Abstract: In a double-effect absorption chiller wherein the vapor of a refrigerant produced by a high temperature generator is supplied to a low temperature generator 12 for condensation, and the refrigerant liquified by condensation is supplied to a condenser 11, a pipe 7 for supplying the refrigerant liquified in the low temperature generator 12 to the condenser 11 therethrough is provided with an orifice 71 and a control valve 81 as pressure adjusting means. A control circuit 9 is connected to the control valve 81 to hold the valve 81 fully open during the period form the start-up of the chiller until the load is stabilized and thereafter gradually decrease the opening degree of the valve 81.

Abstract: An apparatus 9 for diagnosing failures in the combustion system to be installed in the regenerator of an absorption chiller is adapted to automatically prepare quantitative diagnosis data from a plurality of items of measurement data. The apparatus comprises an abnormality degree calculating circuit 2 for calculating degrees of abnormality serving as indexes for discriminating failures, from different items of data obtained by a combustion system control unit 1, a binary conversion circuit 4 for converting the abnormality degrees obtained from the circuit 2 to binary data representing "normal" or "abnormal," a condition judging circuit 5 for discriminating types of states of failures from the binary data by driving a diagnosis knowledge base 7, and a diagnosis data calculating circuit 6 for calculating diagnosis data from the abnormality degrees and types of failure states by driving the base 7.

Abstract: A failure diagnosing system for an absorption chiller including an evaporator, absorber, etc. comprises a plurality of sensors for measuring at least one representative temperatures of each of two fluids participating in heat exchange in a specified heat exchange unit, and an arithmetic unit for receiving measurement data from the sensors. The arithmetic unit comprises a circuit for calculating an actual temperature difference using a simple calculation equation defined by a linear expression, a circuit for calculating the amount of heat exchange by the absorber, and a circuit for calculating the degree of abnormality of the absorber by comparing the actual temperature difference with an ideal temperature difference for the same amount of heat exchange as the calculated amount.