In conventional biomass cogeneration unit

steam extracted from the turbine is used to heat the supplywater

and there is a great exergy loss in the process of steam-water heat exchanger. To reduce exergy loss of the heating system

a biomass cogeneration system was proposed. In this system

the heating system uses condensate water of the heat regenerative system instead of steam extraction of the turbine

and a plate heat exchanger is used to heat the supply-water. It not only can increase the power put of the unit by reducing the steam extraction

but also can improve the effect of heat transfer via water-water heat exchange. Moreover

a typical 35 MW biomass cogeneration unit is taken as a case to carry out system retrofitting and thermodynamic analysis and economic analysis. The results show that

the power supply pole per unit consumption of the new system reduces by 18.29 g/(kW·h)

the comprehensive efficiency and power generation efficiency increases by 0.85 percentage points and 1.01 percentage points

respectively. After the retrofitting

the heating supply system gains large financial benefits

of which the annualized net new income can reach 3.618 8 million yuan.