scholarly journals Exergy-based Control of a Dwelling Ventilation System with Heat Recovery

2019 ◽  
pp. 114-116
Author(s):  
Volodymyr Voloshchuk ◽  
Mariya Polishchuk
Keyword(s):  
Power Consumption ◽  
Heat Recovery ◽  
Operation Mode ◽  
Ventilation System ◽  
Primary Energy ◽  
Energy Sources ◽  
Annual Saving ◽  
Operating Modes ◽  
Ventilation Systems

On the base of exergy-based approach it is shownthat for the ventilation systems there are operating modes forwhich heat recovery increases exergy of fuel expended to providethe ventilation air compared to cases without bringing anyrecovery of heat and additional power consumption to drive theair flow by the fans. For the specified system, in case of switchingventilation unit to the operation mode of lower values of spentfuel exergy it is possible to provide annual saving from 5 to 15 %of the primary energy sources.

scholarly journals EXERGY-BASED CONTROL STRATEGY IN A DWELLING VENTILATION SYSTEM WITH HEAT RECOVERY

2020 ◽  
Vol 10 (2) ◽  
pp. 44-47
Author(s):  
Volodymyr Voloshchuk ◽  
Mariya Polishchuk
Keyword(s):  
Heat Recovery ◽  
Operation Mode ◽  
Ventilation System ◽  
Primary Energy ◽  
Climatic Conditions ◽  
Operating Conditions ◽  
Spent Fuel ◽  
Energy And Exergy ◽  
Energy And Exergy Analysis ◽  
Operational Modes

The paper presents energy and exergy analysis of a typical dwelling ventilation system with heat recovery for Ukrainian climatic conditions using a quasi-steady state approach over 24-hour time-steps. Evaluation of such systems on the base of the first law of thermodynamics demonstrates that heat recovery is beneficial for the whole variety of operational modes. Such methodology identifies as a thermodynamic inefficiency only energy losses to the surroundings with the exhaust air. The exergy-based analysis can detect additional inefficiencies due to irreversibilities within the components of the system. As a result the exergetic investigations show that for the ventilation systems there are operating conditions for which heat recovery increases exergy of fuel expended to provide the ventilation air compared to cases without bringing any recovery of heat and additional power consumption to drive the air flow by the fans. For the specified system, in case of switching ventilation unit to the operation mode of lower values of spent fuel exergy it is possible to provide annual saving of the primary energy sources from 5 to 15%.

Air Flow Straighteners’ Application to Reduce the Power Consumption of Exhaust Ventilation Schemes

2018 ◽  
Vol 875 ◽  
pp. 137-140 ◽  
Author(s):  
Valery N. Azarov ◽  
Natalia M. Sergina ◽  
I.V. Stefanenko
Keyword(s):  
Power Consumption ◽  
Air Flow ◽  
Ventilation System ◽  
Aerodynamic Resistance ◽  
Experimental Studies ◽  
Swirling Flows ◽  
Dust Collector ◽  
Exhaust Ventilation ◽  
Outlet Pipe ◽  
Ventilation Systems

It was proposed to use air flow screw straightened units in outlet pipe of the dust collectors to reduce the aerodynamic resistance of exhaust ventilation systems. It is allowed to decrease power consumption for their maintenance operation consequently. The article describes the results of experimental studies to evaluate its effectiveness by applying the tangential screw straightened unit within ventilation system. The obtained results showed that the use of this device allows reducing the aerodynamic resistance of the cyclone by 14.6%, and for counter-swirling flows’ dust collector (CSFC) by 17.2-23.6%. It was found that meanings of the aerodynamic resistance depend on value the share proportion of the flow entering into lower CSFC apparatus’ input.

Determining the impact of air-side cleaning for heat exchangers in ventilation systems

2019 ◽  
Vol 41 (1) ◽  
pp. 46-59 ◽  
Author(s):  
Akram Abdul Hamid ◽  
Dennis Johansson ◽  
Michael Lempart
Keyword(s):  
Pressure Drop ◽  
Energy Loss ◽  
Heat Exchangers ◽  
Heat Recovery ◽  
Energy Use ◽  
Ventilation System ◽  
Field Measurements ◽  
The Impact ◽  
Over Time ◽  
Ventilation Systems

Cleaning coils can be an efficient way to reduce the need for reparations and maintain the functionality of a ventilation system. This study builds upon existing knowledge concerning the contamination of heat exchangers. Through field measurements on coils and heat-recovery units, a laboratory experiment on a coil, and a generic calculation example, this study determines the impact of sustained contamination on heat-recovery units with regards to energy use. Field measurements made before and after cleaning of heat exchangers show an average increase in the pressure drop by 12% and decrease in the thermal exchange efficiency by 8.1% due to mass deposited on the surface of the heat exchangers. Results from a laboratory test show a correlation between the mass deposited on a coil and (1) the increase in pressure drop over the coil, as well as (2) a diminishing heat exchange. Accumulating contamination on heat-recovery units in residential and commercial buildings (over time) is then linked to increasing pressure drop and diminishing thermal efficiency. With models based on these links, energy loss over time is calculated based on a generic calculation example in a realistic scenario. Practical application: The results from this study emphasize the need for maintenance of buildings with ventilation systems with coils, but more so those with heat-recovery units. The presented field measurements and laboratory study correlate energy loss with sustained accumulation of contaminants on coils and heat-recovery units. These results should serve as a recommendation to property owners considering maintenance of such units in their buildings.

The Use of Decentralized Ventilation Systems with Heat Recovery in the Historical Buildings of St. Petersburg

2014 ◽  
Vol 635-637 ◽  
pp. 370-376 ◽  
Author(s):  
Vera Murgul ◽  
Dusan Vuksanovic ◽  
Nikolay Vatin ◽  
Viktor Pukhkal
Keyword(s):  
Heat Recovery ◽  
Ventilation System ◽  
Energy Performance ◽  
Saint Petersburg ◽  
Exhaust Ventilation ◽  
Different Types ◽  
Energy Efficiency Standards ◽  
Energy Efficient Building ◽  
Cultural Monuments ◽  
Ventilation Systems

Historic apartment buildings in Saint-Petersburg no longer meet today’s energy efficiency standards and need upgrading to achieve lower energy-consumption. The possibilities to upgrade old buildings – historic and cultural monuments – are initially limited. A controlled heat recovery ventilation system is considered to be an integral part of energy efficient building. Provided engineering facilities of a building are updated and reequipped energy performance increases without any impact on building exteriors. Different types of decentralized intake and exhaust ventilation systems with heat recovery based on various types of heat exchangers are considered in a detailed way.

NUMERICAL SIMULATION AND PARAMETRIC STUDIES FOR EVALUATION OF BALANCED VENTILATION AND EARTH AIR EXCHANGERS SYSTEM COUPLED TO A DOMESTIC BUILDING

2013 ◽  
Vol 21 (01) ◽  
pp. 1350002 ◽  
Author(s):  
YOUNES KARTACHI ◽  
ABDELLAH MECHAQRANE
Keyword(s):  
Heat Exchanger ◽  
Heat Recovery ◽  
High Efficiency ◽  
Residential Buildings ◽  
Ventilation System ◽  
Primary Energy ◽  
Climatic Conditions ◽  
Design Parameters ◽  
Climate Data ◽  
The Impact

In this study, we analyze the impact of ventilation heat recovery with the heating and cooling potential of earth air heat exchanger in real climatic conditions in domestic buildings in the Middle Atlas region. In our case study, we calculate the primary energy used by a domestic building built as per the conventional house design parameters required by the Moroccan regulation. We use climate data for the city of Fes in Northern Moroccan. Three system configurations were considered. The first was the mechanical extract ventilation system both with and without heat recovery. The second was the mechanical extract ventilation system with earth to air heat exchanger system (EAHEX), and the third system was the mechanical balanced ventilation system coupled with EAHEX system. Primary energy use strongly influences natural resources efficiency and the environmental impacts of energy supply activities. In this study we explore the primary energy implications of the mechanical balanced ventilation system coupled with the EAHEX system in residential buildings. The results of this study shows that the use of a balanced ventilation system, with a high efficiency instead of a mechanical extract ventilation system, decreases the final and primary energy consumption. Moreover, it decreases or increases the CO2 emission depending on the primary energy sources.

scholarly journals ALTERNATYVIŲ VĖDINIMO SISTEMŲ IR MIKROKLIMATO TYRIMAI GYVENAMAJAME NAME / INVESTIGATION OF ALTERNATIVE VENTILATION SYSTEMS AND INDOOR CLIMATE IN LIVING HOUSE

2018 ◽  
Vol 10 (0) ◽  
pp. 1-6
Author(s):  
Rokas Petrašiūnas ◽  
Artur Rogoža ◽  
Violeta Misevičiūtė
Keyword(s):  
Energy Efficiency ◽  
Life Cycle Analysis ◽  
Ventilation System ◽  
Sick Building Syndrome ◽  
Primary Energy ◽  
Indoor Climate ◽  
Operation Costs ◽  
Sick Building ◽  
Residential House ◽  
Ventilation Systems

The purpose of the study was to determine which ventilation system centralized or decentralized in viewpoint of economic, energy and comfort is more advantageous in an individual residential house. The relevance of the work is related to the increasing energy efficiency requirements for newly built buildings and the resulting problems of the sick building syndrome due to insufficient ventilation of the rooms. The installation and operation costs of systems were identified. The Life Cycle Analysis (LCA) method was applied to estimate the amount of pollutants and primary energy consumed throughout the lifetime of ventilation systems. Measurements of indoor climate parameters were made; the results compared with the hygiene norms valid in Lithuania. The results of the analysis showed that the decentralized ventilation system is the most advantageous for economic and environmental impacts, but centralized ventilation system ensuring a better indoor climate. Santrauka Tyrimo tikslas buvo nustatyti, kokia vėdinimo sistema – centralizuota ar decentralizuota – ekonominiu, energiniu bei komforto požiūriu yra pranašesnė individualiame gyvenamajame name. Darbo aktualumas susijęs su didėjančiais energinio efektyvumo reikalavimais naujai statomiems pastatams ir iš to kylančiomis ligoto pastato sindromo problemomis dėl nepakankamo patalpų vėdinimo. Darbe buvo nustatyti sistemų įrengimo bei eksploatavimo kaštai, pritaikytas gyvavimo ciklo analizės (GCA) metodas, kuriuo įvertinti susidarančių teršalų bei suvartotos pirminės energijos kiekiai per visą vėdinimo sistemų gyvavimo laiką, atlikti patalpų mikroklimato rodiklių matavimai, o gauti rezultatai palyginti su Lietuvoje galiojančiomis higienos normomis. Išanalizavus rezultatus nustatyta, kad ekonominiu ir poveikio aplinkai požiūriais pranašesnė yra decentralizuota vėdinimo sistema, tačiau geresnį patalpų mikroklimatą užtikrina centralizuota vėdinimo sistema.

scholarly journals Influence of voltage difference on energy characteristics of ventilation plants

2020 ◽  
pp. 19-26
Author(s):  
◽  
V. Savchenko ◽  
O. Pylypchuk ◽  
M. Melnyk ◽  
◽  
...  
Keyword(s):  
Power Consumption ◽  
Asynchronous Motor ◽  
Ventilation System ◽  
Energy Performance ◽  
Specific Power ◽  
Specific Power Consumption ◽  
Energy Characteristics ◽  
Power Characteristics ◽  
Voltage Deviation ◽  
Ventilation Systems

Deviation of voltage from the nominal value leads to losses that have an electromagnetic and technological component. Due to the voltage deviation, the angular velocity of the motor changes, which causes a change in the technological characteristics of the fan. However, no studies have been conducted on the effect of voltage deviation on the energy performance of ventilation systems. The purpose of the study is to establish the effect of voltage deviation on energy characteristics of ventilation systems. When the voltage deviates, the constant and variable losses in the asynchronous motor are change. It is proposed to conduct an energy assessment of the ventilation unit for the specific power consumption. Theoretical and experimental researches of influence of voltage deviation on power characteristics of ventilating installations are carried out. The dependences of productivity, power of the ventilation installation and specific consumption of electricity on voltage are obtained. It is established that when the voltage is reduced by 20 %, the productivity of the ventilation system is reduced to 3 %, power - up to 8 %, and the specific power consumption increases by 15%.

scholarly journals Heat Recovery Ventilation Systems and their Physical Quantification

2021 ◽  
Vol 1203 (2) ◽  
pp. 022045
Author(s):  
Boris Bielek ◽  
Daniel Szabó ◽  
Josip Klem ◽  
Roman Grolmus
Keyword(s):  
Energy Efficiency ◽  
Heat Recovery ◽  
Ventilation System ◽  
Co2 Concentration ◽  
High Energy ◽  
Operating Conditions ◽  
Indoor Climate ◽  
Measurement Results ◽  
Ventilation Systems

Abstract The essence of ventilation is the exchange of air in the room for fresh outside air. At the same time ventilation is a factor that can significantly affect the energy efficiency of a building. Hygienic requirements for ventilation of interiors of buildings in the context of increasing the energy efficiency of buildings lead to the transformation of unregulated ventilation by infiltration to regulated ventilation systems with heat recovery. The regulated ventilation system makes it possible to optimize the ventilation intensity on the basis of a stimulus from the room user or automatically on the basis of sensors monitoring the quality of the indoor climate (temperature and relative humidity, CO2 concentration in the air, etc.). In addition, if we use a ventilation system with heat recovery from the exhaust air to preheat the fresh supply air to the room, we can achieve high energy efficiency of the building by meeting the hygienic criteria of the indoor climate. The article describes heat recovery ventilation systems and their basic conceptual solutions applied in the modern architecture. The heat exchange between the hot exhaust air and the cold supply air in the winter takes place in heat recovery ventilation units in the heat exchanger. The efficiency of heat recovery defines how much heat we can transfer from the exhaust air to the fresh air in the heat recovery exchanger. The article analyses individual factors influencing the efficiency of heat recovery. Due to the fact that the manufacturers of heat recovery ventilation units declare in their brochures or websites the values of the maximum efficiencies of their products, we were interested in their real efficiencies under normal operating conditions. Therefore, we subjected to experimental research in a large climate chamber a product from the German manufacturer Lunos, namely a specific type of decentralized heat recovery unit Lunos Nexxt E. The article describes the methodology of laboratory experiment, used experimental basis, brings and analyses measurement results and calculates real efficiency of the subject heat recovery in accordance with STN EN 13 141. In the end it compares measured values with the values from the manufacturer.

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.

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