scholarly journals ANALYSIS OF THE THERMODYNAMICAL EFFICIENCY OF AN AIR HANDLING UNIT WITH A HEAT PUMP / VĖDINIMO ĮRENGINIO SU ŠILUMOS SIURBLIU TERMODINAMINIO EFEKTYVUMO TYRIMAS

2012 ◽  
Vol 5 (4) ◽  
pp. 493-498 ◽  
Author(s):  
Vytautas Martinaitis ◽  
Paulius Bareika ◽  
Violeta Misevičiūtė
Keyword(s):  
Heat Pump ◽  
Heat Recovery ◽  
Thermodynamic Potential ◽  
Energy Analysis ◽  
Ventilation System ◽  
Point Of View ◽  
Thermodynamic Efficiency ◽  
Variable Speed ◽  
Air Handling Unit ◽  
Heat Demand

This paper evaluates the seasonal thermodynamic efficiency of the air-to-air heat pump used for a heat recovery ventilation system and several modulations of compressors affecting the thermodynamic efficiency of the heat pump. A variable speed and on/off-type compressors have been selected. In order to evaluate the thermodynamic potential of the device, energy analysis has been performed. Along with modelling the operation of the air handling unit during the cold time of the year, variations in the thermodynamic efficiency or different modulation compressors have been compared. The obtained results have shown that the use of a few simple compressors causes a decrease in the seasonal parameters of the heat pump: heat generated by a condenser is 5% lower compared to the use of variable speed compressors and therefore the seasonal coefficient of the performance (COP) of the heat pump decreases by 5%. Possible improvement on the heat pump can be provided changing the compressor into variable speed or modulatory equipment, which allows adjusting to heat demand and thus increases the seasonal efficiency of the system from a thermodynamic point of view. Santrauka Straipsnyje vertinamas oras-oras šilumos siurblio, naudojamo vėdinimo sistemos šilumogrąžai, sezoninis termodinaminis naudingumas ir kelios kompresorių, turinčių įtakos termodinaminiam šilumos siurblio naudingumui, moduliacijos. Analizei pasirinkti kintamo greičio ir įjungiamo / išjungiamo tipo kompresoriai. Siekiant įvertinti įrenginio termodinaminį potencialą atliekama ekserginė analizė. Modeliuojant vėdinimo įrenginio veikimą šaltuoju metų laiku, lyginama, kaip kinta skirtingų moduliacijų kompresorių termodinaminis naudingumas. Tyrimo rezultatai rodo, kad naudojant kelis paprastus kompresorius sezoniniai šilumos siurblio parametrai krenta: kondensatoriaus atiduodamas šilumos srautas yra 5 % mažesnis, lyginant su kintamo veikimo kompresorių naudojimu, be to, 5 % sumažėja sezoninis šilumos siurblio efektyvumo koeficientas (COP). Šilumos siurblį galima tobulinti kompresorių keičiant į kintamo greičio arba moduliacinį, kuris leistų prisitaikyti prie šilumos poreikio ir tokiu būdu termodinaminiu požiūriu pagerintų sezoninį sistemos efektyvumą.

scholarly journals Experimental exergy and energy analysis of a novel high-temperature heat pump with scroll compressor for waste heat recovery

2019 ◽  
Vol 253 ◽  
pp. 113504 ◽  
Author(s):  
Carlos Mateu-Royo ◽  
Joaquín Navarro-Esbrí ◽  
Adrián Mota-Babiloni ◽  
Francisco Molés ◽  
Marta Amat-Albuixech
Keyword(s):  
High Temperature ◽  
Heat Pump ◽  
Heat Recovery ◽  
Waste Heat Recovery ◽  
Energy Analysis ◽  
Waste Heat ◽  
Scroll Compressor ◽  
Temperature Heat ◽  
High Temperature Heat Pump

Study of a prototype of an advanced mechanical ventilation system with heat recovery integrated by heat pump

2016 ◽  
Vol 133 ◽  
pp. 111-121 ◽  
Author(s):  
F. Fucci ◽  
C. Perone ◽  
G. La Fianza ◽  
L. Brunetti ◽  
F. Giametta ◽  
...  
Keyword(s):  
Mechanical Ventilation ◽  
Heat Pump ◽  
Heat Recovery ◽  
Ventilation System

PERFORMANCE CHARACTERISTICS OF A SIMULTANEOUS HEATING AND COOLING HEAT PUMP IN THE HEAT RECOVERY MODE

2010 ◽  
Vol 18 (03) ◽  
pp. 237-245
Author(s):  
JONGMIN CHOI ◽  
HYUN JOON CHOUNG ◽  
YOUNGJU JOO ◽  
HOON KANG ◽  
YONGCHAN KIM
Keyword(s):  
Heat Pump ◽  
Heat Recovery ◽  
High Efficiency ◽  
Waste Heat ◽  
Variable Speed ◽  
Heating And Cooling ◽  
Simultaneous Heating ◽  
Useful Heat ◽  
Simultaneous Heating And Cooling ◽  
Heating Mode

The cooling load in winter is significant in buildings and hotels because of the usage of office equipments and the high efficiency of wall insulation. Hence, the development of a multi-heat pump that can cover heating and cooling simultaneously for each indoor unit is required. In this study, the performance of a simultaneous heating and cooling heat pump was investigated in the heat recovery mode (HR mode). The system adopted a variable speed compressor using R-410A with four indoor units and one outdoor unit. In the HR mode, the capacity and COP were improved as compared with those in the cooling or heating mode because the waste heat in the outdoor unit was utilized as useful heat in the indoor units. However, energy imbalance between heating and cooling capacities of each indoor unit was observed in the 2H–1C HR mode. Therefore, the performance of the system in the 2H–1C HR mode was enhanced by controlling refrigerant flow rate through the outdoor unit.

scholarly journals The hydrothermal liquefaction as a promising procedure for microalgae-to-biofuel conversion: A general review and some thermophysical problems to be solved

2020 ◽  
Vol 48 (4) ◽  
pp. 309-351
Author(s):  
MIKHAIL S. VLASKIN ◽  
ANATOLY V. GRIGORENKO ◽  
NADEZHDA I. CHERNOVA ◽  
SOPHIA V. KISELEVA ◽  
IRINA A. LIPATOVA ◽  
...  
Keyword(s):  
Heat Recovery ◽  
Aqueous Media ◽  
Food Additives ◽  
Environmental Issues ◽  
Hydrothermal Liquefaction ◽  
Point Of View ◽  
Thermodynamic Efficiency ◽  
Microalgal Biomass ◽  
Bio Oil ◽  
Co2 Capturing

At present, microalgae are industrially produced mainly for the extraction of high-value products for food additives. At the same time, the microalgae possess also environmental advantages as it can be used for wastewater treatment, mitigation of industrial CO2 emissions as well as for oxygen production and atmospheric CO2 capturing. Due to increasing the environmental problems, it is reasonable to expand the “green” applications of microalgae and increase significantly their output. From this point of view, the problem of utilization of the microalgal biomass becomes more important and one of the most reliable ways to do it is a conversion of the biomass to a biofuel. It is expected that such a conversion can be implemented into the existing infrastructure for traditional hydrocarbons. In the case of microalgae, the hydrothermal liquefaction (HTL) with the production of bio-oil as a target product has attracted more attention in recent years because the bio-oil can be used in the existing refinery industry. The paper is also concerned with the use of microalgae to solve the environmental issues on the basis of HTL as a convenient and efficient method for the biomass-to-biofuel conversion. The known advantages of the HTL are the possible use of fresh microalgae just after harvesting, the processing of the whole biomass and high thermodynamic efficiency. In the paper it is shown that the latter is achieved due to the high HTL pressure that keeps the high-temperature potential of aqueous media after hydrothermal treatment and so creates the opportunity of more efficient heat recovery. The fundamental aspects of the process thermodynamics are discovered in the paper. It is shown that one of the main advantages of the process is provided by a combination of thermodynamic parameters. The problem of solar radiative transfer in photobioreactors with suspended microalgae and the desired thermophysical properties of the refined biofuels are also briefly discussed in the paper.

Energy Analysis of Gas Engine Driven Heat Pump

2011 ◽  
Vol 130-134 ◽  
pp. 771-774
Author(s):  
Ning Jiang ◽  
Zeng Liang Gao
Keyword(s):  
Heat Pump ◽  
Heat Recovery ◽  
Energy Analysis ◽  
Analytical Investigation ◽  
Vapor Compression ◽  
Gas Engine ◽  
Process Comparison ◽  
Energy Conversion Process ◽  
The Face ◽  
Power Shortages

In the face of power shortages, an analytical investigation on the displacement of electrically driven heat pump by gas engine driven heat pump is undertaken. The energy conversion process comparison based on existing data between electrically driven vapor compression heat pump (EVCHP) and gas engine driven vapor compression heat pump (GVCHP) indicates that GVCHP can improve the energy efficiency and exergy efficiency with the application of waste engine heat recovery for heat supply and the majority of loss in GVCHP occurs in the engine.

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 Energy analysis of heat recovery plants

2021 ◽  
Vol 808 (1) ◽  
pp. 012008
Author(s):  
T A Faiziev ◽  
I Muradov ◽  
G Yu Ruzikulov ◽  
S Ernafasov
Keyword(s):  
Heat Recovery ◽  
Energy Analysis
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