Abstract: A high-efficiency, motorless purge system for closed-cycle absorption heat pumps, adapted for both absorption heat transformers and absorption chillers, using a series of valves to control the entry and exit of absorbent solution into a low-pressure, secondary absorption vessel. A small percentage of the total circulating solution is forced under pressure into the secondary absorption vessel via a spray nozzle, causing adiabatic absorption of absorbate vapor by the solution. Non-condensable gases accumulate in the secondary absorber until a certain vapor pressure is reached, upon which, gas, and possibly liquid, are transferred to an exhaust vessel having an exit vent for non-condensable gases. In an absorption chiller system, the secondary absorber has an internal heat exchanger to lower the temperature of the solution within, to facilitate the absorption process.

Abstract: A high-efficiency, motorless purge system for closed-cycle absorption heat pumps, adapted for both absorption heat transformers and absorption chillers, using a series of valves to control the entry and exit of absorbent solution into a low-pressure, secondary absorption vessel. A small percentage of the total circulating solution is forced under pressure into the secondary absorption vessel via a spray nozzle, causing adiabatic absorption of absorbate vapor by the solution. Non-condensable gases accumulate in the secondary absorber until a certain vapor pressure is reached, upon which, gas, and possibly liquid, are transferred to an exhaust vessel having an exit vent for non-condensable gases. In an absorption chiller system, the secondary absorber has an internal heat exchanger to lower the temperature of the solution within, to facilitate the absorption process.

Abstract: A linear compressor employing a piezoelectric actuator operating in resonance at a frequency substantially below its natural resonant frequency, which is usually of the order of 10 kHz. Low frequency resonance operation of the actuator, of the order of 100 Hz., is achieved by incorporating the actuator and its housing with the moving compression piston, such that the moving mass is substantially increased, and by reduction of the effective piezoelectric stiffness using hydraulic amplification of the actuator displacement. Both these procedures result in a reduction of the actuator resonant frequency. The hydraulic amplification is achieved by using a hydraulic chamber with different sized pistons, linking the actuator motion with motion of the actuator housing, to which the compressor piston is attached. The high efficiency achieved and the lack of moving parts or the need for lubricating oil makes the compressor ideal for use in high reliability and high purity applications.

Abstract: A linear compressor employing a piezoelectric actuator operating in resonance at a frequency substantially below its natural resonant frequency, which is usually of the order of 10 kHz. Low frequency resonance operation of the actuator, of the order of 100 Hz., is achieved by incorporating the actuator and its housing with the moving compression piston, such that the moving mass is substantially increased, and by reduction of the effective piezoelectric stiffness using hydraulic amplification of the actuator displacement. Both these procedures result in a reduction of the actuator resonant frequency. The hydraulic amplification is achieved by using a hydraulic chamber with different sized pistons, linking the actuator motion with motion of the actuator housing, to which the compressor piston is attached. The high efficiency achieved and the lack of moving parts or the need for lubricating oil makes the compressor ideal for use in high reliability and high purity applications.

Abstract: A heat and mass exchanger for a liquid desiccant air conditioning/dehumidification system. The exchanger comprises an absorber solution section operably connected to the system's absorber/dehumidification section and a desorber solution section operably connected to the system's desorber/regeneration section. A partition separating those sections includes at least two interconnecting ports positioned to facilitate flow of relatively weak solution from the absorber solution section into the desorber solution section; and the flow of relatively strong solution from the desorber solution section into the absorber solution section—as well as allowing heat transfer therebetween.

Abstract: A heat and mass exchanger for a liquid desiccant air conditioning/dehumidification system. The exchanger comprises an absorber solution section operably connected to the system's absorber/dehumidification section and a desorber solution section operably connected to the system's desorber/regeneration section. A partition separating those sections includes at least two interconnecting ports positioned to facilitate flow of relatively weak solution from the absorber solution section into the desorber solution section; and the flow of relatively strong solution from the desorber solution section into the absorber solution section—as well as allowing heat transfer therebetween.

Abstract: In recent years piezoelectric actuation has been identified as a promising means of driving miniature Stirling devices. It supports miniaturization, has a high power to volume ratio, can operate at almost any frequency, good electrical to mechanical efficiencies, and potentially has a very long operating life. This invention uses a valve-less hydraulic amplification, creating an oscillating pressure wave sufficiently large to drive a high frequency miniature pulse tube cryocooler. The actuator may be separated from the main body of the cryocooler. The system lack of rubbing parts in the power conversion processes.

Abstract: An improvement in an absorption heat pump cycle is obtained by adding adiabatic absorption and desorption steps to the absorber and desorber of the system. The adiabatic processes make it possible to obtain the highest temperature in the absorber before any heat is removed from it and the lowest temperature in the desorber before heat is added to it, allowing for efficient utilization of the thermodynamic availability of the heat supply stream. The improved system can operate with a larger difference between high and low working fluid concentrations, less circulation losses, and more efficient heat exchange than a conventional system.

Abstract: The efficiency of an absorption heat pump system is improved by conducting liquid from a second stage evaporator thereof to an auxiliary heat exchanger positioned downstream of a primary heat exchanger in the desorber of the system.

Abstract: Connecting of a steel tube grid to a thin aluminum sheet to form a solar collector plate is carried out by explosive bonding to ensure a high thermal conductivity between sheet and tubes. Herein the sheet is prepressed in a pattern of channels of substantially semicircular cross section conforming to the shape of the tube grid. A heavy supporting plate is provided, in its flat surface, with a similar pattern of channels, but in mirror symmetry; the tubes of the grid are completely filled with water and the grid is laid into the channels of the supporting plate. Then the grid is covered by the sheet, with the channels covering the tubes and the flat sheet portions in contact with the surface of the supporting plate. Explosive charges in ribbon shape are laid onto the sheet along the apices of all channels on their outside, and the charges are detonated, whereafter the joined grid and sheet are removed from the plate.

Abstract: A solar collector panel consists of a metal sheet and a number of straight metal tubes intimately connected to the sheet in order to obtain maximum thermal conductivity. One tube each is connected to a sheet by slotting the latter along a straight line by equidistant parallel short cuts and pressing the areas between two consecutive cuts into semi-cylindrical bulges alternately in opposite direction from the sheet surface. These bulges have a concave semi-circular cross section of a diameter slightly larger than the outer diameter of the tube, and all bulges along the straight line form a continuous passage into which the tube is inserted. After insertion the tube is expanded by mechanical means or by hydraulic pressure and pressed onto the semi-cylindrical portions of the sheet, satisfactory contact being obtained by dimensioning the expanding pressure to a magnitude that the tube material is stressed beyond its yield point, while the sheet metal is stressed below its elastic limit.