Experimental performance evaluation and comparison of an absorption refrigeration prototype driven by exhaust heat operating with NH3/LiNO3 and NH3/LiNO3+H2O
4
Citation
22
Reference
10
Related Paper
Citation Trend
Keywords:
Coefficient of performance
Absorption refrigerator
The purpose of the work is a comparison of indirect carbon dioxide emissions between the different heat pump types that operate in Polish climate conditions. The analysis embraces air-to-water heat pump, ground-to-water heat pump, water-to-water heat pump and water-to-water heat pump with separating heat exchanger in the selected towns one in each climatic zone in the country. The study starts from determining seasonal coefficient of performance in each location using heating degree days to estimate seasonal heat demand. Seasonal coefficient of performance values enable an assessment which kind of heat pump meets the European Union requirements in every location. Eventually, indirect CO2 emissions that is caused by electrical energy production, are estimated for every heat pump in each location. Ground-to-water heat pump and water-to-water heat pump satisfy these requirements in each climatic zone in Poland. Air-to-water heat pump would be an energetic and ecological viable on a condition that substantial changes were done in Polish electrical energy mix.
Coefficient of performance
Renewable heat
Cite
Citations (13)
Abstract In this study, some heat pumps having multiple heat source combinations were investigated experimentally. Multiple systems including mentioned heat pump systems, such as solar assisted-ground source, solar assisted-air source, and ground source-air source heat pumps, were tested. All the heat pump systems were designed and constructed in a test room with 60 m2 floor area at Firat University, Elazig (38.41°N, 39.14°E), Turkey. In evaluating the efficiency of the heat pump systems, the most commonly used measure is the energy or the first law efficiency, which is modified to a coefficient of performance for heat pump systems. However, for indicating the possibilities for thermodynamic improvement, energy analysis inadequate and exergy analysis is needed. The coefficient of performance (COP) of solar assisted-ground source, solar assisted-air source, and ground-air source heat pumps as multiple source heat pump systems were also determined to be 3.36, 2.90, and 2.14, while the exergy losses of the refrigerant subsystems were approximately 2.13, 2.996, and 3.113 kW, respectively. Consequently, the energy and exergy loss analysis results show that the COP increases when the exergy loss of the condenser decreases. Exergetic performance coefficient is introduced and is applied to the heat pump systems having various heat sources. The results imply that the functional forms of the exergetic performance coefficient and first law efficiency are different. Results show that Exloss,total becomes a minimum value where exergetic performance coefficient is the maximum value.
Coefficient of performance
Condenser (optics)
Exergy efficiency
Cite
Citations (8)
In present study, a novel heat pump named multi-functional heat pump systems for dishwashers is introduced. 45 oC hot water cycle and hot air cycle are provided by the single-stage heat pump cycle to complete the cleaning and drying process. Moreover, the high temperature water at 85 °C is provided by the two-stage heat pump cycle system to achieve the disinfection function, and the 26°C cold air is realized by the single-stage refrigeration cycle for rapid cooling. Thermodynamic analysis of multi-functional heat pump systems for dishwashers under four different operating conditions with R22 / R134a as working fluid was carried out. The results show that COP (coefficient of performance) of the system is above 3.2 under all four conditions, which meets the energy efficiency rating index. Comparing energy efficiency and environmental benefits and operating costs of multi-functional heat pump systems for dishwashers with the traditional electric heating dishwashers, these can be known that primary energy consumption, carbon dioxide emissions and operating cost of multifunctional heat pump dishwasher are 1.24 * 105kJ, 10.5 5 kg and 21.70 Yuan respectively under the condition of per running energy consumption for 40kW·h, above three all lower than the traditional electric heating dishwasher.
Coefficient of performance
Working fluid
Cite
Citations (0)
A novel hybrid solid adsorption-steam ejection refrigeration cycle is presented and thermodynamically analyzed.The refrigerant steam with high temperature and high pressure desorbed from the adsorbent bed is led into an ejector before it enters the condenser.Therefore the hybrid refrigeration system may produce cold not only in the adsorption course but also desorption course,and refrigeration capacity is increased.The influences of some operating parameters,such as desorption temperature and ejecting pressure,on the hybrid refrigeration cycle are discussed.The coefficient of performance of the hybrid system is comparable to that of adsorption cycle with heat recovery when operated with high desorption temperature,and the hybrid adsorption-ejection refrigeration cycle with heat recovery will greatly improve the performance of the system.Simulated results show that the hybrid refrigeration system is attractive when it is powered by high-temperature exhaust heat.
Coefficient of performance
Condenser (optics)
Cooling capacity
Chiller
Thermodynamic cycle
Cite
Citations (0)
The NH3-H2O absorption refrigeration requires the least amount of energy,its coefficient of performance is not very high.This paper introduces pinch point analysis to analyze the NH3-H2O absorption refrigeration system,After the optimization of the system,the performance coefficient is 0.623,it is 11.58% higher than the previous system.So the new method to the NH3-H2O absorption refrigeration have the guiding significance.
Absorption refrigerator
Coefficient of performance
Pinch point
Cite
Citations (3)
Coefficient of performance
Thermodynamic cycle
Thermal efficiency
Cite
Citations (6)
Ground source heat pump systems are becoming more and more popular, even though their high initial cost is an obstacle to their wider penetration of the heating and cooling market. The purchase of the heat pump itself is one of the dominant costs, and the heat pump selection also influences the operation costs through its coefficient of performance (COP) value. However, few studies are available on this topic. Based on 23 water–water heat pump models available on the market, a correlation was developed to estimate their purchase cost as a function of the nominal cooling load of the heat pump. These heat pumps can be used in geothermal applications as well as in other heating, ventilating, air conditioning and refrigeration (HVAC&R) systems. The correlation is valid for a nominal cooling load between 20 and 841 kW. The nominal COP of the heat pumps was found to have virtually no effect on their purchase costs. Also, two correlations were developed to relate variations of cooling power and COP to the temperature levels on both sides of the heat pump. The heating mode is also considered. The correlations are useful to estimate the required nominal size of a heat pump given design operating conditions and to optimize ground source heat pump systems from a techno-economical standpoint. Copyright © 2014 John Wiley & Sons, Ltd.
Coefficient of performance
Cite
Citations (23)
This paper presents the whole year performance simulation model of heat pump water heater for its characteristic analysis,with the two sub-models involved for simulating heat pump system and meteorological data.The sub-model for heat pump system contains the components like compressor and plate type condenser.The whole year performance prediction and analysis are made for a heat pump water heater located in Qingdao district,including an evaluation of its daily coefficient of performance(DCOP) and daily electricity consumption(DEC),performance comparison between the heat pump water heater and the electric water heater,discussion on performance variation in four different typical days.Results show that heat pump water heater is of a higher energy saving ratio.
Coefficient of performance
Condenser (optics)
Storage water heater
Water heating
Cite
Citations (0)
In this study heat pump systems having different heat sources were investigated experimentally. Solar-assisted heat pump (SAHP), ground source heat pump (GSHP) and air source heat pump (ASHP) systems for domestic heating were tested. Additionally, their combination systems, such as solar-assisted-ground source heat pump (SAGSHP), solar-assisted-air source heat pump (SAASHP) and ground–air source heat pump (GSASHP) were tested. All the heat pump systems were designed and constructed in a test room with 60 m2 floor area in Firat University, Elazig (38.41°N, 39.14°E), Turkey. In evaluating the efficiency of heat pump systems, the most commonly used measure is the energy or the first law efficiency, which is modified to a coefficient of performance for heat pump systems. However, for indicating the possibilities for thermodynamic improvement, inadequate energy analysis and exergy analysis are needed. This study presents an exergetic evaluation of SAHP, GSHP and ASHP and their combination systems. The exergy losses in each of the components of the heat pump systems are determined for average values of experimentally measured parameters. Exergy efficiency in each of the components of the heat pump systems is also determined to assess their performances. The coefficient of performance (COP) of the SAHP, GSHP and ASHP were obtained as 2.95, 2.44 and 2.33, whereas the exergy losses of the refrigerant subsystems were found to be 1.342, 1.705 and 1.942 kW, respectively. The COP of SAGSHP, SAASHP and GSASHP as multiple source heat pump systems were also determined to be 3.36, 2.90 and 2.14, whereas the exergy losses of the refrigerant subsystems were approximately 2.13, 2.996 and 3.113 kW, respectively. In addition, multiple source heat pump systems were compared with single source heat pump systems on the basis of the COP. Exergetic performance coefficient (EPC) is introduced and is applied to the heat pump systems having various heat sources. The results imply that the functional forms of the EPC and first law efficiency are different. Results show that Exloss,total becomes a minimum value when EPC has a maximum value. Copyright © 2008 John Wiley & Sons, Ltd.
Coefficient of performance
Exergy efficiency
Cite
Citations (32)
Absorption refrigerator
Thermodynamic cycle
Cite
Citations (1)