A Pilot Study on the Microclimate of a Multi-span Solar Energy Greenhouse

2019 ◽  
Vol 35 (4) ◽  
pp. 601-616 ◽  
Author(s):  
Mengwei Ni ◽  
Dun Lan ◽  
Mohammad Shah Jahan ◽  
Jian Wang ◽  
Shirong Guo
Keyword(s):  
Solar Energy ◽  
Energy Saving ◽  
Air Temperature ◽  
Natural Ventilation ◽  
Thermal Environment ◽  
Winter Season ◽  
Soil Surface ◽  
Cost Effective ◽  
Effective Accumulated Temperature ◽  
North Wall

Abstract. Extreme low and high temperature is the main obstacle to grow plants in an ambient environment. Due to climate change, these problems are getting worse day by day. To resolve this dilemma a new type of energy-saving greenhouse structure, a multi-span solar energy greenhouse (SEG), was designed and constructed in the Yangtze valley region of China. Using a multi-span plastic greenhouse as a control greenhouse (CG), the microclimate characteristics of the SEG were studied in winter and summer. The results showed that, because the SEG adopted the cooling way of the combination of external shading and natural ventilation in summer, on a sunny day and cloudy day, the average air temperature of the SEG were 3.9°C and 0.9°C lower than CG, respectively, the average solar transmittance were 40% and 18% lower than CG, respectively, indoor microclimate distribution was more uniform. In an acute temperature condition, the effect of natural ventilation on cooling inside the SEG was better than CG during the daytime. Additionally, during the winter season, on a sunny day and cloudy day, compared with CG, the average solar transmittances of the SEG were 24% and 12% lower than CG, respectively, at the same time, the average air temperature of the SEG were 2.1°C and 2.3°C higher than CG, respectively. During the nighttime, the soil surface as well as the film temperature of the SEG, was higher than CG, whether it was on a sunny or a cloudy day, the daily effective accumulated temperature in SEG was more than CG. A north wall was built inside the SEG could effectively improve indoor nighttime temperature, and per unit volume of the SEG could save 0.63 L of diesel per day in winter, thereby saving $0.53, and reducing carbon emissions by 1.74 kg. Taken together, considering all aspect we concluded that the indoor environment of the SEG was more suitable for plant growth and cost-effective for crop cultivation as well. Keywords: Energy-saving, Greenhouse, Microclimate characteristics, Solar energy, Thermal environment.

Study on Sustainable Construction and Improvement of Dwellings in Huhhot and Baotou Area of Middle Inner Mongolia

2013 ◽  
Vol 689 ◽  
pp. 149-152
Author(s):  
Li Ping Sun ◽  
Jun Feng Yin
Keyword(s):  
Sustainable Development ◽  
Solar Energy ◽  
Energy Saving ◽  
Inner Mongolia ◽  
Natural Ventilation ◽  
Green Space ◽  
Thermal Environment ◽  
Sustainable Design ◽  
Sustainable Construction ◽  
Space Layout

The idea of sustainable development has made energy saving of buildings increasingly popular. In this paper, the dwellings in Huhhot and Baotou area of Inner Mongolia are taken as the research object. After analyzing the original characteristics of the dwellings, some problems identified in the process of the construction and use are put forward, and the necessity of green sustainable design is confirmed. Then some specific strategies of sustainable construction and improvement are discussed, namely: reasonable partition of thermal environment, energy saving design of enclosure structure, the utilization of solar energy, natural ventilation design, green space layout, and the collection and recycling of rainwater.

The Investigation of Residential Energy Consumption in Rural Areas Surrounding the Xi'an City

2011 ◽  
Vol 374-377 ◽  
pp. 316-321
Author(s):  
Mei He ◽  
Hua Guo ◽  
Jin Wu ◽  
Xin Zhang
Keyword(s):  
Energy Consumption ◽  
Solar Energy ◽  
Rural Areas ◽  
Thermal Environment ◽  
Residential Buildings ◽  
Economic Status ◽  
Cost Effective ◽  
Space Heating ◽  
Local Conditions ◽  
Xi’An City

The main purpose that should be put in the first place on residential constructions in the rural areas is how to guide the consumers to build residential buildings that are energy effective, comfortable, cost effective, and with construction techniques that are appropriate for the local conditions. Before investigating residential buildings that are suitable for local conditions, we have to discover the local economic status and their living habit in depth. This article puts emphasis on to survey the relationship between dwelling habits and energy consumption in the rural areas, also, space heating and cooling method, the use of solar energy, marsh gas and any other renewable sources of energy, as well as the thermal environment of residential buildings are investigated and analyzed. we conclude that, in the rim of Xi'an city, most of the fuel sources for space heating in winter used in the rural areas are fireweed and cornstock. Most of the energy sources are crops waste materials that are not environmental friendly, thus, it's necessary to popularize the use of solar energy and marsh gas.

scholarly journals Performance of Garlic (Allium sativum) Varieties under Zero Tillage Mulch Condition in Southern Coastal Region of Bangladesh

Proceedings ◽  
2020 ◽  
Vol 36 (1) ◽  
pp. 159
Author(s):  
Rina Rani Saha ◽  
Md. Abul Khayer Mian ◽  
Subarna Kundu ◽  
Khokan Kumer Sarker
Keyword(s):  
Crop Production ◽  
Allium Sativum ◽  
Agricultural Research ◽  
Block Design ◽  
Winter Season ◽  
Coastal Region ◽  
Soil Surface ◽  
Cost Effective ◽  
Zero Tillage ◽  
Local Cultivar

The experiment was carried out under ACIAR-KGF project at farmers’ field of Tildanga village at Dacope Upazilla under Khulna District during rabi season of 2018–19 after harvest of previous transplanted aman rice to find out the suitable variety of garlic (Allium sativum) for cultivation in southern coastal region of Bangladesh and to observe the effect of straw mulching on the yield of garlic. The experimental area faces slight to moderately drought and saline prone at later part of winter season and beginning of summer. The salinity causes unfavorable environment and hydrological situation restricting the normal crop production. Farmers generally cultivate only single transplanted aman (T.aman) rice in a year at south and south-western coastal saline areas. Garlic is one of the important spices crop in Bangladesh. The treatments of the experiment were five garlic varieties viz., V1 = BARI Roshun-1, V2 = BARI Roshun-2, V3 = BARI Roshun-3, V4 = BARI Roshun-4 which were developed by Bangladesh Agricultural Research Institute (BARI) and V5 = Local cultivar. The experiment was laid out in a randomized complete block design with three replications. All five varieties of garlic were sown on 17 December 2018 under zero tillage condition. BARI Roshun-1 gave the highest number of bulb/m2 (57), pseudostem height (37 cm), weight of individual bulb (7.65 g) and bulb yield (5.81 t/ha). BARI Roshun-3 gave the lowest yield (3.87 t/ha). It was also observed that the soil moisture of the farmers’ field were higher during sowing of garlic which was not suitable for ploughing the land. So timely establishment of garlic is possible by following hand dibbling methods under zero tillage condition on the muddy soil surface and also cost effective. Mulching can protect the evaporation loss and reduces the salinity stress which ultimately influence the crop establishment and yield. Earlier farmers of Tildanga at Dacope under Khulna District had no idea about the cultivation of garlic under zero tillage along with straw much. When the experimental results were demonstrated and discussed about the technology to the farmers gathering during Field Day then they were impressed and interested to grow garlic. Fallow land of coastal areas of Bangladesh could be utilized through disseminating this technology and ultimately cropping intensification increased.

Research on the Effect of Natural Ventilation on Buses in Summer Based on CFD Numerical Simulation Method

2011 ◽  
Vol 361-363 ◽  
pp. 1056-1060 ◽  
Author(s):  
Bao Lin ◽  
Xue Ting Wang ◽  
Xiao Hu
Keyword(s):  
Numerical Simulation ◽  
Thermal Comfort ◽  
Natural Ventilation ◽  
Thermal Environment ◽  
Air Flow ◽  
Cost Effective ◽  
Simulation Method ◽  
Computational Domain ◽  
Cfd Numerical Simulation ◽  
Different Parts

Because of the relatively narrow space and high density distribution of the passengers, the bus interior environment deteriorates in summer. Natural ventilating introduces a fresh natural freeze, provides the bus interior with appropriate distribution of air supply temperature and velocity field. Making good use of natural ventilation is an operating strategy ideal for improving passengers’ satisfaction, which is considered as an environmental friendly and cost effective approach. Based on CFD numerical simulation, with a whole-domain approach, this paper predicts air flow and thermal comfort in naturally ventilated bus. The outside and inside airflow is modelled simultaneously and within the same computational domain. The thermal environment in different parts of the bus interior is compared. Different vehicle velocities and conditions of windows are taken into account, analysis are made regarding to the effect of both of them on the interior thermal comfort. The result shows, air disturbance at the bus rear parts are intenser than the other parts with better thermal satisfaction; the quality of air flow in different parts makes the temperature difference in bus achieve as high as 3°C; the use of roof openings distributes the temperature more evenly.

Analysis of Natural Ventilation Systems in Schoolrooms

2016 ◽  
Vol 824 ◽  
pp. 625-632
Author(s):  
Mária Budiaková
Keyword(s):  
Mechanical Ventilation ◽  
Thermal Comfort ◽  
Energy Saving ◽  
Air Temperature ◽  
Natural Ventilation ◽  
Winter Period ◽  
Experimental Measurements ◽  
Air Velocity ◽  
The Future ◽  
Ventilation Systems

The paper is oriented on the analysis of the ventilation systems in schoolrooms. Correct and sufficient ventilation of schoolrooms is very important because students and pupils spend in the schoolrooms the majority of their time in school. In our schools the ventilation is incorrect and insufficient. The biggest problem is winter period when the ventilation is provided only by opening the doors to corridor. This way, there is insufficient intake of oxygen, which causes distractibility and feeling of tiredness of pupils. In current schoolrooms we can use only natural ventilation and thus the schoolrooms have to be ventilated using windows. Therefore this research was focused on the comparison and the analysis of different systems of natural ventilation in schoolrooms. The experimental measurements were carried out in schoolroom, where the parameters of thermal comfort were measured in the different systems of natural ventilation with device Testo 480 which was connected to computer. Gained values of air temperature, air velocity and index PMV are presented in graphs. On the base of analysis of measured values were evaluated the systems of natural ventilation for schoolrooms. In the future, the mechanical ventilation in schoolrooms can be assumed, therefore the recommendation on modern energy saving system of mechanical ventilation is in the end of this paper.

Design and Application of a Seasonal Solar Soil Heat Storage System Applied in Greenhouse Heating

2014 ◽  
Vol 672-674 ◽  
pp. 21-25
Author(s):  
Liang Zhang ◽  
Peng Xu ◽  
Jia Chen Mao ◽  
Xu Tang
Keyword(s):  
Solar Energy ◽  
Energy Saving ◽  
Air Temperature ◽  
Indoor Air ◽  
Solar Collector ◽  
Heat Storage ◽  
Storage System ◽  
Control Subsystem ◽  
And Control ◽  
Design And Application

A seasonal solar soil heat storage (SSSHS) system applied in greenhouse heating has been designed and introduced. The system consists of solar collector subsystem, soil heat storage subsystem, greenhouse heating subsystem, hydronic subsystem and control subsystem. By applying soil heat storage, solar energy stored in the soil under the greenhouse can be transferred and utilized in winter to realize the utilization of cross-seasonal energy. TRNSYS is used to simulate the process and effect in the system of the solar energy collection and soil heat storage in Shanghai, and the simulation is calibrated to improve the precision of the TRNSYS model. When the indoor air temperature of the greenhouse is kept at 12°C throughout the year, the energy saving by using the SSSHS system in Shanghai can be 46.2kWh/(m2∙year).

Indoor Thermal Environment Studies and Comparisons of Representative Residential Buildings in Urban Village of Guangzhou during Typical Weather in Summer

2011 ◽  
Vol 374-377 ◽  
pp. 66-69
Author(s):  
Zhi Sheng Li ◽  
Jia Wen Liao ◽  
Xu Hong Liu
Keyword(s):  
Air Temperature ◽  
Natural Ventilation ◽  
Thermal Environment ◽  
Residential Buildings ◽  
Correlation Coefficients ◽  
Environment Design ◽  
Indoor Thermal Environment ◽  
Human Thermal Comfort ◽  
Urban Village ◽  
And Control

In order to improve human thermal comfort of residential buildings in urban village, the study of indoor thermal environment is necessary. Three typical selected houses in Huangpu Village were taken as an example to study. After a seven-day field measurement under the condition of natural ventilation, thermal neutral temperature and PMV indices were calculated based on the collected data. It is shown that the PMV values of the houses vary from -0.5 to 2.1, and the acceptance rate differ significantly in different houses and human activities states. The parameters including outdoor air temperature, indoor air temperature and PMV were studied through the linear regression, and the results demonstrate that their correlation coefficients are high, and their relationships have been developed. The results of this work create a precedent for the indoor thermal environment design and control of urban village buildings in China.

New Correlations Including Hourly Horizontal Radiation for Predicting Indoor Thermal Environment

2011 ◽  
Vol 71-78 ◽  
pp. 2671-2674
Author(s):  
Sheng Xian Wei ◽  
Shi Mei Guo ◽  
Xi Jia He
Keyword(s):  
Solar Radiation ◽  
Air Temperature ◽  
Natural Ventilation ◽  
Thermal Environment ◽  
Thermal Sensation ◽  
Environmental Parameters ◽  
Newton’S Iterative Method ◽  
Indoor Thermal Environment ◽  
One Year ◽  
Radiant Temperature

Fanger’s PMV is the most famous thermal sensation index but it is too complex to be applied in practice. Besides, the PMV index does not include the effect of horizontal solar radiation on the indoor thermal environment. In order to obtain simple and applicable correlations with consideration of solar radiation, a one-year measurement has been conducted in a naturally ventilated residential room in Qujing Normal University of Yunnan province, China. Based on collected data, PMV indices are calculated by using Newton’s iterative method. The relationships of the PMV and the environmental parameters — outdoor air temperature, indoor mean air temperature, mean radiant temperature, wind velocity, relative humidity, and hourly horizontal solar radiation — have been studied by the multivariable regression techniques. Large numbers of correlations with high correlativity have been developed in the present paper. It is convenient to use them to evaluate and predict the indoor thermal environment in the natural ventilation buildings.

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 Building Energy an Simulation Model for Analyzing Energy Saving Options of Multi-Span Greenhouses

2020 ◽  
Vol 10 (19) ◽  
pp. 6884
Author(s):  
Adnan Rasheed ◽  
Cheul Soon Kwak ◽  
Hyeon Tae Kim ◽  
Hyun Woo Lee
Keyword(s):  
Energy Demand ◽  
Natural Ventilation ◽  
Thermal Environment ◽  
Dynamic Control ◽  
Weather Conditions ◽  
Building Energy ◽  
Design Parameters ◽  
Heating And Cooling ◽  
North Wall ◽  
Local Weather

This study proposes a multi-span greenhouse Building Energy Simulation (BES) model using a Transient System Simulation (TRNSYS)-18 program. A detailed BES model was developed and validated to simulate the thermal environment in the greenhouse under different design parameters for the multi-span greenhouse. Validation of the model was carried out by comparing the results from computed and experimental greenhouse internal temperatures. The statistical analyses produced an R2 value of 0.84, a root mean square error (RMSE) value of 1.8 °C, and a relative (r)RMSE value of 6.7%, showing good agreement between computed and experimental results. The validated proposed BES model was used to evaluate the effect of multi-span greenhouse design parameters including thermal screens, number of screens, orientation, covering materials, double glazing, north-wall insulation, roof geometry, and natural ventilation, on the annual energy demand of the greenhouse, subjected to Taean Gun (latitude 36.88° N, longitude 126.24° E), Chungcheongnam-do, South Korea winter and summer season weather conditions. Additionally, the proposed BES model is capable of evaluating multi-span greenhouse design parameters with daily and seasonal dynamic control of thermal and shading screens, natural ventilation, as well as heating and cooling set-points. The TRNSYS 18 program proved to be highly flexible for carrying out simulations under local weather conditions and user-defined design and control of the greenhouse. The statistical analysis of validated results should encourage the adoption of the proposed model when the underlying aim is to evaluate the design parameters of multi-span greenhouses considering local weather conditions and specific needs.

Sign in / Sign up

Export Citation Format

Share Document