Experimental assessment of an absorption heat transformer prototype at different temperature levels into generator and into evaporator operating with water/Carrol mixture J. Ibarra-Bahena a , R.J. Romero b,⇑ , J. Cerezo c , C.V. Valdez-Morales a , Y.R. Galindo-Luna a , L. Velazquez-Avelar a a Posgrado en Ingeniería y Ciencias Aplicadas, FCQeI - CIICAp, Universidad Autónoma del Estado de Morelos, Av. Universidad 1001, C.P. 62209 Cuernavaca, Morelos, Mexico b Centro de Investigación en Ingeniería y Ciencias Aplicadas, Universidad Autónoma del Estado de Morelos, Av. Universidad 1001, C.P. 62209 Cuernavaca, Morelos, Mexico c Instituto de Ingeniería, Universidad Autónoma de Baja California, Blvd. Benito Juárez y calle de la Normal S/N, C.P. 21280 Mexicali, Baja California, Mexico article info Article history: Received 6 March 2014 Received in revised form 4 July 2014 Accepted 21 September 2014 Keywords: Absorption heat transformer Water/Carrol Prototype Heat recovery Water purification PHE abstract Absorption Heat Transformer (AHT) is a device to recovery heat waste by a thermodynamic cycle. In this paper, an experimental AHT prototype operated with four temperature levels and two pressure levels was analyzed. This prototype was build with commercial Plate Heat Exchangers (PHE) and operates with water/Carrol mixture. The heat powers measured were 1.03, 1.48 and 1.51 kW for the generator, 1.19, 1.54 and 1.61 kW for the condenser, 1.21, 1.57 and 1.64 kW for the evaporator, and finally, 0.59, 0.98 and 1.09 kW for the absorber. Experimental Gross Temperature Lift (GTL) was 18.0, 17.4 and 16.5 °C and the dimensionless values of Coefficient of Performance (COP) calculated for those operating condi- tions were 0.26, 0.32 and 0.35. Absorber temperatures were 106.8, 105.3, 103.9 °C. Ó 2014 Elsevier Inc. All rights reserved. 1. Introduction As the probed reserves of fossil fuels decreases and the Kyoto protocol has urged nations to mitigate the negative effect of green house, the efficient use of energy is an important topic for many industries. A major cause of energy inefficiency is the generation of waste heat and the lack of waste heat utilization, particularly low grade heat. Technologies such as Absorption Heat Transform- ers (AHT) which allow the recycling of waste heat energy are very attractive methods of improving performance in this area. AHT is a closed cycle system which upgrades a fraction of the energy con- tained by an intermediate temperature waste heat stream to a higher temperature to it will be reused. These cycles require a negligible mechanical or electrical work and thus have very low running costs [1–3]. As a very effective technique, the AHT can be applied to improve low-grade waste heat with temperatures ranging from 60 to 100 °C. The AHT system can effectively recover about 50% of this waste heat and give an opportunity to reuse it in industrial processes [4,5]. Applications of AHTs technology include, mainly: Thermal energy revalorization, purification water process and desalination seawater. Horuz and Kurt [6] proposed an AHT in a textile company in order to produce hot process water by utilizing the hot water generated by a cogeneration system. The case of study had four dif- ferent units which each produces 15 ton/h water at 90 ± 2 °C. A theoretical analysis shows that is possible increase the source tem- perature at 120 °C, and the heat waste revalorization by an AHT is around 50%. Rivera et al. [7] carried out a theoretical analysis for AHT coupled to a butane and pentane distillation column in order to reduce the heat load supplied to the reboiler; the heat delivered in the condenser, at 82 °C, may be used as heat input in the gener- ator and evaporator of the AHT system and revalorizes at high tem- perature level in the absorber to preheat the stream entering to the reboiler at 155 °C. Authors concluded that with the use AHT is pos- sible to save up to 43% of the energy supplied to the reboiler of the distillation for the process conditions. Ma et al. [8] reported an AHT for 5000 kW of heat flow in a synthetic rubber plant. It was used to recover the waste heat released from mixture of steam and organic vapor at 98 °C. The heat recovered was used to heat water process from 95 to 110 °C, in order to feeding back to the coagulator as heating source. The COP calculated was 0.47, and the gross temper- ature lift of 25 °C. An economical analysis demonstrated that the http://dx.doi.org/10.1016/j.expthermflusci.2014.09.013 0894-1777/Ó 2014 Elsevier Inc. All rights reserved. ⇑ Corresponding author. E-mail address: rosenberg@uaem.mx (R.J. Romero). Experimental Thermal and Fluid Science 60 (2015) 275–283 Contents lists available at ScienceDirect Experimental Thermal and Fluid Science journal homepage: www.elsevier.com/locate/etfs