Modeling of a Heat Pump With Evaporator Air Dehumidification for Reduced Frost Formation

1999 ◽  
Vol 121 (3) ◽  
pp. 189-195 ◽  
Author(s):  
J. Marti´nez-Fri´as ◽  
S. M. Aceves
Keyword(s):  
Energy Consumption ◽  
Heat Pump ◽  
Energy Savings ◽  
Ambient Air ◽  
Operating Conditions ◽  
Energetic Cost ◽  
Time Intervals ◽  
Frost Formation ◽  
Reduce Energy Consumption

This paper presents an analysis of a heat pump that uses a solid desiccant dehumidifier to reduce the humidity of the ambient air that flows into the evaporator, with the purpose of decreasing frost formation on the evaporator. The heat pump is analyzed by adding a dehumidifier model to a previously developed heat pump model that includes frost formation. The dehumidifier reduces the amount of energy required for evaporator defrosting, but introduces the need for energy for regenerating the desiccant. The purpose of the analysis is to search for operating conditions and optimum dehumidifier designs for which the use of the dehumidifier results in energy savings. The results show that the use of a dehumidifier may reduce energy consumption if the energetic cost of defrosting the evaporator is high. Other benefits of dehumidification include an increase of the time intervals between defrost cycles, a better stability in the conditions in the controlled space, and the potential for increased reliability and reduced maintenance of the heat pump.

Saving Primary Energy Consumption Through Exergy Analysis of Combine Distillation and Power Plant

2012 ◽  
Vol 9 (2) ◽  
pp. 65
Author(s):  
Alhassan Salami Tijani ◽  
Nazri Mohammed ◽  
Werner Witt
Keyword(s):  
Energy Consumption ◽  
Power Plant ◽  
Heat Pump ◽  
Heat Recovery ◽  
Energy Savings ◽  
Primary Energy ◽  
Heat Pumps ◽  
Saturated Steam ◽  
Distillation Unit ◽  
Primary Energy Consumption

Industrial heat pumps are heat-recovery systems that allow the temperature ofwaste-heat stream to be increased to a higher, more efficient temperature. Consequently, heat pumps can improve energy efficiency in industrial processes as well as energy savings when conventional passive-heat recovery is not possible. In this paper, possible ways of saving energy in the chemical industry are considered, the objective is to reduce the primary energy (such as coal) consumption of power plant. Particularly the thermodynamic analyses ofintegrating backpressure turbine ofa power plant with distillation units have been considered. Some practical examples such as conventional distillation unit and heat pump are used as a means of reducing primary energy consumption with tangible indications of energy savings. The heat pump distillation is operated via electrical power from the power plant. The exergy efficiency ofthe primary fuel is calculated for different operating range ofthe heat pump distillation. This is then compared with a conventional distillation unit that depends on saturated steam from a power plant as the source of energy. The results obtained show that heat pump distillation is an economic way to save energy if the temperaturedifference between the overhead and the bottom is small. Based on the result, the energy saved by the application of a heat pump distillation is improved compared to conventional distillation unit.

scholarly journals Estimated potential for energy savings in heating residential buildings in Poland

2018 ◽  
Vol 49 ◽  
pp. 00068 ◽  
Author(s):  
Piotr Lis
Keyword(s):  
Energy Consumption ◽  
Energy Savings ◽  
Residential Buildings ◽  
Dominant Role ◽  
Ventilation System ◽  
Energy Effect ◽  
Central Statistical ◽  
The Face ◽  
Central Statistical Office ◽  
Reduce Energy Consumption

In the face of a constant increase in demand for energy, one of the important sources will be its saving and efficient use. The search for the greatest opportunities in this area should focus on the areas where the highest energy consumption occurs. The dominant role here is played by the communal and living sector, to the extent that it is the sub-sector of buildings with a majority share of residential buildings. The article presents the expected energy effects of measures reducing energy consumption for heating residential buildings in the whole country. The author used statistical data of the Central Statistical Office available in the database of this institution. These data were identified and searched for as suitable for the purposes of this article and were used as a basis for calculations and analyses. The calculations show that only thanks to simple actions such as improvement of thermal insulation of envelope components it is possible to reduce energy consumption for heating of residential buildings by over 70% in relation to the situation in 2011. The potential energy effect will also translate into an economic and environmental effect. Qualitative measures such as improving the performance of the heating and ventilation system of a building and/or changing the energy carrier will also reduce energy consumption for this purpose, but they are not the subject of this study.

scholarly journals An exploration of load-shifting potential in real in-situ heat-pump/gas-boiler hybrid systems

2017 ◽  
Vol 38 (4) ◽  
pp. 450-460 ◽  
Author(s):  
Anne Stafford
Keyword(s):  
Energy Consumption ◽  
Heat Pump ◽  
Significant Proportion ◽  
Electricity Consumption ◽  
Operating Conditions ◽  
Heat Output ◽  
Electrical Load ◽  
Additional Energy ◽  
Operational Conditions ◽  
Smart Systems

Monitoring data from two hybrid air-source heat-pump/gas-boiler systems were used to explore the systems’ potential for energy flexibility, i.e. the potential for shifting electrical load in response to grid requirements while maintaining acceptable performance in the overall hybrid system. In both cases, a significant proportion of the heat-pump load could potentially be shifted to the gas boiler with only a modest increase in the overall energy consumption, provided certain operational conditions were met. Furthermore, under these operational conditions, it is possible to estimate this additional energy consumption for a given system from simple heat output, and gas and electricity consumption data. This provides a potential basis for groups of similar systems equipped with smart technology to offer flexibility to the grid, while minimising the resulting energy penalty by choosing to use the most appropriate systems at any given time with respect to their operating conditions at that time. In addition, this type of flexibility means that the thermal comfort within the dwelling remains unaffected since overall heating requirement is met at all times by one of the two heating sub-systems. Practical application: The ability to shift or shed electrical load in response to grid requirements is likely to become a significant, commercially incentivised aspect of building energy systems in the future, to mitigate the stress on electrical grids at times of peak consumption. For domestic systems, aggregation will be a key factor, requiring ‘smart’ systems to provide real-time information to potential aggregators or grid operators. This article explores what type of system information may be necessary in the case of hybrid heat-pump/gas-boiler systems if loads are to be shifted from the heat-pump to the gas-boiler element, while minimising the resulting energy penalties.

Energy-Saving Characteristics of Benzene-Toluene Mixtures in Heat Pump Distillation Column

2012 ◽  
Vol 455-456 ◽  
pp. 630-634
Author(s):  
Zheng Ming Tong ◽  
Chao Li ◽  
Jia Lei Lu ◽  
Kai Zhu
Keyword(s):  
Energy Saving ◽  
Heat Pump ◽  
Distillation Column ◽  
Energy Savings ◽  
Operating Conditions ◽  
Material System ◽  
Industrial Energy ◽  
Energy Consuming ◽  
Benzene Toluene ◽  
Consuming Country

China is a big industrial energy consuming country. The largest proportion of energy consuming is the operations of separation in chemical industry, and the energy consumption of the distillation is the highest in separation. Therefore, it is very important to research energy-saving issues of the process of distillation in today's circumstances of the energy shortage. This article describes the model of heat pump distillation column,and its characteristics, uses static simulation programs to simulate operating conditions in the atmospheric pressure for the benzene-toluene material system, and studys effects of the different feed states on the energy-saving of heat pump distillation column. The results will be compared with the conventional distillation column, and it was showed that for benzene-toluene system, the heat pump distillation column is more remarkable than the conventional distillation column in energy savings, and its energy saving rate can reach 46%.

scholarly journals The Strategy of Implementing Energy Efficiency Standards and Labels for Domestic Air Conditioners in Libya

2019 ◽  
Vol 8 (1) ◽  
Author(s):  
Salah M Alabani ◽  
Ibrahim H Tawil
Keyword(s):  
Energy Efficiency ◽  
Energy Consumption ◽  
Energy Savings ◽  
Residential Buildings ◽  
Total Energy Consumption ◽  
Air Conditioners ◽  
Improve Energy Efficiency ◽  
Reduce Energy Consumption ◽  
Two Stages ◽  
Energy Efficiency Standards

The residential sector in Libya has grown over the past decade in the construction of residential buildings due to the increase in the population. Moreover, the increase in the level of income has contributed to the increase in the purchase of household appliances, which leads to increased demand for energy. Energy consumption in the household sector accounted for 31% of total energy consumption during 2010, and the share of air conditioners in this sector consumed 18.35%. To reduce energy consumption and improve energy efficiency in this sector, policies should be considered to apply energy efficiency standards and markers to household electrical appliances, as they are considered one of the most successful programs used in the world. Countries are implementing such programs to reduce energy consumption in the domestic sector. This paper presents the possibility of implementing such programs to introduce the importance of energy efficiency standards and labeling programs for home appliances in Libya. The calculations required to design such programs show the energy savings that can be achieved during cooling loads in the summer period of 4 months July, August, September). A strategic plan has been developed during 10-year (2020-2030) to estimate the expected savings of energy consumed and to identify possible obstacles and difficulties by gradually increasing the energy efficiency ratio for comestic air conditioners in two stages, from EER10 to EER11 in the first stage is then raised to EER12 as the second stage.

scholarly journals The impact of building envelope retrofit measures on postwar MURBS in Toronto

2021 ◽  
Author(s):  
Sara Damyar
Keyword(s):  
Energy Consumption ◽  
Energy Saving ◽  
Energy Use ◽  
Energy Savings ◽  
Building Envelope ◽  
Simulation Software ◽  
Energy Simulation ◽  
Reduce Energy Consumption ◽  
The Impact ◽  
Current Standards

Building envelope retrofits is one of the options available to reduce energy consumption of postwar MURBs in Toronto. This study evaluates the impact of building envelope retrofits that meet current standards on energy consumption of a Toronto postwar MURB; utilizing eQUEST energy simulation software. Further upgrades also take place to evaluate how the impact of building envelope retrofits on energy use can be increased and optimized for all assemblies of building envelope and airtightness. Moreover, the retrofit strategies are ranked based on cost and energy-saving effectiveness. The results of the analysis reveal that building envelope retrofit based on OBC-2012 standards can reduce the energy consumption by up to 44%. Furthermore, the optimal RSI values of all building envelope components were found to be equal or less than code requirements which outcomes significant energy savings. Lastly, the ranking of the strategies helps to identify the best option according to the priorities of a project.

Saving Primary Energy Consumption Through Exergy Analysis of Combine Distillation and Power Plant

2012 ◽  
Vol 9 (2) ◽  
pp. 65
Author(s):  
Alhassan Salami Tijani ◽  
Nazri Mohammed ◽  
Werner Witt
Keyword(s):  
Energy Consumption ◽  
Power Plant ◽  
Heat Pump ◽  
Heat Recovery ◽  
Energy Savings ◽  
Primary Energy ◽  
Heat Pumps ◽  
Saturated Steam ◽  
Distillation Unit ◽  
Primary Energy Consumption

Industrial heat pumps are heat-recovery systems that allow the temperature of waste-heat stream to be increased to a higher, more efficient temperature. Consequently, heat pumps can improve energy efficiency in industrial processes as well as energy savings when conventional passive-heat recovery is not possible. In this paper, possible ways of saving energy in the chemical industry are considered, the objective is to reduce the primary energy (such as coal) consumption of power plant. Particularly the thermodynamic analyses of integrating backpressure turbine of a power plant with distillation units have been considered. Some practical examples such as conventional distillation unit and heat pump are used as a means of reducing primary energy consumption with tangible indications of energy savings. The heat pump distillation is operated via electrical power from the power plant. The exergy efficiency of the primary fuel is calculated for different operating range of the heat pump distillation. This is then compared with a conventional distillation unit that depends on saturated steam from a power plant as the source of energy. The results obtained show that heat pump distillation is an economic way to save energy if the temperature difference between the overhead and the bottom is small. Based on the result, the energy saved by the application of a heat pump distillation is improved compared to conventional distillation unit. 

Energy Saving in a Heat Pump Air-Conditioning System Using Liquid Desiccant and Membrane Contactors

2011 ◽  
Author(s):  
Stefano Bergero ◽  
Anna Chiari
Keyword(s):  
Energy Saving ◽  
Heat Pump ◽  
Hybrid System ◽  
Air Conditioning ◽  
Energy Savings ◽  
Climatic Conditions ◽  
Operating Conditions ◽  
Membrane Contactor ◽  
Traditional System ◽  
Vapour Compression

It has been demonstrated in the literature that significant energy savings can be achieved in air-conditioning through the use of so-called hybrid systems, in which a chemical dehumidification system is combined with a vapour-compression heat pump. The advantage of such systems lies in the fact that the heat pump can operate at a higher evaporation temperature than that of a traditional system in which dehumidification is achieved through condensation, thereby achieving higher coefficients of performance. The hybrid system described in the present paper operates as follows: the air supplied to the conditioned ambient is simultaneously cooled and dehumidified in an air-solution membrane contactor. The LiCl solution is cooled by means of a vapour-compression heat pump using the refrigerant KLEA 410A. The solution is regenerated in another membrane contactor by exploiting the exhaust air and the heat rejected by the condenser. A study of the steady-state behaviour of the system in summer climatic conditions was carried out, on varying some significant operating parameters, such as the thermal efficiency of the heat exchangers, the outdoor temperature and the sensible load of the conditioned room. The performances of the hybrid system were compared with those of a traditional direct-expansion air-conditioning plant; the results of the simulations reveal that, in particular operating conditions, energy saving can exceed 50%.

scholarly journals Numerical Analysis and Preliminary Experiment of a Solar Assisted Heat Pump Drying System for Chinese Wolfberry

Energies ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 4306 ◽  
Author(s):  
Zhongting Hu ◽  
Sheng Zhang ◽  
Wenfeng Chu ◽  
Wei He ◽  
Cairui Yu ◽  
...  
Keyword(s):  
Energy Consumption ◽  
Heat Pump ◽  
Electric Energy ◽  
Energy Performance ◽  
Operating Conditions ◽  
Pump System ◽  
Heat Pump System ◽  
Electric Energy Consumption ◽  
Drying System ◽  
Heat Pump Drying

The present work investigated a solar assisted heat pump system for drying Chinese wolfberry. The kinetic characteristic was firstly analyzed through a series of lab experiments. It was concluded that the Page model was the most suitable for predicting the heat and mass transfer of the wolfberry. Based on the wolfberry kinetic model, solar collector model and chamber air model, the coupled drying system model was developed. The accuracy of the mathematic model was determined through comparing with the preliminary experimental results. The influence of operating conditions on the thermal and energy performance of the dryer for the different operating mode was discussed. The drying weight of no more than 75 kg may be preferable in the stand-alone solar drying mode, and less than 15 h was needed to be dried. The electric energy consumption in the solar assisted the heat pump drying mode was lower than that in the stand-alone heat pump mode, and it was recommended that about 50 kg of wolfberry to be dried in the solar assisted heat pump system. Compared to the autumn drying, the reduction in the electric energy consumption was around 9.1 kWh during the 11 h summer drying process. The obtained results demonstrated the feasibility of the combined system for drying wolfberry, and also can provide the basic theoretical and experimental data support for the following research.

scholarly journals “Big, Medium, Little”: Reaching Energy Proportionality with Heterogeneous Computing Scheduler

2015 ◽  
Vol 25 (03) ◽  
pp. 1541006 ◽  
Author(s):  
Violaine Villebonnet ◽  
Georges Da Costa ◽  
Laurent Lefevre ◽  
Jean-Marc Pierson ◽  
Patricia Stolf
Keyword(s):  
Energy Consumption ◽  
Power Consumption ◽  
Heterogeneous Computing ◽  
Energy Savings ◽  
Processing Variable ◽  
Computing Power ◽  
High Part ◽  
Heterogeneous Architectures ◽  
Energy Proportionality ◽  
Reduce Energy Consumption

Energy savings are among the most important topics concerning Cloud and HPC infrastructures nowadays. Servers consume a large amount of energy, even when their computing power is not fully utilized. These static costs represent quite a concern, mostly because many datacenter managers are over-provisioning their infrastructures compared to the actual needs. This results in a high part of wasted power consumption. In this paper, we proposed the BML (“Big, Medium, Little”) infrastructure, composed of heterogeneous architectures, and a scheduling framework dealing with energy proportionality. We introduce heterogeneous power processors inside datacenters as a way to reduce energy consumption when processing variable workloads. Our framework brings an intelligent utilization of the infrastructure by dynamically executing applications on the architecture that suits their needs, while minimizing energy consumption. In this paper we focus on distributed stateless web servers scenario and we analyze the energy savings achieved through energy proportionality.

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