Methods and systems for energy storage and management are provided. In various embodiments, heat pumps, heat engines and pumped heat energy storage systems and methods of operating the same are provided. In some embodiments, methods include controlling thermal properties of a working fluid by virtue of the timing of the operation of cylinder valves. Methods and systems for controlling mass flow rates and charging and discharging power independent of working fluid temperature and system state-of-charge are also provided.

A heat exchange system comprises vertical centermost plenum surrounded by the heat exchange coil and housed in a plurality of side panels and a base, the plurality of side panels have air intakes that communicate outside air into the cabinet above the heat exchange coil and sprayers, a stream of spray water and air is drawn downwardly over a heat exchange coil, a portion of the spray water is separated from the air by drawing the air inward to the plenum, the air is then drawn upwardly within the plenum to an exhaust external to the enclosure.

A refrigerator includes a body, first and second storage compartments and a machine compartment formed in the body, a blower fan disposed in the machine compartment, first and second refrigerating units comprising first and second compressors to compress first and second refrigerants, respectively, first and second condensers to condense the first and second refrigerants, respectively, first and second expansion valves to expand the first and second refrigerants, respectively, and first and second evaporators to evaporate the first and second refrigerants, respectively, the first and second refrigerating units supplying cold air to the first and storage compartments, respectively. The first compressor, the second compressor, and the first condenser are disposed in the machine compartment and are cooled by forcible flow of air caused by the blower fan, and the second condenser is disposed outside the machine compartment and is cooled by natural convection of air.

A refrigerator includes a body, first and second storage compartments and a machine compartment formed in the body, a blower fan disposed in the machine compartment, first and second refrigerating units comprising first and second compressors to compress first and second refrigerants, respectively, first and second condensers to condense the first and second refrigerants, respectively, first and second expansion valves to expand the first and second refrigerants, respectively, and first and second evaporators to evaporate the first and second refrigerants, respectively, the first and second refrigerating units supplying cold air to the first and storage compartments, respectively. The first compressor, the second compressor, and the first condenser are disposed in the machine compartment and are cooled by forcible flow of air caused by the blower fan, and the second condenser is disposed outside the machine compartment and is cooled by natural convection of air.

A refrigerator may include a cabinet defining a low-temperature storage space and a machine chamber in which a compressor and a condenser are disposed; and an evaporator disposed in rear of the storage space, wherein air flows upwards along the evaporator and thus cools down to lower a temperature of the storage space. The evaporator may include a cooling pipe in and along which refrigerant flows; and a plurality of cooling fins surrounding an outer face of the cooling pipe. The cooling pipe may be constructed so that the refrigerant flows downward along and in the cooling pipe.

A heat exchanger fixing structure, for two or more heat exchangers bent in multiple layers, includes two or more plates respectively fixed to one ends of the two or more heat exchangers, wherein portions of the two or more plates may overlap each other, and the two or more heat exchangers are connected and fixed to each other by fastening a fastening member to the overlapping portions.

A heat exchanger fixing structure, for two or more heat exchangers bent in multiple layers, includes two or more plates respectively fixed to one ends of the two or more heat exchangers, wherein portions of the two or more plates may overlap each other, and the two or more heat exchangers are connected and fixed to each other by fastening a fastening member to the overlapping portions.

An air conditioner includes: a first refrigerant tube that includes a first portion, and through which a liquid refrigerant flows; and a second refrigerant tube that includes a second portion that is disposed above the first portion and overlaps the first portion when viewed vertically, and through which a liquid refrigerant flows. The first portion is surrounded with a first heat insulating material.

A heat exchanger includes a refrigerant flow path into which a gas refrigerant flows from two gas-side inlets in the second row, that are positioned off from each other. Refrigerant flow paths from the two gas-side inlets converge in the one end portion. The refrigerant flow path connects to a heat-transfer pipe in the first row from the second row. The refrigerant flow path includes a refrigerant flow path which is formed in a range from the same stage as one of the gas-side inlets of the second row to the same stage as the other of the gas-side inlets of the second row, while being arranged along both ways between the one end portion and the other end portion in the first row, and the refrigerant flow path extends to a liquid-side outlet.

An improved water management system with improved airflow distribution for counterflow evaporative heat exchangers is provided. Such heat exchangers include open cooling towers, closed circuit cooling towers, and evaporative condensers. The improved water management system eliminates water splash out and the noise associated with water splashing. Further when the fan assemblies are located below the evaporative heat exchanger, the improved water management system keeps the fans dry and prevents freezing in subzero climates.