Research On Low-Temperature Radiation Ground Heating Temperature Controller

Along with the rapid development of the national economy and the improvement of modern living standards, low-temperature water radiant floor heating technology is widely promoted and has become the preferred method of heating system. As the key factor of low-temperature water radiant floor heating system, temperature control has become the study focus in HVAC industry.This paper chooses fuzzy predictive control and Fuzzy-PID as the research topic, which has crucial significance in theory and practical field, conducts research upon the theory study of low-temperature radiant floor heating system and the control theory, and complete the design task of the low-temperature radiant floor heating temperature controller and experiments.First, according to the basic heating transfer principle and the floor radiator structure which used for low-temperature radiant floor heating experiment, a simplified dynamic mathematical model has been put forward. And the temperature distribution of rooms in different conditions and the regular indoor temperature changes has been concluded in the MATLAB simulation which differs in several conditions with different property parameters.Second, to solve the problem that numeric PID control is difficult to adapt the dynamic changes of nonlinear systems, and the bad dynamic performance of the system in which the numeric PID control has been applied, this paper conduct research upon self-tuning PID-type fuzzy control method. With the adjustment of the three parameters in self-tuning PID-type fuzzy control method, the shortcomings which traditional numeric PID can not resolve have been overcome. In addition, this paper also inquiry another method, which has limited the use of T-S models to input non-linear, time-delay system modeling is proposed predictive fuzzy control, input constraints into the form of linear matrix inequalities. Simulation results show that the method is effective.Finally, freescale single-chip has been selected as the control unit to design a low-temperature radiant floor heating temperature controller, to which the Fuzzy-PID control algorithm has been applied. In the following low-temperature water radiant floor heating experiment, the temperature controller gave out a good performance, such as better control precision, dynamic performance and stability because of the applied Fuzzy-PID algorithm and the selected Freescal single chip.