Abstract:
A refrigeration system (12) includes a free cooling system (52) having an air-cooled heat exchanger (56), where the air-cooled heat exchanger includes a fan (60) configured to move air (59) over coils of the air-cooled heat exchanger to remove heat from a coolant (58) flowing through the air-cooled heat exchanger, and a mechanical cooling system (68) with a refrigerant loop that includes an evaporator (66), a compressor (70), and a condenser (72) disposed along the refrigerant loop, where the compressor is configured to circulate a refrigerant through the refrigerant loop, and wherein the evaporator (66) is configured to receive the coolant and transfer heat from the coolant to the refrigerant. The refrigeration system (12) also includes a controller (78) configured to adjust a fan speed of the fan (60) up to a threshold fan speed, to initiate operation of the compressor (70) when the fan speed reaches the threshold fan speed, wherein the fan speed and a compressor speed of the compressor are based at least on an ambient air temperature (89) and a cooling load demand.
Abstract:
A refrigeration unit may include a first compressor constructed and arranged to compress a first refrigerant, and a second compressor constructed and arranged to compress a second refrigerant. A first condenser of the refrigeration unit is operatively coupled to the first compressor, and a second condenser is operatively coupled to the second compressor. An evaporator of the refrigeration unit is constructed and arranged to flow the first and second refrigerants received from the respective first and second condensers for chilling a heat transfer fluid. A controller of the refrigeration unit includes a computer processor and a storage media for executing a pre-programmed algorithm for initialing the second compressor when a predetermined crossover frequency of the first compressor is reached as a system load increases.
Abstract:
A beverage dispensing apparatus is characterized by a beverage dispenser and a refrigeration system for chilling beverage to be dispensed by the beverage dispenser. The refrigeration system has a compressor coupled to an evaporator for chilling the beverage, and a controller determines the amount of chilling that must be provided by the refrigeration system to chill the beverage and adjusts cut-in and cut-out beverage temperature set-points for the compressor accordingly. Advantageously, the cut-in and cut-out set-points are adjusted to beverage temperature values such that the chilling capacity of the refrigeration system is made to closely match to the amount of chilling required by the beverage, and also such that on/ off cycles of the refrigeration system are decreased.
Abstract:
The present invention involves a method and a device for regulating the capacity of a vapour-compression-cycle that comprises a compressing device, a condenser, at least one cooler, a variable-flow control means, and an evaporator, connected in series and forming an integral closed circuit with a refrigerant that operates under trans-critical conditions, where in the capacity is regulated by regulating the number of revolutions of the drive shaft of the compressing device as a function of the required capacity; and that the variable flow control means is regulated as a function of the temperature and/or pressure of the refrigerant measured at the high pressure side of the system with respect to optimizing the COP. Hereby it is optained to provide a novel, improved, efficient and simple means for regulating the capacity of a trans-critical vapour-compressing-cycle device avoiding the above shortcomings; and to improve the efficiency of the vapour-compression-cycle process.