Abstract:
The disclosure relates to an optical measurement device (100) adapted for determining the temperature in a flame and for determining the particle size of the fuel present in the flame. The optical measurement device (100) includes a colour camera (10) for measuring light information in the flame and outputting measurement results and an evaluation unit (20) adapted for evaluating the measurement results. Further, a coal burning power plant (200) is provided with a multitude of burners (35) for burning milled coal each in a flame and a multitude of optical measurement devices (100) described. Further, an according method for determining the temperature and particle size of the fuel present in a flame is provided.
Abstract:
A thermoelectric energy storage (TEES) system having a charging cycle (10) for providing thermal energy to a hot thermal storage arrangement (18, 22, 24), and a discharging cycle (30) for generating electricity by retrieving the thermal energy from the hot thermal storage arrangement (18, 22, 24), the thermoelectric energy storage system including regenerative heat exchange. The system comprises a working fluid circuit adapted to circulate a gaseous working fluid through the hot thermal storage arrangement (18, 22, 24) and a cold thermal storage arrangement (14, 26, 28), wherein the hot thermal storage arrangement comprises a hot storage heat exchanger (18) and at least two hot storage tanks (22, 24) coupled via the hot storage heat exchanger (18). The cold thermal storage arrangement comprises a cold storage heat exchanger (14) and at least two cold storage tanks (26, 28) coupled via a cold storage heat exchanger (14). The system also provides a regenerative heat exchanger (20), adapted to further cool the working fluid at the output of the hot thermal storage arrangement during the charging cycle (10), and to pre-heat the working fluid at the input into the hot thermal storage arrangement during a discharging cycle (30). Notably, the working fluid is constantly in gas phase during the charging and discharging cycles.
Abstract:
A system and method for storing and retrieving energy in a thermoelectric energy storage system is described. The thermoelectric energy storage system comprises a working fluid which is circulated through a first and second heat exchanger (18, 14, 30), and a thermal storage medium which is circulated through the first heat exchanger (18). The second heat exchanger (14, 30) is in connection with a first thermal bath (20) during a charging cycle and with a second thermal bath (34) during a discharging cycle. In this way roundtrip efficiency is improved through minimizing the temperature difference between the first thermal bath (20) and the hot storage tank (24) during charging, and maximizing the temperature difference between the second thermal bath (34) and the hot storage tank (24) during discharging.
Abstract:
A system and method for electro-thermal energy storage, wherein the system comprises: a hot thermal storage arrangement (1) comprising a hot storage heat exchanger (11); a cold thermal storage arrangement (2) comprising a cold storage heat exchanger (21); a thermodynamic cycle unit configured to transfer thermal energy from the cold storage arrangement to the hot storage arrangement in a charging mode, and to convert thermal energy from the hot storage arrangement into work and, preferably, subsequently into electric energy in a discharging mode, wherein the thermodynamic cycle unit comprises a fluid circuit for circulating a working fluid through the hot storage heat exchanger as well as through the cold storage heat exchanger, wherein the fluid circuit further comprises a pump (31) for maintaining a circulation of working fluid in the discharging mode and a first turbine (321) for expanding working fluid in the discharging mode; and wherein the thermodynamic cycle unit comprises a second turbine (322) for expanding working fluid in the discharging mode, said second turbine being connected in series with the first turbine so that working fluid may flow from the first to the second turbine in the discharging mode, and an intercooling heat exchanger (33) located in the fluid circuit between the first and the second turbine.
Abstract:
A system and method for thermoelectric energy storage is described. The system has a charging cycle (10)for providing thermal energy to a hot thermal storage arrangement (18, 20, 22) and an evaporative ice storage arrangement(24) and a discharging cycle (30) for generating electricity by retrieving the thermal energy. The evaporative ice storage arrangement (24) comprises a heat exchanger(14, 36), an ice slurry storage tank (26), a vacuum evaporation chamber (28) and a slurry heat exchanger(40). The evaporative ice storage arrangement(24) of the present invention functions as a dedicated cold storage for the thermoelectric energy storage system. The cold storage is realized by producing an ice-water mixture during charging of the storage, and using the stored ice-water mixture to condense the working fluid during the discharge cycle (30). Use of this sub-triple-point evaporation arrangement functions to increase the round-trip efficiency of the TEES system through minimising the maximum temperature difference between the working fluid and the thermal storage medium during operating cycles.
Abstract:
A thermoelectric energy storage system (10) has an intercooler for intercooling a working fluid between two compression stages. The intercooling may be carried out by flashing a portion of the working fluid taken from the output of a expander (20) in a flash intercooler (28) and/or by heating a secondary thermal storage (46) with a further heat exchanger (30).
Abstract:
A method for controlling an energy storage system is described. The method makes use of a model based predictive controller to optimise the charging/discharging rates of energy storage elements in a hybrid energy storage system.
Abstract:
A system and method for thermoelectric energy storage is described. A thermoelectric energy storage system (22, 36) having a heat exchanger (30) which contains a thermal storage medium, and a working fluid circuit for circulating a working fluid through the heat exchanger (30) for heat transfer with the thermal storage medium. The working fluid undergoes transcritical cooling during the charging and transcritical heating during the discharging cycle as it exchanges heat with the thermal storage medium. Improved roundtrip efficiency is achieved through minimising the maximum temperature difference (ΔTmax) between the working fluid and the thermal storage medium during operating cycles.
Abstract:
A system and method for electro-thermal energy storage is described. The system has a charging cycle (10) for providing thermal energy to a hot thermal storage arrangement (18, 20, 22) and an evaporative ice storage arrangement (24) and a discharging cycle (30) for generating electricity by retrieving the thermal energy. The evaporative ice storage arrangement (24) comprises a heat exchanger (14, 36), an ice slurry storage tank (26), a vacuum evaporation chamber (28) and a slurry heat exchanger (40). The evaporative ice storage arrangement (24) of the present invention functions as a dedicated cold storage for the electro-thermal energy storage system. The cold storage is realized by producing an ice-water mixture during charging of the storage, and using the stored ice-water mixture to condense the working fluid during the discharge cycle (30). Use of this subtriple-point evaporation arrangement functions to increase the round-trip efficiency of the ETES system through minimising the maximum temperature difference between the working fluid and the thermal storage medium during operating cycles.
Abstract:
Steam bled from a turbine (14) of a power plant (12) is used to heat, through a split stream heat exchanger (20), an energy storage system (10) with a low temperature storage (26), an intermediate thermal storage (24) and a high temperature storage (22). A further split stream heat exchanger (30) is used to efficiently heat the working fluid of a heat engine cycle (29) for generating electricity. During times when the load on the power plant (12) is low, surplus heat from the turbine (14) may be stored in the energy storage system (10). The stored heat may be used to generate electricity for compensating load peaks on the power plant (12). For example, the heat engine cycle (29) may drive an additional generator (40).