| 摘要 |
A fuel-powered engine is provided to drive a mobile air conditioning or refrigeration unit such as a portable chiller, a container refrigeration unit, a portable packaged system, a transport tractor-trailer or truck refrigeration unit, etc. A control rapidly changes the engine speed between the predefined set of discreet engine speeds to precisely adjust the capacity of the refrigerant system. If the engine operates only at a single speed, then the control cycles the engine between this operating speed and a zero speed (the engine is shut off). If the engine can operate at multiple discreet speeds, then the control can cycle the engine between any of these speeds (including a zero speed). When a lower capacity is desirable, the engine operates for a longer time interval at a lower speed, and when a higher capacity is desirable, the engine operates for a longer period of time at a higher speed. The cycle rate is selected to control the comfort (e.g. temperature and/or humidity) of the conditioned environment within the specified tolerance band, while conforming to the reliability requirements. |
