The principle of thermal power extraction steam energy storage

How efficient is thermal energy storage with reheat steam as a heat source?

Thermal energy storage options with reheat steam as a heat source are introduced. A energy-exergy-economic comparison of three heat storage options is investigated. Minimum power load ratio of thermal power system can be reduced by 12%-points. The largest round-trip efficiency is achieved at 67.54% by two-stage heat storage.

How efficient is a thermal energy storage system?

The condenser and evaporator corresponding to the storage and heat processes account for 60 % of the total exergy losses in thermal energy storage system. The retrofitted system has a maximum cycle efficiency of 70–80 % with low and peak modulation rates of 16.5 % and 11.7 %.

What is the basic principle of thermal energy storage (TES)?

The basic principle of TES is to store surplus heat to be used later and overcome the mismatch between energy supplies and demands in time and space . The TES is mainly classified into three categories: sensible, latent, and thermochemical heat storage .

How to calculate energy extraction from reheat steam?

The energy extraction from the reheat steam, Q ̇ re, is calculated as follow: (1) Q ̇ re = m ̇ s ( h s - h c), where m ̇ s is the mass flow rate of the steam extraction from the reheat steam, kg/s; hs is the enthalpy of the reheat stream entering the TES system, kJ/kg; and hc is the enthalpy of the sub-cooled stream leaving the TES system, kJ/kg.

How does main steam and reheat steam affect tpse?

Main steam and reheat steam are the energy sources for the TES system and turbine power generation, so the extraction of different flow rates of main steam (EMS) and reheat steam (ERS) significantly impacts the heat storage and release processes of TPSE.

How do thermal and nuclear power systems work?

Thermal and nuclear power systems often use main steam or reheated steam as the high-pressure stream and direct the low-pressure extracted or exhausted steam from the turbine as the heat source, which has good industrial application prospects and strong technical feasibility.