Abstract
By using a distillation tower as the regenerator, the coefficient of performance (COP) of the ammonia-water absorption refrigeration cycle is calculated in this work. Two types of distillation towers, namely an equilibrium-stage tower with a total condenser and a packed-bed tower with a partial condenser, are used in the cycle. From the simulation results, it is found that both types of distillation towers can successfully increase the COP of the cycle due to increased ammonia concentration in the vapor phase of the ammonia-water refrigerant. It was also found that the tower equipped with a partial condenser provides higher COP than that of the tower equipped with a total condenser. The value of COP can be further increased when the generator is replaced by the packed-bed tower in this water-ammonia absorption cycle. The effects of the mass flow rate ratio of NH3/H2O, stage number, reflux ratio and energy duty of the tower on the COP of the cycle are also studied in the present paper.
Highlights
Conventional refrigeration cycles using vapor compressors are known to consume electricity intensively, during hot summer season
Ouadha and EI-Gotni [6] had examined the feasibility of using waste heat from marine Diesel engines to drive an ammonia-water absorption refrigeration system, and found that the coefficient of performance (COP) of the cycle increases with the increase of the generator temperature to a value of 0.65, which is the upper limit COP performed by a conventional ammonia-water refrigeration system
The effect of separator heat duty on the COPs agrees well with the reported experimental data with a maximum percentage deviation of 1.8%. They found that introducing a throttling process directly before the separator can alleviate the separator heat load and enhance the COP by up to 20%. We adopted this software (Aspen version-10.0) to simulate the COPs of the present modified ammonia-water absorption refrigeration cycle equipped with four types of distillation tower under different operating conditions
Summary
Conventional refrigeration cycles using vapor compressors are known to consume electricity intensively, during hot summer season. Since the results of the above works indicate that the operating conditions of the generator such as temperature, pressure and mass flow rates of water and ammonia play a major role in determining the COPs of the whole cycle (which can be controlled by the governing operating principles of distillation towers), it reminds us that the generator of the cycle may be replaced by a distillation tower. The results of simulation done in this work will show that the replacement of the generator by the packed-bed tower can give the best COPs in general
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
