基于相位差法的超声波热量表测量技术研究

发布时间：2018-02-17 07:04

本文关键词： 超声波热量表相位差法流量检测热量计量时间-电压转换　出处：《济南大学》2015年硕士论文　论文类型：学位论文

【摘要】：在国家大力提倡节能减排的时代背景下,以及市场对实现分户热量计量的强烈需求声中,经过广泛查阅国内外相关技术资料和进入热量表研发生产企业进行调研和实践,笔者认为随着热量表技术的不断完善,超声波热量表已经成为目前比较符合国内分户供热计量需求现状的热量计量仪表。但是,由于各个生产厂家和科研院所在设计超声波热量表时采取的设计方案不同,生产出的成品表在热量计量精确性、运行稳定性等方面依然存在不少问题。考虑到流量测量是热量表达到精确热量计量目标的关键所在,超声波换能器收、发超声波的相关时间间隔测量又是流量测量的核心部分。本文在对超声波热量表的时差法原理和相位差法原理作出比较的基础上,选择相位差法对热量表进行硬件系统设计和相关软件系统编程。以MSP430低功耗处理器为运算核心,通过流量测量模块中的时间-电压转换电路,实现将前级电路测得的以电压信号形式表示的相位差脉冲信号,通过MSP430处理器A/D转换表示为相位差计数数据形式,以此表示传播时间差,从而最终实现对微小时间的准确测量。在热量表样表制作完成后,使用热量表专用检测装置对基于相位差法的超声波热量表样表进行流量实际检测,并对实际测得数据进行分析。使用MATLAB软件将检测中所获得的与不同检测温度点、不同流量点对应的表显相位差计数数据(即极微小时间)进行曲线拟合,并对单个样表的实验数据进行综合曲线拟合,将所得修正方程导入热量表软件系统,以此方法对超声波热量表实际运行中出现的误差进行修正。将经过误差修正后的热量表样表再次接入专用检测装置进行流量检测,从而获得新的实验数据。并采用其他补偿方式,使流量测量更加准确。通过以上工作,配合其他分量检测,验证了基于相位差法的超声波热量表可以实现较高精确度的计量,可最终实现热量的精确计量要求。
[Abstract]:In the context of the country's efforts to promote energy conservation and emission reduction, and in the sound of strong market demand for the realization of household heat metering, through extensive reference to relevant technical information at home and abroad and access to heat meter R & D and production enterprises to conduct research and practice, The author thinks that with the continuous improvement of the heat meter technology, the ultrasonic heat meter has become a heat metering instrument which accords with the domestic domestic heating metering demand. Due to the different design schemes adopted by various manufacturers and scientific research institutes in the design of ultrasonic calorimeter, the finished product meter produced is accurate in heat metering. There are still many problems in operation stability. Considering that flow measurement is the key to accurate heat measurement, ultrasonic transducer receives, The correlation time interval measurement of ultrasonic wave is also the core part of flow measurement. In this paper, the principle of time difference method and phase difference method of ultrasonic calorimeter are compared. The phase difference method is selected to design the hardware system of the heat meter and to program the related software system. The MSP430 low-power processor is used as the core of the operation, and the time-voltage conversion circuit in the flow measurement module is used. The phase difference pulse signal measured by the former stage circuit is expressed in the form of voltage signal, which is represented by MSP430 processor A / D conversion to the phase difference counting data form, which indicates the propagation time difference. After the heat meter is made, the flow rate of ultrasonic heat meter based on phase difference method is measured by using a special measuring device. And the actual measured data are analyzed. The phase difference counting data (i.e. minimal time) obtained in the detection are fitted by the MATLAB software, which is corresponding to the different temperature points and different flow points. The experimental data of a single sample table were fitted with a comprehensive curve, and the modified equations were imported into the software system of the heat meter. This method corrects the error in the actual operation of ultrasonic calorimeter. The error-corrected calorimeter sample meter is again connected to a special detecting device for flow detection. The new experimental data are obtained, and other compensation methods are adopted to make the flow measurement more accurate. Through the above work and other component detection, it is verified that the ultrasonic heat meter based on phase difference method can achieve high accuracy measurement. The requirement of accurate measurement of heat can be realized finally.
【学位授予单位】：济南大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TH81

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