Performance analysis of a solar-assisted OTEC cycle for power generation and fishery cold storage refrigeration

Abstract

15The cold storage in fishery industry is in great demand in tropical coastal regions. This research 16 proposes an ocean thermal energy conversion (OTEC) based solar-assisted combined power and 17 refrigeration cycle, which can be used for both electricity generation and fishery cold storage 18 application. In this proposed combined cycle, the ammonia/water is selected as the working fluid and 19 the warm/cold seawater is utilized as the heating/cooling source. A two-stage ejector system is 20 2 introduced, the turbine is used to produce power and the evaporator is used to produce refrigeration 21 output. Besides, a flat-plate solar collector is utilized to increase the heating source temperature. To 22 evaluate the performance of the proposed cycle, a mathematical model is developed and a simulation 23 program is developed; the performance comparison between it and a previous two-stage ejector 24 OTEC cycle is made, which shows this solar-assisted cycle has a slightly lower power-production 25 efficiency of 2.27% but a much higher comprehensive-production efficiency of 7.89% under the 26 given working condition. Furthermore, parametric analysis is performed to guide the theoretical 27 performance of this combined cycle. The results show that the generator pressure, solar collector 28 outlet temperature and rich solution concentration all affect the cycle performance; the entrainment 29 ratio of the first-stage ejector is greatly affected by the rich solution concentration. 30

Effects of working conditions on the performance of an ammonia ejector used in an ocean thermal energy conversion system

“…In the present work, the selections of boundary conditions are based on the operating conditions of OTEC systems. As shown in Yuan et al, [9,10] the evaporation temperature for ammonia vapour is lower than 60 C for the OTEC system coupled with solar energy. Considering pressure losses, we adopted As the secondary inlet of the ejector is connected to the turbine, a 1 MPa pressure drop was assumed for all cases in this work.…”

“…The authors also used a flat-plate solar collector to increase the heating source temperature, which improved the efficiency of the OTEC. [10] The numerical results indicated that the comprehensiveproduction efficiency was 7.89% for the new system.…”

A Review of Key Technologies and Trends in the Development of Integrated Heating and Power Systems in Agriculture

“…In addition, a new type of microalgae-bacterial biological fuel cell (MBBFC) was designed for aquaculture wastewater treatment and energy recovery [ 121 ]. Since fishery refrigeration consumes more energy in fishery activities, Yuan et al [ 122 ] proposed the use of a solar-assisted hybrid power generation and refrigeration cycle system based on ocean thermal energy conversion (OTEC) to provide power for fishery refrigeration and reduce the power pressure related to refrigeration. Using a self-powered electrochemical water treatment system with a triboelectric nanogenerator (TENG) combined with seawater electrolysis technology, the energy consumption and costs of algae removal and sterilization in fishery were effectively reduced [ 123 ].…”

Presenting and optimization of a novel ammonia‐water combined power and compression cooling system

“…9 Water-ammonia mixture is one of the most efficient known zeotropic mixtures that is applied frequently as the working fluid of combined plants. 10,11 Yuan et al 12 proposed a combined ammonia-water power cycle and a refrigeration cycle integrated with a solar system. They demonstrated that ammonia-water with higher concentrations improved the performance of the proposed system.…”

“…Yuan et al 12 proposed a combined ammonia‐water power cycle and a refrigeration cycle integrated with a solar system. They demonstrated that ammonia‐water with higher concentrations improved the performance of the proposed system.…”