VG

V. Gudjonsdottir

13 records found

Authored

Heat pumps can efficiently upgrade waste heat from the industry and in that way reduce emissions. One of the main reasons why heat pumps are not applied to a greater extent in industry are large payback periods. Compression–resorption heat pumps (CRHP) enhanced by wet compression ...
One of the most important steps we can take to minimize global warming is to become more energy efficient. An important example with potential for improvement is the large amount of energy wasted through waste heat streams in industry. For a long time there has already existed a ...

Heat pumps can drastically reduce energy requirements in industry. Operating a compression resorption heat pump with an NH3-CO2-H2O mixture has been identified as a promising option that can have an increased performance compared to only NH

Compression-resorption heat pumps (CRHP) utilizing wet compression are a very promising option to upgrade waste heat from industry. CRHPs have the potential to have higher coefficient of performance (COP) than the traditionally used vapour-compression heat pumps (VCHP). Howeve ...

Compression-resorption heat pumps (CRHP) enhanced by wet compression are considered a very promising option to upgrade low grade waste heat from the industry. This is especially true for applications where the heat source and/or sink have a large temperature glide. But commercial ...
This paper identifies the advantages of compression resorption heat pumps for the recovery of waste heat and its upgrading to temperatures significantly above 100 oC. Experimental work illustrates the operation of the heat rejection side of the heat pump which indicates the feasi ...
Compression resorption heat pumps (CRHP) are a promising option to upgrade waste heat from industry. Alternative working fluids can further improve the efficiency of CRHP. The ternary mixture NH3-CO2-H2O has been identified as a promising working fluid for CRHP and has the potent ...

Upgrading waste heat by compression resorption heat pumps (CRHP) has the potential to make a strong impact in industry. The efficiency of CRHP can be further improved by using alternative working fluids. In this work, the addition of carbon dioxide to aqueous ammonia solutions ...

Compression resorption heat pumps (CRHP) are a promising option to upgrade waste heat from industry. One way to optimize a CRHP is by minimizing the entropy production rate of the heat pump; that is to minimize the lost work of the system. In this paper a CRHP operating with an a ...
Couple of models have been developed to calculate thermodynamic properties of NH3-CO2-H2O systems. These models are typically an equation of state for the vapor phase and an activity coefficient model for the liquid phase (Que & Chen, 2011). The activity coefficient models can be ...

Contributed

Absorption of ammonia in an ammonia - ionic liquid solution

A detailed experimental and numerical study of the absorption process

Excessive consumption of non - renewable resources in the recent times has negative effects on the environment, one of the important of which include global warming. This suggests an urgent need for adaption to the sustainable use of the resources, for which the thermal technolog ...
Energy consumption is still growing worldwide and due to the problems of global warming, sustainable developments become of more importance. Heat pumps are one of the technologies that can contribute to energy savings of industrial processes, for example by heat recovery from was ...
The main objective of this study was to develop a quick model for an oil free twin screw compressor. The computational time of the model was to be kept as low as possible so that the model could be used for quick estimations and optimizations of the process. This was done by usin ...