日光温室热压-风压耦合通风机理及计算模型构建

项目名称： 日光温室热压-风压耦合通风机理及计算模型构建

项目编号： No.51508560

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 建筑科学

项目作者： 方慧

作者单位： 中国农业科学院农业环境与可持续发展研究所

项目金额： 20万元

中文摘要： 自然通风是日光温室环境调节的重要手段，直接影响室内的热量平衡、水蒸气含量以及CO2浓度等环境因子。自然通风是一个动态的物理过程，受热压与风压等要素的驱动，但由于缺乏对这种动态过程的模拟与分析，日光温室自然通风的工程设计与调控仍无据可依。本项目拟在探明日光温室通风量与室外风速、风向以及室内外温差等多元定量关系的基础上，分析热压-风压耦合作用对通风量的影响机理，并以此为基础构建通风速率与热压-风压作用关系的数理模型，采用CO2气体示踪法测试室内气流动态变化规律和通风速率，通过Marquardt算法对模型与实验值进行非线性拟合，形成相关性最高的通风计算模型以及流量系数与风压系数计算方法。本项目研究为日光温室自然通风理论计算提供了新的方法，对温室自然通风的结构设计与调节控制具有重要的参考价值。

中文关键词： 日光温室；通风率；能量交换；模拟

英文摘要： Natural ventilation between the interior of a greenhouse and its environment is the main governing mechanism for the control of the greenhouse climate. It has its impact not only on the energy balance, but also on the concentration of water vapor, carbon dioxide and other gases. Ventilation is a dynamic physical process involves the wind pressure due to outside wind, and the stack effect due to buoyancy forces and temperature differences. The adjustment of ventilation and design of structure cannot be well arranged since lack of modelling and analyzing to the ventilation dynamic processes. The object of this research is to analyze the relationship between ventilation flux and temperature difference, wind velocity, wind direction. The coupling mechanisms between the stack and wind effects will be analyzed and models of air exchange in a solar greenhouse will be derived considering the two main driving forces of ventilation. The tracer gas technique using carbon dioxide will be used to analyze the variations of identified coefficients in relation to the wind and temperature characteristics for estimating the ventilation flux. The model parameters will be identified by fitting the experimental data to the models. Non-linear regressions using Marquardt’s algorithm will be used to identify thermal buoyancy coefficient and wind pressure coefficient. In this study a theoretical approach to design solar greenhouse ventilation flux will be developed and it is helpful for a proper design of vent construction therefore to control inside greenhouse climate.

英文关键词： Solar greenhouse;ventilation rate;energy exchange;modelling