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• Kalina cycle based power/refrigeration cogeneration cycle (PPRAT-KC) was studied. • Adjustable range of refrigeration temperature is about from -22℃ to 7.5℃. • Adjustment of refrigeration temperature has no effect on amounts of energy outputs. • Amount of net power or refrigeration energy output can be flexibly adjusted. • The PPRAT-KC can maintain high performance when altering refrigeration temperature. Two schemes of power and refrigeration cogeneration Kalina cycle with adjustable refrigeration temperature (PPRAT-KC) based on the efficient cogeneration cycle PPR-KC are proposed and studied. In the PPRAT-KC, the refrigerant vapor is absorbed in a pressure adjustment absorber with dilute solution either from the separator or the low-pressure pump, and by altering the flow rate of the dilute solution, the refrigeration temperature is able to be adjusted with nearly no effect on the amounts of energy outputs. The amount of net power or refrigeration capacity in the PPRAT-KC can be also adjusted by changing the flow rate of solutions fed to the power and refrigeration sub-cycles. Under temperatures of heat source and cooling water of 400℃ and 30℃, respectively, the change range of refrigeration temperature for the two schemes of the PPRAT-KC are about from -22℃ to 7.5℃, and the performances of the two schemes are similar. With the same work concentration of 0.5 and refrigeration temperature of -15℃, the effective exergy effeciency of PPRAT-KC is 0.5653, which is 4.145% and 10.97% higher than those of the PPR-KC and the triple pressure Kalina cycle, respectively. [ABSTRACT FROM AUTHOR]

• Air conditioning refrigeration achieves by guiding refrigerant vapor to mid-absorber. • Parallel PR cogeneration KC matches heat source well in cascade boiler and generator. • Leading generator dilute solution to low-pressure absorber has better performance. • Performances are improved by optimizing solution concentrations and boiler superheat. • Refrigeration/power ratio extends to 1.192 with boiler bubble point Δ t rises to 60 K. A parallel power/refrigeration cogeneration Kalina cycle (PPR-KC) system with adjustable refrigeration/power ratio that developed on the basis of the triple-pressure Kalina cycle system was analyzed. The PPR-KC system can produce refrigeration with temperature ranging in either air conditioning or ice making by switching the exhaust refrigerant vapor to the mid-pressure absorber or to the low-pressure one. The influences of the dilute solution from generator to the destination of either mid-pressure absorber (plan A) or low-pressure absorber (plan B) via recuperators on the performances of the PPR-KC system for air conditioning were investigated. The results show that the PPR-KC system matches well the heat source in cascade arranged boiler and generator thus showing excellent thermal performance by optimizing the solution concentrations, boiler superheat and other parameters. Under the given temperatures of heat source 400°C and cooling water 30°C respectively, the variation trends of the cycle parameters and performances of both plan A and plan B are presented. The power recovery efficiency of plan B is about 1.6% higher than that of plan A. When boiler bubble point temperature difference increases from 20 K to 60 K the refrigeration/power ratio of plan B climbs from 0.475 to 1.192. [ABSTRACT FROM AUTHOR]