【正文】 in more than one phase, but the chemical position is the same in all phases一個(gè)周期進(jìn)程的一個(gè)過(guò)程或一個(gè)系列，其中系統(tǒng)的初始和最終狀態(tài)是相同的的。焓H，一個(gè)屬性相結(jié)合的結(jié)果，被定義為：H = U + PV其中u是每單位質(zhì)量的內(nèi)部能量Each property in a given state has only one definite value, and any property always has the same value for a given state, regardless of how the substance arrived at that state. A process is a change in state that can be defined as any change in the properties of a system. A process is described by specifying the initial and final equilibrium states, the path (if identifiable), and the interactions that take place across system boundaries during the process. 中的每一個(gè)給定的狀態(tài)的屬性只有一個(gè)定值，和任何財(cái)產(chǎn)總是有相同的值給定的狀態(tài)，不管如何抵達(dá)該國(guó)的物質(zhì)。最常見的熱力學(xué)性質(zhì)的溫度T，壓力P，和特定的體積V或密度ρ。熱是積極的，當(dāng)能量被添加到系統(tǒng)中。熵措施分子系統(tǒng)紊亂。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。這些邊界可以是動(dòng)產(chǎn)或固定的，真實(shí)的或想象。更為復(fù)雜的系統(tǒng)，其熵值越大，反之，有序或純配置是低熵之一。 功是指通過(guò)存在壓差（任一種力）的系統(tǒng)邊界傳遞能量的作用過(guò)程，總是指向低壓，如果系統(tǒng)中產(chǎn)生的總效果能被簡(jiǎn)化為一個(gè)重物的提升，那么只有功通過(guò)了邊界，當(dāng)能量從系統(tǒng)中一出時(shí)，功是正的。其他熱力學(xué)性質(zhì)包括熵，能量?jī)?chǔ)存形式，和焓。因此，在一個(gè)周期結(jié)束時(shí)，所有屬性具有相同的價(jià)值，他們開始。純物質(zhì)均勻的和不變的化學(xué)成分。當(dāng)蒸汽溫度大于飽和溫度，它是一個(gè)熱蒸氣。第二定律可能在幾個(gè)方面?？赡嫜h(huán)有兩個(gè)重要的屬性：（1）無(wú)制冷循環(huán)的性能系數(shù)之間相同的溫度限制經(jīng)營(yíng)的可逆循環(huán)高于，（2）之間相同的溫度極限運(yùn)行時(shí)，所有可逆循環(huán)，同樣的性能系數(shù)Flowing fluids in heating, ventilating, airconditioning, and refrigeration systems can transfer heat, mass, and momentum. This chapter introduces the basics of fluid mechanics related to HVAC processes, reviews pertinent flow processes, and presents a general discussion of singlephase fluid flow analysis.流動(dòng)的液體在加熱，通風(fēng)，空調(diào)和制冷系統(tǒng)，可以傳遞熱量，質(zhì)量和動(dòng)量。在施加剪切力時(shí)，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(huì)連續(xù)變形。雖然液體和氣體的分子運(yùn)動(dòng)特性有著很大的區(qū)別，但是他們的主要的力學(xué)區(qū)別在于可壓縮性的程度和液體自由表面（界面）的形成?？紤]采取分類流體為牛頓或非牛頓粘性的影響。Heat is energy in transit due to a temperature difference. The thermal energy is transferred from one region to another by three modes of heat transfer: conduction, convection, and radiation. Heat transfer is among a group of energy transport phenomena that includes mass transfer, momentum transfer or fluid friction and electrical conduction. 熱是由于溫差在傳輸過(guò)程中的能量。 in liquids and electrically nonconducting solids, it is believed to be caused by longitudinal oscillations of the lattice structure. Thermal conduction in metals occurs, like electrical conduction, through the motion of free electrons. Thermal energy transfer occurs in the direction of decreasing temperature. In solid opaque bodies, thermal conduction is the significant heat transfer mechanism because no net material flows in the process and radiation is not a factor. 熱傳導(dǎo)傳熱，使能量是連續(xù)部分之間的運(yùn)輸粒子在原子水平上的顆?；驁F(tuán)體之間的動(dòng)能轉(zhuǎn)移的機(jī)制。熱能量轉(zhuǎn)移發(fā)生在溫度降低的方向。當(dāng)流體的電流是由外部來(lái)源（例如，一個(gè)鼓風(fēng)機(jī)或泵），固 液傳熱被稱為強(qiáng)迫對(duì)流。減號(hào)表示熱流溫度降低的方向積極。減號(hào)表示熱流溫度降低的方向積極。A principal purpose of heating, ventilating, and airconditioning systems is to provide conditions for human thermal fort. A widely accepted definition is, “Thermal Comfort is that condition of mind that expresses satisfaction with the thermal environment”. This definition leaves open what is meant by condition of mind or satisfaction, but it correctly emphasizes that the judgment of fort is a cognitive process involving many inputs influenced by physical, physiological, psychological, and other processes. 供暖，通風(fēng)和空調(diào)系統(tǒng)的一個(gè)主要目的是提供人體熱舒適的條件。在一般情況下，舒適性發(fā)生時(shí)體溫都在窄幅內(nèi)舉行，皮膚水分低，調(diào)節(jié)生理努力最小化。盡管粒子的運(yùn)動(dòng)是用相同的方程用來(lái)描述氣體運(yùn)動(dòng)，甚至最小的粒子（約1納米），遠(yuǎn)遠(yuǎn)高于單個(gè)氣體分子較大，有更大的質(zhì)量，擴(kuò)散速率低得多。他們中的濃度每立方厘米在受污染的城市環(huán)境的范圍在清潔的環(huán)境中從100 particles/cm3百萬(wàn)的氣氛。存儲(chǔ)容量為夏季負(fù)荷平衡安裝，也可能是在冬季使用，高熱不退更可行的選擇。無(wú)論是自然通風(fēng)或機(jī)械通風(fēng)冷卻塔或噴池塘用于拒絕到大氣中的熱量。蒸發(fā)式冷凝器，通水噴灑線圈，室外空氣。無(wú)論是自然通風(fēng)或機(jī)械通風(fēng)冷卻塔或噴池塘用于拒絕到大氣中的熱量。蒸發(fā)式冷凝器，通水噴灑線圈，室外空氣。使用較高的水溫度上升和較低的送風(fēng)溫度，降低了所需的泵和風(fēng)扇能源在某些情況下，抵消，由于冰所需溫度較低的能量損失。Many electric utilities impose very high charges for peak power use or, alternatively, offer incentives for offpeak use. This policy has renewed interest in both water and ice thermal storage. The storage capacity installed for summer load leveling may also be available for use in the winter, making heat reclaim a more viable option.許多電力公司施加非常高的峰值功率使用收費(fèi)，或者也可以提供非高峰期使用的激勵(lì)機(jī)制。然而，它需要在一個(gè)中央位置的空間和一個(gè)潛在的大分配制度。The particula