Computational Model of a Biomass Driven Absorption Refrigeration System

Abstract

Abstract:The impact of vapour compression refrigeration is the main push for scientists to find an alternative sustainable technology. Vapour absorption is an ideal technology which makes use of waste heat or renewable heat, such as biomass, to drive absorption chillers from medium to large applications. In this paper, the aim was to investigate the feasibility of a biomass driven aqua-ammonia absorption system. An estimation of the solid biomass fuel quantity required to provide heat for the operation of a vapour absorption refrigeration cycle (VARC) is presented; the quantity of biomass required depends on the fuel density and the efficiency of the combustion and heat transfer systems. A single-stage aqua-ammonia refrigeration system analysis routine was developed to evaluate the system performance and ascertain the rate of energy transfer required to operate the system, and hence, the biomass quantity needed. In conclusion, this study demonstrated the results of the performance of a computational model of an aqua-ammonia system under a range of parameters. The model showed good agreement with published experimental data.

Thermodynamic Evaluation of LiCl-H2O and LiBr-H2O Absorption Refrigeration Systems Based on a Novel Model and Algorithm

“…Equations (1) and (2) represent the mass and species balances applied to the component k (G, A, C, E, SHE) and ensure that the amounts of each substance j (LiBr, LiCl, water) entering into component k equal the total amount of j leaving k. The energy balance in Equation (3) reflects that the difference between the inlet and outlet energy flows of stream i add the heat supplied by external utility u must be equal to the work done by the component k. In these equations, m indicates the mass flow rate of stream i (kg•s −1 ), x denotes mass fraction of substance j in stream i (kg•kg −1 ), H is the energy flow rate (kW), Q refers to the heat transfer capacity (kW), and W represents power (kW).…”

“…According to Equations (1) and (2), the mass balance equation and species balance equation in the generator and absorber can be expressed as the following Equations (5) and (6), respectively:…”

“…As a promising technology to use low thermal potential energy and renewable energy, an absorption refrigeration system (ARS) is getting significant attention nowadays because it can be driven by waste heat [1], biomass [2], solar [3], geothermal energy [4], etc., instead of conventional compression-work-driven chillers. Furthermore, the ARS typically uses water as a refrigerant and the working fluids of system operation are environmentally friendly with zero global warming potential (GWP) and ozone depletion potential (ODP) [5].…”

Comparison the start-up time of the key parameters of aqua-ammonia and water–lithium bromide absorption chiller (AC) under different heat exchanger configurations

“…Investigation the behavior of the absorption cycle in dynamic mode by applying the step change in the cycle [5,6,8,12,13] and during start-up [7,14,15] have been already carried out. Dynamic simulation of ammonia-water heat pump [8,[16][17][18][19] was accomplished to predict the transient performance and design characteristics as well.…”

“…Some researchers have presented dynamic model for absorption chillers by using TRNSYS software and Simulink environment [10,13,15,17,[19][20][21]. Altun and Kilic [20] developed a dynamic model for a 10 KW cooling capacity solar-assisted absorption cycle for different cities of Turkey by TRNSYS software.…”