基于ARM的地源热泵U形埋管换热性能测试系统

发布时间：2018-01-12 07:05

本文关键词：基于ARM的地源热泵U形埋管换热性能测试系统　出处：《杭州电子科技大学》2013年硕士论文　论文类型：学位论文

更多相关文章：地源 参数测试 ARM嵌入式 Linux Qt

【摘要】：地源是一种绿色的可再生能源。通过地下埋管，夏季可以把室内的热量排入地下,从地下带回冷水，而冬天则相反。开发利用经济、实用、绿色、环保的地源能具有广泛深厚的社会意义。岩土热物性参数是设计地热换热器的重要参数，该参数测量需要通过测试系统完成。本文基于ARM设计制作了地源空调U形埋管换热性能测试系统。该测试系统采用ARM芯片作为主芯片，可以达到减小系统体积、增加功能、提高系统稳定性的作用。土壤导热系数测试的工作原理是根据系统采集的U形埋管的进出口温度，得到系统运行的实际平均温度曲线，，通过将该曲线与计算的平均温度曲线进行拟合，确定岩土的平均导热系数；系统换热量的测试是根据系统采集的进出口水温和流量后通过能量守恒原理计算得到。因此，在ARM嵌入式最小系统和电源电路上增加了温度测量电路，流速测量电路及功率测试电路。系统可以工作在两种模式：恒温模式和恒功率模式。两种工作模式能更加全面的得到热平衡时岩土的热物性参数。系统测试导热系数时工作在恒功率模式；测试换热量时，工作在恒温模式。为了在恒温工作时能对功率进行控制，系统增加了功率测量电路和功率控制电路。在编程方面，对ARM系统进行了u-boot程序、Linux操作系统、Qt4曲线插件QWT以及嵌入式数据库Sqlite的移植；进行了温度、流量、和功率采集、PWM功率控制等模块的底层驱动程序开发；进行了系统应用界面的开发。驱动程序按照Linux字符设备驱动模式进行设计。温度模块对18B20进行了读写操作。流量模块对ADC进行了读操作(流量的频率信号已转化为电压信号)。功率模块是通过SPI对5460功率计量芯片进行控制并读取功率数值。人机界面程序是基于Qt4进行开发，采用QMainWindow作为界面图形显示的基类，定义了DS18B20等类用来负责数据采集和处理。系统运行时，在LCD触摸屏上会显示实时采集值和参数计算值的数据和曲线，通过触摸屏可以设置设置系统参数。界面还可进行历史数据保存、查询和显示。触摸操作提高了用户的可操作性，减小了系统体积。系统经测试和应用，能够达到地源热泵系统工程技术国家标准，目前已对几十处的地热情况进行了测试。
[Abstract]:Ground source is a kind of green renewable energy. Through underground buried pipes, summer can drain indoor heat into the ground and bring back cold water from underground, whereas in winter, it is economic, practical and green. The geoenergy of environmental protection has extensive and profound social significance. The parameters of thermal properties of rock and soil are important parameters in the design of geothermal heat exchangers. The measurement of this parameter needs to be carried out by a testing system. Based on ARM, a testing system for the heat transfer performance of U-shaped buried pipe of ground-source air conditioning is designed and manufactured in this paper. The ARM chip is used as the main chip in the test system, which can reduce the volume of the system and increase the function. The working principle of soil thermal conductivity test is to get the actual average temperature curve of the system according to the inlet and outlet temperature of the U-shaped buried pipe collected by the system. By fitting the curve with the calculated average temperature curve, the average thermal conductivity of rock and soil is determined. The measurement of system heat transfer is calculated by the principle of energy conservation after collecting the inlet and outlet water temperature and flow rate. Therefore, the temperature measurement circuit is added to the ARM embedded minimum system and power supply circuit. Flow rate measurement circuit and power test circuit. The system can operate in two modes:. Constant temperature mode and constant power mode. The two working modes can get the thermal physical parameters of rock and soil in thermal equilibrium more comprehensively. The constant power mode is used when the thermal conductivity is measured systematically. In order to control the power at constant temperature, the power measurement circuit and the power control circuit are added in the system. In the aspect of programming, the u-boot program of u-boot program and the plug-in QWT of QT4 curve of operating system and the embedded database Sqlite are transplanted to the ARM system. The bottom driver of temperature, flow rate and power acquisition PWM power control module is developed. The driver is designed according to the Linux character device driver mode. The temperature module reads and writes 18B20. The flow module reads the ADC (. The frequency signal of flow has been transformed into voltage signal. The power module controls 5460 power metering chip by SPI and reads the power value. The man-machine interface program is developed based on Qt4. QMainWindow is used as the basic class of interface graphic display, and DS18B20 and other classes are defined to be responsible for data acquisition and processing. When the system is running, the data and curves of the real-time collection value and parameter calculation value will be displayed on the LCD touch screen, and the system parameters can be set up through the touch screen, and the historical data can be saved by the interface. Query and display. Touch operation improves user's maneuverability and reduces system volume. After testing and application, the system can reach the national standard of engineering technology of ground-source heat pump system. At present, dozens of geothermal conditions have been tested.
【学位授予单位】：杭州电子科技大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TP368.1;TN702

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