scholarly journals The distribution of air temperature and velocity in the selected boiler room

2018 ◽  
Vol 44 ◽  
pp. 00020 ◽  
Author(s):  
Robert Cichowicz ◽  
Artur Stelęgowski
Keyword(s):  
Air Temperature ◽  
Thermal Environment ◽  
Physical Factors ◽  
Limit Values ◽  
Air Supply ◽  
Industrial Buildings ◽  
Boiler Room ◽  
Environment Parameters ◽  
The Impact

The crucial impact on the indoor air quality in technological rooms, including boiler plant buildings, is made by operation of technological devices and ventilation systems. Therefore, the distribution of air temperature and velocity in these rooms mainly depends on location and heat gains generated by combustion devices, as well as emplacement of air supply and air exhaust elements. The temperature and airflow volume of supplied air is also an issue, because the indoor environment parameters are formed by the flow of air in the working area. Determination of the impact of physical factors on the thermal environment in a room is possible using an analysis of the air temperature and velocity. This issue is vital in terms of necessity to maintain the adequate heat conditions in the working area. Therefore, basing on the experimental measurements and numerical calculations (made in DesignBuilder software), the distribution of air temperature and velocity was analyzed in the selected industrial boiler room, located in the Lodz city, in Poland. The results obtained were compared with the recommended and limit values in the industrial buildings.

Mathematical and experimental analysis of the thermal effectiveness of an oscillating jet with side-to-side swing louvers in a cassette split type air conditioner

2019 ◽  
Vol 29 (2) ◽  
pp. 240-254 ◽  
Author(s):  
Yunqing Fan
Keyword(s):  
Thermal Environment ◽  
Thermal Sensation ◽  
Control Strategies ◽  
Heating Time ◽  
Air Conditioner ◽  
Beta Distributions ◽  
Air Supply ◽  
The Face ◽  
Heating Mode ◽  
The Impact

The impact of air supply control strategies (louvers movement) on indoor thermal environment were evaluated in this study. The temperature uniformity was evaluated by: (i) the air distribution performance index (ADPI) to determine the air diffusion performance in heating mode; (ii) the air draught rate (DR%) on the face to determine the local discomfort due to cold draught; (iii) the mathematically determined vertical temperature stratification in a room with Beta distributions. A comparison of the conventional type with three different oscillating type airflows (louvers swing angle ±20°, ±40° and ±60°) were experimentally analysed to determine appropriate air supply control strategies. The results indicated that Beta distributions could capture the overall trend of the oscillating airflow, to establish the acceptable thermal uniformity and higher thermal effectiveness. The oscillating airflow as generated by the side-to-side swing type delivery louvers mounted inside a cassette split type air conditioner could shorten heating time by 20% to attain room temperature from 9°C. The data reveal that oscillating airflow can provide a better thermal sensation to feeling warm in the heating mode at both ankle and neck level. The ADPI is approximately 85% in the occupied zone. The actual draught rates on the face ranged 0–35%.

scholarly journals The influence of air conditioning changes on the effective dose due to radon and its short-lived decay products

Nukleonika ◽  
2016 ◽  
Vol 61 (3) ◽  
pp. 239-244
Author(s):  
Dominik Grządziel ◽  
Krzysztof Kozak ◽  
Jadwiga Mazur ◽  
Bernard Połednik ◽  
Marzenna R. Dudzińska ◽  
...  
Keyword(s):  
Effective Dose ◽  
Air Conditioning ◽  
Indoor Environments ◽  
Radon Progeny ◽  
Inhalation Dose ◽  
Decay Products ◽  
Air Supply ◽  
Industrial Buildings ◽  
The Mean ◽  
The Impact

Abstract Most people spend the majority of their time in indoor environments where the level of harmful pollutants is often significantly higher than outdoors. Radon (222Rn) and its decay products are the example of radioactive pollutants. These radioisotopes are the main source of ionizing radiation in non-industrial buildings. The aim of the study was to determine the impact of air-conditioning system on radon and its progeny concentrations and thus on the effective dose. The measurements were carried out in the auditorium at the Environmental Engineering Faculty (Lublin University of Technology, Poland). Measurements of radon and its progeny (in attached and unattached fractions) as well as measurements of the following indoor air parameters were performed in two air-conditioning (AC) operation modes: AC ON and AC ON/OFF. The air supply rate and air recirculation were taken into consideration. The separation of radon progeny into attached and unattached fractions allowed for determining, respectively, the dose conversion factor (DCF) and the inhalation dose for teachers and students in the auditorium. A considerable increase of the mean radon progeny concentrations from 1.2 Bq/m3 to 5.0 Bq/m3 was observed in the AC ON/OFF mode compared to the AC ON mode. This also resulted in the increase of the inhalation dose from 0.005 mSv/y to 0.016 mSv/y (for 200 h/year). Furthermore, the change of the air recirculation rate from 0% to 80% resulted in a decrease of the mean radon concentration from 30 Bq/m3 to 12 Bq/m3 and the reduction of the mean radon progeny concentration from 1.4 Bq/m3 to 0.8 Bq/m3. This resulted in the reduction of the inhalation dose from 0.006 mSv/y to 0.003 mSv/y.

scholarly journals Effect of supply air temperature on conservation of energy in air conditioning of space

2011 ◽  
pp. 51-54
Author(s):  
V. N. Bartari ◽  
S. P. S. Rajput
Keyword(s):  
Air Temperature ◽  
Distribution System ◽  
Energy Savings ◽  
Thermal Environment ◽  
Temperature Sensors ◽  
Air Distribution ◽  
Conservation Of Energy ◽  
Buoyancy Flow ◽  
Flow Energy ◽  
The Impact

In HVAC applications, huge amount of energy is utilized in fans and blowers to maintain the flow. In this paper energy savings associated with air distribution is discussed. In a most commonly used air distribution system, uniform thermal environment in the occupied space is established. An alternative to this method is the under floor air distribution system (UFAD) which is in its fantasy state. Thermal stratification can be established in this method due to the buoyancy flow of the air. In this paper assessment of the impact of temperature sensors in energy savings is done in UFAD system. It is observed that by the placement of temperature sensors in the occupied space, supply air temperature can be controlled while maintaining the comfort conditions. By optimal conditions of the temperature and volume flow, energy savings can be achieved due to reduction in energy requirements in refrigeration and ventilation. The comfort criteria of ASHRAE standard 55-92 is taken.

scholarly journals Effect of thermal environment on performance of broiler chickens using fuzzy modeling

Revista CERES ◽  
2017 ◽  
Vol 64 (4) ◽  
pp. 337-343
Author(s):  
Flávio Alves Damasceno ◽  
Déborah Cunha Cassuce ◽  
Lucas Henrique Pedrozo Abreu ◽  
Leonardo Schiassi ◽  
Ilda de Fátima Ferreira Tinôco
Keyword(s):  
Set Theory ◽  
Air Temperature ◽  
Fuzzy Set ◽  
Fuzzy Set Theory ◽  
Broiler Chickens ◽  
Thermal Environment ◽  
Second Phase ◽  
Feed Conversion ◽  
Productivity Losses

ABSTRACT This study aimed to develop a decision-support system based on fuzzy set theory, which can estimate welfare depending on the production responses of broiler chickens raised in climatic chambers. In the first phase, the influence of four different air temperature conditions on the performance of broilers was identified. Thus, the effect of air temperature on productivity was evaluated. In the second phase, a model was developed using the fuzzy set theory, in which feed intake responses, weight gain, and feed conversion were established according to age and the air temperature at which the birds were maintained, obtaining an efficient evaluation of the thermal environment. The results indicate that the proposed methodology is a promising technique for the determination of the level of thermal comfort endured by broilers, capable of assisting in making decisions on control of the thermal environment, avoiding productivity losses.

A STUDY OF THE IMPACT OF DYNAMIC GROUND ACTIONS ON MOMENTARY VALUES OF FRICTION FORCES AT THE GAS PIPELINE-BACKFILL INTERFACE

Tribologia ◽  
2018 ◽  
Vol 278 (2) ◽  
pp. 21-28
Author(s):  
Wacław GAWĘDZKI ◽  
Dariusz LEPIARCZYK ◽  
Jerzy TARNOWSKI
Keyword(s):  
Heavy Traffic ◽  
Soil Surface ◽  
Test Method ◽  
Limit Values ◽  
Friction Forces ◽  
Test Methodology ◽  
Short Time ◽  
Changes Over Time ◽  
The Impact

Buried pipelines are subjected to the action of static forces and moments caused by friction forces at the pipeline-ground contact. At the same time, pipelines are subjected to dynamic actions generated by paraseismic pulses, in particular, in areas of mining and heavy traffic. The paper presents and experimentally verifies a test method of tribological pipeline-soil interaction in conditions of artificially induced soil static and dynamic actions. The applied test methodology allows the determination of friction forces at the tested pipeline section. The friction forces changes over time on the pipeline and soil surface for the varying pipeline tensioning forces were continuously recorded during the tests. Based on the Short-Time Fourier Transform (STFT) of signals, the paper presents the impact of dynamic actions on momentary values of measured friction forces. Relationships are given that allow the determination of friction forces between the pipeline and the soil, including their limit values resulting in the loss of the mutual adhesion of the pipeline and the soil.

scholarly journals Exergy of heat flows in exchanger consisting f gravity heat pipes

2012 ◽  
Vol 51 (No. 3) ◽  
pp. 73-78
Author(s):  
D. Adamovský ◽  
P. Neuberger ◽  
D. Herák ◽  
R. Adamovský
Keyword(s):  
Heat Flow ◽  
Air Temperature ◽  
Thermal Efficiency ◽  
Heat Pipes ◽  
Exergy Efficiency ◽  
Heat Flows ◽  
Heat Processes ◽  
The Impact

The paper deals with the analysis of the impact of inlet air temperature on the exergy efficiency and exergy of the losing heat flow and determination of the relation between the exergy and thermal efficiency in an exchanger consisting of gravity heat pipes. The assessment of heat processes quality and transformation of energy in the exchanger are also dealt with.

scholarly journals Thermal and Geometric Controls on the Rate of Surface Air Temperature Changes in a Medium-Sized, Midlatitude City

2007 ◽  
Vol 46 (2) ◽  
pp. 241-247 ◽  
Author(s):  
Tomohiko Tomita ◽  
Hiroyuki Kusaka ◽  
Ryo Akiyoshi ◽  
Yoshiyuki Imasato
Keyword(s):  
Time Dependence ◽  
Air Temperature ◽  
Urban Areas ◽  
Mesoscale Model ◽  
Thermal Environment ◽  
Surface Air Temperature ◽  
Anthropogenic Heat ◽  
View Factor ◽  
Temperature Changes ◽  
The Impact

Abstract Gradual cooling in the evening forms a wintertime nocturnal urban heat island. This work, with a mesoscale model involving urban canopy physics, is an examination of how four thermal and geometric controls—anthropogenic heat QF, heat capacity C, thermal conductivity k, and sky-view factor ψs—modify the rate of surface air temperature changes ΔT/Δt. In particular, the time dependence is diagnosed through numerical experiments. The controls QF and k are major agents in the evening, when QF changes the evening ΔT/Δt linearly and k is logarithmic. The effects of C and ψs are large in the morning and in the afternoon with those of k. The impact of QF is, however, substantial only in the evening. Because the time dependence of C and k is different, the thermal inertia used as a parameter in the urban climate studies should be divided into two parameters: C and k. To improve the thermal environment in urban areas, the modification of QF and k could be effective.

scholarly journals Survey on thermal environments in bathrooms and elderly behavior while bathing in old residential buildings in Nanjing, China

2020 ◽  
Vol 172 ◽  
pp. 15009
Author(s):  
Pengcheng Shi ◽  
Yonghui Li ◽  
Yuan Ying ◽  
Shuichi Hokoi
Keyword(s):  
Blood Pressure ◽  
Air Temperature ◽  
Thermal Environment ◽  
Residential Buildings ◽  
The Elderly ◽  
Personal Factors ◽  
Physiological Models ◽  
Thermal Environments ◽  
Daily Behavior ◽  
The Impact

Bathing is a typical daily behavior among Chinese elderly people, which causes large thermal environmental fluctuations especially in winter. Rapid fluctuations of the thermal environment can lead to a drastic change in human blood pressure and may cause accidents while bathing. The most common style of Chinese bathing is showers. Information on the thermal environment during bathing is limited, making analysis difficult. This study aims to understand the current situation of bathing in old residences in Nanjing, China. To examine elderly bathing behaviors and thermal environments in bathrooms during bathing, we monitored the thermal environment in three elderly families and administered a questionnaire survey from which 49 responses were obtained. Results were categorized into environmental and personal factors that affect blood pressure during bathing. In winter, the temperature in a bathroom is often below 10℃. A heating device is installed close to the head (87%); thus, the thermal environment is vertically non-uniform (air temperature difference often exceeds 10℃). Most elderly individuals bathe for less than 30 minutes and the rise in air temperature often exceeds 10℃. This information will be used as the boundary conditions for thermo-physiological models that can quantitatively assess the impact of the environment on the elderly, and for the renovation of bathrooms.

scholarly journals The Evolution of Climate Changes in Portugal: Determination of Trend Series and Its Impact on Forest Development

Climate ◽  
2019 ◽  
Vol 7 (6) ◽  
pp. 78 ◽  
Author(s):  
Leonel J. R. Nunes ◽  
Catarina I. R. Meireles ◽  
Carlos J. Pinto Gomes ◽  
Nuno M. C. Almeida Ribeiro
Keyword(s):  
Rural Communities ◽  
Air Temperature ◽  
Critical Period ◽  
Large Scale ◽  
Climate Changes ◽  
Variable Precipitation ◽  
The Impact ◽  
The Relationship ◽  
Climatic Normal

Climate changes are a phenomenon that can affect the daily activities of rural communities, with particular emphasis on those directly dependent on the agricultural and forestry sectors. In this way, the present work intends to analyse the impact that climate changes have on forest risk assessment, namely on how the occurrence of rural fires are affecting the management of the forest areas and how the occurrence of these fires has evolved in the near past. Thus, a comparative analysis of the data provided by IPMA (Portuguese Institute of the Sea and the Atmosphere), was carried out for the period from 2001 to 2017 with the climatic normal for the period between 1971 to 2000, for the variables of the average air temperature, and for the precipitation. In this comparative study, the average monthly values were considered and the months in which anomalies occurred were determined. Anomalies were considered in the months in which the average air temperature varied by 1 °C than the value corresponding to the climatic norm, in at least 50% of the national territory. The same procedure was repeated for the variable precipitation, counting as anomaly the occurrence of a variation in precipitation of 50%, also in 50% of the national territory. Then the calculation of the moving averages for cycles of 3, 5 and 7 periods were applied, and the trend lines were projected. Subsequently, the relationship between the results obtained and the occurrence of rural fires as well as the spatial distribution of forest area, species and structure were analyzed. From the results obtained it was possible to confirm the existence of a tendency for the occurrence of climatic anomalies, highlighting the occurrence of an increasing number of months with temperatures higher by at least 1 °C. It was possible to foresee the relation between the occurrence of rural fires and the periods of anomaly and absence of precipitation. From the results obtained it is also possible to infer that, analyzing the tendency for these phenomena to occur, it can be necessary to change the “critical period of rural fires”, since it is verified that what is currently in use does not covers the entire period where anomalies occur and where large-scale rural fires potentially can happen.

scholarly journals Determination of Colistin in Contents Derived from Gastrointestinal Tract of Feeding Treated Piglet and Broiler

Antibiotics ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 422
Author(s):  
Chun Peng ◽  
Sanling Zuo ◽  
Yinsheng Qiu ◽  
Shulin Fu ◽  
Lijuan Peng
Keyword(s):  
Bacterial Infections ◽  
Ecological Environment ◽  
Resistant Bacteria ◽  
Quantitative Mass Spectrometry ◽  
Limit Values ◽  
Quantitation Limit ◽  
The Mean ◽  
Potential Impact ◽  
The Impact

Colistin is considered as the last-resort treatment for multiantibiotic-resistant Gram-negative bacterial infections in humans. However, the oral administration of colistin to livestock and poultry results in the introduction of large amounts of colistin to the surrounding environment via urine and feces, potentially inducing the prevalence of colistin-resistant bacteria and the impact on the ecological environment. We established a quantitative mass spectrometry (MS) based method to measure colistin in contents recovered from the gastrointestinal segments of piglets and broilers, as well as colistin in feces from the animals. The mean recoveries of colistin from different matrices were between 73.2% and 103.9%. The quantitation limit values for different matrices ranged from 0.37 to 1.85 ng/g. In colistin-treated swine samples, the highest concentration of colistin was detected in feces samples at a level of 1248.3 ng/g. However, the highest concentration of colistin in broiler samples was around 4882.9 ng/g, which was found in the contents derived from broilers’ ceca. The employment of the proposed method to assess colistin in animals’ gastrointestinal tracts might help to understand the colistin absorption in animals’ guts and the potential impact of colistin on the emergence of resistant bacteria in animals’ gut flora and the ecological environment.

Sign in / Sign up

Export Citation Format

Share Document