【正文】 ons no solar radiation is included. If solar radiation were present, the absolute calculated HVACenergy use would be affected. In the parison between the control strategies, the affection would be in the same direction and therefore the difference would be small. Solar radiation will not affect the supply air temperature optimization because from the system perspective there is no difference in solar gain or internal heat load. Therefore, solar radiation can be treated as a part of the internal heat load. . The efficiency of the boilet, hband the radiator system is set to be . . The temperature efficiency, ht of the heat recovery unit is assumed to be constant. The supply air flow and the exhaust air flow are equal.. The coefficient of performance (COP) of the chiller is assumed to be constant. The specific heat, cp=1000j/(kg℃), of air and the air density, r ( kg/m3),
are assumed to be constant. The density affects the fan power which would, in this case, vary approximately 1% if the density was treated as temperature dependent.. To simplify the model, the water pump energy used in the boiler and the heat recovery unit is assumed to be zero. Fan electricity, cooling electricity and heating energy are treated as equal.. Supply air temperature The supply air temperature, tSA, is limited by an upper temperature, tSAhigh, due to mixing ventilation and ventation effectiveness, and a lower temperature, tSAlow due to thermal fort: . Heat balance of the zone Eq. (1) describes the total load, Pload in a single zone that has to be cooled or heated by the system. Heating when the load is negative and cooling when the load is positive: Eq. (2) describes the cooling power, Pcooling provided by the supply air. The cooling power must be positive, meaning the supply air temperature, tSA, must be lower than the zone temperature, tzone: Eq. (3) is valid when the zone temperature set point and steady state condition are reached: . HVAC unit To meet the load in the zone, the HVAC unit must produce an air flow at a certain temperature. The radiator power, Prad is included in the HVAC unit power. The power, PHVAC, used to produce this is described in Eq. (4): The theoretical relationship between fan power, Pfan and air flow, q, is cubic (i = 3). However, in practice there are losses in the frequency converter and motor, and the fan efficiency is not constant. Therefore, a squared approach (i = 2) is more appropriate: Eq. (6) describes the air temperature after the supply fan. Pfan is the sum of supply and exhaust fan power and it is assumed that the supply fan electricity ((1/2)Pfan) converts into a rise in temperature of the supply air: The boiler and the heating coil are used to increase the supply air temperature after the heat recovery unit. As far as the supply air temperature is higher than the maximum air temperature after heat recovery, it does not matter in energy perspective whether radiator or boiler is used to heat the zone : The power saved by the heat recovery unit, PHR, is described in Eq. (8): The temperature efficiency of the heat recovery unit, is expressed in Eq. (9). It is assumed that it is not air flow dependent: Perfectly mixed air is assumed in the zone, that results in Eq. (10): If the calculated supply air temperature is higher than the highest supply air temperature, then Eq. (11) is used to calculate the radiator power input (Prad 0): The power input to the chiller, PCM, described in Eq. (12): When the supply air is cooled below the dew point temperature, there will be an extra energy loss in the chiller for condensation. Here, it is assumed that the condensed mass is equal to the outdoor moisture content minus the saturation moisture content at the supply air temperature. The power used to decrease the temperature of the condensed water is relatively small and therefore neglected. To find a manageable expression for the condensed power, a linear regression analysis of the moisture content dependent on the saturation temperature is done. The analyzed range was between 12 and 26 .C. The regression analysis results in Eq. (13): The constant, a is gH2O/m3 .C and the correlation coefficient is .The condensed mass when decreasing the temperature from tsat to tSA is expressed in Eq. (14), where b is reduced: The cooling power input caused by condensation is expressed in Eq. (15): Based on the equations given, the operation of the HVAC unit can be divided into four different cases.附錄B變流量系統(tǒng)中送風(fēng)溫度的優(yōu)化設(shè)計(jì)蘭德大學(xué)，物理樓byggnadsfysikLTH，118信箱，蘭德22100，瑞典摘要在以100%室外空氣送風(fēng)的變空氣容積系統(tǒng)（VAV）中，當(dāng)送風(fēng)溫度一定時(shí)，房間所需的制冷量與空氣的流動(dòng)情況有關(guān)。為了使系統(tǒng)功耗最小化，系統(tǒng)最優(yōu)的送風(fēng)溫度需要根據(jù)制冷負(fù)荷、風(fēng)機(jī)功率（SFP）、制冷系數(shù)（COP）以及室外空氣相對(duì)濕度來(lái)確定。在現(xiàn)有的送風(fēng)溫度優(yōu)化理論下，采暖通風(fēng)空調(diào)系統(tǒng)（HVAC）功耗主要取決于送風(fēng)溫度的控制方式、樓房外表面的平均換熱系數(shù)以及兩種室外氣候條件。分析表明：控制送風(fēng)溫度使之最優(yōu)的系統(tǒng)與在恒溫系統(tǒng)相比，HAVC的功耗會(huì)得到顯著的降低。在實(shí)際工作中，樓房外表面的最優(yōu)換熱系數(shù)大概為零。關(guān)鍵詞：采暖通風(fēng)系統(tǒng)（HVAC）；送風(fēng)溫度；變流量系統(tǒng)（VAV）使用HVAC主要是為了在使用者在健康、室內(nèi)空氣質(zhì)量（IAQ）以及熱力舒適度方面感到舒適。變空氣容積系統(tǒng)（VAV）主要提供滿足國(guó)家規(guī)定的最少量的空氣流量來(lái)達(dá)到健康要求的各項(xiàng)指標(biāo)和室內(nèi)空氣流量。當(dāng)有制冷要求時(shí)，可以增加空氣流動(dòng)，并且使空氣溫度低于室內(nèi)溫度來(lái)滿足人體的熱力舒適度。在有VAV控制的空間中，當(dāng)熱負(fù)荷增加時(shí)空氣流動(dòng)也會(huì)隨之增加。房間控制器通過(guò)測(cè)量室內(nèi)空氣溫度和送風(fēng)流動(dòng)狀態(tài)來(lái)控制室內(nèi)空氣流動(dòng)。送風(fēng)流動(dòng)狀態(tài)取決于制冷負(fù)荷以及制冷空間與送風(fēng)溫度的溫差，低溫的送風(fēng)與高溫的送風(fēng)相比，要求較低的流動(dòng)。送風(fēng)溫度的控制是通過(guò)HVAV機(jī)組來(lái)控制的。使用VAV控制室內(nèi)溫度有以下原因：Hang et al [1]分析了VAV中的流動(dòng)控制器，通過(guò)模擬器與測(cè)量?jī)x，他們發(fā)現(xiàn)流動(dòng)控制器可以提供穩(wěn)定的空氣溫度，同時(shí)提出了設(shè)備、空間內(nèi)表面恒溫動(dòng)力學(xué)。Inoue和Mastumoto [2]進(jìn)行了VAV系統(tǒng)的能量分析，并且與其他系統(tǒng)（比如：雙管恒定空氣容積系統(tǒng)、雙管感應(yīng)機(jī)組）進(jìn)行了比較。根據(jù)Tokyo的氣象學(xué)數(shù)據(jù)，VAV系統(tǒng)可以達(dá)到最低的制冷負(fù)荷和最低的年風(fēng)機(jī)功耗。本節(jié)首先論述用來(lái)計(jì)算HVAC機(jī)組和制冷空間內(nèi)不同設(shè)備正常運(yùn)轉(zhuǎn)所要求的功率。（見(jiàn)圖1）在第一節(jié)中，建筑物房間被看作是具有同一溫度狀態(tài)，同一流動(dòng)狀態(tài)的制冷空間。根據(jù)室外環(huán)境不同和HVAC機(jī)組運(yùn)行部件是否需要能耗，分為四種不同情況進(jìn)行論述。考慮功率要求對(duì)四種情況分別進(jìn)行送風(fēng)溫度的最優(yōu)化設(shè)計(jì)。之后，論述了多制冷空間送風(fēng)理論。最后，論述了在能量計(jì)算中所采用的狀態(tài)數(shù)據(jù)和對(duì)送風(fēng)溫度的控制方法。假定在制冷空間和空間周圍的墻壁中都沒(méi)有熱量?jī)?chǔ)存。當(dāng)外部溫度變化時(shí)，計(jì)算所得的空間冷、熱負(fù)荷將會(huì)偏大。這并不會(huì)影響到最優(yōu)化設(shè)計(jì)采用的公式，但是在實(shí)際中在是存在熱量?jī)?chǔ)存的，而且能耗也是不同的。假設(shè)墻壁內(nèi)表面是完全絕熱的。否則，墻壁內(nèi)表面與制冷空間之間會(huì)有熱交換，可以將熱交換看成內(nèi)部熱負(fù)荷的變化，這樣所用公式仍然是有效的。如果有夜間制冷時(shí)，對(duì)于有熱量?jī)?chǔ)存的比較大的建筑物也可以用同樣的方法對(duì)待。從而可以假設(shè)狀態(tài)是穩(wěn)定的。在能量計(jì)算時(shí)，對(duì)于最大空氣流動(dòng)速率沒(méi)有限定。如果有最高速率的限定，那么不同的控制方式，制冷空間的舒適度將會(huì)不同，此外，也不可以地不同的控制方式進(jìn)行比較，但是可以降低能耗。假設(shè)滲入量為0。如果有滲入，將會(huì)影響到制冷空間所需的制冷負(fù)荷和制熱負(fù)荷，因