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Ecological adsorption technology is becoming a focus of attention by industry due to the utilization of low grade thermal energy sources for cooling production. It can be a promising part of sustainable development concept of the global economy. Therefore, research aiming at improving their performance i.e. Coefficient of Performance (COP) by optimizing the construction of sorption beds with a built in heat exchanger system is crucial. The heat transfer characteristics between the bed of porous media (sorbent) and surface of the heat exchanger system determine the heating power of an adsorption chiller. The HP increase can be obtained by heat transfer intensification due to the increase in the thermal conductivity of the sorbent layer in the vicinity of the heat exchanger’s surface. The novel modification of the sorbent layer structure is proposed in the paper in order to improve the heat transfer processes in the heat exchanger boundary layer. The analysis of desorption process conditions in the parametric model of a coated and fixed adsorption bed design is presented in the paper. The computational fluid dynamics (CFD) with conjugate heat transfer analysis is used to determine the crucial input parameters (temperature distribution in the sorbent bed) for further analytical calculations. The commercial code Ansys Fluent was used to perform numerical simulations. The developed computational model consisted of three subdomains representing heating water, heat exchanger material (copper) and sorbent (silica gel). The comparison of a novel coated design and a conventional fixed bed is discussed in the paper. The numerical analysis is based on experimental thermal conductivity measurements of the sorbent layer in different configurations, which were performed using Laser Flash Method.

The calcium looping (CaL) process usually employs a dual-fluidized bed (DFB) solid circulating unit. In the regenerator (calcinator or calciner), decomposition of CaCO3proceeds. To supply the heat of decomposition, oxyfuel combustion of coal is conducted. However, since coal contains nitrogen, the NOxformation occurs during oxyfuel combustion. Because of the fact that NOxformation and destruction during combustion of solid fuels in a fluidized bed is a complex process, a predictive approach of NOxemissions has not yet been sufficiently recognized, especially during oxyfuel combustion conditions in the CaL systems. The paper introduces a regression-based method for the prediction of NOxemissions from a CaL DFB experimental unit. Effects of fuel type, excess oxygen feed, and NO addition to primary or secondary feed gas on NOxemissions in the regenerator were evaluated. The presented way constitutes a straightforward method to run a complementary technique in relation to other methods of data handling, including the programmed computing approach and measurements. The developed model can be simply employed by scientists as well as engineers for optimization purposes.

Energy efficiency is one of the most important topics nowadays. It is strictly related to the problem of energy demand, energy policy, environmental pollution, and economic issues. Because of the technological development, using more advanced processes in almost every part of industry and increasing demands both for a high standard of living and simplification of processes, the energy demand is growing. This can be observed, e.g., in the building sector—air conditioning is present in almost every new building and people expect high quality thermal conditions. At the same time, many technological processes result in dissipating energy to the environment. Energy efficiency can be increased and operation costs reduced by using waste heat in other processes. One of the possibilities is to use sorption chillers to produce cool and desalinated water. Low temperature waste heat is not easy to utilize because of low energy potential. Using adsorption chillers in low temperature conditions allows utilizing waste heat and producing useful products in many regions of the world. The paper presents the results of experimental study carried out on three-bed adsorption chiller with desalination, using silica gel and water as the working pair. The chiller was equipped with plate-fin tube heat exchanger filled with silica gel with a grain size of 0.5–1.5 mm. The laboratory test stand included one evaporator, one condenser, and three separate tanks for water, desalinated water, and brine, respectively. The test stand scheme and description were presented. All results were obtained during a few hours test with stable temperature conditions in the range of 55–85 °C for the heating water.