The invention relates to a quality-divided and graded utilization method and
system of
coal-burning
supercritical carbon dioxide power generation
flue gas energy and working
medium energy. The quality-divided and graded utilization method and
system of
coal-burning
supercritical carbon dioxide power generation
flue gas energy and working
medium energy have the benefits as follows: firstly, high-grade
flue gas energy and working
medium energy multistage reheat expansion measures are utilized, so that a isothermal heat absorbing process being close to the temperature of a high temperature heat source is realized, the average heat absorbing temperature is improved, and the circulating efficiency of the
system is improved; secondly, middle-grade
flue gas energy and working medium
energy coupling, graded dividing and backheating measures are utilized, the energies of the
flue gas and working medium in a medium temperature zone are fully utilized in a graded manner, the
heat transfer temperature difference of cold and heat fluids are reduced as far as possible, the
irreversible loss of available energy due to large
temperature difference is reduced, and both the heat exchange efficiency and circulating efficiency are improved; thirdly, a low-grade
flue gas energy and working medium energy graded heating
cold air and fuel system is utilized, the low temperature
exhaust heat of flue gas and working medium is utilized, the heat of flue gas and working medium released to the environment is reduced, a isothermal heat releasing process being close to the environment temperature is realized, the cold end loss is reduced, and the circulating efficiency is improved.