| 1. |
|
|
| 2. |
- Bales, Chris, et al.
(författare)
-
Final Report of Subtask B “Chemical and Sorption Storage” : Report B7 of Subtask B
- 2008
-
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
|
|
| 3. |
- Bales, Chris, et al.
(författare)
-
Laboratory Prototypes of Thermo-Chemical and Sorption Storage Units : Report B3 of Subtask B
- 2007
-
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.
|
|
| 4. |
- Bales, Chris, et al.
(författare)
-
Laboratory Tests of Chemical Reactions and Prototype Sorption Storage Units : Report B4 of Subtask B
- 2008
-
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.
|
|
| 5. |
- Bales, Chris, et al.
(författare)
-
Store Models for Chemical and Sorption Storage Units : Report B5 of Subtask B
- 2008
-
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.
|
|
| 6. |
|
|
