses are reported. Four of the five prototypes are closed sorption units and act as thermally driven heat pumps. Two work with absorption: three phase absorption process, Thermo Chemical Accumulator (TCA) with Lithium Cloride/water, and two phase absorption with Sodium Hydroxide/water. Two work with adsorption, one with zeolite and the other with silica gel. The fifth prototype that is reported, Monosorp, uses an open adsorption process integrated into a standard ventilation system with heat recovery. The different technologies are at very different stages of development. The TCA technology is in the process of commercialisation by the Swedish company ClimateWell AB, and over 35 storage systems have been delivered, mostly in Spain. The other technologies are in the prototype stage with no companies intending to develop and market them. The Modestore store (silica gel /water) was developed in a European project, and the main company within the project (Sortech) is commercialising the technology as a heat pump with essentially no heat storage. The storage density for cold (based on total system volume), when compared to water, is more favourable than for heat. For the ClimateWell 10 commercial heat pump/store, the storage density for cold is 4.7 that of water whereas for heat it is only 1.2 times greater. This is due to the fact that the temperature range available for water storage for cold is much smaller (~10°C) than for heat (~60°C). For short term heat storage, none of the technologies have a significant advantage compared to water in terms of storage density. The energy density can only be slightly greater than that for water, mainly due to the space required for heat exchangers and other components. The best technology in this aspect is Monosorp, which has a density twice that of water. In addition all of the storage systems have irreversibilities in the processes themselves during charge and discharge. Most of this is due to the different temperature levels of charge/discharge and the related sensible energy between these. For longer term storage (1000 kWh) the energy density for the TCA technology and NaOH storage systems is nearly three times that of water, for Monosorp twice and for MgSO4.7H2O nearly. In addition, once the sensible heat from the solution has been lost (or at best recovered), the energy can be stored indefinitely, a significant advantage compared to water. In terms of material cost, all materials are expensive compared to water. However, NaOH, zeolite 4A and MgSO4.7H2O are significantly less expensive than the other materials reported, LiCl, silica gel and zeolite 13X. The cost for the whole storage system has not been estimated here. For the ClimateWell 10, the projected cost is ~8000€ for a heat pump system consisting of two units in parallel, with a total heat storage capacity of 70 kWh.
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| 33. |
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| 34. |
- Bales, Chris, et al.
(författare)
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Optimized solar and heat pump systems, components and dimensioning : Deliverable 7.3 - MacSheep - New Materials and Control for a next generation of compact combined Solar and heat pump systems with boosted energetic and exergetic performance
- 2015
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Rapport (populärvet., debatt m.m.)abstract
- This report describes the optimised solar and heat pump systems developed in the MacSheepproject as well as the simulation results for these systems. Four systems have been developed by four different development groups, each with one private company participating. The development groups have chosen different types of systems as well as different target loads for their systems, which give a wide coverage of the potential markets. The aim of the project was to achieve a 25% performance increase compared to state of the art systems, while being cost-competitive compared to the state of the art.Two reference state of the art solar and heat pump systems have been defined, modelled,and simulated to derive benchmark electricity demands and SPF values for the boundary conditions that were defined for the MacSheep project. The reference systems usedtheground (boreholes) orair as a heat source for the heat pump. The chosen boundary conditions were the climates of Zurich and Carcassone, arealistic DHW load,and two buildings, one representing a modern low energy building (SFH45) and one representing an existing building (SFH100). These reference systems and boundary conditions were defined within the first year of the project, and are used throughout the project.New components were developed for the MacSheepsolar and heat pump systems and these developments are reported in the reportsof work packages 3 –6. Component models have been programmed and validated with laboratory measurements.In this report, simulation results for the four MacSheep systems arecompared to the relevant reference system in order to quantify the expected performance increase. These simulations include the component models with their validated parameters and performance obtained from phase 3 of the project.In addition, the costs of the systemswere estimated. The key performance indicator for the final system developments was defined as a figure for electric savings (25%) compared to the state of the art at competitive (i.e. comparable) cost. Therefore, cost-savings that were achieved for some of the components that were developed were allowed to be compensated by increased cost for other components or increased collector areasin order to show the project's achievements in the light of the defined key performance indicator.At present, the updated simulations show electric savings of 17%, 24%, 26%, and 30%, respectively, for the different developments and the different target heat loads.Threeof these systems will be built and tested during 2015,using the whole system test method that was further developed within the MacSheep project (see report D2.3 for more details). The results from these tests will give benchmark energy used of these systems both for the test sequence itself but also on an annual base. In addition, the simulation models described in this report will be verified against the measurements and then used for annual simulations for otherboundary conditionsthan the once that are represented in the test sequence.
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| 35. |
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| 36. |
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| 37. |
- Bales, Chris
(författare)
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”Röriga” förluster i solvärmesystem
- 2011
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Ingår i: Energimagasinet. - Halmstad, Sweden : Energimagasinet. - 0348-9493. ; 2011:1, s. 42-43
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Villaägare med solvärme i kombination med annan värmekälla är nöjda med sina installationer. Solvärmekretsarna är väl installerade men ägarna och installatörerna är ovetandes om att det finns stora förluster i andra delar av systemen.
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| 38. |
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| 39. |
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| 40. |
- Bales, Chris, et al.
(författare)
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Seven Phd Studies on Solar District Heat
- 2014
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Ingår i: Proceedings EuroSun 2014 / ISES Conference Proceedings (2014). - : ISES. ; , s. 652-661
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The Solar Heat Integration NEtwork (SHINE) is a European research school in which 13 PhD students in solar thermal technologies are funded by the EU Marie-Curie program. It has five PhD course modules as well as workshops and seminars dedicated to PhD students both within the project as well as outside of it. The SHINE research activities focus on large solar heating systems and new applications: on district heating, industrial processes and new storage systems. The scope of this paper is on systems for district heating for which there are six PhD students, three at universities and two at companies. In addition there is a seventh PhD in a Swedish national research school focused on energy efficiency within district heating networks (Reesbe). The initial work has concentrated on literature studies and on setting up initial models and measurement setups to be used for validation purposes. Some results of these studies are presented in the paper. The PhD students will complete their studies in 2017-18.
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| 41. |
- Bales, Chris, et al.
(författare)
-
SHINE Doctoral School : Results from six PhD studies on large scale solar thermal
- 2016
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Ingår i: 4th International Solar District Heating Conference.
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The Solar Heat Integration NEtwork (SHINE) is a European research school in which 13 PhD students in solar thermal technologies are funded by the EU Marie-Curie program. It has five PhD course modules as well as workshops and seminars dedicated to PhD students both within the project as well as outside of it. The SHINE research activities focus on large solar heating systems and new applications: on district heating, industrial processes and new storage systems. The scope of this paper is on systems for district heating for which there are six PhD students, five at universities and one at a company. The initial work concentrated on literature studies and on setting up initial models and measurement setups to be used for validation purposes. The measurements have been used for validating simulation models, including those used for extending the capabilities of the planning tool Polysun to simulate smaller district heating systems. Some results of these studies are presented in the paper. The PhD students will complete their studies in 2017-18.
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| 42. |
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| 43. |
- Bales, Chris, et al.
(författare)
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Slutrapport för EU-projekt Polysmart P22374-1
- 2010
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Följande sammanfattar erfarenheterna inom projektet: - Besparing av primärenergi är väldigt beroende av ett fåtal faktorer där primärenergi faktor för generering av el till nätet är avgörande. I projektet använde man termen ”non-renewable primary energy” där förnybara källor som bioenergi och även sopförbränning har väldigt låga värden. Om man använder den europeiska mixen för elproduktion ger enbart kraftvärme nästan alltid besparing av primär energi. Det samma gäller system där man använder förnybar energi eller sopförbränning. För system med trigenerering som använder fossila bränslen måste man ha både hög andel elproduktion från kraftvärmeaggregatet och relativt hög COP för den värmedrivna kylmaskinen om man ska få en besparing av primärenergi. - Systemen är komplexa och man har lärt sig mycket inom projektet. Dock har man inte kommit så långt som standard systempaket. - Elförbrukning är oftast högre än förväntat och i verklighet högre än specificerat. - Värmesänkan i systemet är en nyckelkomponent som är kritiskt för bra systemprestanda. Mer FoU krävs för att få fram komponenter som lämpar sig väl till sådana system (och som skulle också gynna andra system). - Mätning av systemet med tillhörande analys har behövts för att förbättra systemprestanda, vilket är kopplat till att system är komplexa och att det inte fanns en grundläggande kompetens i början av projektet hos alla partners. - Lovande nischmarknader har identifierats men de kräver förmodligen paketlösningar som inte finns på marknaden än. - Man ska enbart täcka baslasten med trigenereringssystem. - Koppling med fjärrvärme kan fungera bra men leverantören måste acceptera relativt höga returtemperaturer.
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| 44. |
- Bales, Chris
(författare)
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Slutrapport för EU-projekt SolNET P22416-1
- 2010
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- SolNET var den första europeiska forskarskolan för termisk solvenergi med 10 doktorander, där sju gemensamma doktorandkurser utvecklades och genomfördes under projektets gång. Projektet stöddes av EU-programmet Marie-Curie från juni 2006 till maj 2010. Centrum för solenergiforskning SERC vid Högskolan Dalarna deltog med en doktorand, Janne Paavilainen. SERC genomförde den första av doktorandkurserna, om dynamisk systemsimulering. 30 studenter deltog från 16 länder varav 22 var doktorander och tre var från industri. Under 2007 genomförde Paavilainen en teknoekonomisk utvärdering av mellanstora pellet- och solvärmesystem för närvärme som presenterades vid konferensen Eurosun 2008. Resultaten visar under vilka förutsättningar som solvärme kan vara ekonomisk lönsamt i närvärmesystem i Sverige och Finland. Paavilainen har varit medförfattare till en tidsskriftsartikel om SERCs simuleringsmodell för pelletspannor och –kaminer samt varit medförfattare till två tidsskriftsartiklar tillsammans med SPF (Schweiz) och TU Graz (Österrike) om en ny pannmodell för gas, olja och pellets. Dessa två validerade modeller i programmet TRNSYS används nu rutinmässigt i Sverige av SP och SERC och i Europa av ett flertal forskargrupper. Den nya pannmodellen som utvecklades med SPF och TU Graz har också införlivats i programmet Polysun som används av flera hundra användare runt hela världen, inkl. SERCs magisterstudenter.
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| 45. |
- Bales, Chris
(författare)
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Solar Cooling and Storage with the Thermo-Chemical Accumulator
- 2006
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Ingår i: Eurosun 2006. - Glasgow, UK.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The Thermo-Chemical Accumulator, a three-phase chemical heat pump with integral thermal storage, has been tested and modelled in the TRNSYS simulation environment. Base case system models for solar cooling applications were created for the Madrid and Stockholm climates and a number of parametric studies were carried out. The results show that the temperature lift, partially dependent on state of charge, is a limiting factor. For a purely sensible cooling load, wet cooling is required for the Madrid climate, whereas in Stockholm a dry cooler can be used for the simulated office and hotel. Dehumidification is not possible. It was shown that the machine itself has sufficient thermal storage for the office load but that it limited the solar fraction for the more uniform hotel load.
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| 46. |
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| 47. |
- Bales, Chris, et al.
(författare)
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Store Models for Chemical and Sorption Storage Units : Report B5 of Subtask B
- 2008
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Storage models have been developed for four of the storage concepts that have been studied within Subtask B of IEA-SHC Task 32. These are available from the authors. They are: 1. Thermo-chemical accumulator model for the commercial product ClimateWell 10; 2. detailed model for open adsorption in a zeolite honeycomb structure; 3. simple theoretical model for generic chemical reactions; and 4. closed adsorption store model. Two of the models have been developed in TRNSYS directly, whereas one has been developed in Matlab and the fourth as a PEDX routine. The latter two models can be linked to TRNSYS and can thus be used in system simulations with the Task 32 boundary conditions. The models vary significantly in detail and require varying degrees of measurements for identifying parameters. For each model, the basic function of the store is described in addition to the model itself. The main assumptions and limitations of each model are stated. Finally details are supplied about the validation of the model.
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| 48. |
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| 49. |
- Bales, Chris, et al.
(författare)
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TCA Evaluation : Lab Measurements, Modelling and System Simulations
- 2005
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- The study reported here is part of a large project for evaluation of the Thermo-Chemical Accumulator (TCA), a technology under development by the Swedish company ClimateWell AB. The studies concentrate on the use of the technology for comfort cooling. This report concentrates on measurements in the laboratory, modelling and system simulation. The TCA is a three-phase absorption heat pump that stores energy in the form of crystallised salt, in this case Lithium Chloride (LiCl) with water being the other substance. The process requires vacuum conditions as with standard absorption chillers using LiBr/water. Measurements were carried out in the laboratories at the Solar Energy Research Center SERC, at Högskolan Dalarna as well as at ClimateWell AB. The measurements at SERC were performed on a prototype version 7:1 and showed that this prototype had several problems resulting in poor and unreliable performance. The main results were that: there was significant corrosion leading to non-condensable gases that in turn caused very poor performance; unwanted crystallisation caused blockages as well as inconsistent behaviour; poor wetting of the heat exchangers resulted in relatively high temperature drops there. A measured thermal COP for cooling of 0.46 was found, which is significantly lower than the theoretical value. These findings resulted in a thorough redesign for the new prototype, called ClimateWell 10 (CW10), which was tested briefly by the authors at ClimateWell. The data collected here was not large, but enough to show that the machine worked consistently with no noticeable vacuum problems. It was also sufficient for identifying the main parameters in a simulation model developed for the TRNSYS simulation environment, but not enough to verify the model properly. This model was shown to be able to simulate the dynamic as well as static performance of the CW10, and was then used in a series of system simulations. A single system model was developed as the basis of the system simulations, consisting of a CW10 machine, 30 m2 flat plate solar collectors with backup boiler and an office with a design cooling load in Stockholm of 50 W/m2, resulting in a 7.5 kW design load for the 150 m2 floor area. Two base cases were defined based on this: one for Stockholm using a dry cooler with design cooling rate of 30 kW; one for Madrid with a cooling tower with design cooling rate of 34 kW. A number of parametric studies were performed based on these two base cases. These showed that the temperature lift is a limiting factor for cooling for higher ambient temperatures and for charging with fixed temperature source such as district heating. The simulated evacuated tube collector performs only marginally better than a good flat plate collector if considering the gross area, the margin being greater for larger solar fractions. For 30 m2 collector a solar faction of 49% and 67% were achieved for the Stockholm and Madrid base cases respectively. The average annual efficiency of the collector in Stockholm (12%) was much lower than that in Madrid (19%). The thermal COP was simulated to be approximately 0.70, but has not been possible to verify with measured data. The annual electrical COP was shown to be very dependent on the cooling load as a large proportion of electrical use is for components that are permanently on. For the cooling loads studied, the annual electrical COP ranged from 2.2 for a 2000 kWh cooling load to 18.0 for a 21000 kWh cooling load. There is however a potential to reduce the electricity consumption in the machine, which would improve these figures significantly. It was shown that a cooling tower is necessary for the Madrid climate, whereas a dry cooler is sufficient for Stockholm although a cooling tower does improve performance. The simulation study was very shallow and has shown a number of areas that are important to study in more depth. One such area is advanced control strategy, which is necessary to mitigate the weakness of the technology (low temperature lift for cooling) and to optimally use its strength (storage).
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| 50. |
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