José R. García-Cascales

José R. García-Cascales
Universidad Politécnica de Cartagena | UPCT · Department of Thermal and Fluid Engineering

Doctor of Engineering
Researcher and lecturer at University

About

101
Publications
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1,193
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Introduction
Industrial Engineer (1995) and PhD in Thermal Engineerging and Thermal Properties of Matter (2001), both at Technical University of Valencia, Spain. Research interests: Refrigeration: - Heat pumps, refrigeration systems modelling. - Hot water production by means of heat pumps. - Heat exchanger modelling. - CO2 and other alternative refrigerants. Internal ballistics - Combustion of propellants. Thermohydraulics - H2/CO/H2O combustion in nuclear scenarios.

Publications

Publications (101)
Article
Full-text available
Transcritical R744 (CO2) heat pumps are a low-GWP high-efficiency alternative for domestic hot water generation and space heating. For high set-point temperatures, however, the COP drops and the optimum operating pressure increases. For this reason, the effect on system performance achieved by the inclusion of an Intermediate Heat Exchanger (IHX) i...
Conference Paper
Full-text available
With the aim to analyse the thermo-hydraulic performance of the hot water storage tank, the test procedure and conditions are based on the EN 16147 Standard. The test consists of heating the water contained in the storage tank at 10 ºC until its temperature reaches 60 ºC using CO2 heat pump. The impact of the gas cooler flowrate on the thermal beha...
Article
Full-text available
This work presents an experimental study of the dynamic performance of a CO2 water-to-water heat pump in a domestic hot water production system. A facility was developed and used to characterize the time evolution of the COP of this heat pump, the heating and stratification processes of the hot-water storage tank, and the global COP of the system....
Article
Full-text available
After considering heating sector, one realises that there is no clear and consensual way to quantify or qualify the thermal comfort of the different technologies available to satisfy the heating demand of a home. This contribution tries to call attention to this by means of an experimental study of the thermal comfort provided by two very different...
Article
Full-text available
This paper presents a numerical study on the influence of internal heat exchanger (IHX) exchanging surface in the performance of a transcritical CO 2 heat pump water heater at different operating conditions. Five different IHX geometries and four different evaporation temperatures have been studied with water temperature ranging from 10 °C to 60 °C...
Article
Full-text available
The processes that take place within the Internal Ballistics cycle of an artillery round are highly influenced by geometric effects. They are also highly affected by the presence of a combination of energetic materials, such as the propellant, igniter, primer, and the combustible cartridge cases. For a more realistic simulation of these phenomena,...
Article
Full-text available
This work evaluates the capabilities of Large Eddy Simulation with perfectly stirred reactor (PSR) assumption and detailed chemistry to predict unsteady, premixed, hydrogen combustion sequences. The model was benchmarked with hydrogen-air experimental tests and with numerical data of flame acceleration in an obstructed channel. Results permit to id...
Article
Full-text available
This paper reports the results of an experimental and numerical study of different configurations of a CO2 water-to-water heat pump for hot water generation. The experimental installation developed to test the heat pump unit is briefly described and then the experimental results are presented. Numerical results of a model previously developed are c...
Article
Full-text available
The numerical modelling of turbulent combustion of H2–air mixtures with solid graphite particles is a challenging and key issue in many industrial problems including nuclear safety. This study presents a Eulerian–Eulerian model based on the resolution of the Navier–Stokes equations via large eddy simulation (LES) coupled with a system of ordinary d...
Conference Paper
Full-text available
The use of CO 2 heat pumps for water heating combined with energy recovery from greywater is a promising technology that can help to improve the efficiency of both domestic hot water (DHW) generation and space heating. A key aspect to keep in mind during the design of any CO 2 refrigeration or heat pump system is the fact that the optimal gas coole...
Article
This paper presents an experimental and numerical model-based approach for the estimation and control of the optimal heat rejection pressure in a one-stage transcritical CO2 heat pump equipped with an internal heat exchanger (IHX) and a liquid receiver. Once mass flow rate and compressor power consumption has been experimentally characterized, the...
Preprint
Full-text available
The modelling of premixed combustion in the presence of a turbulent field in three-dimensional (3-D) confined scenarios was studied in this work, and applied to hydrogen combustion within ITER vacuum vessel (VV). Two different combustion approaches were tested with Large Eddy Simulation: a Flamelet Progress Variable (LES-FPV) and a Thickened Flame...
Article
Full-text available
This work presents an experimental assessment on the use of R513A refrigerant as a drop-in replacement for R134a in a water chiller for air-conditioning applications. The study discusses from an energy efficiency point of view this replacement option for warm countries. A vapor-compression refrigeration system (VCRS) working with a minichannel air...
Article
Full-text available
Indoor swimming pools are high energy demand facilities. Current knowledge about their energy demand does not offer reliable information for a correct design of their thermal installations. A deeper knowledge about actual energy needs of these installations is then necessary to improve their energy efficiency. The objective of this work is to defin...
Article
Full-text available
Unexpected detonation of granular solid energetic materials is a key safety issue in the propellants manufacturing industry. In this work, a model developed for the characterization of the early stages of the detonation process of granular solid energetic materials is presented. The model relies on a two-phase approach which considers the conservat...
Article
In this work, a model for the characterization of unsteady combustion of AP/HTPB composite propellants is benchmarked against experimental data. The model describes a change of phase of the propellant from condensed to gas phase and afterwards its combustion by a simplified chemistry scheme. A Finite Volume approximation is used to solve the system...
Article
Indoor swimming pools are high energy demand sport or leisure facilities and this fact puts at risk their financial viability. The objective of this paper is to demonstrate that the use of predictive control can improve the energy efficiency of theses installations when using hybridised solar+boiler systems (eventually biomass-fired) for thermal su...
Article
In this work, the use of R1234yf as a drop-in replacement for R134a in an air to water refrigeration system used to produce cool water at 7 °C is studied. This equipment was constructed in our laboratory with a minichannel heat exchanger working as condenser and a plate heat exchanger working as evaporator resulting in a 2.5 kW water chiller, which...
Article
In this paper, the authors propose the use of Artificial Neural Networks (ANN) coupled with Group of Method Data Handling (GMDH) to develop a new tool to optimise the development of empirical models. Additionally, to show its potential, this technique is applied to a dataset of experimental measurements of condensing two-phase flows within minichan...
Article
This paper analyses the performance of an air/water chiller typically used for residential air conditioning when a minichannel condenser is used in replacement of a conventional fin-and-tube condenser. The experimental facility, the data reduction process and the uncertainty analysis are briefly described and then the experimental results are prese...
Article
Base bleed technology is a common strategy used for body drag reduction. This work assessed the capacity of different RANS, DES and LES models to estimate the drag coefficient of slender bodies with spin and Base Bleed technology under transonic and supersonic (Mach number 0.99–1.5) quasi-steady conditions. 2-dimensional and 3-dimensional numerical...
Article
A one-dimensional model is introduced in this paper for problems of internal ballistics involving solid propellant combustion. First, the work presents the physical approach and equations adopted. Closure relationships accounting for the physical phenomena taking place during combustion (interfacial friction, interfacial heat transfer, combustion)...
Article
This paper reports the results of an experimental and numerical study of the use of a minichannel coil and a fin-and-tube coil in an air/water heat pump working as evaporator when the system is working in heating mode. The experimental installation developed to test the heat pump unit is briefly described and then the experimental results are prese...
Article
This article reports the condensing flow heat transfer coefficient and pressure drop results of propane (R290) flowing through a square section horizontal multiport mini-channel tube made of aluminium having an internal diameter of 1.16 mm and a condensing length of 259 mm. Pressure drop and two phase flow experiments were performed at saturation t...
Conference Paper
Full-text available
This paper presents a numerical model (Fin1D-MB) to predict the performance of minichannel evaporators under dehumidifying conditions. The presented model applies a segment-by-segment discretization to the evaporator, adding in each segment a novel bi-dimensional discretization to the fluids flow, fin, and tube wall. The Fin1D-MB model introduces a...
Article
Full-text available
This work presents a numerical approach for modelling the detonation of H2–O2–N2 mixtures in the presence of reactive solid particles. The model relies on Euler-type equations with one-step Arrhenius chemistry and the inclusion of source terms accounting for interphase transport. A splitting method that uses AUSM+ and Rusanov schemes and the linear...
Article
The present paper reports the construction of an experimental installation to measure local condensing two-phase flow heat transfer coefficient and frictional pressure drop within mini-channel tubes, the validation measurements developed with R134a and the experimental measurements of heat transfer coefficient and frictional pressure drop made with...
Conference Paper
El uso de minicanales en los intercambiadores de calor se ha incrementado en las últimas décadas. Contribuyen a incrementar la eficiencia y compacidad y a reducir la carga de refrigerante. El objetivo de este trabajo es la determinación experimental del coeficiente de transferencia de calor bifásico en minicanales con el refrigerante R32 y comparar...
Article
This study analyzes the refrigerant R134a non-uniform condensation flowing through a 10-port multiport mini-channel tube. The idea is to show that non-uniform flow yields a lower overall heat transfer coefficient. Experimental data are analyzed to get the influence of non-uniform flow over the global heat transfer coefficient taking into account th...
Conference Paper
Moisture control has become an important fact for the last years. It has influence on human health and comfort, as well as the quality of certain services and processes. Therefore, it plays an important role for many industries, storage systems, transport and the preservation of products. For this reason, air-conditioning systems are integrating a...
Article
In this study, two-phase flow pressure drop was experimentally measured in condensation and evaporation fluid flow. Refrigerants R134a and R32 were tested in a multiport extruded aluminium tube (MPEs) with hydraulic diameters of 0.715 and 1.16 mm. Experimental conditions were in a range: mass velocity 200–1229 kg/m2s, heat flux 2.55–70 kW/m2, satur...
Article
The use of micro- and mini-channels in heat exchanger has increased in recent decades. They contribute to increasing efficiency and to reducing refrigerant charge and compactness of heat exchangers. The aim of this study is to experimentally determine heat transfer coefficient in mini-channels two-phase flow processes with the low GWP refrigerant R...
Article
Full-text available
En este estudio se presentan los resultados de una investigación experimental para caracterizar la caída de presión durante el proceso de ebullición saturada del R32 en el interior de un tubo multipuerto con orientación horizontal, el tubo consiste de 18 mini-canales con geometría triangular y un diámetro hidráulico 0715 mm. El rango de condiciones...
Article
SUMMARYA model formulated in terms of conserved variables is proposed for its use in the study of internal ballistic problems of pyrotechnical mixtures and propellants. It is a transient two-phase flow model adapted from the non-conservative Gough model. This conversion is mathematically attractive due to the wide range of numerical methods for thi...
Article
The selection of the suitable correlations for calculating the heat transfer coefficients and the pressure drop plays a fundamental role in the use of semi-empirical models for the simulation of the performance of a heat exchanger. Therefore, a discussion about the best way for validating a condenser model and choosing the best set of correlations...
Article
Full-text available
The code DUST is a CFD code developed by the Technical University of Cartagena, Spain and the Institute of Radioprotection and Nuclear Security, France (IRSN) with the objective to assess the dust explosion hazard in the vacuum vessel of ITER. Thus, DUST code permits the analysis of dust spatial distribution, remobilisation and entrainment, explosi...
Article
Full-text available
Pd–imidate complexes have been employed as efficient catalysts for the Heck alkenylation of unprotected 5-iodo-2′-deoxyuridine in acetonitrile. The protocol was also shown to work well for the unprotected 5-iodo-2′-deoxycytidine. A highly efficient scale-up synthesis of the HSV-1 inhibitor Brivudine (BVDU) is also accomplished in an overall yield o...
Article
New cyclometalated palladium complexes of general formula [Pd(Bmim)(X)(C∧N)] have been synthesized by a novel reaction route involving di-μ-hydroxo-palladacycles [{Pd(μ-OH)(C∧N)}2] (C∧ N = 2-benzoylpyridine (Bzpy), I, previously unreported, or C∧N = 2-phenylpyridine (Phpy), II)] and 1,3-butylmethylimidazolium salts [HBmim]X (X: Cl, Br, I, or saccha...
Article
The present paper reports condensing two-phase flow pressure drop gradient and heat transfer coefficient (HTC) inside a mini-channel multiport tube with R1234yf and R134a. Several models available in the literature are used to compare predictions of these two fluids. Experimental data are analysed to get the influence of saturation temperature, mas...
Article
Full-text available
This work describes the use of splitting methods in the analysis of reactive two-phase mixtures of gases and particles under conditions that make the source terms very stiff. In our particular case, these are low pressure, small particles, high solid concentration, and very dense solids. The gas phase is considered a perfect gas and the solid one i...
Conference Paper
The use of micro- and mini-channels in heat exchanger has increased in recent decades. They contribute to increasing efficiency and compactness of heat exchangers and, also, to reduce refrigerant charge. The aim of this study is to experimentally determine single- and two-phase pressure drop in mini-channels with the new low GWP refrigerant R1234yf...
Conference Paper
In this study, the characteristics of local heat transfer coefficient (HTC) and pressure drop are experimentally investigated in multiport aluminium tube at low vapour qualities. The tube consists in 18 parallel triangular channels and hydraulic diameter of 0.715mm. Two refrigerants, medium (R134a) and high (R32) reduced pressure are using as worki...
Conference Paper
The use of micro- and mini-channels in heat exchanger has increased in recent decades. They contribute to improving efficiency and reducing refrigerant charge and compactness of heat exchangers. The aim of this study is to experimentally determine heat transfer coefficient in mini-channels two-phase flow processes with the new low GWP refrigerant R...
Article
The present paper reports condensing two-phase flow pressure drop inside a mini-channel tube with 1.16 mm inner hydraulic diameter with R1234yf, R134a and R32. According to the available data, most of the models checked capture the trend correctly. Experimental data are analysed to show the influence of saturation temperature, mass velocities, vapo...
Conference Paper
Full-text available
The use of micro- and mini-channels in heat exchanger has increased in recent decades. They contribute to increasing efficiency and to reducing refrigerant charge and compactness of heat exchangers. The aim of this study is to experimentally determine heat transfer coefficient in mini-channels two-phase flow processes with the low GWP refrigerant R...
Conference Paper
Este trabajo presenta una discusión sobre la metodología de validación de diferentes correlaciones para el cálculo de los coeficientes de intercambio de calor durante la condensación. Los límites de la metodología tradicional han sido puestos de relieve y una diferente metodología ha sido propuesta, eligiendo un diferente conjunto de condiciones de...
Conference Paper
New environmental policies in the European Union require that emissions of ozone-depleting substances should be decreased in order to reduce the global warming. The refrigeration industry contributes direct or indirectly to those emissions, by that reason in last decades scientists and engineers associated with the refrigeration field have been wor...
Conference Paper
The use of micro- and mini-channels multiport tubes in heat exchangers has become widespread in recent decades, partly due to their being very commonly used in air conditioning equipment. They increase efficiency and compactness of heat exchangers while reducing refrigerant charge. Minimising charge is decisive in present day refrigeration systems...
Article
Full-text available
The title catalyst is a universal precatalyst for Suzuki-Miyaura cross-coupling of synthetically important coumaryl and pyrone halides (I) and (VII) with aryl and heteroaryl boronic acids.
Conference Paper
En este artículo se estudia el modelado de la caída de presión experimentada por el refrigerante a su paso por tubos de geometría de minicanal mediante el uso de redes neuronales con y sin realimentación, su entrenamiento y posterior validación. Para la obtención de los datos experimentales se dispone de una instalación ubicada en la Universidad Po...
Article
Full-text available
The main priority in photovoltaic (PV) panels is the production of electricity. The transformation of solar energy into electricity depends on the operating temperature in such a way that the performance increases with the decreasing temperatures. In the existing literature, different cooling techniques can be found. The purpose of most of them is...
Article
Full-text available
This paper presents the maps of solar radiation on the surface of south-east region of Spain named Región de Murcia . These maps are the result of treatment, study, and correlations obtained by data of 35 weather stations distributed throughout the region. These stations have collected data for 6 to more than 25 years. The paper presents the work p...
Article
Full-text available
This work describes the use of splitting methods in the analysis of two-phase mixtures of gas and particles under conditions that make the source terms very stiff. In this case, these are low pressure and very dense solids. The integration of the source terms proposed seems to help to tackle without difficulty the type of problems of interest. Inte...
Conference Paper
Full-text available
The use of multiport micro- and mini-channels in heat exchangers has increased in recent decades. They contribute to increasing efficiency and to reducing the refrigerant charge and compactness of heat exchangers. In this study we have considered a multiport tube with ten ports, 1.27 metres length and a hydraulic diameter of 1.17 mm. During condens...