Abstract: A refrigerant system is provided where the functions of an economizer heat exchanger and liquid-suction heat exchanger are combined. The two configurations are disclosed with a single common heat exchanger construction. In a first configuration, a series of valves selectively routes only one of two possible refrigerant flows through a common heat exchanger such that a control can selectively activate either an economizer heat exchanger circuit or a liquid-suction heat exchanger function. In a second configuration, both refrigerant flows are passed to the common heat exchanger through separate fluid lines and are selectively activated by the control. Variations of the second configuration are also disclosed.

Abstract: In a shell-and-tube heat exchanger with the tubes disposed within the shell for conducting the flow of a fluid to be in heat transfer interaction with a refrigerant contained in the volume formed by the heat exchanger shell and the external surfaces of the tube bundle, the tubes are elongated in their cross-section, with the elongation axis being oriented in the vertical direction to thereby enhance the heat transfer process and potentially reduce the heat exchanger size or tube count. The design features can be applied to both flooded and falling film heat exchangers and are equally applicable to both evaporators and condensers.

Abstract: A multiple circuit refrigerant system includes a single economizer heat exchanger utilized for each of at least two circuits. The use of the single economizer heat exchanger reduces the cost of adding an economizer cycle, and further reduces other associated costs. Additionally, heat exchanger and overall system performance is enhanced further. Embodiments show the inclusion of two, three and four circuits, although greater numbers may also benefit from this invention.

Abstract: In an air conditioning system including a compressor, a condenser, and an evaporator, a process includes the steps of feeding discharged refrigerant from the compressor to the condenser so as to provide a condensed refrigerant flow; splitting the condensed refrigerant flow into a main flow and an auxiliary flow wherein the auxiliary flow includes between about 8 and about 12% wt. of total mass flow rate of the condensed refrigerant flow; reducing temperature and pressure of the auxiliary flow so as to provide an economizer flow; passing the economizer flow and the main flow through a heat exchanger so as to provide a sub-cooled main flow and an economizer discharge flow; feeding the economizer discharge flow to the compressor; and feeding the sub-cooled main flow through the evaporator to the compressor.