Thermal power plant with regenerator and method of producing same

Abstract

A thermal power plant includes a unit producing heat energy, a regenerator including energy-storage elements, a consumer of heat energy, and a circulation device. During charging, the circulation device circulates a charging heat-transfer fluid from the unit producing heat energy through the regenerator, entering the regenerator at a charging temperature of less than 1000° C. During discharging, the circulation device circulates a discharging heat-transfer fluid through the regenerator, entering the regenerator at a discharging temperature. The energy-storage elements have material with a melting point higher than the charging temperature plus 50° C. and lower than 2000° C. The concentration of all elements leached from the material is less than or equal to 0.5 g/l. The material of the energy-storage elements has a characteristic ratio higher than 0.3, with: A=(Cp(Tc)−Cp(Td))/Cp(Td), where Cp(Tc) and Cp(Td) are the specific heat capacity of the material at the charging and discharging temperatures, respectively.

1 . Thermal power plant comprising:
 a unit producing heat energy,   a regenerator comprising a bed of energy-storage elements,   a consumer of heat energy, and   a circulation device which:   during a charging phase, circulates a charging heat-transfer fluid from the unit producing heat energy to the regenerator, then through the regenerator, the charging heat-transfer fluid entering the said regenerator at a charging temperature Tc of less than 1000° C., and
 during a discharging phase, circulates a discharging heat-transfer fluid through the regenerator, the discharging heat-transfer fluid entering the regenerator at a discharging temperature Td, 
   
       the energy-storage elements being made of a material which has a melting point higher than Tc+50° C. and lower than 2000° C., 
       the concentration of all the elements leached from the said-material, as measured in accordance with standard EN 12457-2 of December 2002, being less than or equal to 0.5 g/l, and 
       wherein the material of the energy-storage elements has a characteristic ratio A higher than 0.3, with:
     A =( Cp ( Tc )− Cp ( Td ))/ Cp ( Td )
 
 
       where
 Cp(Tc) is the specific heat capacity of the said-material at the charging temperature, and 
 Cp(Td) is the specific heat capacity of the material at the discharging temperature. 
 
     
     
         2 . Plant according to  claim 1 , in which the characteristic ratio A is higher than 0.45. 
     
     
         3 . Plant according to  claim 1 , in which the unit producing heat energy produces more than 50 kW of heat energy. 
     
     
         4 . Plant according to  claim 1 , in which the charging temperature is higher than 350° C. 
     
     
         5 . Plant according to  claim 4 , in which the charging temperature is higher than 500° C. 
     
     
         6 . Plant according to  claim 1 , in which the discharging temperature is lower than the charging temperature. 
     
     
         7 . Plant according to  claim 1 , in which over 90% of the mass of the said-material consists of oxides. 
     
     
         8 . Plant according to  claim 1 , in which the material contains over 50 wt % of aluminium-magnesium spinels and/or of steatite, of forsterite Mg2SiO4, and/or of ilmenite FeTiO3, and/or of iron oxides. 
     
     
         9 . Plant according to  claim 8 , in which, of the balance to 100 wt %, over 90 wt % of the balance material consists of at least one oxide chosen from boron oxide, sodium oxide, copper oxides, iron oxides, silica, alumina and mixtures thereof. 
     
     
         10 . Plant according to  claim 1 , in which the concentration of all of the elements leached from the material, measured in accordance with standard EN 12457-2 of December 2002, is less than or equal to 0.1 g/l. 
     
     
         11 . Plant according to  claim 1 , in which the said-regenerator is a sensible-heat regenerator. 
     
     
         12 . Plant according to  claim 1 , comprising a consumer of heat energy, the said-circulation device, during the discharging phase, causing the discharging heat-transfer fluid to circulate through the regenerator, then from the regenerator to the consumer of heat energy. 
     
     
         13 . Plant according to  claim 1 , in which the unit producing heat energy consists of a compressor mechanically or electrically powered by an incineration plant or by an electricity power station. 
     
     
         14 . Plant according to  claim 1 , comprising a heat exchanger designed to perform direct or indirect heat exchange with the regenerator. 
     
     
         15 . Plant according to  claim 1 , the discharging temperature being lower than the temperature at which the heat-transfer fluid leaves the regenerator at the end of the charging phase by less than 200° C. 
     
     
         16 . Plant according to  claim 1 , the discharging temperature being higher than 50° C. 
     
     
         17 . Method for producing a plant according to  claim 1 , in which the material chosen for the energy-storage elements, from a set of several materials, is the material that has the highest characteristic ratio A. 
     
     
         18 . Method for designing, producing and operating a thermal power plant, in which:
 (a) a thermal power plant according to  claim 1  is designed and produced,   and   (b) the thermal power plant is operated by using the said-circulation device such that:
 during a charging phase, it circulates a charging heat-transfer fluid from the unit producing heat energy to the regenerator, then through the regenerator, the said charging heat-transfer fluid entering the said-regenerator at a charging temperature Tc below 1000° C., and 
 during a discharging phase, it circulates a discharging heat-transfer fluid through the regenerator, the discharging heat-transfer fluid entering the said-regenerator at a discharging temperature Td.