The invention relates to a method for regulating the indoor temperature and a dual-
temperature control valve for implementing the method. The method is used for regulating the indoor temperature of an
air conditioning system in a
cascade manner by means of cooling and dehumidifying
indoor air by the aid of cold water in summers and heating the
indoor air by the aid of hot water in winters, and the dual-
temperature control valve is used for implementing the method. The method and the dual-
temperature control valve have the advantages that an indoor temperature
cascade regulation
system comprises two regulators which are serially connected with each other to work, and the temperature of supplied air or the temperature of return water is used as an auxiliary variable, so that the indoor temperature which is a main variable can be stabilized; the auxiliary variable has a largest limiting value when refrigerating and dehumidifying requirements need to be met simultaneously in summers, regulating valves are switched off when the indoor temperature is close or equal to a given value, accordingly, the indoor
humidity can be taken into consideration while the requirement on the indoor temperature is met, the refrigerating capacity of the cold water is saved, the comfortableness of an indoor environment can be guaranteed, a
water flow rate and the overshoot further can be reduced, the
transition time can be shortened, dynamic characteristics of procedures can be improved, particularly, secondary disturbance resistance such as water-
temperature resistance and water-pressure-variation resistance can be greatly improved, and purposes of further improving the regulation quality of the
system, reducing
power consumption of water pumps and improving the efficiency of a main unit can be achieved.