Operation method of energy-saving fluid transporting machineries in parallel array with constant pressure

An operation method of energy-efficient and constant-pressure fluid-transport machines coupled in parallel, comprising:

• providing a system impedance curve of a load, wherein said system impedance curve is determined by a flow rate and impedance of said load;
• providing a performance curve and an equal-efficiency curve of a fluid-transport machine, wherein said performance curve of said fluid-transport machine is determined by a flow rate and pressure of said fluid-transport machine;
• coupling a plurality of said fluid-transport machines in parallel to calculate a performance curve of said fluid-transport machines in parallel, wherein said performance curve of said fluid-transport machines in parallel intercepts said system impedance curve with an operational point, and said operational point is corresponding to said pressure and said flow rate of said load;
• comparing a plurality of total output powers to acquire a number of fluid-transport machines in parallel according to said pressure of said load, said flow rate of said load and said performance curves of said fluid-transport machines, wherein said total output power corresponding to said number of fluid-transport machines in parallel is minimum in said total output powers;
• determining a flow rate of fluid-transport machines in parallel by dividing said flow rate of said load with said number of fluid-transport machines in parallel;
• and
• adjusting a rotation speed of each of said fluid-transport machines in parallel to make said flow rate of fluid-transport machines in parallel fixed.