Feasibility of Employing a Heat Insulation Wall as the North Wall of a Chinese Solar Greenhouse in a Severely Cold Area of China

2019 ◽  
Vol 35 (6) ◽  
pp. 903-910
Author(s):  
Ming Li ◽  
Pingzhi Wang ◽  
Weitang Song
Keyword(s):  
Heat Loss ◽  
Air Temperature ◽  
Heat Insulation ◽  
Environmental Damage ◽  
The North ◽  
Solar Greenhouse ◽  
Cold Area ◽  
North Wall ◽  
Insulation Wall ◽  
The Impact

Abstract. The conventional north wall of a Chinese solar greenhouse (hereafter referred to as a “solar greenhouse”) can release heat inside and help maintain a high indoor air temperature (T) during winter nights. However, the construction of conversational walls face problems of high cost, low construction quality, environmental damage, etc. Based on this, heat insulation walls have aroused much interest. However, this kind of wall can barely store and release heat, putting the solar greenhouse at risk of low T. The purpose of this study is to investigate whether the impact of the heat insulation wall could be weakened by decreasing the heat loss through the greenhouse envelope. The thermal environment of a solar greenhouse located in a severe cold area of China (Mohe County, Heilongjiang Province) was examined during sunny days, of which the north wall was constructed from polystyrene boards and plastered with 10 mm-thick mortar. During the experiment, the outdoor air temperature (T) was -22.8±5.6°C during the night, reaching a low of -34.7°C. The amount of heat released from the north wall can be neglected, as it was 5.4% of the total heat obtained by the test solar greenhouse. In comparison with conventional solar greenhouses, both heat loss through the building envelope and the heat obtained from the test solar greenhouse during the night decreased. As a result, T was maintained at 10.6±2.9°C, with a low of 6.8°C, during the night, which was within the normal range of a conventional solar house located in northern China. Thus, the impact of the heat insulation wall on T in the sunny days was weakened by decreasing the heat loss through the greenhouse envelope. Nevertheless, more work on the performance of test solar greenhouse on cloudy days and summer days should be conducted to fully validate the proposed hypothesis. Keywords: Chinese solar greenhouse, Heat insulation wall, Heat loss, Indoor temperature.

Performance of Solar Utilization System Developed with Capillary Tube Mats to Collect and Release Heat in Chinese Solar Greenhouses

2020 ◽  
Vol 36 (2) ◽  
pp. 167-174 ◽  
Author(s):  
Ming Li ◽  
Liwei Yue ◽  
Weitang Song ◽  
Chaoyuan Wang
Keyword(s):  
Solar Energy ◽  
Air Temperature ◽  
Indoor Air ◽  
Heat Insulation ◽  
Capillary Tube ◽  
Water Tank ◽  
Capillary Tubes ◽  
The North ◽  
North Wall ◽  
Heat Released

HighlightsA solar utilization system was developed with capillary tube mats (SUSCTM) to heat Chinese solar greenhouses (CSGs) actively during winter nights.In the solar day, SUSCTM collected 28~33% of the accumulated solar energy on the north-wall and released 40.3~48.6% of the collected heat in night under the experimental conditions.The thermal performances of SUSCMT can be further improved by improving the heat insulation of the water tank, doubling and elongating the capillary tubes.Abstract.A solar utilization system composed of capillary tube mats, a water tank, recirculating pipes, and a pump (SUSCTM) was developed to improve the temperature of Chinese solar greenhouses (CSGs) during winter nights. The capillary tube mats were mounted on the north-wall to intercept solar radiation. By circulating water within the SUSCTM during the daytime, the solar energy can be absorbed and stored in the water tank. In the same way, the heat stored in the water tank can be recovered to increase the indoor air temperature (Tin) in the night. During the daytime hours of sunny days, SUSCMT stored the heat of 102.4~135.4 MJ under the test conditions, which accounts for 28~33% of the accumulated solar energy on the north wall. The heat released by the SUSCTM during the nighttime hours of sunny days accounted for 40.3~48.6% of the collected heat. As a result, the minimum Tin in the night was elevated by 1.6°C~1.9°C, with the coefficient of performance (COP) of 1.3~1.8. On the other hand, the SUSCMT only operated during the night hours of cloudy day and elevated the minimum Tin by 1.5°C. The COP was 1.2 as a result. In addition, the amount and flux of heat released by the SUSCMT per the north wall area matched the conventional north wall of CSGs. Based on the proposed model, the thermal performances of SUSCMT can be further improved by improving the heat insulation of the water tank, doubling and elongating the capillary tubes. Thus, the SUSCMT has the potential to increase the Tin of CSG during winter nights. Keywords: Capillary tube mats, Chinese solar greenhouse, Indoor air temperature, Solar utilization system, Water circulation.

scholarly journals Effect of the ridge position ratio on the thermal environment of the Chinese solar greenhouse

2021 ◽  
Vol 8 (5) ◽  
Author(s):  
Xiaoyang Wu ◽  
Xingan Liu ◽  
Xiang Yue ◽  
Hui Xu ◽  
Tianlai Li ◽  
...  
Keyword(s):  
Structural Design ◽  
Cfd Simulation ◽  
Thermal Environment ◽  
The South ◽  
The North ◽  
Dependency Relationship ◽  
Solar Greenhouse ◽  
Computational Fluid Dynamics Cfd ◽  
North Wall ◽  
Maximum Air Temperature

This paper clarified the mechanism of the south and north roofs' effect on the thermal environment of the Chinese solar greenhouse (CSG), using a new parameter: ridge position ratio (RPR), which can describe the dynamic dependency relationship between the south and north roofs. A mathematical model was established using a method of combining computational fluid dynamics (CFD) simulation with experiments, then the model was used to further analyse the effect of RPR on the thermal environment of the CSG. The experimental greenhouse was simulated as an empty building to obtain results independently from these factors including crop and ventilation conditions. The results showed that the occurrence time of the maximum air temperature will be delayed when RPR increases to 0.3 during the daytime. As RPR increases, the heat storage layer of the soil gradually becomes thinner, but the north wall remains unchanged. RPR has a relatively small effect on the minimum temperature of each greenhouse part during the night. Mathematical models of the relationships between RPR, the solar energy that entered the greenhouse and the released heat energy of the enclosure structures were established, respectively. This paper can provide theoretical guidance for the structural design of the CSG.

scholarly journals Solar Radiation Allocation and Spatial Distribution in Chinese Solar Greenhouses: Model Development and Application

Energies ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1108 ◽  
Author(s):  
Xiaodan Zhang ◽  
Jian Lv ◽  
Jianming Xie ◽  
Jihua Yu ◽  
Jing Zhang ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Solar Radiation ◽  
Heat Storage ◽  
Light Environment ◽  
Beam Radiation ◽  
Growth Environment ◽  
The North ◽  
Cloudy Weather ◽  
Solar Greenhouse ◽  
North Wall

Solar radiation is the sole energy source for Chinese solar greenhouse agriculture. A favorable light environment is the foundation of a desirable crop growth environment, and it is key in solar greenhouse design. In this study, a mathematical model is established to quantitatively evaluate the solar greenhouse light environment. The model was developed considering the greenhouse shape parameters, materials’ optical properties, and interior solar radiation evolution, including the beam radiation, diffuse radiation, and multi-reflection. The model was validated under different weather conditions, and the results reveal a mean percentage error of 1.67 and 10.30% for clear sunny weather and cloudy weather, respectively, and a determination coefficient of 0.9756. By using this model, the solar radiation allocation in a solar greenhouse was calculated to determine the solar radiation availability for the heat-storage north wall and the entire greenhouse, and the dynamical spatial distribution of the solar radiation was obtained to describe the light environment quality. These allow the optimization of the greenhouse lighting regulation and planting pattern. Moreover, several optimizing measures are derived according to the model for improving the low-light environment near the north wall and maximizing the north wall’s heat storage/release capacity in a solar greenhouse.

scholarly journals Abundance of Ixodes persulcatus ticks in Komi Republic as a function of an air temperature

2020 ◽  
Vol 9 (5-6) ◽  
pp. 811-816 ◽  
Author(s):  
A. A. Tronin ◽  
N. K. Tokarevich ◽  
B. R. Gnativ
Keyword(s):  
Air Temperature ◽  
Komi Republic ◽  
Tick Bite ◽  
Stable Phase ◽  
Tick Population ◽  
Ixodes Persulcatus ◽  
North East ◽  
The North ◽  
Administrative Units ◽  
The Impact

The sharp rising incidence of tick-borne encephalitis (TBE) in Komi Republic at the North-east of European Russia was recorded last decades. Tick-bite incidence also was grown. Rapid rise of TBE incidence growth and Ixodidae ticks depends on a number of factors, and the impact of climate change being one of them. Ixodes persulcatus ticks is considered as a main vector of TBE in Komi. Our objective is to estimate the influence of air temperature change on the tickbite incidence and Ixodes persulcatus population in Komi. Komi Republic is located near the Polar circle where the northern frontier of Ixodes persulcatus ticks situated and we expected the growth of tick’s population. The number of Komi inhabitants seeking medical care after tick bites in 1992–2014 was considered. Gridded monthly air temperature data with grid size 0.5 degree were recalculated to temperature referred to Komi administrative units. The time series of annual number of tick victims from 1992 till 2014 and model air temperature from 1948 till 2016 for all Komi administrative units were compiled. We analyzed the data on tick-bite incidence in Komi administrative units in relation to changes in local annual average air temperature within the study area. The linear dependence of the tick-bite incidence on air temperature was established when of the tick-bite incidence is represented in logarithm form. The tick population depends not only on temperature but humidity, landcover and hosts. Described areas of Komi belong to humid climate, where precipitations exceed evaporation. Most of the Komi territory is covered by taiga with underwood, grass and bush. Hosts of the first and the major levels are represented by birds and rodents. The dependence of tick-bite incidence and temperature looks like “Malthus’s law”, but the development of population depends on temperature not on time. The exponential growth in the nearest future will ceased and the population will proceed to stable phase. Ticks population in Komi Republic is moving to the North and the air temperature determines the dynamics of population.

scholarly journals Impact of macro-scale circulation types on the occurrence of frosty days in Poland

2015 ◽  
Vol 9 (1) ◽  
pp. 55-65 ◽  
Author(s):  
Arkadiusz Marek Tomczyk
Keyword(s):  
Air Temperature ◽  
North Atlantic ◽  
Research Study ◽  
The North ◽  
Circulation Types ◽  
Daily Data ◽  
Macro Scale ◽  
The North Atlantic ◽  
The North Atlantic Oscillation ◽  
The Impact

AbstractThe research aimed at determining the variability of occurrence of frosty days in Poland and defining the impact of macro-scale circulation types on the occurrence of these days from December to March. The study used daily data on the minimum, maximum and mean daily air temperature for 15 stations located in Poland from 40 winter seasons between 1970/71 and 2009/10. During that period, a decrease in the number of frosty days was noticed across the greater part of Poland; still, these changes were not statistically significant. The conducted research study showed that, of macro-scale circulation types, the North Atlantic Oscillation and Scandinavian type had the most significant impacts on the number of frosty days in Poland.

scholarly journals Numerical investigation of the north wall passive thermal performance for Chinese solar greenhouse

2020 ◽  
Vol 24 (6 Part A) ◽  
pp. 3465-3476
Author(s):  
Yiming Li ◽  
Xingan Liu ◽  
Fengsheng Qi ◽  
Li Wang ◽  
Tianlai Li
Keyword(s):  
Solar Energy ◽  
Wall Thickness ◽  
Thermal Performance ◽  
Thermal Environment ◽  
Energy Utilization ◽  
Wall Material ◽  
The North ◽  
Solar Energy Utilization ◽  
Solar Greenhouse ◽  
North Wall

The fully passive solar energy utilization system of Chinese solar greenhouse is efficient for ensuring year-round cultivation of vegetables, owing to the high amount of heat charge and discharge characteristic of the north wall enclosure. In the present research, the thermal performance is investigated using CFD. A 3-D mathematical model has been established to evaluate the wall thickness, layered configuration and material property. The predicted thermal environments are in good agreement with the experimental measurements, indicating the reliability of the established numerical model. The results showed that the increase of north wall thickness could cause the waste of resources due to the thermal masses mainly concentrate in the superficial layer. Constructing layered configuration is rec-ommended for the north wall which uses Styrofoam in the outer layer to reduce heat loss. Nevertheless, the property of north wall material has little effect on the thermal environment. The research results, thus obtained, will give good guidance for completing the Chinese solar greenhouse engineering database and optimizing the solar energy utilization.

scholarly journals EFFECTIVE FISHERIES MANAGEMENT: TO REDUCE ENVIRONMENTAL DAMAGE AND SOCIAL CONFLICTS OF FISHERMEN DUE TO THE USE OF TRAWLING

2021 ◽  
Vol 1 (2) ◽  
pp. 277-294
Author(s):  
Faisal Matriadi ◽  
Marbawi Marbawi ◽  
Chalirafi Chalirafi ◽  
Mariyudi Mariyudi
Keyword(s):  
Social Impact ◽  
East Coast ◽  
Fishing Communities ◽  
Environmental Damage ◽  
Fishing Gear ◽  
Social Conflicts ◽  
North East ◽  
The North ◽  
The Government ◽  
The Impact

The use of trawling as a fishing tool has long been known to have a very bad impact on the environment and creates social conflict in fishing communities. Likewise, on the North-East coast of Aceh there are still fishermen who use trawlers as fishing gear. On the other hand, the use of trawling is very damaging to the environment and causes social conflicts for fishermen. The cessation of trawling operations also has an economic and social impact on fishermen who have been using trawling for their livelihood. This study tries to explore how the impact of environmental damage and social impacts or fishing conflicts that occur due to the use of trawling and how the social and economic impacts if trawling operations are stopped on the North-East coast of Aceh. The research method was carried out with an exploratory descriptive qualitative approach. The results showed that there was significant environmental damage in the research area, namely in the waters of Lhokseumawe, North Aceh, East Aceh and Langsa. This is marked by the destruction of coral reefs and the reduced population of various types of fish, some of which are even very rare. The use of trawling also has an impact on social conflicts among fishermen which often occur. Meanwhile, the prohibition of trawling also has an impact on the loss of income for trawler fishermen and those who depend on trawling operations for their livelihoods. This study recommends stopping trawling permanently to preserve the aquatic environment and avoid social conflicts with fishing communities. Furthermore, to save trawler fishermen, the government must try to convert trawler fishing gear to fishing gear that is more economical and environmentally friendly.

scholarly journals Contribution of Surface Solar Radiation and Precipitation to Spatiotemporal Patterns of Surface and Air Temperature Warming in China from 1960 to 2003

2016 ◽  
Author(s):  
Jizheng Du ◽  
Kaicun Wang ◽  
Jiankai Wang ◽  
Qian Ma
Keyword(s):  
Solar Radiation ◽  
Air Temperature ◽  
Energy Budget ◽  
South China ◽  
North China Plain ◽  
North China ◽  
Spatiotemporal Patterns ◽  
The North ◽  
The North China Plain ◽  
The Impact

Abstract. Although the global warming has been successfully attributed to the elevated atmospheric greenhouses gases, the reasons for spatiotemporal patterns the warming rates are still under debate. In this paper, we report surface and air warming based on observations collected at 1977 stations in China from 1960 to 2003. Our results show that the warming of daily maximum surface (Ts-max) and air (Ta-max) temperatures showed a significant spatial pattern, stronger in the northwest China and weaker in South China and the North China Plain. These warming spatial patterns are attributed to surface shortwave solar radiation (SSR) and precipitation, the key parameters of surface energy budget. During the study period, SSR decreased by −1.50 W m−2 10 yr−1 in China and caused the trends of Ts-max and Ta-max decreased by 0.139 and 0.053 °C 10 yr−1, respectively. More importantly, South China and the North China Plain had an extremely higher dimming rates than other regions. The spatial contrasts of trends of Ts-max and Ta-max in China are significantly reduced after adjusting for the impact of SSR and precipitation. For example, the difference in warming rates between North China Plain and Loess Plateau reduce by 97.8 % and 68.3 % for Ts-max and Ta-max respectively. After adjusting for the impact of SSR and precipitation, the seasonal contrast of Ts-max and Ta-max decreased by 45.0 % and 17.2 %, and the daily contrast of warming rates of surface and air temperature decreased by 33.0 % and 29.1 % over China. This study shows an essential role of land energy budget in determining regional warming.

Energy efficiency for cooling buildings in hot and dry regions using sol-air temperature and ground temperature effects

2019 ◽  
Vol 17 (3) ◽  
pp. 613-628 ◽  
Author(s):  
Ali Mostafaeipour ◽  
Hossein Goudarzi ◽  
Ahmad Sedaghat ◽  
Mehdi Jahangiri ◽  
Hengameh Hadian ◽  
...  
Keyword(s):  
Energy Loss ◽  
Heat Loss ◽  
Air Temperature ◽  
Building Envelope ◽  
Ground Temperature ◽  
Climatic Data ◽  
Total Energy Consumption ◽  
Shape Factors ◽  
Content Type ◽  
The Impact

Purpose In hot and dry climates, air conditioning accounts for a large portion of total energy consumption; therefore, this paper aims to investigate the impact of sol-air temperature and ground temperature on the loss of cooling energy in hot and dry regions of Iran. Design/methodology/approach In line with this objective, the values of sol-air temperature along different directions and ground temperature at different depths were assessed with respect to climatic data of Yazd City. The impact of sol-air temperature and ground temperature on the rate of heat loss was investigated. So, energy loss of the walls aligned to four primary directions was calculated. This process was repeated for a 36 m2 building with three different shape factors. All analyses were conducted for the period from May to September, during which buildings need to be cooled by air conditioners. Findings Numerical analyses conducted for hot and dry climate show that sol-air temperature leads to a 41-17 per cent increase in the wall’s energy loss compared with ambient temperature. Meanwhile, building the wall below the surface leads to a significant reduction in energy loss. For example, building the wall 400 cm below the surface leads to about 74.8-79.2 per cent energy saving compared with above ground design. The results also show that increasing the direct contact between soil and building envelope decreases the energy loss, so energy loss of a building that is built 400 cm below the surface is 53.7-55.3 per cent lower than that of a building built above the surface. Originality/value The impact of sol-air temperature and ground temperature on the cooling energy loss of a building in hot and dry climate was investigated. Numerical analysis shows that solar radiation increases heat loss from building envelope. Soil temperature fluctuations decrease with depth. Heat loss from building envelope in an underground building is lower than that from building envelope in a building built above the ground. Three different shape factors showed that sol-air temperature has the maximum impact on square-shaped plan and minimal impact on buildings with east-west orientation.

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