Niagara-based Monitoring Management Platform For Solar-air Source Heat Pump Air Conditioning System

With the development of social economy and the improvement of people's living standards,the problem of building energy is becoming increasingly serious.The energy consumption of air-conditioning systems accounts for the largest proportion of building energy consumption.Therefore,the research on green energy-saving of air-conditioning systems has become the focus of the current era.Facing the development trend of green buildings and intelligent buildings,as well as the rapid development of today's Internet of Things technology,the monitoring and management platform based on the Internet of Things technology can provide real-time monitoring and intelligent control for air-conditioning systems,and better guarantee the green energy-saving operation of air-conditioning systems.This paper takes a solar-air source heat pump air conditioning system on the sixth floor of the Science and Technology Building of Shandong Jianzhu University as the object and builds its IoT monitoring and management platform.The air conditioning system is divided into three subsystems: the solar-air source heat pump composite system,the primary air system,and the air conditioning terminal room system.The system can use the air source heat pump to provide refrigerating capacity for the terminal room in summer.While in winter,the solar collector acts as an auxiliary heating device,together with the air source heat pump,supplies heat to the terminal room.The fresh air unit provides outdoor fresh air for the terminal room,and the fresh air will be precooled or preheated by the residual heat of the indoor return air in the fresh air unit.This project is based on the Niagara Framework and the Internet of Things technology,it develops a monitoring and management platform for solar-air source heat pump air conditioning systems.The hardware system is based on the JACE8000 network controller and is used to connect multiple devices and subsystems.Data acquisition and communication are mainly carried out through Modbus and TCP/IP protocols.The software is developed using theNiagara Workplace N4 platform.The monitoring and management platform realizes the network integration of the three subsystems including the solar-air source heat pump composite system,the primary air system,and the air conditioning terminal room system,and can access the platform remotely through a web browser.In order to save energy in the system,the monitoring and management platform is designed with energy-saving measures such as integrated control of fan coils and the heat pump unit,variable frequency control of circulating pump,and control of fresh air unit.The platform tests the solar-air source heat pump air-conditioning system for winter heating,and obtains the operating performance data,the environmental parameter data etc.of the solar collector and air source heat pump unit of the air-conditioning system under operation modes of different designs,and study the effect of system operation modes on the unit operation results based on the data.The research results show that the platform runs steadily and achieves the design goal.The IoT monitoring and management platform based on the Niagara technology can effectively integrate multiple systems into one platform for online management,so that each subsystem can have a favorable visual representation.Through the platform,the system operation data can be remotely monitored in real time via a web browser,and the start or stop of the unit or equipment can be automatically or manually controlled,thereby realizes the overall energy saving and consumption reduction of the solar-air source heat pump air conditioning system.At last,the experimental test of the practical operation of the monitoring and management platform was carried out.After the collected data being processed,calculated,compared and analyzed,the heat metering error of the system caused by the stop of the air source heat pump unit due to the energy saving strategy was found.By studying the energy-saving start-stop and heat meter measurement principle of the air source heat pump unit,the heat production of the fan coil of the terminal room was tested through monitoring.Ultimately,the actual heat production of the air source heat pump unit from the compressor being stopped to the compressor being restarted,and a new system total heat measurement strategy was designed through the monitoring and management platform.The conclusion that passed the practical verification can provide a more reasonable analysis for the energy-saving operation and adjusting control of the solar-air source heat pump system,and ensure theaccuracy of the platform for controlling building energy data collection.