In order to evaluate the heating performance of gas engine heat pump（GEHP） for air-conditioning and hot water supply, a test facility was developed and experiments were performed over a wide range of engine speed（1...In order to evaluate the heating performance of gas engine heat pump（GEHP） for air-conditioning and hot water supply, a test facility was developed and experiments were performed over a wide range of engine speed（1400-2600 r/min）, ambient air temperature（2.4-17.8 ℃） and condenser water inlet temperature（30-50℃）. The results show that as engine speed increases from 1400 r/min to 2600 r/min, the total heating capacity and energy consumption increase by about 30% and 89%, respectively; while the heat pump coefficient of performance（COP） and system primary energy ratio（PER） decrease by 44% and 31%, respectively. With the increase of ambient air temperature from 2.4 ℃ to 17.8 ℃, the heat pump COP and system PER increase by 32% and 19%, respectively. Moreover, the heat pump COP and system PER decrease by 27% and 15%, respectively, when the condenser water inlet temperature changes from 30 ℃ to 50 ℃. So, it is obvious that the effect of engine speed on the performance is more significant than the effects of ambient air temperature and condenser water inlet temperature.展开更多
In Morocco, the phosphate industry generates by washing during the ore beneficiation in humid way, big quantities of sludge loaded in fine mineral particles （or slimes） with contents of water in the order of 90-95%....In Morocco, the phosphate industry generates by washing during the ore beneficiation in humid way, big quantities of sludge loaded in fine mineral particles （or slimes） with contents of water in the order of 90-95%. The specific consumption in water for the beneficiation of one tone of dry ore is approximately 0.6 m3. The management of this sludge and the recycling of process water are played to a schema of solid-liquid separation by flocculation, settling then stocking in basins of several dozens hectares. Recovered clear waters are recycled into the circuit of washing. The principal motivation of this work which is a part of EL MAA project is dedicated to the study of the impact of the speed of agitation on the flocculation behavior in terms of dewatering of the phosphate slimes and recycling of the process water. Study was driven on sample of slimes taken in entrance of the thickeners of a Moroccan washing plants, before flocculation. The raw slimes have a concentration in solid of 75.5 g·L^-1, a P205 grade of 17.3% and a free settling velocity 9 cm·h^-1. Fine fraction -2 μm, responsible for the poor settling of slimes is composed in practice of nearly 96% of smectite. It represents 9% of the dry solid content in the slimes. Measurements reveal important variations of the granulometric and textural properties of large floes in response to flocculation, opening ways of optimization for the velocity gradient.展开更多
基金Project(hx2013-87)supported by the Qingdao Economic and Technology Development Zone Haier Water-Heater Co.Ltd.,China
文摘In order to evaluate the heating performance of gas engine heat pump（GEHP） for air-conditioning and hot water supply, a test facility was developed and experiments were performed over a wide range of engine speed（1400-2600 r/min）, ambient air temperature（2.4-17.8 ℃） and condenser water inlet temperature（30-50℃）. The results show that as engine speed increases from 1400 r/min to 2600 r/min, the total heating capacity and energy consumption increase by about 30% and 89%, respectively; while the heat pump coefficient of performance（COP） and system primary energy ratio（PER） decrease by 44% and 31%, respectively. With the increase of ambient air temperature from 2.4 ℃ to 17.8 ℃, the heat pump COP and system PER increase by 32% and 19%, respectively. Moreover, the heat pump COP and system PER decrease by 27% and 15%, respectively, when the condenser water inlet temperature changes from 30 ℃ to 50 ℃. So, it is obvious that the effect of engine speed on the performance is more significant than the effects of ambient air temperature and condenser water inlet temperature.
文摘In Morocco, the phosphate industry generates by washing during the ore beneficiation in humid way, big quantities of sludge loaded in fine mineral particles （or slimes） with contents of water in the order of 90-95%. The specific consumption in water for the beneficiation of one tone of dry ore is approximately 0.6 m3. The management of this sludge and the recycling of process water are played to a schema of solid-liquid separation by flocculation, settling then stocking in basins of several dozens hectares. Recovered clear waters are recycled into the circuit of washing. The principal motivation of this work which is a part of EL MAA project is dedicated to the study of the impact of the speed of agitation on the flocculation behavior in terms of dewatering of the phosphate slimes and recycling of the process water. Study was driven on sample of slimes taken in entrance of the thickeners of a Moroccan washing plants, before flocculation. The raw slimes have a concentration in solid of 75.5 g·L^-1, a P205 grade of 17.3% and a free settling velocity 9 cm·h^-1. Fine fraction -2 μm, responsible for the poor settling of slimes is composed in practice of nearly 96% of smectite. It represents 9% of the dry solid content in the slimes. Measurements reveal important variations of the granulometric and textural properties of large floes in response to flocculation, opening ways of optimization for the velocity gradient.
