The Study Of The Stability Of The Central Heating System With Distributed Variable Speed Pump

The traditional central heating system’s heating effect is lower and energyconsumption is much higher. The promoting of the energy efficiency and the reducingof the transportation energy is the main work to reduce the central heating system’senergy. The work on this two part attached a lot of attention. The central heatingsystem with distributed variable frequency drive pumps is a new central heatingsystem. This new system’s transportation energy is lower and it’s energy efficiency ishigher. This paper study the stability of the central heating system with distributedvariable frequency drive pumps through theoretical calculations and analysis.The central heating system with distributed variable frequency drive pumps is aclosed water circulation system with pumps in parallel. This new system’s workprinciple is different from the traditional central heating system. This paper builds themathematical model based on the work of the predecessors to study the new system’sstability. This paper focuses on the choice of the pump、 dynamic configuration、pipeline characteristic to study the system’s stability.Study the applicability of the pump proportion law in the central heatingsystem with distributed variable frequency drive pumps through theoretical analysisand analyze the influence of flow changing to the system’s stability by changingpump speed and impedance regulation. Drawing the following conclusions: the pumpproportion law can’t be applied in the central heating system with distributed variablefrequency drive pumps when the working condition changed. The influence of pumpspeed changing regulation and impedance regulation to the stability of the centralheating system is the same.Build a mathematical model by using the offset coefficient methodkirchhoff’s voltage drop’s law and flow law to study the stability of the system anddraw the flowing conclusion: To the central heating system, the source pump shouldchoose the pump with flat pump characteristic curve, the branch pump should choosethe pump with precipitous pump characteristic curve. The zero pressure drop point atthe head of the central heating system with distributed variable speed pump which have source pump is better and the zero pressure drop point at the extremity is worseand the zero pressure drop point at the middle is the worst; In all the typical centralheating system, the stability of the central heating system with distributed variablespeed pump which do not have source pump is the best, the traditional central heatingsystem is better, the central heating system with distributed variable speed pumpwhich have source pump is the last.