Heat pump assisted distillation. IV: An experimental comparison of R114 and R11 as the working fluid in an external heat pump

1987 ◽  
Vol 11 (1) ◽  
pp. 21-33 ◽  
Author(s):  
S. Supranto ◽  
R. Jaganathan ◽  
S. Dodda ◽  
P. J. Diggory ◽  
F. A. Holland
Keyword(s):  
Heat Pump ◽  
External Heat ◽  
Experimental Comparison ◽  
Working Fluid

An experimental evaluation of R11 as a heat pump working fluid in comparison with some other working fluids

1983 ◽  
Vol 7 (2) ◽  
pp. 129-135
Author(s):  
S. E. Ogbeide ◽  
S. A. K. El-Meniawy ◽  
S. Devotta ◽  
F. A. Watson ◽  
F. A. Holland
Keyword(s):  
Heat Pump ◽  
Experimental Evaluation ◽  
Working Fluid ◽  
Working Fluids

scholarly journals Performance Research on Heat Pump Using Blends of R744 with Eco-friendly Working Fluid

2017 ◽  
Vol 205 ◽  
pp. 2297-2302 ◽  
Author(s):  
Xianping Zhang ◽  
Fang Wang ◽  
Zhiming Liu ◽  
Junjie Gu ◽  
Feiyu Zhu ◽  
...  
Keyword(s):  
Heat Pump ◽  
Working Fluid ◽  
Performance Research

Performance Evaluation of a Vertical U-Tube Ground Heat Exchanger Using a Numerical Simulation Approach

2013 ◽  
Vol 724-725 ◽  
pp. 909-915
Author(s):  
Ping Fang Hu ◽  
Zhong Yi Yu ◽  
Fei Lei ◽  
Na Zhu ◽  
Qi Ming Sun ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Performance Evaluation ◽  
Heat Exchanger ◽  
Heat Pump ◽  
Heat Transfer Process ◽  
Working Fluid ◽  
Outlet Temperature ◽  
Ground Heat Exchanger ◽  
Ground Source Heat Pump ◽  
Ground Source

A vertical U-tube ground heat exchanger can be utilized to exchange heat with the soil in ground source heat pump systems. The outlet temperature of the working fluid through the U-tube not only accounts for heat transfer capacity of a ground heat exchanger, but also greatly affects the operational efficiency of heat pump units, which is an important characteristic parameter of heat transfer process. It is quantified by defining a thermal effectiveness coefficient. The performance evaluation is performed with a three dimensional numerical model using a finite volume technique. A dynamic simulation was conducted to analyze the thermal effectiveness as a function of soil thermal properties, backfill material properties, separation distance between the two tube legs, borehole depth and flow velocity of the working fluid. The influence of important characteristic parameters on the heat transfer performance of vertical U-tube ground heat exchangers is investigated, which may provide the references for the design of ground source heat pump systems in practice.

scholarly journals Heat Pump Cycle Efficiency for Heat Supply

2020 ◽  
pp. 136-142
Author(s):  
Mykola Bosiy ◽  
◽  
Olexandr Kuzyk ◽  
Keyword(s):  
Heat Pump ◽  
Heat Supply ◽  
Exergy Analysis ◽  
Conversion Factor ◽  
Working Fluid ◽  
Heating Systems ◽  
Energy And Exergy ◽  
Energy And Exergy Analysis ◽  
Heat Supply Systems ◽  
Supply Systems

The aim of the article is to analyze the literature and scientific publications on the effectiveness of the heat pump in heat supply systems and to study the efficiency of using the steam compression cycle of a heat pump in a heat supply system. Тo conduct energy and exergy analysis of heat pump efficiency indicators, the working fluid of which is freon R134a, when using natural waters as a source of low-potential thermal energy. The article analyzes the literature sources and scientific publications on the effectiveness of the heat pump in heat supply systems. The results of research of efficiency of application of the heat pump in systems of heat supply at use of natural waters as a source of low-potential thermal energy are presented. Energy and exergy analysis of heat pump efficiency indicators, the working fluid of which is R134a freon, was performed. The energy efficiency of the heat pump cycle was determined by the conversion factor of the heat pump. The thermodynamic efficiency of the heat pump in heat supply systems was evaluated using exergetic efficiency, which is one of the main indicators of the efficiency of heat pump processes and cycles. The calculation of energy indicators of the heat pump, such as: specific heat load in the evaporator and condenser, as well as the conversion factor of the heat pump. The calculation of exergetic efficiency for ambient temperature from +10 to -10 ºC. Thus, the energy and exergy analysis of the efficiency of the heat pump, the working fluid of which is Freon R134a with a conversion factor = 4.8. This indicates that the heat pump is a reliable, highly efficient, environmentally friendly source of energy for use in heating systems. A heat pump heating system will always consume less primary energy than traditional heating systems if natural water is used as a low-temperature heat source for the heat pump. The efficiency of the steam compression cycle of the heat pump largely depends on the temperature of low-potential heat sources. The use of HV in heating systems reduces greenhouse gas emissions compared to conventional types of heat supply, which is relevant to the ecological state of the environment.

Designing a novel solar-assisted heat pump system with modification of a thermal energy storage unit

2019 ◽  
Vol 233 (5) ◽  
pp. 588-603 ◽  
Author(s):  
Mustafa Aktaş ◽  
Meltem Koşan ◽  
Erhan Arslan ◽  
Azim Doğuş Tuncer
Keyword(s):  
Energy Storage ◽  
Solar Energy ◽  
Heat Pump ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Solar Collector ◽  
Working Fluid ◽  
Storage Unit ◽  
Heating Systems ◽  
Energy Storage Unit

The integrated usage of solar energy systems, heat pump applications, and thermal energy storage units is an effective way for heating systems due to their sustainability and stability in operations. In this study, a novel direct solar-assisted heat pump with thermal energy system has been designed which uses the solar collector as the evaporator of the heat pump. Besides, two-dimensional transient numeric analyses have been conducted for the thermal energy storage unit using the ANSYS Fluent 16.2 commercial software package. With this direct system, the heat required for heating systems is supplied from the condenser with the heat received from the solar collector of the working fluid. For an effective and high performance system, the solar collector is designed as a double-pass which provided superheating of the working fluid. It is aimed to store the surplus energy from the solar energy in the thermal energy storage unit and to operate the system continuously and efficiently in both sunny and overcast weather conditions. Furthermore, the system has been analyzed theoretically and the results show that coefficient of performance may improve. As a result, this newly designed system can be successfully applied for thermal applications.

scholarly journals Theoretical and Experimental Cost–Benefit Assessment of Borehole Heat Exchangers (BHEs) According to Working Fluid Flow Rate

Energies ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4925
Author(s):  
Borja Badenes ◽  
Miguel Ángel Mateo Pla ◽  
Teresa Magraner ◽  
Javier Soriano ◽  
Javier F. Urchueguía
Keyword(s):  
Exchange Rate ◽  
Heat Exchange ◽  
Heat Pump ◽  
Flow Rate ◽  
Cost Benefit ◽  
Operating Costs ◽  
Working Fluid ◽  
Geothermal Systems ◽  
Operational Parameters ◽  
Pumping Rate

In ground-source heat-pump systems, the heat exchange rate is influenced by various design and operational parameters that condition the thermal performance of the heat pump and the running costs during exploitation. One less-studied area is the relationship between the pumping costs in a given system and the heat exchange rate. This work analyzes the investment and operating costs of representative borehole heat-exchanger configurations with varying circulating flow rate by means of a combination of analytical formulas and case study simulations to allow a precise quantification of the capital and operational costs in typical scenario. As a conclusion, an optimal flow rate minimizing either of both costs can be determined. Furthermore, it is concluded that in terms of operating costs, there is an operational pumping rate above which performance of geothermal systems is energetically strongly penalized.

Optimization of Working Ground Heat Storage With Seasonal Regeneration

2006 ◽  
Author(s):  
Pawel Olszewski
Keyword(s):  
Energy Storage ◽  
Heat Exchange ◽  
Heat Pump ◽  
Input Data ◽  
Heat Storage ◽  
Target Function ◽  
Working Fluid ◽  
Solar Collectors ◽  
Pump System ◽  
Heat Pump System

The aim of the research was an optimization of long-term heat storage with seasonal regeneration. Energy consumption for central heating during wintertime, transfererred from ground energy storage using a heat exchange device, is the operating principle of such systems. Warmed working fluid is then used in a heat pump system. However, more accurate calculations showed that over time of usage, there is a trend toward cooling at deeper round layers. Such a situation leads to a lowering of ground potential when using heat pump systems. A possible solution to this problem is the application of summer regeneration: during summer months, the working fluid is firstly warmed in solar collectors, and then forced into the same boreholes. The numerical model of a vertical, ground heat exchange device (configured as a "pipe in pipe", known as a Fields' pipe) was specially developed. Temperature distribution of the working fluid along the pipe was one of the boundary conditions, for the co-axial, time-variable, heat conduction task, which described the heat flow in energy storage. The numerical simulation of solar collectors work was based on the Hottel - Whillier - Bliss equation, in which energy flow from the solar collector is calculated, dependant on external parameters such as: insulation or ambience temperature. The combination of three computational parts- the ground heat exchange device, energy storage area and solar collectors battery- allows the target function to be defined for task optimization. The subject of optimization was an energy quantity, which can be taken from energy underground storage, and then utilized by the heat pump system. In the summarized paper, a combination of the input data, which influenced the efficiency of energy storage, was chosen. Hypothetical data were: outside diameter and length of heat exchange device, distance between pipes, fluid flow through the pipe during charge and discharge processes or temperature of inlet working fluid. The influence of individual parameters on the target function, holding all input data constant, was analyzed. A developed evolutionary numerical code known as GENOCOP I (GEnetic algorithm for Numerical Optimization for COnstrained Problems) [3] was used for optimization. After preliminary correction of boundary values of the input data, nine attempts of optimization were taken up. The research results identified optimal values of input parameters for which maximum energy could be taken from ground storage.

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