Investigation and determination of the geothermal parameters of the ground in Cyprus for the exploitation of geothermal energy and the impact of the results in the design of the geothermal systems

The Energy Service of the Ministry of Commerce, Industry and Tourism has the overall responsibility for Energy matters in Cyprus and specifically for preparing and implementing programmes for energy conservation, the promotion of renewable energy sources (RES) and the development of technologies for the utilization of RES. The Government of Cyprus being aware of the benefits of geothermal energy and in order to increase the share of energy from renewable sources consumed in heating and cooling in 2020, promotes the geothermal energy systems through a Scheme that provides financial incentives for the utilization of RES for heating and cooling. However, the lack of valid data for the ground thermal properties in Cyprus was one of the main obstacles for the design of efficient geothermal systems, the implementation of the Schemes in the field of geothermal energy and the calculation of the share of energy from renewable sources for heating and cooling according to the methodology defined by the E.U in the directive 2009/28/EC. In an effort to identify suitable energy efficient systems for heating and cooling of buildings and the correct calculations of their contribution to the national targets, the Energy Service participated in a project founded by the Research Promotion Foundation of Cyprus to investigate and determine the geothermal parameters of the ground of Cyprus at six representative sites in Cyprus, for use in the design of ground heat exchanger applications and ground thermal storage. The paper presents the importance of the Isothermal map that helps consultants to design efficiently geothermal energy systems, calculate effectively heat losses of buildings to the ground and design the thermal energy storage equipment. The importance’s of the results are analyzed by national authorities’ experts’ point of view for evaluating geothermal applications bridging in this way the gap between technical output and commercial reality

Processing acoustic emission signal data for characterising cutting tool wear and chip management

The paper is concerned with monitoring tool wear using Acoustic Emission (A. E. ) sensors. The sensitivity of A. E. to chip form is substantiated. It is shown that strain rate is a predominant parameter governing A. E. activity in metal cutting. The semi-empirical cutting theory due to Oxley and Hastings successfully predicts trends in the A. E. r. m. s. signal for a variety of semi-orthogonal cutting conditions and offers potential for development of a computer based tool wear monitoring system

Retraction notice to “Reviewing the effect of CO2 and the sun on global climate” [Renew. Sustain. Energy Rev., 26(2013) 639–651]

This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). This article has been retracted at the request of the Editor-in-Chief due to duplicate publication based on parts of the authors’ own book chapter ‘Global Warming: CO2 vs Sun,’ by Georgios Florides, Paul Christodoulides and Vassilios Messaritis, published: September 27th 2010, DOI: 10.5772/10283. One of the conditions of submission of a paper for publication is that authors declare explicitly that their work is original and has not appeared in a publication elsewhere. Re-use of any data should be appropriately cited. As such this article represents a severe abuse of the scientific publishing system. The scientific community takes a very strong view on this matter and apologies are offered to readers of the journal that this was not detected during the submission process

Reviewing the effect of CO2 and the sun on global climate

This paper discusses the effect of the greenhouse phenomenon and CO2 on global climate and suggests that numerical models that lack adequate knowledge of fundamental related factors cannot be used to extract “sound” conclusions. A very basic demonstration of this is done through a simple comparison between estimates of the forecast for global temperature increase obtained by various independent studies. Observing the global temperature and the CO2 atmospheric concentration though the geological aeons implies no obvious correlation. Physical observation on other planets like Mars and Venus, needing no numerical modeling, demonstrates the effect of the atmospheric-CO2 partial pressure on the temperature of the atmosphere. Moreover the CO2 role as a factor of danger or a benefactor for life is also addressed. On the other hand the role of the sun in the presently observed global warming has been greatly underestimated. Scientific evidence shows that the orbit of the earth and the Milankovitch cycles greatly affect the climate. A discussion follows pointing out the prime role that the sun should have on the earth's climate with regard to solar cycles’ activity and irradiance, cosmic rays and cloud formation. The conclusion drawn here is that a natural signal of solar forcing has been mistakenly overlooked for an anthropogenic change, maybe owing to their quite similar effects on climate. For the moment science does not really have a complete and total understanding of the factors affecting the earth's complex climate system and therefore no sound conclusions can be drawn

Testing of a ground coupled heat pump

A Ground Coupled Heat Pump (GCHP) exploits the ground thermal capacity and the difference in temperature between ambient air and ground with the aid of Ground Heat Exchangers (GHE) for improving its efficiency. The main interest of this study is to determine the efficiency of a ground coupled heat pump used for the acclimatization of a typical office in the Athalassa region, Nicosia, Cyprus and investigate how its efficiency is affected by the operating conditions. The data collection was done in October, 2008 and January, 2009. In summer the results clearly indicate that there is a significant improvement in the sensible capacity over the input power ratio from about 2 to 2.52 when the cooling temperature of the condenser drops from 36.5°C to 22.4°C. In winter, the COP of the pump is 3.6 when the temperature of the evaporator is about 22°C. Significant savings in power can result when GCHPs are used instead of the air-cooled systems

Testing of a ground coupled heat pump

A Ground Coupled Heat Pump (GCHP) exploits the ground thermal capacity and the difference in temperature between ambient air and ground with the aid of Ground Heat Exchangers (GHE) for improving its efficiency. The main interest of this study is to determine the efficiency of a ground coupled heat pump used for the acclimatization of a typical office in the Athalassa region, Nicosia, Cyprus and investigate how its efficiency is affected by the operating conditions. The data collection was done in October, 2008 and January, 2009. In summer the results clearly indicate that there is a significant improvement in the sensible capacity over the input power ratio from about 2 to 2.52 when the cooling temperature of the condenser drops from 36.5°C to 22.4°C. In winter, the COP of the pump is 3.6 when the temperature of the evaporator is about 22°C. Significant savings in power can result when GCHPs are used instead of the air-cooled systems

Performance investigation of a Ground Source Heat Pump system for space heating and cooling of a typical house in moderate climates

Air Source Heat Pumps (ASHPs) are commonly used for the air-conditioning of buildings. They practically use the atmosphere as a heat source/sink to absorb/reject heat. A Renewable Energy System (RES) that exploits the ground to absorb/reject heat from the building is called Shallow Geothermal Energy System (SGES). The ground temperature is always lower in the summer and higher in winter compared to atmospheric air temperature. In such systems, the usual tool are Ground Source Heat Pumps (GSHPs) that are employed to further increase the heat pump efficiency and reduce the required electricity. The evolution of the SGEs has led to competition with the ASHPs and the manufacturing of custom designed inverter technology ducted series HPs. It has also initiated the debate whether it is economically feasible to install GHEs as an alternative to the custom designed HP. This study presents such a case with the introduction of a typical house in moderate climate (Cyprus weather conditions) by using an experimentally validated Computational Fluid Dynamics model. Different water inlet temperatures are examined for both summer and winter. The system efficiency is discussed in relation to the power rejected to the ground and the length of the GHE. Finally, a system cost analysis is presented for different length GHEs and a comparison of the total energy savings is obtained. The GSHP systems, although providing a sustainable and higher performance when compared to custom designed ASHPs, are proven to still fail to be a viable investment