Design And Implementation Of Thermoelectric Water Heater Constant Temperature Performance Testing System

Though the thermostatic water heater has been in the market,enterprises have never stopped the pace of research and development for the improvement of thermostatic performance,which is affected by the control algorithm,structure,heater and so on.Faced with the complexity of the electricity and water environment,effective testing and adjustment are required to ensure the reliability of the thermostatic performance.A large number of data should be collected and analyzed to get an effective improvement plan.Under the circumstance,the paper will focus on designing a simple data-recording detection system,aiming to help testing and research personnel to better detect and improve product performance.This design uses STM32F103ZET6 as the main control chip which has the rich functions with the corresponding peripheral circuits,combined with PID and feedforward control theory.The software and hardware are designed by transplanting UCOS? operating system,FATFS file system and STEMWIN graphics system to realize the constant temperature function and achieve a better human-computer interface and data storage function.Finally the purpose of the design is realized.The design of the system hardware is divided into two parts,which are the constant temperature hardware module circuit and the detection system hardware circuit.Constant temperature module circuit includes power circuit,temperature detection circuit,water flow detection circuit,heating output control circuit and zero-crossing detection circuit.The hardware circuit of the detection system includes SRAM extension circuit,SD card interface circuit and TFT touch screen module interface circuit.This paper first analyzes the control theory used by the constant temperature control,then describes concretely how to combine these control theories to achieve the constant temperature function in the design.For the detection part,the FATFs file system and the STEMWIN graphics system are transplanted.The data storage and display functions are realized by combining the SD card reading and writing functions,TFT LCD screen drive and other functions.Through the reasonable use of the control provided by STEMWIN,a good user interface is designed,which is convenient for users to observe and read the relevant data for analysis.The whole software is designed in the way of task management,and the UCOS? operating system is transplanted into the system.During the design process,the constant temperature control algorithm the graphical interface and data saving function are setted as tasks to achieve the separation of constant temperature function and detection function,which is convenient for modification and transplantation.Finally,through the physical test,the design realizes the constant temperature control function and real-time display,storage and reading of various control data.It can be used as an auxiliary tool for testing and research personnel to effectively verify and research the product performance in later use.