| In this paper,the thermal and hydraulic characteristics of the on-off regulation system are studied by simulation method,and the law of flow change from individual to user is explored.And from the point of view of energy saving and effective room temperature control,a calculation method of controlling the opening time of on-off valve according to the actual heat load demand in the heating room is put forward.The main work of this paper is as follows: The physical model and mathematical model of each component of the heating system are set up and the steady state verification is carried out.A model predictive control method based on the weather forecast data and the state space method is proposed to predict the room temperature,heat load and the heat dissipation of the radiator.Based on single room model,the influence of external factors such as room location and climatic conditions on room temperature changes,on-off valve switch and radiator heat dissipation of heating room was analyzed.And from the control cycle to adjust and adjust the valve mode two aspects,to analyze the system’s on-off control characteristics,to explore the appropriate control cycle.This paper analyzes the change of the whole flow from the individual user to the multi-user,and optimizes the opening time and opening cycle of the on-off valve,and explores the on-off valve control method which can stabilize the heat network flow.The main conclusions of the paper are as follows: The model predictive control method proposed in this paper can control the room temperature fluctuation within ± 0.5 ℃;the on-off control system which adjusts the work and rest adjusts slowly after long-term closing,Consider the hot users of the heat needs to open the valve in advance to preheat the room to ensure the timely use of thermal demand;by staggering the opening time of on-off valve by the floor can effectively avoid the same valve with the opening and closing to reduce the user group of traffic fluctuations.The results of this paper will help to understand the thermodynamic and hydraulic characteristics of on-off regulation metering heating system and to promote the development of on-off control technology.It provides some ideas and reference for the design of on-off regulating metering heating system. |
