太阳能热水工程系统热能计量与监测方法

Energy measurement and monitoring for solar water heating system

针对单个贮水箱有效容积大于0.6m3的太阳能热水工程系统提出了一种热能计量与监测方法,该文介绍了包括太阳能供热量、耗电量、辅助热源供热量、用户管路循环热量损失量、热负荷等能量的计量方法及其理论推导过程。并对太阳能热水工程系统的传感器精度、安装要求及远程监测等技术要求进行了介绍。系统实现的流量检测准确度为±1%,水位检测准确度±2%,水温检测准确度±0.2℃,总耗电量准确度±2%,热能计量的准确度为±2%,实际应用表明该方法能准确有效的计量出太阳能热水工程中的各种能量,适合中国太阳能热水工程的热能计量与监测,为制定中国太阳能热水工程系统热能计量和监测国家标准提供了试验和技术储备。

A large number of non-pressure solar water heating systems have been installed in China, the majority of them possess storage tank which the effective volume are greater than 0.6 m3, and their influent and effluent are non-simultaneity, then directly using a calorimeter to calculate heat is inappropriate by measure the temperature difference between the inlet and outlet. Considering the operability of actual system, this paper presents a method for calculating the heat load of the solar water heating system by measurement parameters, such as inlet water temperature and flow, outlet water temperature and flow, storage tanks water temperature and water level. A variety of energy measurement methods and theoretical derivation are introduced in this paper, which including solar energy for heating, electricity consumption, auxiliary heat source energy, piping loop heat loss and heat load. And the sensors accuracy, installation requirements and remote monitoring technology are introduced exhaustively in this paper. The energy measurement and monitoring methods have been used successfully in the BHL solar water heating engineering control systems. A calorimeter has been developed for measuring the solar heat load which uses the heat load calculation formula, and another calorimeter for measuring the solar heat energy and piping heat loss which uses the simultaneity heat calculation formula. The calorimeter can get the amount of hot water used and calculate the cost for each user, which supports ModBus communication protocol. The system uses a three-phase auxiliary heating to provide energy when solar energy is insufficient. And the remote three-phase energy meter supports Modbus communication protocol too. Actually it shows that this method can accurately and effectively measure all kinds of energy of the solar water heating system, and it is suitable for energy measurement and monitoring of the solar water heating system in China. The experiment can provide technical reserves for developing the energy measurement and monitoring national standards of solar water heating system.