A field measurement of temperature and humidity in a utility tunnel and a brief analysis of the exhaust heat recovery system

Tai, Chuanmin; Gao, Tian; Lei, Wenjun; Wang, Jianwei

doi:10.1177/1420326x19897097

Cited by 12 publications

(11 citation statements)

References 37 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…If humid air is continuously formed inside the utility tunnel, it can cause corrosion of metal facilities including various pipes, and a humid environment accelerates the formation of mold and bacteria, which can adversely affect the health of workers. In addition, in the case of power lines and telecommunication lines, improper temperature and humidity can cause electric sparks and ignite combustibles [19][20][21][22]. Air conditioners and dehumidifiers are generally used to remove high humidity in general buildings.…”

Section: Problems With Air Environment and Condensation In Undergroun...mentioning

confidence: 99%

Air Conditioning System Design to Reduce Condensation in an Underground Utility Tunnel Using CFD

Park

Lee

et al. 2022

IEEE Access

View full text Add to dashboard Cite

In this study, the internal environment such as the air temperature, humidity, and wall temperature of the underground utility tunnel, was analyzed. The current status and problems of the air conditioning system were examined by analyzing the capacity of the exhaust fan and the air velocity inside the utility tunnel. The field experiment showed that the utility tunnel has a relative humidity of 95% or higher for most sections during summer. The deviation of the internal air temperature was about 4 ℃ depending on the section, and the dew condensation occurred. However, most of the exhaust fans has a capacity below the standard minimum air velocity of 2.5m•s -1 . In particular, in the section where dew condensation occurred, the air velocity was 0.26 to 0.97 m•s -1 , indicating the presence of stagnant air inside the facility. Therefore, this study attempted to minimize dew condensation by calculating the proper exhaust fan capacity using computational fluid dynamics and installing circulation fans and duct systems in the section where the dew condensation occurred. As a result, when a circulation fan was installed, it was possible to increase the air velocity inside the utility tunnel, and the relative humidity could be reduced by about 78%. By installing a duct, the direct supply of external air or the discharge of internal humid air was simulated for the section where dew condensation occurred. The result showed that the relative humidity could be reduced by about 78% when the duct system was operated in the intake direction. INDEX TERMSCondensation, CFD, Circulation fan, Duct, Ventilation, Underground utility tunnel I. INTRODUCTION A. THE CONCEPT AND CURRENT STATUS OF THE UNDERGROUND UTILITY TUNNELAn underground utility tunnel is a structure that accommodates and supplies two or more types of urban lifelines such as pipelines for electricity, gas, water supply, telecommunication, and sewage. In addition, it is a facility installed underground to improve the aesthetics, preservation of road structures, and smooth flow of traffic, especially in urban areas [1]. If a single pipeline for each electricity, gas, and water is constructed in underground, the increased cost due to construction work and the formation of a complex underground structure network can cause problems in the This article has been accepted for publication in IEEE Access.

show abstract

Section: Problems With Air Environment and Condensation In Undergroun...mentioning

confidence: 99%

Air Conditioning System Design to Reduce Condensation in an Underground Utility Tunnel Using CFD

Park

Lee

et al. 2022

IEEE Access

View full text Add to dashboard Cite

show abstract

“…23 Seong et al 24,25 measured the temperature, RH, surface temperature and air velocity in an underground utility tunnel located in Incheon, Korea, during the autumn and winter seasons and considered a few risk factors under normal conditions, such as weakening structural durability, the corrosion of indoor facilities, and leakage of electricity from electric power facilities. Wu et al 26 quantitatively and qualitatively studied airborne fungi in three comprehensive compartments of a utility tunnel in Nanjing; the fungal concentrations found in three compartments were 931 CFU/m, 3 895 CFU/m 3 and 729 CFU/m, 3 which exceeded the suggested low threshold levels for fungal spores in indoor air (200 CFU/m 3 ). 27 Ventilation of a utility tunnel can considerably improve the air quality.…”

Section: Introductionmentioning

confidence: 97%

“…3 Because of these advantages, utility tunnels have been widely constructed in many modern cities. 3,4…”

Section: Introductionmentioning

confidence: 99%

Measurement of indoor environmental parameters and analysis of the condensation phenomenon in urban utility tunnels

Tai

Gao

Lei

2022

Indoor and Built Environment

Self Cite

View full text Add to dashboard Cite

Condensation is a major issue in the safe operation of utility tunnels. To address the condensation problem, the indoor air temperature, relative humidity (RH) and surface temperature in an urban utility tunnel in Jining were continuously measured, and the condensation conditions were surveyed and analysed. The results indicated that under natural ventilation conditions, the air temperature in the comprehensive cabin varied from 23.4°C to 24.5°C, the RH fluctuated between 86.4% and 95.3%, and the corresponding air dew point temperature (DPT) remained in the range of 22.2°C–22.9°C. The surface temperature of the water supply pipeline ranged from 17.8°C to 18.5°C, which was far lower than the DPT in the tunnel, resulting in serious condensation. A water supply pipeline with an anti-condensation design was developed based on environmental test data. A 25-mm-thick rubber plastic sponge insulation layer was used to thermally insulate the water supply pipeline, preventing further dew condensation. Furthermore, mechanical ventilation had little effect on reducing the RH in the tunnel and may actually cause dew condensation; therefore, a ventilation control mode was proposed in this study. These results are expected to provide basic data for further research and reference for the safe management of utility tunnels.

show abstract

“…1,5 Therefore, tunnels are often the subject of air pollution research with different purposes. The analysis of air pollutant emissions from road vehicles or source apportionment, [6][7][8][9][10] the pollutant composition and species, [11][12][13] the exposure and potential health impacts, [14][15][16][17][18] the efficient removal of pollutants by chemical compositions and catalysts, 19,20 the effect of meteorological parameters and the condition on pollutant dispersion [21][22][23][24] and mechanical ventilation technologies or design principles [25][26][27][28][29] form some important areas of these research. As a result, many parameters such as the ventilation rate, the critical pollutants, the exposure time, the type and peak time of passing cars, the road safety, building material and the geographical position should be considered in tunnel design.…”

Section: Introductionmentioning

confidence: 99%

Reconnaissance study of air quality in traffic tunnels: A case study of Aba-Saleh Al-Mahdi tunnel, Iran

Tavakoli

2022

Indoor and Built Environment

View full text Add to dashboard Cite

Traffic tunnels have the potential to reduce the traffic congestion, but in some cases, they lead to the accumulation of air pollutants. The present study focused on the analysis of chemical and biological pollutants inside and outside of the largest tunnel in Iran. The measurements were done during different hours and days in four seasons (2018–2019). The collected data showed that the inside of the tunnel was more polluted than the outside, and the type, the number of passing cars and the weather condition had an effect on concentrations. Winter, summer and evenings are the most polluted periods. Comparison of data with national and WHO standards revealed that SO2 is a critical pollutant for all periods; NO2 is a problem during summer, winter and evenings. The concentration of PM2.5 exceeded these standards in the evenings. A high correlation between PM2.5 and PM10, in concentration, changes and spatial distribution points to the same emission sources. For biological pollutants, a high microbial population was found during the summer and afternoons. Among the isolated Gram-positive bacterium, the Bacillus sp (38%) and Aspergillus sp (32%) were the highest population of bacteria and fungi, respectively. Measurement results in combination with a high rate of hospital admissions emphasized the poor air quality inside the tunnel and the necessity for the installation of mechanical ventilation systems.

show abstract

A field measurement of temperature and humidity in a utility tunnel and a brief analysis of the exhaust heat recovery system

Cited by 12 publications

References 37 publications

Air Conditioning System Design to Reduce Condensation in an Underground Utility Tunnel Using CFD

Air Conditioning System Design to Reduce Condensation in an Underground Utility Tunnel Using CFD

Measurement of indoor environmental parameters and analysis of the condensation phenomenon in urban utility tunnels

Reconnaissance study of air quality in traffic tunnels: A case study of Aba-Saleh Al-Mahdi tunnel, Iran

Contact Info

Product

Resources

About