Application of the hottest Ba control system in ai

2022-08-12
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Research on the application of Ba control system in air conditioning Abstract: This paper discusses several technical links of implementing Ba control in air conditioning system; Make the BA system better serve the controlled air conditioning system, and try to make the two closely combined in technology; Through the discussion of this paper, some preliminary conclusions are obtained

key words: Ba control system air conditioning system application research 1 Introduction with the rapid development of science and technology, mature computer detection, control, communication technology and corresponding products with moderate prices continue to emerge; It is no longer difficult to realize the distributed control system (DCS) of air conditioner; As one of the 3A systems of intelligent buildings, building automation system (BAS) has increasingly become an essential configuration in modern buildings for centralized monitoring and management of electromechanical equipment such as water, electricity, air conditioning and so on; Compared with the old system, it is not only energy-saving, but also quite convenient to manage; But how to make the air conditioning system work effectively is not an easy task. There are many intelligent buildings in China, among which the ventilation and air conditioning systems mostly realize computer distributed control (DCS), which is reflected in the automatic control of fans, pumps, refrigeration equipment and the automatic detection and control of room temperature and humidity in the building. Few systems truly realize optimal control and management. It can be said that the realization of computer distributed control of ventilation and air conditioning system is only the primary class of building equipment automation. Only by introducing artificial intelligence technology and expert knowledge into the internal environment and equipment management system to optimize the operation of the whole system, will the automation of building equipment reach a higher level and truly reflect its advantages. Aiming at the ventilation and air conditioning system of the new wing building of Guangzhou Department store, the author has made a preliminary study on the realization of its intelligent control and management automation, and has achieved good results in the operation of practical projects. The energy-saving and management benefits brought by the implementation of BAS are well-known, and the owners often have high expectations for this unity in the implementation. However, from the perspective of many completed projects, the expected results have not been achieved, which highlights the following two aspects: (1) the opening rate is at the bottom, which is no more than 20% away from the estimates of insiders; (2) At present, most of the bas systems that have been opened only realize the automatic start-up, stop and monitoring of building equipment, and their energy saving is mainly reflected in the regular start-up and shut-down of some equipment. As the key air conditioning system of building energy consumption, how to optimize the operation and how to carry out energy-saving and economic operation according to the actual system is far from being realized. The central air-conditioning system, with complex pipelines and variable operating conditions, is a major energy consumer of buildings. For this reason, the implementation of BA system generally takes the air conditioning system as the focus of monitoring, often investing more than 60% of the monitoring points and more than the total investment of hydropower monitoring. Considering the investment capacity of some small and medium-sized projects, it is not uncommon to limit BA system to HVAC system. In fact, due to the complexity of the central air-conditioning system, the overall function of the air-conditioning monitoring system has become one of the bottleneck factors that restrict the success or failure of bas. To do a good job of BA system, it is not enough to rely on the strength of weak current engineers alone. It is very necessary for HVAC engineers to actively participate in the formulation of system scheme. 2 Optimization of BAS control scheme of air conditioner 2.1 selection and layout of direct digital controller (DDC). Mainstream BA system suppliers can provide DDC with different processing capacities in large, medium and small sizes. Large controllers should be preferred in dense occasions of refrigerator room and heating station monitoring points, so as to reduce the failure rate and communication between controllers. The typical feature of this controller is that it has a powerful processor (such as Motorola 68302) and IMB ral4, especially it can connect with the I/O expansion module to achieve the expansion of human radiation output function. For example, Siemens SMBC can connect the fatigue testing machine required for 4 experiments. Generally, there are 0 I/O modules for the zigzag fatigue testing machine and the tension compression testing machine. Trendiq251 controller allows 8.16 interface expansion capability. Medium or small controllers are generally used for air handlers, fresh air fans and ventilators. In recent years, programmable logic control device (PLC) has made rapid progress, and its application is no longer limited to industrial occasions. It should not be excluded in the field equipment programming engineering of air conditioning and ventilation. Generally, the controller should be close to the controlled equipment, which is arranged in parallel with the corresponding distribution box to facilitate most manufacturers to test the pressure resistance line of the carton under normal temperature and humidity. The air conditioning and ventilation equipment in the same machine room can share a controller, but whether the computing power and control points of the controller are sufficient should be considered. Some system integrators share a controller with several fresh air fans on different floors. Although this practice saves a certain amount of cost, it is not conducive to future management and commissioning and is not worth recommending. The power supply of the controller should be centralized. If possible, steel handle: hard wood can be led out from the ups main power supply; The practice of quoting power from the site of controlled equipment is not recommended. 2. On the premise of meeting the expansibility and flexibility of the control network, the topology of the control network should be as simple and clear as possible, whether based on is485 bus or lontalk bus. The network with many branches and levels has complex management and low reliability. Tontalk bus can theoretically form a network with any topology structure. If the randomness of this wiring design is not used properly, it will still have technical risks in engineering practice and may increase the investment of the system. For large-scale projects, the classification of floor network can be considered. For small-scale projects, the control network based on RS485 bus should be used as much as possible, and the "hand-in-hand" wiring method should be adopted. 2.3 about the support of BACnet and LonWorks, BACnet and LonWorks are proposed to solve the interconnection and interoperability of control systems at different levels. LonWorks adopts Fieldbus Control Technology (FCS), breaking through the previous distributed control technology (DCS). Its proposal is a leap in Ba technology and the technical trend of BAS development in the future. However, limited by various conditions, LonWorks' technical advantages can not be fully brought into play, and the project implementation is not perfect. If the scale of the automatic control system is not very large, it is better not to fully adopt LonWorks technology. If we carefully analyze the current mainstream Ba products, we will find that they have high accuracy. They partially adopt or partially support fieldbus technology to varying degrees. This hybrid mode of learning from each other's strengths and complementing each other's weaknesses is currently practical in engineering and can realize a smooth transition of technology. BACnet protocol, formulated and promulgated by ASHRAE of the United States, is the current national standard of the United States and the preparatory standard of the European community. Using BACnet protocol, the cold and heat source host of air conditioning can be brought by itself

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