Based on the refrigerant state, divides a heat exchanger into three zones with zoned lump method, i. e. superheat, two-phase and subcooling zones, works out the temperature difference and heat transfer coefficients of the three zones.

• 采用分区参数法将换热器按制冷剂状态分为过热、两相、过冷三区，分别计算了各区的换热温差、传热系数等。