Magnetic heat pumps – Configurable hydraulic distribution for a magnetic cooling system

2014 ◽  
Vol 37 ◽  
pp. 165-175 ◽  
Author(s):  
J.M. Gatti ◽  
C. Muller ◽  
C. Vasile ◽  
G. Brumpter ◽  
P. Haegel ◽  
...  
Energies ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 5119
Author(s):  
Tomasz Sliwa ◽  
Tomasz Kowalski ◽  
Dominik Cekus ◽  
Aneta Sapińska-Śliwa

Currently, renewable energy is increasingly important in the energy sector. One of the so-called renewable energy sources is geothermal energy. The most popular solution implemented by both small and large customers is the consumption of low-temperature geothermal energy using borehole heat exchanger (BHE) systems assisted by geothermal heat pumps. Such an installation can operate regardless of geological conditions, which makes it extremely universal. Borehole heat exchangers are the most important elements of this system, as their design determines the efficiency of the entire heating or heating-and-cooling system. Filling/sealing slurry is amongst the crucial structural elements. In borehole exchangers, reaching the highest possible thermal conductivity of the cement slurry endeavors to improve heat transfer between the rock mass and the heat carrier. The article presents a proposed design for such a sealing slurry. Powdered magnesium was used as an additive to the cement. The approximate cost of powdered magnesium is PLN 70–90 per kg (EUR 15–20/kg). Six different slurry formulations were tested. Magnesium flakes were used in designs A, B, C, and magnesium shavings in D, E and F. The samples differed in the powdered magnesium content BWOC (by weight of cement). The parameters of fresh and hardened sealing slurries were tested, focusing mainly on the thermal conductivity parameter. The highest thermal conductivity values were obtained in design C with the 45% addition of magnesium flakes BWOC.


2000 ◽  
Author(s):  
Jens Møller Andersen

Abstract Heat integration with absorption heat pumps requires investigation of many types of plant designs. In this article, it is concluded that in many cases high temperature absorption systems for heat recovery are more economically feasible than absorption systems for cooling purposes. The conclusion is based on a project where the scope was to investigate technical and economical possibilities for heat integration of an absorption heat pump in a milk powder plant. The first idea behind the project was to use the waste heat from the rejected air to drive an absorption cooling system to reduce the electricity consumption for cooling proposes. The model of the plant was based on simulations as a background for a time averaged COP model. It was concluded that an absorption system for generating low temperature steam is more feasible.


2005 ◽  
Vol 128 (1) ◽  
pp. 28-34 ◽  
Author(s):  
Onder Ozgener ◽  
Arif Hepbasli

The main objective in doing the present study is twofold, namely (i) to review briefly the utilization of geothermally heated greenhouses and geothermal heat pumps in Turkey, since the system studied utilizes both renewable energy resources and (ii) to present the Analytical Hierarchy Process (AHP) as a potential decision making method for use in a greenhouse integrated solar assisted geothermal heat pump system (GISAGHPS), which was installed in the Solar Energy Institute of Ege University, Izmir, Turkey. This investigation may also be regarded as the one of the limited studies on the application of the AHP method to GISAGHPs, as no studies on the GISAGHPS have appeared in the literature. In this context, an economic analysis is performed based on the life cycle costing technique first. The results are then evaluated by applying the AHP method to a study, which is a comparative study on the GISAGHPS and split system. The results indicated that the GISAGHPS is economically preferable to the conventional split heating/cooling system under Turkey’s conditions.


2013 ◽  
Vol 38 (3) ◽  
pp. 25-30
Author(s):  
Antonio Frattari

CasaZeroEnergy is the prototype for a building that does not use energy produced from non-renewable sources, but produces its require energy by using alternative energetic systems. Designed according to the principles of bioclimatic architecture, the building was integrated with passive systems for optimizing the site's climatic conditions for heating in winter and for cooling and ventilation in summer. The house was constructed with natural, renewable, recycled and recyclable materials. For this reason it can be classified as a “natural building”. Its main feature is the integration between the building and the alternative systems in order to produce energy from renewable sources: sunspace, solar collectors, photovoltaic panels, a geothermal system and a pellet boiler system. Home automation manages all the mechanical systems to ensure comfort and reduced energy consumption at the same time. The sunspace is a passive solar system used mainly for heating indoor spaces during the winter season. The building's cooling system is based on natural ventilation strategies and on geothermal heat pumps. The building is provided with shading systems. A smart system was devised to guarantee user safety and security. This kind of system can be controlled remotely and provides constant security for the building.


2003 ◽  
Vol 21 (1) ◽  
pp. 1-8 ◽  
Author(s):  
B. Buczek ◽  
L. Czepirski ◽  
E. Komorowska-Czepirska

Of the various gas/solid adsorption processes, the adsorption of methanol on active carbon seems to be most interesting for use in thermodynamic systems such as heat pumps and transformers, as well as in cooling systems. The porous structures of two series of active carbons modified by the successive removal of the external layers from the particle surface, one by abrasion in a spouted bed and the other by subsequent demineralization of the abraded particles, were evaluated on the basis of nitrogen and methanol adsorption data. The porous structure parameters for these two sorbate series agreed reasonably well and allowed the D–R approach to be usefully applied for the characterization of these systems. The methods for calculating the heat effects associated with methanol adsorption over wide ranges of temperature and pressure are discussed.


2014 ◽  
Vol 899 ◽  
pp. 36-41 ◽  
Author(s):  
Dušan Petráš ◽  
Michal Krajčík ◽  
Jozef Bugáň ◽  
Emília Ďurišová

Energy performance and indoor environment were investigated in two modern office buildings equipped by a low temperature heating and high temperature cooling system. Both buildings have the facade made of glass. In the first building, radiant panels are suspended under the ceiling in order to create comfortable conditions, natural gas boilers are the installed in order to generate heat and chillers are used to generate cool. The second building has heat pumps installed to provide the building with heat/cool and capillary pipes are embedded in the plaster on the ceiling surface to emit the heat/cool into the occupied space. The energy performance was calculated in accordance with the set of CEN standards for energy certification and is presented in the form of energy certificates. Thermal comfort and indoor air quality were experimentally studied by long-term and short-term measurements and through questionnaires filled in by the occupants themselves. The study has shown that the low temperature heating/high temperature cooling system has the potential to create a comfortable indoor environment at low energy consumption, but the ability of the heating/cooling systems to do so is closely related to the appropriate control of the systems.


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