Research On The Testing Technology And Device For Comprehensive Performance Of Instantaneous Water Heater

With continuous development of instantaneous water heater, a higher requirement for the automated detection of the performance of instantaneous water heater is put forword. In the past, the detection method of thermal performance of instantaneous water heater mainly depended on testing item by item and logging data artificially. So there exist many disadvantages, such as big workload, low efficiency and poor accuracy caused by the human factors. So that it is urgent for the instantaneous water heater manufacturers to resolve the problems including how to improve work efficiency of the testing efficiency of instantaneous water heater, reduce labor intensity and as far as possible to improve the measurement precision.In view of the above question, this paper designed a test system about comprehensive performance of instantaneous water heater on the basis of the requirement of national standard GB/T26185-2010to instantaneous water heater, realized automatic measurement for comprehensive performance of instantaneous water heater. This system took the microprocessor STM32as the core, adopted currently precision temperature, flow, voltage and current sensors to carry on data acquisition for signals of instantaneous water heater and used internal ADC of STM32to conduct analog-to-digital conversion. The method of wavelet threshold denoising is needed to denoise them on the basis of analysis of instantaneous water heater signals and the denoised data is sent to the upper PC software for processing, display and storage, accordingly achieving the automated measurement of a number of performance of the instantaneous water heater. Firstly, this paper introduced the whole scheme design of the testing system and the main compoents selection, and simply introduced heating principle of instantaneous water heater. Secondly, the data acquisition of temperature, flow, voltage and current was realized, and the data of denoised method was studied. Then, the upper PC software is designed in LABVIEW development environment through using modularization. The upper PC software includes real-time display, curve display function, database analysis and storage functions. Endly, each of sensors is carried on calibration and testing.A large number of experimental results show that the test system meets the design requirements, is stable and precision, improving the test efficiency greatly.