Deduces the simplified equations of head ratio and shaft power ratio of variablespeed chilled water pumps by introducing the conception of controlled pressure differential ratio β.

Location analysis of the pressure difference control point in variable flow rate heat metering charging systems;

Calculates and analyses the piping network characteristics of the systems under pressure difference control of supply/return main pipes and terminal loop pressure difference control.

Presents some hot research topics and their development, including pressure difference control, setting of surge chamber and spray chamber, air change rate and energy saving, numerical simulation of air distribution, and air filter and its leak detecting.

Application of differential pressure control to circuit of load side in a variable volume air conditioning water systems;

To meet the requirement of differential pressure control, a new style pneumatic pressure control valve is developed for some pneumatic projection system to work under environment condition of variable pressure.

Study on the variable pressure difference control of variable-speed pumps;