Experimental investigation on the performance of earth-air pipe heat exchanger for different soil compaction levels

Sun

Mathematical Problems in Engineering

et al. 2021

The earth-to-air heat exchanger (EAHE) system, as a clean and efficient shallow geothermal energy application technology, has obvious effects in reducing the energy consumption of passive low-energy buildings. The traditional horizontal EAHE system is difficult to apply and popularize due to its large occupation, unfavorable shallow soil temperature, and difficulty in timely centralized discharge of condensed water. This paper proposes a new type of vertical earth-to-air heat exchanger (VEAHE) system. The VEAHE system has a number of advantages such as smaller occupation, efficient geothermal energy utilization, and centralized discharge of condensed water. In order to evaluate the influence of different parameters on the thermal performance of the VEAHE system, a mathematical model of the VEAHE system was developed. And, the data calculated by the model highly tallied with the experimental data. The results showed that laying thermal insulation layers at the outlet of risers will effectively restrain the interference of downcomers to risers. It is advisable to set thickness and length of the insulation layer at 30 mm and 3 m. Considering the compromise between thermal performance and construction costs of the VEAHE system, the length of the ducts at 30–50 m and the diameter at 150–250 mm are recommended. The air supply volume of a single shaft can reach 500–1200 m3/h as the air velocity reaches 3–7 m/s.

Section: Influences Of the Length Of Insulationsupporting

confidence: 73%

Numerical Research and Parametric Study on the Thermal Performance of a Vertical Earth-to-Air Heat Exchanger System

Sun

Mathematical Problems in Engineering

et al. 2021

“…Elminshawy et al [15] analyzed compactness level of soil on the thermal performance and revealed that the soil compactness of 91.17% could decline air temperature by 21°C.…”

Section: Literature Reviewmentioning

confidence: 99%

Techno-economic assessment and optimization of a hybrid renewable earth - air heat exchanger coupled with electric boiler, hydrogen, wind and PV configurations

2020

“…The heating and cooling capacity of the EAHE varies depending on different factors such as the climate, type of soil, and the design parameters. This capacity has been studied both experimentally [1][2][3][4] and theoretically (analytical and /or numerical) or a combination of both methods.…”

Section: Introductionmentioning

confidence: 99%

Thermal potential of a geothermal earth-to-air heat exchanger in six climatic conditions of México

Rodríguez-Vázquez

Xamán

Chávez

et al. 2020

Mechanics & Industry

In this paper, the thermal and ventilation potential of a geothermal Earth-to-Air Heat exchanger (EAHE) is studied for six weather in Mexico. The cities for the study and their climate were Villahermosa (hot-humid), Merida (hot-sub humid), Monterrey (dry), Juarez City (very dry), Zacualtipan-Hidalgo (warm-humid) and Mexico City (warm-sub-humid). The thermal behavior of the EAHE was modeled numerically for the corresponding warmest and coldest days of the year for each city and three values of Reynolds number. The 24 hrs simulations were carried out with an in-house code using data every 10 minutes. To get the results, 5,184 computational runs were necessary. The results showed that the EAHE has poor ventilation potential for climates with high levels of humidity such as Villahermosa, while for cities with low levels of humidity such as Chihuahua, the ventilation potential increases significantly, the rest of the cities fall in between. As for its application in Mexico, the results show that the EAHE is highly recommended for dry climates such as at the north of the country and not recommended for humid climates such as at the south and south-east of the country.