Abstract:
The invention discloses a controller for a vapour compression system for cooling a refrigerated space. The system comprises a circuit for circulation of a refrigerant between a compressor (2), a condenser (3), and an evaporator (4). An expansion valve (5) controls a flow of the refrigerant into the evaporator (4) and thereby cooling of the refrigerated space. The control system is adapted to control the expansion valve (5) based on a first temperature (Tl) in the circuit between the evaporator (4) and the compressor (2) and a second temperature (T2) determined in the refrigerated space.
Abstract:
Systems and methods are described for controlling fan-only cooling duration following normal air conditioning operation. Following normal AC cooling, economical fan cooling is used. The duration of the fan cooling period is adjusted based on temperature measurements made during the previous cooling cycle that ended with fan cooling. An expected temperature drop to be provided by fan cooling as well as an expected time to achieve that drop is calculated based on prior measurements. The expected values are then used improve fan cooling for subsequent cooling cycles. In some cases, fan cooling is not initiated unless: (1) a time limit has an elapsed, such that sufficient condensation is allowed to form on the evaporator coil during the first phase, and (2) indoor relative humidity is below a predetermined threshold.
Abstract:
A system and method of loading and unloading a compressor in a cooling system. The method includes detecting a temperature, determining a compressor should be turned on/off to supply/stop supplying cooling based on the temperature, turning the compressor on/off, and opening/closing a plurality of valves when the compressor is turned on/off.
Abstract:
A system and method for controlling an economizer circuit is provided. The economizer circuit includes a valve to regulate refrigerant flow between the economizer and the compressor. The valve can be opened to engage the economizer circuit or closed to disengage the economizer circuit based on the output frequency provided to the compressor motor by a variable speed drive and an operating condition of the economizer.
Abstract:
A system and method of controlling a compressor rack having a plurality of variable capacity components is provided. A variable capacity component is selected from the plurality of variable capacity components as a designated variable capacity component. The designated variable capacity component is operated by varying a capacity of the designated variable capacity component. Each variable capacity component of the plurality of variable capacity components, except for the designated variable capacity component, is operated at a fixed capacity corresponding to one of a maximum and a minimum capacity of the variable capacity component.