Abstract:
A multiple-phase ejector refrigeration system including a capacity control allowing part-load operation. The capacity is varied by bleeding a stream of hot gas from the discharge side of a vapor compressor and introducing it in a controlled manner into the liquid nozzle of the multiple-phase ejector. This has the effect of first increasing and then reducing the efficiency of the nozzle as the bleed rate increases, thereby affecting the efficiency and flow capacity of the ejector unit.
Abstract:
1,168,511. Heating and cooling buildings. BORG-WARNER CORP. 12 Jan., 1967 [24 Jan., 1966], No. 1781/67. Headings F4U and F4V. A multi-room air-conditioning system comprises a number of room air-conditioning units 16 subjected to varying thermal loads and each comprising a liquid-to-air heat exchanger 24 and an air-circulating means such as the fan 22, each unit being connected to an individual inlet conduit 25 and an individual return conduit 27 to a main circulating conduit 10 to which a heater 14 and a chiller 12 of heat exchange fluid are cyclically and alternately connected. Temperature control means associated with each room unit are provided to effect heat transfer between the circulating heat exchange medium and the air in the individual rooms only upon a demand for heating when heating fluid is available and only upon a demand for chilling when chilled fluid is available. The heat exchange medium alternately heated and cooler is bled off to the units 16 in rooms A, B, C via T-fittings 28 and valves 36. The latter are actuated by controls 38 themselves controlled by temperature-responsive bulbs 40, 42 responsive to the temperature in the individual rooms and the temperature in the main conduit 10 respectively. The heater 14 and the chiller 12 are connected alternately into the conduit 10 by two three-way valves 18, 100. The valve 100 responds to the temperature of the returning fluid at 104 and the valve 18 is controlled jointly by a timer 18, and by the temperature drop between the outgoing and returning fluid as senser at the points 114 and 116. The latter sense the relative heating and cooling needs and determine the relative durations of hot water circulation and cold water circulation. The valves 36 may be replaced circulating pumps, or may be omitted and the heat transfer controlled solely by variation of the speeds of the fans 22. In the case of air induction units for the room units control of the heat transfer is effected by dampers. The heater and the chiller may be by-passed for periods intermediate those of heating and cooling.
Abstract:
Condensed refrigerant vapor that forms on the internal surface of a vertical condensing tube in a refrigeration system is removed from the upper portion of the tube by a tree-like insert having upwardly extending branches that contact the tube''s internal surface and, by capillary action and gravity, guide the condensate away from the surface and down the trunk of the insert. Removing the condensate or condensed vapor improves the heat transfer characteristic of the condensing tube and enhances the condensation process. To improve efficiency, liquid subcooling is achieved by returning some of the removed condensate back to the tube''s internal surface in a lower portion of the tube. This is accomplished by having the lowermost branches of the insert extend downwardly to the tube''s internal surface.
Abstract:
An air conditioning system employing separate chilled water and heated water single pipe loops and designed for use with individual room air conditioning units (inductor or fan-coil) equipped with separate heating and cooling heat exchange coils. The system provides local control at each unit, for both heating and cooling at all times when the heated water and chilled water circuits are active, as each circuit in the unit includes a circulating pump and coil, the pumps being under thermostatic control responsive to room temperature requirement.