Feasibility Of Control Plans In Ventilation Networks

The number of control plans for placing control devices in a ventilation network is surprisingly large, but the research result indicates that not all control plans are feasible. The feasibility of a ventilation network control plan depends on two factors. One is the influence of the network structure. The structure must contain one independent variable-flow airway in a non-controlled loop. Otherwise, the control plan is unfeasible. The other is the combination of the air resistance, quantity, pressure and other parameters. Under some conditions, the selected values of these parameters may result in an unfeasible plan. As to the influence of the network structure, when the network structure is simple, the feasibility of a control plan can be judged directly. However, for the influence of the parameters, the feasibility of a control plan must be examined through calculation. The control position has been extended into the natural-splitting subnetwork from the conventional constant-flow subnetwork. This technique is theoretically significant. The extension of control positions results in a great increment in control plans and variation in parameters. At present, the calculation methods of the ventilation network control plans are all available. They are quite useful in selecting desirable plans. However, among the plans found, some are impractical or even unfeasible. If the unfeasible ones can be eliminated at first, much time can be saved in design and calculation. This also facilitates management and decision making.