Abstract: An automobile air conditioner has a refrigeration cycle composed of a compressor, condenser, liquid tank, orifice means and an evaporator, as well as mechanical parts such as a radiator and radiator fan associated with the condenser and a blower combined with the evaporator. The compressor is operatively connected to the automobile engine through a connecting means so as to be driven by the engine selectively in accordance with the temperature in the passenger's compartment. According to the invention, the compressor is driven when the automobile is being braked, even if the temperature in the compartment is lower than a set temperature, to make an efficient use of the kinetic energy possessed by the mass of the automobile. The cold energy generated during braking is suitably stored and is released into the passenger's compartment as desired.

Abstract: In a Rankine-cycle-engine-driven cooling-and-heating system comprising a power generating cycle including at least an expander, an oil separator, a condenser and a generator and a cooling-and-heating cycle including at least a compressor, an oil separator, a condenser, an expansion means and an evaporator, the housings of the expander and the compressor are so securely joined that a hermetically sealed space may be defined between them. This space is used as an oil separator which is common to both the cycles and is communicated with the outlet port of the expander and the discharge port of the compressor. As a result, the system can be made considerably compact in size as compared with the prior art systems in which the oil separator is disposed outside of the expander and the compressor.

Abstract: In a refrigerating and air-conditioning system provided with a heat storage tank, variation patterns of load and weather conditions are predicted. On the basis of the predicted values, optimum outputs of a refrigerating machine at individual time points within a predetermined operation period are determined for possible water temperatures of the heat storage tank and stored in a memory. In accordance with the actual water temperature of the heat storage tank, the optimum output of the refrigerating machine is retrieved from the memory and utilized for the operation thereof.

Abstract: In an operating method for refrigerating machines which is disclosed, a variation pattern of an air-conditioning load on a prearranged day for refrigerating operation and a variation pattern of ambient temperature on the prearranged day are predicted. A period for refrigerating operation on that day is properly divided into plural time intervals. Priority ranking is allotted to those time intervals on the basis of the ambient temperature predicted. The refrigerating machine is operated in accordance with an operating pattern set on the basis of the priority ranking.

Abstract: An apparatus for manufacturing heat transfer tubes for use in evaporators and coolers for freezers, air conditioning units, refrigerators, and the like, with close machining tolerances. It forms cavities, with small openings communicating them with the outside, on the inside of a tube, through three steps of forming a multiplicity of alternate grooves and ribs in parallel on the inner surface of the tube, forming cuts in the concentrically directed crests of the ribs, and then forcing the crests sidewise so that the crest of each rib is bent down onto an intermediate part of the adjacent rib to form a cavity in between.