PDF Publication Title:
Text from PDF Page: 008
Sustainability 2018, 10, 191 8 of 32 it is possible to achieve much higher power rates from an aquifer since water can be pumped at a high rate. Cavern storage and pit storage are based on large underground water reservoirs created in the subsoil to serve as TES systems. Caverns are the same in their principles of operation as the tanks discussed in the previous section. Energy is added to or removed from the store by pumping water into or out of the storage unit. The major difference will be in the mechanisms for heat loss and the possible thermal coupling with the ground. These storage options are technically feasible, but applications are limited because of the high investment costs. A German central solar heating plant with seasonal storage is described by Bauer et al. [32], who also discuss the heat losses from certain installations. For example, for seasonal water storage with a volume of 12,000 m3 in Friedrichshafen, the yearly heat losses from the store were between 322 and 482 MWh, yielding a storage utilization factor of Sustainability 2018, 10, 191 8 of 32 around 60%. The solar fraction for this system was lower than expected (between 21 and 33% instead of a projected 43%), and the reasons given are a higher heat demand from the buildings and higher For high-temperature (i.e., above 100 °C) SHS, the technology of choice is based on the use of return temperatures to the store. For a seasonal borehole storage evaluated by Heier et al. [33], the liquids (e.g., oil or molten salts, the latter for temperatures up to 550 °C). For very high borehole storage itself is shown to have a yearly heat loss of approximately 50% of the solar energy temperatures, solid materials (e.g., ceramics and concrete) are also taken into consideration. that is charged into the store. However, most of such high-temperature◦-sensible TES options are still under development or For high-temperature (i.e., above 100 C) SHS, the technology of choice is based on the use of ◦ A packed-bed (pebble-bed) storage unit uses the heat capacity of a bed of loosely packed demonstration. liquids (e.g., oil or molten salts, the latter for temperatures up to 550 solid materials (e.g., ceramics and concrete) are also taken into consideration. However, most of such C). For very high temperatures, high-temperature-sensible TES options are still under development or demonstration. 3.3. Packed-Bed Storage 3.3. Packed-Bed Storage particulate material to store energy. A fluid, usually air, is circulated through the bed to add or remove energy. A variety of solids may be used, rock and pebble being the most widely used A packed-bed (pebble-bed) storage unit uses the heat capacity of a bed of loosely packed materials. particulate material to store energy. A fluid, usually air, is circulated through the bed to add or A pebble-bed storage unit is shown in Figure 5. In operation, flow is maintained through the remove energy. A variety of solids may be used, rock and pebble being the most widely used materials. bed in one direction during addition of heat (usually downward) and in the opposite direction A pebble-bed storage unit is shown in Figure 5. In operation, flow is maintained through the bed during removal of heat. Note that heat cannot be added and removed at the same time; this is in in one direction during addition of heat (usually downward) and in the opposite direction during contrast to water storage systems, where simultaneous addition to and removal from storage is removal of heat. Note that heat cannot be added and removed at the same time; this is in contrast to possible. water storage systems, where simultaneous addition to and removal from storage is possible. Figure 5. Pebble-bed storage system [4]. Figure 5. Pebble-bed storage system [4]. A major advantage of a packed-bed storage unit is its high degree of stratification. The pebbles A major advantage of a packed-bed storage unit is its high degree of stratification. The pebbles near the entrance are heated, but the temperature of the pebbles near the exit remains unchanged near the entrance are heated, but the temperature of the pebbles near the exit remains unchanged and the exit-air temperature remains very close to the initial bed temperature. As time progresses a and the exit-air temperature remains very close to the initial bed temperature. As time progresses a temperature front passes through the bed. When the bed is fully charged, its temperature is temperature front passes through the bed. When the bed is fully charged, its temperature is uniform. uniform. A packed bed in a solar heating system does not normally operate with constant inlet A packed bed in a solar heating system does not normally operate with constant inlet temperature. During the day, the variable solar radiation, the ambient temperature, the collector inlet temperature. During the day, the variable solar radiation, the ambient temperature, the collector inlet temperature, load requirements, and other time-dependent conditions result in a variable collector outlet temperature. Many studies on the heating and cooling of packed beds have been published. The first analytical study was by Schumann [34], and the basic assumptions leading to this model are a one-dimensional plug flow, no axial conduction or dispersion, constant properties, no mass transfer, no heat loss to the environment, and no temperature gradients within the solid particles.PDF Image | Comprehensive Review of Thermal Energy Storage
PDF Search Title:
Comprehensive Review of Thermal Energy StorageOriginal File Name Searched:
a554bca3a326b394928e3ab67fdd8d40c756.pdfDIY PDF Search: Google It | Yahoo | Bing
Turbine and System Plans CAD CAM: Special for this month, any plans are $10,000 for complete Cad/Cam blueprints. License is for one build. Try before you buy a production license. More Info
Waste Heat Power Technology: Organic Rankine Cycle uses waste heat to make electricity, shaft horsepower and cooling. More Info
All Turbine and System Products: Infinity Turbine ORD systems, turbine generator sets, build plans and more to use your waste heat from 30C to 100C. More Info
CO2 Phase Change Demonstrator: CO2 goes supercritical at 30 C. This is a experimental platform which you can use to demonstrate phase change with low heat. Includes integration area for small CO2 turbine, static generator, and more. This can also be used for a GTL Gas to Liquids experimental platform. More Info
Introducing the Infinity Turbine Products Infinity Turbine develops and builds systems for making power from waste heat. It also is working on innovative strategies for storing, making, and deploying energy. More Info
Need Strategy? Use our Consulting and analyst services Infinity Turbine LLC is pleased to announce its consulting and analyst services. We have worked in the renewable energy industry as a researcher, developing sales and markets, along with may inventions and innovations. More Info
Made in USA with Global Energy Millennial Web Engine These pages were made with the Global Energy Web PDF Engine using Filemaker (Claris) software.
Sand Battery Sand and Paraffin for TES Thermo Energy Storage More Info
CONTACT TEL: 608-238-6001 Email: greg@infinityturbine.com (Standard Web Page)