Research On General Control System Of Building Environment Cooling And Heating Source Based On Self-configuration Technology

HVAC system has close relationship with people’s production and life, Onthe one hand, HVAC system provides people with a comfortable working andliving environment, on the other hand, it ensures the production processoperating normally, which needs special requirements of the buildingenvironment. At the same time, HVAC system brings huge energy consumption,increase energy tense situation. Reducing energy consumption of HVAC systemsespecially cooling and heating source system and improves the managementlevel of the system operation is the trend of The Times, the key to solving thisproblem is the system control technology. With the development of HVACsystems new technology, new energy technologies and renewable energytechnologies, the cooling and heating system is developing towards the directionof the diversified, large-scale and complicated, this situation has put forwardhigher requirements on the control system.The conventional way of the implementation of the control system needscontrol professionals and HVAC professionals to be close coordination with theconstruction personnel and control equipment manufacturers. This is a complex process with numerous constraints and difficult effective monitoring.Additionally, the non-open architecture of control system leads to the operationand maintenance complex, so that it must be completed by professionals. Allthese factors have made it difficult for meeting to the requirements of buildingenvironment cooling and heating source system well, then could not assure theimplementation effect of control system, and maximize energy efficiency.The research has developed general control system of building environmentcooling and heating source system based on self-configuration technology. Thetypical features of the control system are "self-configuration","generality" and"all-open”. Self-configuration technology differs from conventionalconfiguration technology of control system. With the help of the new technology,the HVAC specialists may construct the control system of cooling and heatingsource easily without the help of any professional tools (such as the controlsoftware development platform, emulators, programmer, etc.), and even do notneed to write a single line of program code; The generality makes thisarchitecture to adapt to all kinds of cooling and heating source system almost,not only the control algorithm and control strategy are universal, but also thecontroller and the necessary control software are general, even the controlcabinets also are general; Compared with the conventional control system, theall-open general control system is a kind of parameterized system, and allparameters can be set easily.This research first established a general physical model of cooling andheating source system and control package object model of the general controlsystem, and then discussed the control algorithm and the control strategy ofcooling and heating source system in detail. On this basis, this researchdeveloped the controller board based on the Cortex M3core and I/O dataexpansion board. The main content of research including:(1) Starting with building a simple physical model of cooling and heating system with three elements, the research introduces two kinds of virtual switches,one expresses connection relationship between one equipment and the otherequipment, and the other expresses whether the equipment does exist. With thehelp of the two virtual switch and number of elements research constructedstandard sub-system physical model of cooling and heating source system.Through the combination of physical model of sub-system, research finallyestablished general physical model of cooling and heat source system. All thosemodels are verified.(2) The research introduces Degrees of Freedom (DOF) theory into HVACcontrol system, and discusses the importance of DOF theory for generalconstruction method of control loop in detail. The research points out explicitlythat DOF of sub-system is2, furthermore makes a detailed study about how toselect controlled variables and manipulated variables of control loop. DOFtheory provides a solid theoretical foundation for the research about generalcontrol system.(3) Self-configuration technology is the core technology of general controlsystem for cooling and heating source system, and control package object is thekey to the technical implementation. Process attributes, control attributes andcontrol methods of process equipment and control instruments encapsulated inthe data model are called the control package objects. These control packageobjects add control attributes to process equipment and add process attributes tocontrol instruments, which are similar with building blocks. Self-configurationtechnology is to set the attributes of these control package objects. Separatecontrol package object can be grouped, and control package object grouped canbe organized into system control package object. These entire control packageobjects make the process system and the control system perfect fusion and canconstruct the perfect control system. This research has made a detaileddescription on each kind of package objects. (4) The control algorithms and control strategies for the control system hasa decisive role in the implementation of control effects. Cooling and heatingsource system has the characteristics of multi-variable, nonlinear, large delay,the characteristics of large capacity, so the research developed controlalgorithms and control strategies. Through in-depth research,the researchproposes several common control strategies which are suitable to cooling andheating source system, and deeply study the general control strategies, includingthe system startup, shutdown strategies, loop continuous control strategy,ADD-SUB machine strategy, water pump Anti-overload strategy etc,.(5) For the purpose to realize general control of cooling and heating system,the research developed of the core controller board based on32-bit CPU, I/Odata expansion board and the necessary control software. The Controller withpowerful features, reliability, networking capability is the basis for therealization of the general control system of cooling and heating source.(6)With the actual building environment cooling and heating source projectas an example, described in detail the complete implementation process of thegeneral control system for HVAC cooling and heating syetem, and it is alsoverification for the study of the theories and techniques related with the generalcontrol system.