In power plant applications, detailed transient analysis of the evaporator results in very large fluid systems, i.e. the model consists of many equations. This is because the evaporator has many tubes and the spatial discretization has to be quite fine in order to appropriately model transient evaporation processes. In such cases, due to performance and workflow reasons, we use a specialized in...

In the present investigation, a nonlinear mathematical model is developed for the analysis of Septuple effect flat falling film evaporator (SEFFFE) system used for concentrating weak black liquor in a nearby paper mill. This model is capable of simulating process of evaporation considering variations in boiling point rise (), overall heat transfer coefficient (U), heat loss from evaporator (Ql...

A dynamic model for the simulation of a new single-effect water/lithium bromide absorption chiller is developed. The chiller is driven by two distinct heat sources, includes a custom integrated falling film evaporator-absorber, uses mixed recirculation and is exclusively cooled by the ambient air. Heat and mass transfer in the evaporator-absorber and in the desorber are described according to a...

Interfacial solar steam generation is emerging as a promising technique for efficient desalination. Although increasing efforts have been made, challenges exist achieving balance among plethora of performance indicators—for example, rapid evaporation, durability, low-cost deployment, and salt rejection. Here, we demonstrate that carbonized manure can convert 98% sunlight into heat, the strong c...

The errors associated with therModynamic performance calculations are discussed with particular reference to systems with a high oil charge. It is shown that calculations made using published refrigerant data can be very misleading as no account is taken of the oil solubility effects. Pressure-enthalpy charts are presented for refrigerant R12 oil mixtures, for a range of oil concentrations. The...

Water as a refrigerant (R718) is compared with other modern refrigerants (R717, R290 R134a, R12, R22, and R152a) regarding refrigeration capacity and COP (coefficient of performance). A computer program simulating a theoretical vapor compression refrigeration cycle was developed to calculate COPs, compression ratios, and discharge temperatures of the refrigerants from the compressor. The effect...

The modelling of the parameters that influence the continuous evaporation of an alcoholic extract was considered using Doehlert matrices. The work was performed with a wiped falling film evaporator that allowed us to study the influence of the pressure, temperature, feed flow and dry matter of the feed solution on the dry matter contents of the resulting concentrate, and the productivity of the...

A thermodynamic simulation of a double effect generator heat exchanger absorption refrigeration cycle using biogas as source of energy has been carried out. The binary mixture considered in the present investigation was NH3 – H2O (Ammonia Water). This simulation was performed in order to investigate the effect of the temperature and pressure of the high temperature generator and the pressure of...

Finite time exergoeconomic performance of a combined cooling, heating and power generation (CCHP) plant composed of one endoreversible closed Brayton cycle and one endoreversible four-heat-reservoir absorption refrigeration cycle is investigated by using finite time thermodynamics. Heat conductance distribution among hot-, cold-, thermal consumer-, generator-, absorber-, condenserand evaporator...