Article

Performance analysis of a new type desalination unit of heat pump with humidification and dehumidification

Institute of Air-Conditioning & Solar Energy, School of Dynamics and Energy, Northwestern Polytechnical University, Xi'an, ShaanXi, 710072, China
Desalination 01/2008; DOI: 10.1016/j.desal.2007.01.053

ABSTRACT Desalination with humidification and dehumidification process is deemed as an efficient and promising means of utilizing the condenser and evaporator of heat pump to produce freshwater from seawater. This paper presents a new type desalination unit driven by mechanical vapor compression pump which was designed and fabricated by the Institute of Air-Conditioning & Solar Energy of the Northwestern Polytechnical University. The unit utilized the heat from condenser and the cold from evaporator of heat pump adequately, and reclaimed most latent heat. The air, firstly, was humidified in the humidifier with the alveolate structure, and then was cooled in the precondenser and the evaporative condenser to produce freshwater. A mathematical model of the unit is presented, in which the hydrokinetics method was used to study the flow and the heat and mass transfer inside the alveolate humidifier. The effects of some of the operation such as flow rates, temperatures of cooling water and air, and etc., were studied in detail. The comparison between the numerical and experimental results was accepted. The desalination unit that is considered in the study produces freshwater 60 kg/day with the less electric power that is 500W and is proven to be an efficient desalination device to obtain freshwater.

0 Bookmarks
 · 
80 Views
  • [Show abstract] [Hide abstract]
    ABSTRACT: Heat pump systems offer economical alternatives of recovering heat from different sources for use in various industrial, commercial and residential applications. As the cost of energy continues to rise, it becomes imperative to save energy and improve overall energy efficiency. In this light, the heat pump becomes a key component in an energy recovery system with great potential for energy saving. Improving heat pump performance, reliability, and its environmental impact has been an ongoing concern. Recent progresses in heat pump systems have centred upon advanced cycle designs for both heat- and work-actuated systems, improved cycle components (including choice of working fluid), and exploiting utilisation in a wider range of applications. For the heat pump to be an economical proposition, continuous efforts need to be devoted to improving its performance and reliability while discovering novel applications. Some recent research efforts have markedly improved the energy efficiency of heat pump. For example, the incorporation of a heat-driven ejector to the heat pump has improved system efficiency by more than 20%. Additionally, the development of better compressor technology has the potential to reduce energy consumption of heat pump systems by as much as 80%. The evolution of new hybrid systems has also enabled the heat pump to perform efficiently with wider applications. For example, incorporating a desiccant to a heat pump cycle allowed better humidity and temperature controls with achievable COP as high as 6. This review paper provides an update on recent developments in heat pump systems, and is intended to be a “one-stop” archive of known practical heat pump solutions. The paper, broadly divided into three main sections, begins with a review of the various methods of enhancing the performance of heat pumps. This is followed by a review of the major hybrid heat pump systems suitable for application with various heat sources. Lastly, the paper presents novel applications of heat pump systems used in select industries.
    Applied Energy 12/2010; · 5.26 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Accurate and reproducible interpretation of nonalcoholic fatty liver disease (NAFLD) histology has significant clinical and research-related implications. We evaluated the impact of 2 interventions ([1] review of illustrative histologic images of NAFLD with the study pathologists; [2] use of a scoring sheet with written diagnostic criteria for different NAFLD phenotypes) on intra- and interobserver agreement on interpretation of NAFLD histology. Before and after the interventions, 2 pathologists twice read 65 liver biopsies done for evaluation of suspected NAFLD. The intra- and interobserver agreement was highest on assessment of steatosis and fibrosis. The interventions significantly improved the intraobserver agreement only on assessment of hepatocellular ballooning. The interobserver agreement was only fair on assessment of lobular inflammation, ballooning, and diagnostic classification and did not improve after the interventions. Methods to improve interobserver agreement on assessment of lobular inflammation and ballooning are needed and would likely increase pathologists' agreement on NAFLD diagnostic classification.
    Annals of diagnostic pathology 02/2011; 15(1):19-24.
  • [Show abstract] [Hide abstract]
    ABSTRACT: A heat pump is a high-efficiency energy converting system, which can combine endothermic and exothermic functions. This study used a heat pump, combining an air conditioner and a boiler, in a factory to assess the energy utilization efficiency. The result showed that when the heat pump was used the entire year, 96,824 L of fuel oil, 136,953 kW of electricity, and 2,165 m 3 of water could be saved. In addition, carbon dioxide emissions could be reduced by 386,642 kg-CO2. Investment costs could be fully recovered within 0.5 years. The system justifies an immediate investment.
    01/2011;

Full-text

Download
0 Downloads
Available from