Case study of Net Zero Energy Apartment in Shanghai

A case study regarding an apartment of net zero energy (NZEA) in Shanghai is introduced in this article. The passive design of energy efficient, solar collector system, HVAC&DHW system, indoor terminal units and renewable energy power system of the building are introduced briefly, particularly the concept of the energy system. Based on performance curves obtained from the experiment, a simulation model for the whole system is established for the evaluation. The performance of NZEA was evaluated in terms of the indoor comfort, energy balance and life cycle assessment

AMMONIA-WATER ABSORPTION CYCLE FOR TRANSPORTATION OF LOW-GRADE THERMAL ENERGY OVER LONG DISTANCE

International audienceThis paper presents the thermodynamic and hydrodynamic feasibility of the application of the ammonia-water absorption system for transportation of low-grade thermal energy over long distance. A model is built and analyzed, and it shows satisfactory and attractive results. When a steam heat source at the temperature of 1200C is available, the user site can get hot water output at about 550C with the thermal COP of about 0.6 and the electric COP of about 100 in winter, and cold water output at about 80C with the thermal COP of about 0.5 and the electric COP of 50 in summer. A small-size prototype is built to verify the performance analysis. Basically the experimental data show good accordance with the analysis results. The ammonia-water absorption system is a potential prospective solution to utilize the waste heat which locates far away

Performance testing of a cross-flow membrane-based liquid desiccant dehumidification system

A membrane-based liquid desiccant dehumidification system is one of high energy efficient dehumidification approaches, which allows heat and moisture transfers between air stream and desiccant solution without carryover problem. The system performance is investigated experimentally with calcium chloride, and the impacts of main operating parameters on dehumidification effectiveness (i.e. sensible, latent and total effectiveness) are evaluated, which include dimensionless parameters (i.e. solution to air mass flow rate ratio m∗ and number of heat transfer units NTU) and solution properties (i.e. concentration Csol and inlet temperature Tsol,in). The sensible, latent and total effectiveness reach the maximum values of 0.49, 0.55, and 0.53 respectively at m∗= 3.5 and NTU = 12, and these effectiveness are not limited by m∗ and NTU when m∗ > 2 and NTU > 10. Both the latent and total effectiveness increase with Csol , while almost no variation is observed in the sensible effectiveness. All effectiveness can be improved by decreasing Tsol,in. The experimental data provide a full map of main design parameters for the membrane-based liquid desiccant air conditioning technology

A rechargeable molecular solar thermal system below 0 °C

An optimal temperature is crucial for a broad range of applications, from chemical transformations, electronics, and human comfort, to energy production and our whole planet. Photochemical molecular thermal energy storage systems coupled with phase change behavior (MOST-PCMs) offer unique opportunities to capture energy and regulate temperature. Here, we demonstrate how a series of visible-light-responsive azopyrazoles couple MOST and PCMs to provide energy capture and release below 0 °C. The system is charged by blue light at -1 °C, and discharges energy in the form of heat under green light irradiation. High energy density (0.25 MJ kg-1) is realized through co-harvesting visible-light energy and thermal energy from the environment through phase transitions. Coatings on glass with photo-controlled transparency are prepared as a demonstration of thermal regulation. The temperature difference between the coatings and the ice cold surroundings is up to 22.7 °C during the discharging process. This study illustrates molecular design principles that pave the way for MOST-PCMs that can store natural sunlight energy and ambient heat over a wide temperature range.This work was supported by the National Key Research and Development Program of China (2017YFA0207500), National Natural Science Foundation of China (22022507 and 51973111), Beijing National Laboratory for Molecular Sciences (BNLMS202004), China Postdoctoral Science Foundation (2020M681279) and European Research Council (ERC) through CoG 101002131 “PHOTHERM”.With funding from the Spanish government through the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000917-S).Peer reviewe