Abstract:
A refrigerator according to an embodiment of the present invention includes a power input part through which power is input from a UPS device connected to a commercial power source and an auxiliary power source; a voltage sensor configured to sense a voltage of the power input through the power input part; and a control part configured to analyze a voltage signal sensed by the voltage sensor and to determine whether the input power is commercial power or auxiliary power.
Abstract:
A method operates a set of heating, ventilation and air-conditioning (HVAC) units by optimizing jointly operations of the set of HVAC units subject to constraints to determine times of switching each HVAC unit ON and OFF and by controlling each HVAC unit according to the corresponding times of switching. The operation of each HVAC unit is represented by a continuous function. The constraints include a complementarity constraint for each HVAC unit, such that the complementarity constraint for the HVAC unit defines a discontinuity of the operation of the HVAC unit at corresponding times of switching.
Abstract:
Ein Kältegerät, insbesondere Haushaltskältegerät, umfasst wenigstens eine Lagerkammer (2), einen Verdampfer (3) zum Kühlen der Lagerkammer (2), einen Verdichter (7) zum Antreiben eines Kältemittelflusses durch den Verdampfer (3) und eine Steuereinheit (17), die eingerichtet ist, den Verdichter (7) mit Strom zu versorgen und zwischen einem Normalkühlmodus, in dem Kältemittel auf dem Weg vom Verdichter (7) zum Verdampfer (3) eine Drosselstelle (12) passiert, und einem Abtaumodus umzuschalten, in dem das Kältemittel unter Umgehung der Drosselstelle (12) vom Verdichter (7) zum Verdampfer (3) gelangt. Die Steuereinheit (17) ist ferner zwischen einem Antriebsbetriebsmodus, in dem ein Strom, mit dem die Steuereinheit (17) den Verdichter (7) beaufschlagt, eine den Kältemittelfluss antreibende Bewegung des Verdichters (7) bewirkt, und einem Heizbetriebsmodus umschaltbar, in dem sie den Verdichter (7) mit Strom beaufschlagt, ohne eine Bewegung des Kältemittels zu bewirken.
Abstract:
Provided are a refrigerant based system (36) and a method for improving efficiency of the refrigerant based system (36). The refrigerant based system (36) comprises a heat exchanger (30), a heat exchanger temperature sensor (34), at least one compressor (20), a microprocessor (52) for controlling the compressor (20), a medium temperature sensor (32) and a computer-readable storage medium (50) encoded with computer-readable instructions for causing the microprocessor (52) to execute the operation steps. The compressor (20) will be turned off in a controlling step if the following conditions are satisfied: 1) the temperature of the medium has reached a first predetermined value; 2) the temperature of the heat exchanger (30) has reached a value below a compressor control temperature; 3) the compressor (20) has operated for a predetermined period of operation time; and 4) the minimum heat exchanger temperature has been found. The refrigerant based system (36) has the advantage of saving running cost.