【正文】 nd quantifies processes that only proceed in a certain direction (irreversible) from those that are reversible. The second law may be described in several ways. One method uses the concept of entropy flow in an open system and the irreversibility associated with the process. The concept of irreversibility provides added insight into the operation of cycles. 熱力學第二定律的區(qū)別和量化，只有在某一個方向，是可逆的（不可逆）進行的過程。 gases may range from pressible to nearly inpressible. 流體與固體區(qū)別在于他們對剪切力的反應作用。 most fluids in the HVAC industry (., water, air, most refrigerants) can be treated as Newtonian. In nonNewtonian fluids, the relationship between the rate of deformation and shear stress is more plicated.粘度是流體的抗剪切的措施。Thermal conduction is the mechanism of heat transfer whereby energy is transported between parts of continuum by the transfer of kinetic energy between particles or groups of particles at the atomic level. In gases, conduction is caused by elastic collision of molecules。如果是內部所產生的溫度變化所造成的非均質密度的流體流動，傳熱稱為自然對流或自然對流。比例系數(shù)，導熱系數(shù)K。此參數(shù)是在熱力學濕球和露點溫度的部分分開考慮。確定搬遷戰(zhàn)略和設備時，粒子和氣體之間的區(qū)別是重要的的。Water from condensers is usually cooled by the atmosphere. Either natural draft or mechanical draft cooling towers or spray ponds are used to reject the heat to the atmosphere. Aircooled condensers pass outdoor air over a dry coil to condense the refrigerant. Evaporative condensers pass outdoor air over coils sprayed with water. Water from condensers is usually cooled by the atmosphere. Either natural draft or mechanical draft cooling towers or spray ponds are used to reject the heat to the atmosphere. Aircooled condensers pass outdoor air over a dry coil to condense the refrigerant. Evaporative condensers pass outdoor air over coils sprayed with water.通常是由大氣冷卻水從冷凝器。風冷冷凝器越過室外空氣凝結的制冷劑的干燥線圈。通常是由大氣冷卻水從冷凝器。風冷冷凝器越過室外空氣凝結的制冷劑的干燥線圈。這一政策已重新在水和冰蓄冷的興趣。粒子可能是液體，固體或液體包圍了堅實的核心。The conscious mind appears to reach conclusions about thermal fort and disfort from direct temperature and moisture sensations from the skin, deep body temperatures, and the efforts necessary to regulate body temperatures. In general, fort occurs when body temperatures are held within narrow ranges, skin moisture is low, and the physiological effort of regulation is minimized.意識的頭腦似乎達到熱舒適性和不適的結論，直接從皮膚，深部體溫，以及必要的努力來調節(jié)體溫的溫度和水分的感覺。比例系數(shù)，導熱系數(shù)K。金屬的熱傳導時，如導電，通過自由電子的運動。在非牛頓流體，變形和剪切應力率之間的關系更為復雜。液體和氣體都是流體。The Carnot cycle, which is pletely reversible, is a perfect model for a refrigeration cycle operating between two fixed temperatures, or between two fluids at different temperatures and each with infinite heat capacity. Reversible cycles have two important properties: (1) no refrigerating cycle may have a coefficient of performance higher than that for a reversible cycle operated between the same temperature limits, and (2) all reversible cycles, when operated between the same temperature limits, have the same coefficient of performance卡諾循環(huán)，這是完全可逆的，是一個完美的模型之間的兩個固定的溫度，或在不同溫度和熱容量無限每個的兩種流體之間的制冷循環(huán)的運行。If a substance exists as a vapor at saturation temperature and pressure, it is called a saturated vapor. When the vapor is at a temperature greater than the saturation temperature, it is a superheated vapor. Pressure and temperature of a superheated vapor are independent properties, because the temperature can increase while pressure remains constant. Gases such as air at room temperature and pressure are highly superheated vapors.如果一種物質在飽和溫度和壓力的蒸氣存在，它被稱為飽和蒸氣。熱是積極的，當能量被添加到系統(tǒng)中。周圍環(huán)境包括一切外部系統(tǒng)，系統(tǒng)是從周圍環(huán)境隔開的系統(tǒng)邊界。更為復雜的系統(tǒng)，其熵值越大，反之，有序或純配置是低熵之一。其他熱力學性質包括熵，能量儲存形式，和焓。因此，在一個周期結束時，所有屬性具有相同的價值，他們開始。純物質均勻的和不變的化學成分。第二定律可能在幾個方面。在施加剪切力時，固體只發(fā)生有限的變形，而只要有剪切力的作用流體就會連續(xù)變形?？紤]采取分類流體為牛頓或非牛頓粘性的影響。 in liquids and electrically nonconducting solids, it is believed to be caused by longitudinal oscillations of the lattice structure. Thermal conductio