José Mª Marín

Bio: José Mª Marín is an academic researcher from University of Zaragoza. The author has contributed to research in topics: Thermal energy storage & Heat transfer. The author has an hindex of 2, co-authored 4 publications receiving 3810 citations.

Review on thermal energy storage with phase change: materials, heat transfer analysis and applications

Abstract: Thermal energy storage in general, and phase change materials (PCMs) in particular, have been a main topic in research for the last 20 years, but although the information is quantitatively enormous, it is also spread widely in the literature, and difficult to find. In this work, a review has been carried out of the history of thermal energy storage with solid–liquid phase change. Three aspects have been the focus of this review: materials, heat transfer and applications. The paper contains listed over 150 materials used in research as PCMs, and about 45 commercially available PCMs. The paper lists over 230 references.

Improvement of a thermal energy storage using plates with paraffin–graphite composite

Abstract: This work aims at designing a thermal energy storage (TES) using air as heat transfer medium, efficient mainly for free-cooling but also for other applications, improving the low heat transfer rates dues to the thermal conductivity of the materials usually employed in these systems, phase change materials (PCM). In this paper, free-cooling means the storage of cold from the night to be used during the day to cool down a room. An experimental set-up has been constructed to simulate the application. The loading and unloading processes (melting and freezing of the PCM) have two disadvantages: a relative long duration, in the range from 3 to 8 h, and a very high power consumption of the fans. Using a porous matrix of graphite where the PCM is embedded, both handicaps can be noticeably overcome. The application is studied, both experimentally and numerically.

Effect of glycopyrronium vs tiotropium on pulmonary function and morning symptoms in patients with moderate-to-severe COPD: The SPRING study

Abstract: Background: Inhaled long-acting antimuscarinic agents are first line bronchodilator options for treatment of stable moderate-to-severe COPD patients (pts). In the GLOW2 trial glycopyrronium (GLY) demonstrated faster onset of action vs open-label tiotropium (TIO), with greater levels of bronchodilation in the initial 4 h following administration. Aim: To show superiority of GLY (50 μg) compared to TIO (18 μg)in FEV1AUC0-4h after first dose in symptomatic patients with moderate to severe COPD. Secondary efficacy objectives included comparisons of symptoms on Day 1 and 28. Methods: This was a prospective multi-centre, randomized, blinded, two-period cross-over study; each treatment lasted 28 days, with 14-19 days wash-out between treatments. Results: Of 124 pts randomized, 70.2% were male, mean age was 65.7 y. Least square means (95% CI) FEV1AUC0-4h after first treatment dose was 1.74 (1.71, 1.77)L for GLY and 1.71 (1.68, 1.74)L for TIO; difference 0.030 (0.004, 0.056)L, p=0.025, in favour of GLY. A numerical difference in improvement of morning COPD symptoms was observed in favour of GLY [mean (SD) -6.9 (6.6) vs -5.9 (6.6) for GLY and TIO respectively (p=0.144)]. GLY was also numerically better in FEV1AUC0-4h when compared to TIO on Day 28. The Day 28 PRO-morning COPD symptom score was not different between treatments. There were no differences in the safety profile between GLY and TIO. Conclusions: GLY demonstrated superiority of GLY compared to TIO in terms of FEV1AUC0-4h after the first dose of treatment, further supporting better bronchodilation with GLY during the 4 h following administration.

Carbon-based Supercapacitors Produced by Activation of Graphene

Abstract: Supercapacitors, also called ultracapacitors or electrochemical capacitors, store electrical charge on high-surface-area conducting materials. Their widespread use is limited by their low energy storage density and relatively high effective series resistance. Using chemical activation of exfoliated graphite oxide, we synthesized a porous carbon with a Brunauer-Emmett-Teller surface area of up to 3100 square meters per gram, a high electrical conductivity, and a low oxygen and hydrogen content. This sp 2 -bonded carbon has a continuous three-dimensional network of highly curved, atom-thick walls that form primarily 0.6- to 5-nanometer-width pores. Two-electrode supercapacitor cells constructed with this carbon yielded high values of gravimetric capacitance and energy density with organic and ionic liquid electrolytes. The processes used to make this carbon are readily scalable to industrial levels.

A review on phase change energy storage: materials and applications

Abstract: Latent heat storage is one of the most efficient ways of storing thermal energy. Unlike the sensible heat storage method, the latent heat storage method provides much higher storage density, with a smaller temperature difference between storing and releasing heat. This paper reviews previous work on latent heat storage and provides an insight to recent efforts to develop new classes of phase change materials (PCMs) for use in energy storage. Three aspects have been the focus of this review: PCM materials, encapsulation and applications. There are large numbers of phase change materials that melt and solidify at a wide range of temperatures, making them attractive in a number of applications. Paraffin waxes are cheap and have moderate thermal energy storage density but low thermal conductivity and, hence, require large surface area. Hydrated salts have larger energy storage density and higher thermal conductivity but experience supercooling and phase segregation, and hence, their application requires the use of some nucleating and thickening agents. The main advantages of PCM encapsulation are providing large heat transfer area, reduction of the PCMs reactivity towards the outside environment and controlling the changes in volume of the storage materials as phase change occurs. The different applications in which the phase change method of heat storage can be applied are also reviewed in this paper. The problems associated with the application of PCMs with regards to the material and the methods used to contain them are also discussed.

A review of materials, heat transfer and phase change problem formulation for latent heat thermal energy storage systems (LHTESS)

Abstract: This paper reviews the development of latent heat thermal energy storage systems studied detailing various phase change materials (PCMs) investigated over the last three decades, the heat transfer and enhancement techniques employed in PCMs to effectively charge and discharge latent heat energy and the formulation of the phase change problem. It also examines the geometry and configurations of PCM containers and a series of numerical and experimental tests undertaken to assess the effects of parameters such as the inlet temperature and the mass flow rate of the heat transfer fluid (HTF). It is concluded that most of the phase change problems have been carried out at temperature ranges between 0 °C and 60 °C suitable for domestic heating applications. In terms of problem formulation, the common approach has been the use of enthalpy formulation. Heat transfer in the phase change problem was previously formulated using pure conduction approach but the problem has moved to a different level of complexity with added convection in the melt being accounted for. There is no standard method (such as British Standards or EU standards) developed to test for PCMs, making it difficult for comparison to be made to assess the suitability of PCMs to particular applications. A unified platform such as British Standards, EU standards needs to be developed to ensure same or similar procedure and analysis (performance curves) to allow comparison and knowledge gained from one test to be applied to another.

Review on thermal energy storage with phase change materials (PCMs) in building applications

Abstract: Thermal energy storage with phase change materials (PCMs) offers a high thermal storage density with a moderate temperature variation, and has attracted growing attention due to its important role in achieving energy conservation in buildings with thermal comfort. Various methods have been investigated by previous researchers to incorporate PCMs into the building structures, and it has been found that with the help of PCMs the indoor temperature fluctuations can be reduced significantly whilst maintaining desirable thermal comfort. This paper summarises previous works on latent thermal energy storage in building applications, covering PCMs, the impregnation methods, current building applications and their thermal performance analyses, as well as numerical simulation of buildings with PCMs. Over 100 references are included in this paper.

State of the art on high temperature thermal energy storage for power generation. Part 1—Concepts, materials and modellization

Abstract: Concentrated solar thermal power generation is becoming a very attractive renewable energy production system among all the different renewable options, as it has have a better potential for dispatchability. This dispatchability is inevitably linked with an efficient and cost-effective thermal storage system. Thus, of all components, thermal storage is a key one. However, it is also one of the less developed. Only a few plants in the world have tested high temperature thermal energy storage systems. In this paper, the different storage concepts are reviewed and classified. All materials considered in literature or plants are listed. And finally, modellization of such systems is reviewed.