Applying refrigerant mixtures with thermal glide in cold climate air-source heat pumps

2014 ◽  
Vol 62 (2) ◽  
pp. 714-722 ◽  
Author(s):  
Ali Hakkaki-Fard ◽  
Zine Aidoun ◽  
Mohamed Ouzzane
2021 ◽  
Vol 298 ◽  
pp. 126799
Author(s):  
S. Smitt ◽  
I. Tolstorebrov ◽  
P. Gullo ◽  
A. Pardiñas ◽  
A. Hafner
Keyword(s):  

MRS Bulletin ◽  
2022 ◽  
Author(s):  
Shuang Cui ◽  
Adewale Odukomaiya ◽  
Judith Vidal

Abstract Because of the complexity of modern buildings—with many interconnected materials, components, and systems—fully electrifying buildings will require targeted R&D and efficient coordination across those material, component, and system levels. Because buildings that consume the smallest amount of energy are easier to electrify, energy efficiency is a crucial step toward fully electrified buildings. Materials advances will play an important role in both reducing the energy intensity of buildings and electrifying their remaining energy use. Materials are currently being explored, discovered, synthesized, evaluated, optimized, and implemented across many building components, including solid-state lighting; dynamic windows and opaque envelopes; cold climate heat pumps; thermal energy storage; heating, ventilating, and air conditioning (HVAC); refrigeration; non-vapor compression HVAC; and more. In this article, we review the current state-of-the-art of materials for various buildings end uses and discuss R&D challenges and opportunities for both efficiency and electrification. Graphical abstract


2016 ◽  
Vol 68 ◽  
pp. 50-58 ◽  
Author(s):  
Sugirdhalakshmi Ramaraj ◽  
James E. Braun ◽  
Eckhard A. Groll ◽  
W. Travis Horton

1994 ◽  
Vol 116 (2) ◽  
pp. 148-154 ◽  
Author(s):  
M. S. Kim ◽  
W. J. Mulroy ◽  
D. A. Didion

The reduction in chlorofluorocarbon (CFC) and hydrochlorofluorocarbon (HCFC) production and the scheduled phase-out of these ozone-depleting refrigerants require the development and determination of environmentally safe refrigerants for use in heat pumps, water chillers, air conditioners, and refrigerators. This paper presents a performance evaluation of a generic heat pump with two azeotropic refrigerant mixtures of HFC-134a (1,1,1,2-tetrafluoroethane) with R-290 (propane) and R-600a (isobutane); R-290/134a (45/55 by mass percentage) and R-134a/600a (80/20 by mass percentage). The performance characteristics of the azeotropes were compared with pure CFC-12, HFC-134a, HCFC-22, and R-290 at the high temperature cooling and heating conditions including those using liquid-line/suction-line heat exchange. The coefficient of performance of R-290/134a is lower than that of HCFC-22 and R-290, and R-134a/600a shows higher coefficient of performance than CFC-12 and HFC-134a. The capacity for R-290/134a is higher than that for HCFC-22 and R-290, and R-134a/600a exhibits higher system capacity than CFC-12 and HFC-134a. Experimental results show that the discharge temperatures of the studied azeotropic mixtures are lower than those of the pure refrigerants, CFC-12 and HCFC-22.


2013 ◽  
Author(s):  
Van D Baxter ◽  
Dr. Eckhard A. Groll ◽  
Omar Abdelaziz ◽  
Bo Shen ◽  
Mr. Gerald Groff ◽  
...  

2020 ◽  
Vol 172 ◽  
pp. 16009
Author(s):  
Lowell Lingo ◽  
Kristin Lingo ◽  
Mark Bomberg

A decade ago, Geo-solar Exergy Storage Technology (GEST) was introduced as a means of utilizing natural, diurnal and seasonal transfers of exergy between a building and its surroundings to significantly decrease heating and cooling requirements. This is accomplished by retrofitting the structure with a dynamic skin to the existing building enclosure that is provided with internal conduits to carry air and fluids, for coupling geothermal storage surrounding the building with the exterior environment. This system was developed by engineers as an affordable, low-tech solution for providing seasonal heat storage in cold climate regions. Meanwhile another holistic but high-tech means to the same goal was initiated by an international group of building scientists by defining concepts for environmental quality management (EQM). Using heat pumps, ‘smart controls’, and newly developed wall coating materials, a fully integrated HVAC (plus moisture control and indoor air quality (IAQ)) system was proposed. The experience gained with GEST methods is now combined with the leading edge of Building Science to permit our international team to re-evaluate the concept of Geo-solar Exergy Storage and Dynamic Building Enclosure incorporated in a system with a heat pump as a new basis for retrofitting buildings in any climate.


2021 ◽  
pp. 51-55
Author(s):  
Pavel A. Khavanov

Energy saving in small-scale heat power engineering is directed to increasing the efficiency of using fossil energy carriers, electric power, and their wider replacement with alternative sources in housing and communal complex. The practical use of active solar energy systems, both photovoltaic and with direct water heating, has found widespread use. At the same time, the specificities of these systems deployment are caused by climatic and technical conditions of their application. For countries found in climatic zones with temperate and cold climate, water heating installations design is most rational when used seasonally. Low coolant potential, heat supply frequency in active solar energy systems, linked to seasonality of their operation, daytime and weather require several technical solutions. For example, solutions with the use of other equipment in form of thermal energy accumulators, heat pumps and other equipment, which in any case must be combined with a traditional source of thermal energy using fossil fuels or electric power, performing the functions of both other and emergency source of heat energy. Capacity reserving of alternative energy sources is most efficient and least energy-consuming when conducting with heat sources using gaseous or degasified fuel. The use of electric power for heat supply purpose, with few capital investments, requires from a developer significant installed capacities of heat source with a low efficiency for primary fuel. In the article one considers thermal schemes of autonomous heat supply installations for objects using modern condensing boilers of low power and along them various heat cumulating devices, supplying full year operation of equipment at heat supply facilities to get the highest efficiency of energy use.


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