Configuration optimization of series flow double-effect water-lithium bromide absorption refrigeration systems by cost minimization. (15th February 2018)

• Record Type: Journal Article
• Authors: Mussati, Sergio F.; Cignitti, Stefano; Mansouri, Seyed Soheil; Gernaey, Krist V.; Morosuk, Tatiana; Mussati, Miguel C.
• Is Part Of: Energy conversion and management. Volume 158(2018)
• Page Start: 359
• Page End: 372
• Publication Date: 2018-02-15
• Subjects: Absorption refrigeration -- H2O-LiBr -- Double-effect -- Optimization -- Cost -- NLP; Direct energy conversion -- Periodicals; Energy storage -- Periodicals; Energy transfer -- Periodicals; Énergie -- Conversion directe -- Périodiques; Direct energy conversion; Periodicals; 621.3105
• DOI: 10.1016/j.enconman.2017.12.079
• Languages: English
• ISSNs: 0196-8904

Abstract

Highlights: Mathematical optimization of series flow double-effect absorption system is performed. Weak lithium bromide solution is first passed through the high-temperature generator. A new configuration is found by total cost minimization using nonlinear programming. The low-temperature solution heat exchanger is removed in the found optimal solution. Cost is 9.5% lower than the cost of the optimized conventional double-effect system. Abstract: An optimal process configuration for double-effect water-lithium bromide absorption refrigeration systems with series flow – where the solution is first passed through the high-temperature generator – is obtained by minimization of the total annual cost for a required cooling capacity. To this end, a nonlinear mathematical programming approach is used. Compared to the optimized conventional double-effect configuration, the new optimal configuration obtained in this paper allows reducing the total annual cost, the capital expenditures, and the operating expenditures by around 9.5%, 11.1% and 4.9%, respectively. Most importantly, the obtained optimal solution eliminates the low-temperature solution heat exchanger from the conventional configuration, rendering a new process configuration. The energy integration between the weak and strong lithium bromide solutions (cold and hot streams, respectively) takes place entirely at the high-temperature zone, and the sizes and operating conditions of the other process units change accordingly in order to meet the problem specification with the minimal total annual cost. This new configuration was obtained for wide ranges of the cooling capacity (150–450 kW) and the temperature of the cooling water (15–35 °C). The results of this work motivate to apply the simultaneous optimization approach to seek for new multi-effect absorption refrigeration system configurations with parallel and reverse flow as well as other series flow arrangements that minimize the total annual cost.