heat pump Articles
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Effect of heat transfer law on the ecological optimisation of a generalised irreversible Carnot heat pump
The optimal exergy-based ecological performance of an irreversible Carnot heat pump with the losses of heat-resistance, heat leak and internal irreversibility, in which the transfer between the working fluid and the heat reservoirs obeys a generalised heat transfer law Q ∝ Δ (Tn), is derived by taking into account an ecological optimisation criterion (E) as the objective function, which ...
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Comparative performance analysis for endoreversible simple air heat pump cycles considering ecological, exergetic efficiency and heating load objectives
The performance analysis and optimisation of endoreversible simple air heat pump with constant-temperature heat reservoirs is carried out by using finite-time thermodynamics. The expressions of the heating load, the exergetic efficiency and the ecological function of the cycle are derived. The influences of the pressure ratio of the compressor and the allocation of heat exchanger inventory on the ...
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Second law based performance analysis of seawater source cascade heat pump system: a case study
This paper presents the second law based analysis of a seawater source cascade heat pump system operating with two different refrigerants. The present cascade heat pump system consists of two different heat pumps attached in such a way that the condenser of the first stage heat pump is the evaporator for the second heat pump and the condenser of the second heat pump is attached to the place to be ...
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Utilisation of air-groundwater exergy potential for improvement of the performance of heat pump systems
This paper reports a study on the use of the non-flow air-groundwater exergy potential for improving heat pump performance. It is shown that for air/groundwater temperature differences of order 15°C, energy savings up to 50% may be expected for heat pumps operating either in the heating mode or in the cooling mode. It is also shown that the reduction in the energy required to drive the heat pump ...
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Exergy analysis of a vapour-compression refrigeration/heat pump cycle with chimney
The greatest speciality of this work is using chimneys with different heights above the condenser instead of a condenser's fan on the vapour-compression refrigeration/heat pump system chosen as an experimental set. Exergy analyses of natural convection with and without chimneys and forced convection on the same experimental set have been made with acceptances of steady state-steady flow system on ...
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Exergy analysis of a counter–flow Ranque–Hilsch vortex tube having different helical vortex generators
In this study, thermodynamic analysis of a counter–flow vortex tube is made. Equations are derived for cold mass fraction (yr), entropy generation and irreversibility. Also, efficiency terms are defined based on the Carnot cycle by considering vortex tubes as both a cooling machine and a heat pump. Experiments are performed for various values of design parameters and working conditions. ...
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Exergy modelling of vapour compression heat pumps using refrigerant mixtures
Our work outlines the variation of exergy efficiency factor, COP and exergy flow related to the replacement of R22 in vapour compression heat pumps with the mixtures R407C and R410A. A mathematical model was developed to simulate the relevant thermodynamic cycles and an attempt was made for our results (efficiency and exergy losses) to be presented. Furthermore, particular attention has been ...
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Thermodynamic modelling of a water-to-water heat pump using propane as refrigerant
The aim of this paper is to develop a thermodynamic model for a water-to-water heat pump using propane as refrigerant. This model is based on the thermodynamic principals and heat transfer fundamental laws. The performances of the heat pump have been looked at as function of the water temperatures at the entry of the evaporator and the condenser. The results show that the cooling and heating COP ...
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Endoreversible thermodynamics approach for optimum oven operation
This paper refers to the problem of how much heat is necessary for oven operation. An endoreversible thermodynamics approach is used here. More accurate upper bounds for the oven heat gain factor are obtained than when the traditional reversible thermodynamics approach is used. The optimum operation temperatures and the oven heat gain factor depend on three parameters incorporating both design ...
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COP and SPF for Heat Pumps Explained
Heat pumps are powered by electricity but unlike conventional electrical heating, a heat pump is highly efficient. If you are looking into heat pumps, you’ll have come across the terms COP and SPF. Coefficient of Performance (COP) of Heat Pumps COP (Coefficient of Performance) is a measure of efficiency. The efficiency of any machine or system can be calculated as the ratio of amount of ...
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Steady versus dynamic exergy analysis: the case of an air source heat pump
Exergy analysis is often performed statically, for given system conditions and reference state. Dynamic exergy analyses, considering the variation of system operation and ambient conditions, would obviously be more time consuming. Therefore comparing the results of the two approaches helps understand when the dynamic methodology should be preferred. In this paper the yearly behaviour of a ...
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What can you get from an Inverpad Pool Heat Pump?
An inverter pool heat pump powered by InverPad technology has multiple advantages with a backward airflow system, Stepless-DC-Inverter, and a unique pad appearance. Let’s see what you can get from an InverPad pool heat pump. ...
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Improvement of regenerative Rankine cycle using absorption heat boosters
In the present work, a new technique is proposed for feedwater heating in Low Pressure (LP) turbine section of regenerative Rankine cycle. Main objective of this technique is to minimise exergy destruction in feedwater heating. The proposed technique comprised of using absorption heat boosters i.e. Absorption Heat Pump (AHP) and Absorption Heat Transformer (AHT) with LiBr–water as the working ...
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Diffusion of innovative heating systems in detached homes in Sweden
The Swedish homeowners' perception of Innovative Heating Systems (IHSs) was studied through a questionnaire survey. Most of the respondents were satisfied with their existing heating systems and were not planning to install a new one. They considered economic factors and functional reliability the most important factors in the choice of a heating system. Hence, economic policy instruments appear ...
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Technical and economic analysis of gas-engine driven heat pump in China
In this paper, the primary energy ratio and economic benefit of five different heating systems are analysed. The results show that the gas-engine heat pump system has the advantages of high primary energy efficiency and favours environmental protection in contrast to the other four heating systems. At the same time, to improve the economic benefit of the energy saving and environmental protection ...
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Environmental thermodynamic limitations on global human population
This paper examines, from a thermodynamic point of view, how many people the Earth can support. The maximum human population allowed by the natural earth ranges from 300 million millions to 1,700 million millions and will not exceed 1,300 million millions if an ambient temperature of 300 K is accepted. A further increase in population number is obtained for macro-engineered earth when heat pumps ...
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Size considerations in applications of exergy analysis
Considerations related to size of application of exergy analysis are examined. Six size categories are considered: sub-device, device, simple system, complex system, macro system, and planetary-scale system. The boundaries between categories are not sharp. It is concluded that many systems investigated with exergy analysis exhibit size-related trends regarding how exergy analysis is performed, ...
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Thermodynamic analysis and assessment of space heating with ground–source heat pump for sustainable future
In this paper, the thermodynamic modelling of exergy loss, exergy efficiency, exergy destruction rate, environmental destruction coefficient, improvement potential, exergy destruction factor, relative irreversibility, productivity lack and exergetic factor of ground source heat pump (GSHP) system are investigated. The results show that these exergy indexes should be used integratively. Compressor ...
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Will your home benefit from ASHP?
We have all seen the shocking headlines about the rising cost in energy prices, and with the energy price cap se to rise again this autumn, it is no surprise that more and more people are looking for ways in which they can heat their homes more efficiently. One solution which many people are turning to is the installation of air source heat pumps. They provide huge amounts of efficiency and can ...
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Do Air Source Heat Pumps Work in the UK?
The simple answer to this question is probably, yes, air source heat pumps do work in the UK. It might be more accurate, however, to say that air source heat pumps can work in the UK. It turns out that not all heat pump installations are equal. Air source heat pumps absorb heat from air outside and deliver heat inside the building via underfloor heating, radiators, convectors etc. You can think ...
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