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131.
Based on the contrast experiment, the condition of air-cooled heat pump operating indoors is analyzed in this paper.The operating performance corresponding to such conditions is gained.The ventilation condition of stable operation for air-cooled heat pump is found.At the same time, the experimental results based on actual work are proved. indoors; air-cooled heat pump; ventilation 相似文献
132.
In this paper, the conditions of air - cooled heat pump operation indoors in winter are analyzed. The corresponding performance of air - cooled heat pump operation is gained. The ventilation condition for stable operation of air - cooled heat pump indoors in winter is found. At the same time, the experimental results are approved by the actual operation effect. 相似文献
133.
Based on the definitions of air conditioning period, dehumidifying period and heating period, this paper puts forward the exchanging conditions and psychrometric process of ventilation system in residences. Because of the remarkable humid climate in hot summer and cold winter regions, the ventilation dehumidification becomes a more important part of the air treatment system. In order to improve the indoor thermal environment quality, new strategies must be founded to control both temperature and humidity of ventilation system. 相似文献
134.
为解决高大平房仓机械通风不均匀等问题,在原有平面通风道的基础上,于粮堆中增设相应数量的直竖式通气竹笼,使之形成粮堆立体通风网络。试验表明:可提高通风效果和均匀度,消除死角,加快降温速度,缩短通风时间,节约费用,为立体通风提供一条新途径。 相似文献
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Karin S Kalchofner DVM Diplomate ECVAA Stephanie Picek Med Vet Simone K Ringer DVM Michelle Jackson DVM Michael Hässig DVM PhD & Regula Bettschart-Wolfensberger DVM PhD PD Diplomate ECVAA 《Veterinary anaesthesia and analgesia》2009,36(5):426-435
Objective To determine, in mildly hypercapnic horses under isoflurane–medetomidine balanced anaesthesia, whether there is a difference in cardiovascular function between spontaneous ventilation (SV) and intermittent positive pressure ventilation (IPPV). Study design Prospective randomized clinical study. Animals Sixty horses, undergoing elective surgical procedures under general anaesthesia: ASA classification I or II. Methods Horses were sedated with medetomidine and anaesthesia was induced with ketamine and diazepam. Anaesthesia was maintained with isoflurane and a constant rate infusion of medetomidine. Horses were assigned to either SV or IPPV for the duration of anaesthesia. Horses in group IPPV were maintained mildly hypercapnic (arterial partial pressure of carbon dioxide (PaCO2) 50–60 mmHg, 6.7–8 kPa). Mean arterial blood pressure (MAP) was maintained above 70 mmHg by an infusion of dobutamine administered to effect. Heart rate (HR), respiratory rate (fR), arterial blood pressure and inspiratory and expiratory gases were monitored continuously. A bolus of ketamine was administered when horses showed nystagmus. Cardiac output was measured using lithium dilution. Arterial blood‐gas analysis was performed regularly. Recovery time was noted and recovery quality scored. Results There were no differences between groups concerning age, weight, body position during anaesthesia and anaesthetic duration. Respiratory rate was significantly higher in group IPPV. Significantly more horses in group IPPV received supplemental ketamine. There were no other significant differences between groups. All horses recovered from anaesthesia without complications. Conclusions There was no difference in cardiovascular function in horses undergoing elective surgery during isoflurane–medetomidine anaesthesia with SV in comparison with IPPV, provided the horses are maintained slightly hypercapnic. Clinical relevance In horses with health status ASA I and II, cardiovascular function under general anaesthesia is equal with or without IPPV if the PaCO2 is maintained at 50–60 mmHg. 相似文献
139.
In allusion to the “5·30”especially serious coal and gas outburst accident of Tonghua coal mine of Songzao Coal Electricity Group CO., LTD in 2009, a detailed simulation of the mutation process of mine ventilation system during gas outburst disaster period is done by using theory of ventilation network with sources and numerical simulation technology (we develop a computer simulation system). Three changing processes, namely outburst overflow, natural flow and ventilation downstream occurs in the ventilation system after outburst. Due to the expanded power of outburst source, gas enters main ventilation roadways at first, and flows outward, and flows counter-current along main intake air roadway, and then enters low air quantity roadways with air doors or underground chamber, which leads to gas concentration overrun and threat to the whole mine. After outburst, gas power disappears. Due to the action of gas natural ventilation pressure, mine ventilation may begin to flow naturally. After the ventilation systems are restored, gas flows with the wind as a result of the power of the main fan. Due to the interference of gas natural ventilation pressure, the operating points of main fans may drift (relative to roadway structure), but the operating points recover with the discharge of gas. It is worth noting that the detention time of gas in low air quantity roadways and underground chambers is relatively long, and the gas becomes continuous gas supply sources, so it is dangerous. In addition, the delayed pour between main roadways and by-pass low air quantity roadways and the gas natural ventilation pressure caused by gas detention may lead to airflow disorder of reversion in some local circuits, and may enlarge the affected range of gas, or lead to the delay and detention of gas discharge. 相似文献
140.
利用小型轴流风机通风降低仓库粮堆温度,通过对小功率轴流风机通风效果分析,观察粮食温度和风机能耗情况,分析其节能通风的效果。 相似文献