Aiming at closed-loop water system, by the method that shutting certain subcircuit, and solving the piping network, computing flow deviation of other subcircuits, then analyzing the rules of variation of stability wit...Aiming at closed-loop water system, by the method that shutting certain subcircuit, and solving the piping network, computing flow deviation of other subcircuits, then analyzing the rules of variation of stability with various factors, following conclusions are obtained： When reducing the resistance in main pipes, increasing resistance of subcircuits, system stability can be improved. Centralized regulation by changing power has no influence on system stability; centralized regulation by changing resistances will decrease system stability. Pump characteristics curve influences system stability, stability of the flat characteristic is superior to the steep one. For direct return system （DRS）, the stability of subcircuit which is farthest from the heat source is the worst. For reverse return system （RRS）, the stability of subcircuit in the middle of the pipe-network has the worst stability. Overall, stability of RRS is inferior to that of DRS.展开更多
文摘Aiming at closed-loop water system, by the method that shutting certain subcircuit, and solving the piping network, computing flow deviation of other subcircuits, then analyzing the rules of variation of stability with various factors, following conclusions are obtained： When reducing the resistance in main pipes, increasing resistance of subcircuits, system stability can be improved. Centralized regulation by changing power has no influence on system stability; centralized regulation by changing resistances will decrease system stability. Pump characteristics curve influences system stability, stability of the flat characteristic is superior to the steep one. For direct return system （DRS）, the stability of subcircuit which is farthest from the heat source is the worst. For reverse return system （RRS）, the stability of subcircuit in the middle of the pipe-network has the worst stability. Overall, stability of RRS is inferior to that of DRS.
文摘鉴于传统中央空调系统温湿度调节速率缓慢、偏差大、能耗高等缺点,提出了一种基于直接数字控制和Lon Works技术的智能建筑中央空调一次回风系统设计方案。系统底层控制网络采用海湾HW-BA5201 DDC控制器组建,上位机监控平台采用力控Force Control 7.0组态软件设计。通过温度和湿度传感器实时检测系统回风温度和湿度,PID自动调节给水阀和加湿阀开度,最终实现控制要求。系统设有压差保护,防冻保护,以及风阀执行器与风机联锁控制功能,具有一定的推广应用价值。
