碰撞射流与混合通风系统在高大空间的供暖效果分析

发布时间：2018-01-23 20:38

本文关键词： 碰撞射流通风混合通风能量利用系数送风口位置吹风感　出处：《东华大学》2017年硕士论文　论文类型：学位论文

【摘要】：冬季采用热风对房间供暖时,由于空气热浮升力的影响,大量热量集聚在室内上部空间而不能得到有效的利用,造成能源不必要的浪费。考虑到城市化进程的加快,城市区域内部空间高大的建筑将越来越多,对于这些高大空间建筑,这种供暖能量浪费就更加严重。对于高大空间的冬季供暖,空调区仅在其空间下部的人员工作和活动区,大空间上部区域实际上无需供暖。然而,热空气在热浮力作用下,房间上部的空气温度会过高,由此造成的供暖无效能耗往往更高。因此,合理的气流组织是减少高大空间混合通风供暖能耗的重要途径。传统的混合通风(Mixing Ventilation,简称MV)是应用最为广泛的通风方式,但这种通风方式的气流组织难以从根本上消除供暖房间室内温度下低上高的缺点。碰撞射流通风(Impinging Jet Ventilation,简称IJV)是一种新型通风方式,它的原理是将新鲜空气从室内下部以相对较高的风速直接送入人员工作区,所以结合了置换通风和混合通风的优势。碰撞射流通风的气流组织形式,理论上可以减小或消除室内热力分层现象,提高供暖能量利用率。但碰撞射流通风在高大空间的供暖效果的研究很少。为此,本文对不同送回风口特征的混合通风与碰撞射流通风的供暖效果进行了比较研究。影响混合通风在高大空间中的供暖气流组织的因素有很多,如:回风方式、送风倾角、送风参数以及送风口位置等,本文通过数值模拟方法研究并对比了碰撞射流通风与不同送风口位置的混合通风的供暖特性。研究结果表明:采用混合通风供暖时,较大送风倾角与较低的送风口位置可有效提高送风能量利用率,但室内人员工作区的舒适性难以得到保证,尤其在送风倾角较大时,室内人员工作区的气流速度可能超出人体可接受范围。送风口位置的升高可有效避免气流速度大造成的室内舒适度问题,但能量利用率却随之减小,大送风倾角室内能量利用率几乎不受送风口位置的升高影响,送风能量始终可得到较为有效地利用,然而室内舒适性并不能得到改善。送风口位置较低时,不同位置的回风口的能量利用率及室内舒适性几乎相同,送风能量可得到有效利用,但人员工作区可能存在吹风感风险。下回风与上回风室内人员工作区的大部分区域舒适性均在人体可接受范围内,然而随着送风口位置的升高,下回风方式体现出了更好的能量利用情况,且送风口位置越高,下回风优势越明显。碰撞射流通风室内温度分布均匀,热风在室内的混合程度与供暖能量利用率明显大于混合通风,且混合通风的送风口位置越高,碰撞射流的节能优势越明显。碰撞射流通风室内的人员吹风感风险大于混合通风,但仍在可接受的范围内。虽然混合通风的送风口位置越高,吹风感就越小,但这是以高能耗为代价。因此在对人体吹风感无特殊限制且混合通风送风口位置不宜过低的高大空间中,使用IJV可以同时实现节能与舒适度的要求。
[Abstract]:The hot air of the room heating in winter, because of the influence of air buoyancy, a large amount of heat in the interior space and the upper concentration could not be used effectively, resulting in unnecessary waste of energy. Taking into account the city to speed up the process, will be more and more space within the city of tall buildings, the large space building, this kind of heating the energy waste is more serious. For large space heating in winter, the air conditioning area only in the lower part of the work space and activity area, the upper region of large space actually without heating. However, the hot air in the heat under the effect of buoyancy, the upper part of the room air temperature is too high, resulting in heating ineffective energy consumption is higher. Therefore, the reasonable airflow organization is an important way to reduce the large space ventilation heating energy consumption. The traditional mixing ventilation (Mixing Ventilation, referred to as MV) is the most widely used The ventilation mode, but this mode of ventilation airflow organization is difficult to fundamentally eliminate the heating room temperature low. The disadvantage of high impinging jet ventilation (Impinging Jet Ventilation, referred to as IJV) is a new type of ventilation, it is the principle of fresh air from the indoor wind speed will be lower at relatively high directly into the staff area, so combined with displacement ventilation and mixing ventilation. Airflow form of impinging jet ventilation theory, can reduce or eliminate the indoor thermal stratification, improve heating energy utilization. But little research impact heating effect of jet ventilation in the large space. Therefore, this paper makes a comparative study on the different characteristics of tuyere back the hybrid ventilation and impinging jet ventilation heating effect. There are many factors influencing the heating airflow mixing ventilation in the large space in the return air way such as: Air, angle, air parameters and the location of the outlet, this paper studied and compared the method of heating characteristics of impinging jet ventilation with different inlet position of mixing ventilation through numerical simulation. The results show that the hybrid ventilation heating, large air inlet position angle and low feeding can effectively improve the air the utilization rate of energy, but the working area of the indoor human comfort is guaranteed, especially in the larger air supply angle, flow velocity of indoor work area personnel may exceed the acceptable range of human body. The location of the outlet increases can effectively avoid the airflow velocity caused by the indoor comfort, but the energy utilization rate decreases. Large supply angle indoor energy utilization rate is almost not affected by the location of the outlet increases, wind energy is always available more effective use, however, indoor comfort cannot be improved. The location of the outlet is low, different location of the return air energy efficiency and indoor comfort is almost the same, wind energy can be effectively utilized, but the staff work area may have sense of hair risk. Much of the region work area under air and return air indoor human comfort in the human body are acceptable, however with the increase of the location of the outlet, under the air return reflects the energy utilization better, and the outlet position of the higher return under the more obvious advantages. The impinging jet ventilation indoor temperature distribution, air heating energy and the mixing degree in the interior of the utilization rate was significantly higher than that of mixed ventilation and mixing ventilation air delivery the higher the more obvious energy-saving advantages of the impinging jet. Air impinging jet ventilation of indoor personnel sense of risk is greater than the mixing ventilation, but still within the acceptable range. Although the mixing ventilation air outlet The higher the location is, the smaller the blowing sense is, but this is at the expense of high energy consumption. Therefore, IJV can achieve the requirement of energy saving and comfort at the same time in the large space with no special restrictions on the drier and the location of the mixed ventilation outlet is not too low.

【学位授予单位】：东华大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU83

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