The Design Of The Large Caliber Ultrasonic Intelligent Heat Meter

Because of the increasing demand of the technology of heat meter,this thesis is going to discuss about the both domestic and overseas technology of large diameter heat meter.Based on the technology of analyzing of Ultrasonic flow detection and the principle of working,this thesis will discuss how to revise the past heat meters fromthe lower cost,measurement of the flow,detection of temperature,meter-bus communication technology and low-power cost by comparing the schemes of this technology and proving those schemes in order to design a large caliber ultrasonic type intelligent heat meter.This thesis figures out a new design of large caliber ultrasonic intelligent heat meter.This design,by using the TDC-GP22 measuring principle,successfully achieves a zero time difference calibration algorithm in order to improve the flow measurement precision and consistency:Using the low power 16-bit microprocessor for MSP430 through the built-in LCD driver module to display the key data of the accumulation of heat and flow.And then use those data to go through the built-in US ART module to complete Meter-Bus communication and finally go through the interaction information from TDC-GP22 chip which is produced by ACAM company,and Complex algorithm to achieve the system architectures of combining Temperature measurement,Flow metering and Heat metering.This design chooses the DN50 diameter of the single channel of Ultrasonic tube,which is generally used in the industry.In this thesis,more details of the structure and characteristics of the tube will be introduced.The flow signal acquisition is gained by the take time difference method of ultrasonic measurement plan.The accuracy of flow measurement plays a key role in the performance of the entire product.In order to analyze the factors’ influence to the product,this thesis,based on looking up both domestic and overseas documents related to ultrasonic flow measurement,thoroughly introduces the axioms of time to digital converter chip solutions and separation device solutions to attain the higher and more reliable measurement accuracy requirements.This kind of large caliber ultrasonic intelligent heat meter has the advantages of having a little pressure loss,non-mechanical transmission parts,high stability,high precision measurement,convenient installation and so on,which make this heat meter widely used in civil heat measurement field.It is a new solution to heat meters.