Energy-Saving Ventilation System Principle

The information age has arrived, and the demand for communication among human society continues to grow. Communication service providers (SP/ISP) are expanding network investment and increasing network coverage, aiming to achieve the effect of communicating with anyone, at any time, in any place. The number of mobile base stations, access sites, and module offices operated by telecom companies is continuously increasing, especially the number of mobile base stations, which is growing very rapidly.
To save costs, the vast majority of mobile base stations are unattended. However, the various electronic equipment in these communication base stations requires a certain temperature environment (the national standard for base station environment GB50174-93 stipulates that the annual base station temperature should be 18°C to 28°C) to operate normally over the long term. To achieve the standard ambient temperature for base stations, each communication base station is equipped with about two air conditioners, which remain in operation year-round. The current situation is:

1.1. Increased electricity expenditure for base stations
According to statistics from a regional mobile communication branch company, in 2006, the electricity expenditure for 138 base stations was RMB 2.12 million; in 2006, the electricity expenditure for 238 base stations exceeded RMB 5.8 million, with the average electricity expenditure per base station increasing by 58%.

1.2. Air conditioner electricity expenditure accounts for a large proportion of base station costs
According to statistical analysis, the average air conditioner electricity expenditure per base station accounts for about 54% of the total base station electricity expenditure, making air conditioners the primary power-consuming equipment in base stations.

1.3. Serious waste of electricity by base station air conditioners

• Currently, most base station air conditioners are set to cool at 18°C, or automatically at 24°C. Since base stations are unattended, many air conditioners run throughout the year, resulting in serious waste.
• According to relevant national regulations for the operation of electronic equipment, the general annual temperature of a base station should be maintained within 18°C to 28°C, with humidity of 10% to 90%. If the base station air conditioners are used in conjunction with the safe intelligent ventilation system produced by our company, there is significant potential for energy savings.
  The electricity consumption of air conditioners represents a substantial expense for communication operating companies. In most regions of China, natural ambient temperatures during many time periods can already meet the temperature requirements for the normal operation of electronic equipment, or only one air conditioner operating intermittently is sufficient to meet these requirements.
  Based on the above reasons, we have adopted internationally advanced control theory and technology, and based on long-term test report data on the optimal environment for the reliable and safe operation of electrical equipment in accordance with international base station general standards, we have developed and designed an intelligent ventilation system for base stations. This system not only provides base station energy-saving functions but also features reliable safety alarm functions and comprehensive networking capabilities.
  2.0 Principle, composition, workflow, and parameters of the energy-saving ventilation system
  2.1 System principle
  Since the temperature rise inside a base station is caused by the long-term operation and heat generation of electrical equipment, rather than by the outdoor ambient temperature, if air conditioners are used year-round to maintain the indoor temperature (mainly for cooling), the favorable conditions for heat dissipation and cooling provided by the low outdoor temperatures during winter, spring, autumn, and the early morning and evening periods of summer are neglected, resulting in wasted electricity and persistently high operating costs.
  The base station intelligent ventilation system fully utilizes the temperature difference between the indoor and outdoor environments of the base station to form heat exchange. Relying on a large volume of air circulation, it effectively transfers the heat inside the base station outward rapidly, achieving indoor heat dissipation. This significantly reduces electricity consumption and operating costs while extending the service life of air conditioners. As shown in the figure.
  2.2. System composition
  The intelligent ventilation system mainly consists of a main control cabinet, an air intake device (intake box), an exhaust device (exhaust box), indoor and outdoor temperature detectors, indoor and outdoor humidity detectors, an outdoor dust detector, a rainproof vent, AC transformers, AC contactors, a dust filtration device, installation accessories and cables, etc.
  Schematic diagram of the base station intelligent ventilation control system
  2.3. System workflow
  Through the main controller, the system sets the outdoor low-temperature threshold (T1) for fan startup, the outdoor high-temperature threshold (T2), the indoor temperature T3, the outdoor humidity S1, the indoor humidity S2, and other setting parameters and items. The system detects indoor and outdoor temperature, humidity, and dust levels in real time. Under the regulation of a special mathematical model algorithm program, it automatically controls the reasonable operation of the fans to achieve cooling, thereby achieving the optimal energy-saving effect.
  The base station intelligent ventilation system can work independently, or it can be connected to the power monitoring module via an RS232 or RS485 bus, uploading data to the monitoring center through different transmission networks. This system mainly aims to improve the operating efficiency of air conditioners by utilizing the principle of automatic air exchange and temperature regulation, thereby saving energy and achieving the goal of reducing operating costs.