Number each pipe segment and determine the diameter of the pipe segment by knowing the heat load of each pipe segment of the system, the flow rate of each pipe segment and the circulating pressure of the system;2. The flow rate and diameter of each pipe section of the system can be known through the above contents, and the necessary circulating pressure (head) can be determined in the system;3. Determine the water flow through the pipe segment by knowing the diameter of each pipe segment of the system and the allowable pressure drop of the pipe segment