Design And Reliability Analysis Of Two-Cogeneration Control System Based On Somatosensory Temperature

With the improvement of living standards,human demand for heating and cooling systems has gradually increased.In recent years,the air source heat pump combined cooling and heating system has gradually become known to users because of its energy saving and comfort characteristics.However,most air-conditioning control systems use air temperature as the control temperature and lack corresponding reliability analysis.This paper designs and implements a combined cooling and heating control system based on body temperature,analyzes the reliability of the designed system,and conducts a criticality analysis(Criticality Analysis,CA analysis)of the 485 communication module in the system.After completion,the CA software is designed and completed using the improved D-S evidence theory(DempsterShafer evidence theory,referred to as D-S evidence theory),and the combination of the two proves the usability of the software.details as follows:1.In view of the shortcomings of the traditional combined heating and cooling system that uses air temperature as the control temperature,in order to comprehensively improve the comfort of users when using the system,a combined cooling and heating system based on body temperature has been researched and developed.Firstly,the overall design and control mode of the system are introduced.Corresponding to the realization of related control modes,STM32(STMicroelectronics 32,referred to as STM32)is used as the core controller,combined with a temperature sensor to calculate the dew point temperature,a temperature and humidity sensor to calculate the dew point temperature,and a relay to control the fan.The coil and floor heating start and stop,the three-way valve controls the water temperature of the floor heating to be higher than the dew point temperature,and the 485 communication realizes the data communication between the thermostat,the system controller and the host computer and other related control logics,and completes the hardware of the cooling and heating dual supply system Design and software design.Effectively realize the expected setting of controlling the corresponding functions of the fan coil unit and the floor heating through the body temperature.2.In view of the lack of reliability design and analysis of most air-conditioning controllers,in order to effectively improve the reliability of the combined cooling and heating control system designed in this paper,this paper uses a preliminary analysis of the system controller and a failure mode and effect analysis(Failure Modes and Effects Analysis(FMEA for short),determined the possible failure modes of the system during the design and manufacturing process,analyzed its failure mechanism,and provided a basis for subsequent improvement of system reliability.3.In view of the simple and single scoring of the traditional risk priority number(RPN)method,which only considers the scoring opinions of a single expert,this paper uses the modified D-S evidence theory for processing and modeling from multiple experts in FMEA discrepancies and uncertainties in the estimated information received.This approach aggregates information from multiple expert assessments of risk factors.The results of each expert’s assessment of each risk factor for each failure mode are considered a new body of evidence.The data fusion of all expert scores is completed,and the RPN value obtained by the D-S data fusion algorithm is closer to the mean value than the traditional RPN method,which proves the feasibility of this fusion algorithm.Finally,based on the D-S data fusion theory,a CA software is developed and implemented,and the usability of the software is proved by analyzing the 485 communication module in the thermostat and the system controller.