scholarly journals Mathematical modeling bringing the operation of air split conditioners heat pumps to the same internal temperature conditions

2021 ◽  
Vol 8 (3) ◽  
pp. 509-514
Author(s):  
V. Yo. Labay ◽  
◽  
V. Yu. Yaroslav ◽  
O. M. Dovbush ◽  
A. Ye. Tsizda ◽  
...  
Keyword(s):  
Air Temperature ◽  
Heat Pumps ◽  
Thermodynamic Efficiency ◽  
Condensation Temperature ◽  
Internal Temperature ◽  
Heating Systems ◽  
Evaporation Temperature ◽  
Temperature Conditions ◽  
Heating Capacity ◽  
The Mathematical Model

Nowadays, the use of heat pumps (HP) of air split-conditioners in air conditioning and heating systems of small industrial, public and residential facilities is becoming more common. It is known that the nominal heat capacity of HP of air split-conditioners is given in catalogs or reference literature under standard outdoor temperature conditions, namely: outdoor air temperature +7oС, indoor air temperature +21oС. At the same time, manufacturers of air split-conditioners do not ensure that, regardless of the size of heating capacity, all air split-conditioners have the same internal temperature conditions, namely: the evaporation temperature of the refrigerant and its condensation temperature. In this case, the thermodynamic efficiency, which can be best assessed by the exergetic output-input ratio (OIR) of different heating capacity of HP of air split-conditioners, is different; this, in our opinion, is incorrect. However, today there is a lack of mathematical models of bringing the operation of air split-conditioners HP to the similar internal temperature conditions, which will allow us to obtain the same exergetic OIR for different heating capacity of HP. To create the mathematical model of bringing the operation of HP of air split-conditioners to the equal internal temperature conditions, we have proposed them, namely: the evaporation temperature of the refrigerant +0.7oC and its condensation temperature +40oC. Taking these temperatures on the basis of the heat balances of the HP evaporator and HP condenser of air split-conditioners, we obtained the dependences for calculating air flow rates on the evaporator and condenser, which respectively maintain the proposed temperatures.

scholarly journals Influence of building orientation on internal temperature in saharan climates, building located in Ghardaïa region (Algeria)

2013 ◽  
Vol 17 (2) ◽  
pp. 349-364 ◽  
Author(s):  
Sidi Bekkouche ◽  
Tayeb Benouaz ◽  
Mohamed Cherier ◽  
Maamar Hamdani ◽  
Mohamed Yaiche ◽  
...  
Keyword(s):  
Thermal Comfort ◽  
Thermal Insulation ◽  
Air Temperature ◽  
Thermal Inertia ◽  
Numerical Data ◽  
Internal Temperature ◽  
And Control ◽  
The Mathematical Model ◽  
Do So

In desert regions, the orientation of buildings has an important influence in the inside air temperature. In the present work, we carry out a study on the influence of the buildings orientation as well as the thermal insulation on the internal temperature. To do so, we have considered the case where only the exposed walls are isolated. The main objective of the current work is to determine the temperatures of the building in question with and without thermal insulation. This study aims at assessing also the geographic parameter enhancing or damping the role of thermal inertia, providing a variety of results. As result, this work proves that stones play a contradictory role on thermal comfort. We have verified that thermal insulation is specified to reduce heat transfer through the building. Concerning the orientation, results indicates that the variation in orientation does not influence significantly the internal air temperature of a well thermally insulated building. Moreover, in hot period, whatever orientation considered, the phenomenon of overheating presents a serious problem to minimize consumption of energy and control of indoor temperature in case of building without insulation. The numerical data was compared to the experimental measurements in order to validate the mathematical model. In conclusion, to achieve a better thermal comfort arid and semi arid regions, the habitation will have to be situated in south flan of a hill to satisfy the two strategies (hot and cold).

Simulation of the internal temperature in the Passol Laboratory, University of Debrecen

2012 ◽  
Vol 3 (1) ◽  
pp. 63-73 ◽  
Author(s):  
I. Csáky ◽  
F. Kalmár
Keyword(s):  
Temperature Variation ◽  
Air Temperature ◽  
Indoor Air ◽  
Storage Capacity ◽  
Building Structures ◽  
Internal Temperature ◽  
The One ◽  
Heavy Structure ◽  
East West ◽  
Made In

Abstract Nowadays the facades of newly built buildings have significant glazed surfaces. The solar gains in these buildings can produce discomfort caused by direct solar radiation on the one hand and by the higher indoor air temperature on the other hand. The amplitude of the indoor air temperature variation depends on the glazed area, orientation of the facade and heat storage capacity of the building. This paper presents the results of a simulation, which were made in the Passol Laboratory of University of Debrecen in order to define the internal temperature variation. The simulation proved that the highest amplitudes of the internal temperature are obtained for East orientation of the facade. The upper acceptable limit of the internal air temperature is exceeded for each analyzed orientation: North, South, East, West. Comparing different building structures, according to the obtained results, in case of the heavy structure more cooling hours are obtained, but the energy consumption for cooling is lower.

scholarly journals Energy Saving Potential of Radiant Floor Heating Assisted by an Air Source Heat Pump in Residential Buildings

Energies ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1321
Author(s):  
Yu-Jin Hwang ◽  
Jae-Weon Jeong
Keyword(s):  
Energy Saving ◽  
Heat Pump ◽  
Residential Buildings ◽  
Heating Systems ◽  
Air Source Heat Pump ◽  
Heating Capacity ◽  
Heating Loads ◽  
Radiant Floor Heating ◽  
Floor Heating ◽  
Floor Temperature

The objective of this research is to establish an appropriate operating strategy for a radiant floor heating system that additionally has an air source heat pump for providing convective air heating separately, leading to heating energy saving and thermal comfort in residential buildings. To determine the appropriate optimal operating ratio of each system taking charge of combined heating systems, the energy consumption of the entire system was drawn, and the adaptive floor surface temperature was reviewed based on international standards and literature on thermal comfort. For processing heating loads with radiant floor heating and air source heating systems, the heating capacity of radiant floor heating by 1 °C variation in floor temperature was calculated, and the remaining heating load was handled by the heating capacity of the convective air heating heat pump. Consequently, when the floor temperature was 25 °C, all heating loads were removed by radiant floor heating only. When handling all heating loads with the heat pump, 59.2% less energy was used compared with radiant floor heating only. Considering the local discomfort of the soles of the feet, the floor temperature is expected to be suitable at 22–23 °C, and 31.5–37.6% energy saving compared with those of radiant floor heating alone were confirmed.

scholarly journals A Method for Optimizing and Spatially Distributing Heating Systems by Coupling an Urban Energy Simulation Platform and an Energy System Model

Resources ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 52
Author(s):  
Annette Steingrube ◽  
Keyu Bao ◽  
Stefan Wieland ◽  
Andrés Lalama ◽  
Pithon M. Kabiro ◽  
...  
Keyword(s):  
District Heating ◽  
Energy Systems ◽  
Energy System ◽  
Heat Pumps ◽  
Energy Simulation ◽  
Heating Systems ◽  
Optimal Amount ◽  
Urban City ◽  
Urban Energy ◽  
Building Level

District heating is seen as an important concept to decarbonize heating systems and meet climate mitigation goals. However, the decision related to where central heating is most viable is dependent on many different aspects, like heating densities or current heating structures. An urban energy simulation platform based on 3D building objects can improve the accuracy of energy demand calculation on building level, but lacks a system perspective. Energy system models help to find economically optimal solutions for entire energy systems, including the optimal amount of centrally supplied heat, but do not usually provide information on building level. Coupling both methods through a novel heating grid disaggregation algorithm, we propose a framework that does three things simultaneously: optimize energy systems that can comprise all demand sectors as well as sector coupling, assess the role of centralized heating in such optimized energy systems, and determine the layouts of supplying district heating grids with a spatial resolution on the street level. The algorithm is tested on two case studies; one, an urban city quarter, and the other, a rural town. In the urban city quarter, district heating is economically feasible in all scenarios. Using heat pumps in addition to CHPs increases the optimal amount of centrally supplied heat. In the rural quarter, central heat pumps guarantee the feasibility of district heating, while standalone CHPs are more expensive than decentral heating technologies.

scholarly journals How to Improve Effectiveness of Renewable Space Heating Programs by Better Understanding Homeowner—Installer Interactions

Energies ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4625
Author(s):  
Alisa Freyre ◽  
Stefano Cozza ◽  
Matthias Rüetschi ◽  
Meinrad Bürer ◽  
Marlyne Sahakian ◽  
...  
Keyword(s):  
Literature Review ◽  
Financial Incentives ◽  
Heating System ◽  
Heat Pumps ◽  
Single Family ◽  
Heating Systems ◽  
Current State ◽  
Ex Post ◽  
Improved Technology

In this paper, we perform a literature review on the current state of knowledge about homeowners in the context of the adoption of renewable heating systems. Despite a considerable number of studies about homeowners, homeowner–installer interactions, and ways to improve the effectiveness of renewable heating programs, based on homeowner knowledge, have not yet been studied in much detail. To address these knowledge gaps, we conduct a qualitative study on single-family house owners who installed heat pumps and took part in a renewable heating program in Geneva, Switzerland. We cover homeowner practices in choosing installers and heating system types, homeowners’ feedback about heat pump installation and use, as well as their experience in participation in the renewable heating program. Based on the literature review and the findings from the interviews, we provide the following recommendations on how to increase the effectiveness of renewable heating programs: (a) support for homeowners should not be limited to financial incentives; (b) partnership programs with installers could help to increase the quality of installation services and enable homeowners to choose qualified installers; and (c) assisting homeowners in pre-qualification and ex-post analysis, in learning how to operate their renewable heating systems and in solving problems during the post-installation period, can contribute to improved technology reputation, which can, in turn, increase technology uptake by other homeowners.

scholarly journals Air Temperature Control System in a Building on the Basis of Mathematical Modelling

2018 ◽  
Vol 155 ◽  
pp. 01041 ◽  
Author(s):  
Aleksandr Pilipenko ◽  
Sergei Petrov
Keyword(s):  
Computer Simulation ◽  
Control System ◽  
Mathematical Modelling ◽  
Mathematical Models ◽  
Air Temperature ◽  
Temperature Control ◽  
Automated System ◽  
Temperature Control System ◽  
Heating Systems ◽  
The Cost

In the article the authors solve a crucial objective of reducing the cost of heating services through the introduction of a system, controlling boilers and heating devices, based on modelling of the building and predicting heating systems functioning and operation. The authors describe the method of mathematical modelling of heating systems of the building and represent the developed mathematical models, pledged and installed into the developed automated system. The authors have offered an automated system of dispatch control of the boilers with the elements of computer simulation and modelling.

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