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设计与控制逻辑案列分析（自适应余风量控制系统）：
实验室布局如下图所示，实验室布置有4台1524型通风柜，实验室的具体信息参数如下：
实验室设计参数：
实验室体积Laboratory size = 18’ x 30’ x 10’ (5,400 ft3)=5.486m*9.144m*3.048m=152.9m3
1524型通风柜(4台)=300CMHmin* 1500 CFM max*
余风量offset = 360–1200 CMH*
通风换气量= 1530CMH* (ACPH = 10/按照换气次数10次/小时设计)
满足实验室制冷所需的送风量 = 2040CMH*
设计压差 = -0.001 “ H2O*=-0.25Pa
设计温度= 72F=22.2℃
房间压力控制系统Room Pressure Control System:
(1) TSI 8682自适应余风量控制系统安装于实验室内/Model 8682 Adaptive Offset Control System mounted in the laboratory.
(2) 同时，实验室安装房间压差传感器用于检测实验室（受控环境）与走廊（压力参照环境）间的压力差/A through-the-wall pressure sensor mounted between the corridor (referenced space) and laboratory (controlled space).
(3)蝶阀、压力相关型VAV box或文丘里阀安装于新风送风管道/Damper, pressure dependent VAV box or valve with actuator assembly mounted in supply air duct(s).
(4) 蝶阀、压力相关型VAV box或文丘里阀安装于房间综合排风管道/ Damper, pressure dependent VAV box or valve with actuator assembly mounted in exhaust air duct.
(5)流量监测站安装于新风送风管道（使用文丘里阀系统除外） /Flow station mounted in supply air duct. (Required for non-venturi valve applications only.)
(6) 流量监测站安装于房间综合排风管道（使用文丘里阀系统除外） /Flow station mounted in general exhaust air duct. (Required for nonventuri valve applications only.)
(7) 流量监测站安装于每个通风柜的排风管道（使用文丘里阀系统除外） /Flow stations mounted in fume hood exhaust duct. (Required for nonventuri valve applications only.)
温度控制系统Temperature Control System:
(1)温度传感器(1000Platinum RTD)安装于实验室内/ Temperature Sensor (1000Platinum RTD) mounted in the laboratory.
(2) 再热盘管安装于新风送风管道上/Reheat coil mounted in supply air duct(s).
通风柜控制系统Fume Hood Control System:
(1) 独立的通风柜变风量控制系统/Independent VAV Face Velocity Control system.
HD1通风柜排风管道截面积0.0725m2/HD1 DCT AREA 0.78 ft2 (12 in. round) Fume hood 1 duct area;
HD2通风柜排风管道截面积0.0725 m2/HD2 DCT AREA 0.78 ft2 (12 in. round) Fume hood 2 duct area;
HD3通风柜排风管道截面积0.0725 m2/HD3 DCT AREA 0.78 ft2 (12 in. round) Fume hood 3 duct area;
HD4通风柜排风管道截面积0.0725 m2/HD4 DCT AREA 0.78 ft2 (12 in. round) Fume hood 4 duct area;
房间综合排风管道截面积0.0929 m2/EX1 DCT AREA 1.0 ft2 (12” *12”) General exhaust duct area;
送风管道截面积0.3094m2/SP1 DCT AREA 3.33 ft2 (24”*20”) Supply duct area
最低补偿风量600CMH/MIN OFFSET 600CMH Minimum offset.
最大补偿风量1200CMH/MAX OFFSET 1200CMH Maximum offset.
10次/小时通风换气次数设置风量1530CMH/VENT MIN SET 1530CMH 10 air changes per hour;
满足实验室制冷所需的送风量2040CMH*/COOLING FLOW 2040CMH Required flow to cool laboratory;
设计温度= 72F=22.2℃/ TEMP SETP 72 F Temperature sensor switches from VENT MIN SET to COOLING FLOW.
设计压差 = -0.001 “ H2O*=-0.25Pa/ SET POINT –0.001 in. H2O Pressure differential set point.
运行顺序/Sequence Of Operation
开始场景：实验室保持微负压-0.25Pa ，实验室的温度满足舒适度要求；
场景一，通风柜移门均关闭，此时总排风量为300CMH*4=1200CMH/ Fume hood sashes are down, total hood exhaust is 1200CMH;
送风量1530CMH(保持通风换气要求,ACPH=10)/ Supply air is 1530CMH(maintain ventilation);
综合排风量690CMH(由以下算式计算出)/ General exhaust 690CMH(calculated from below).
Fume hoods + General exhaust - Offset = Supply air
1200CMH +? – 360CMH= 1530CMH
场景二，实验室工作人员开始实验，其中2台通风柜打开，面风速保持0.5m/s，此时通风柜总排风量=1500CMH*2+300CMH*2=3600CMH
Fume hoods + General exhaust - Offset = Supply air
3600CMH + 0 – 360CMH =3240CMH
实验室送风量变为3240CMH(通风柜总排风量3600CMH-余风量360CMH)，此时，房间的综合排风阀门关闭，因为此时通风柜总排风量满足保持实验室温度或通风换气要求的风量而无需其它排风。/The supply air volume changes to 3240CMH (3600CMH hood exhaust –360CMH offset). The general exhaust is closed since no additional exhaust is needed for temperature or ventilation.
然而，实验室数显控制面板此时显示实验室负压为-0.05Pa（负压不够大），自适应风量控制器通过运算，缓慢的改变余风量值直至压差值重新稳定到设定值。在这种情况下，余风量值重置为660CMH，同时送风量也随之减少300CMH。额外增加的300CMH余风量值将使实验室压差重新稳定到设定值-0.25Pa 。However, the Digital Interface Module indicates the laboratory is now -0.05Pa (not negative enough). The AOC algorithm slowly changes the offset until pressure control is maintained. In this case, the offset changes to 660CMH, which decreases the supply volume by 300CMH. The additional offset maintains the pressure differential at -0.25Pa (set point).
Fume hoods + General exhaust - Offset = Supply air
3600CMH + 0 – 660CMH =2940CMH
当实验完成后通风柜移门关闭，此时最初的状态再次出现
The hoods are shut after the experiments are loaded so the initial conditions prevail.
Fume hoods + General exhaust - Offset = Supply air
1200CMH +? – 360CMH= 1530CMH
此时，实验室的一个烘箱开始工作实验室温度随之不断升高。房间温度传感器将信号传递至自适应余风量控制器，送风量切换至满足实验室制冷所需的最小送风量,此时送风量增加至2040CMH。与此同时，房间综合排风阀门加大开度增加排风量来满足房间的风量平衡。 An oven is turned on and the laboratory is getting warm. The temperature sensor sends the AOC a signal to switch to temperature minimum ventilation (COOLING FLOW). This increases the supply air to 2040CMH. The general exhaust air must also increase (damper opens) to maintain flow balance.
Fume hoods + General exhaust - Offset = Supply air
1200CMH + 1200CMH – 360CMH= 2040CMH
当三个通风柜打开时，此时通风柜排风量为（1500CMH*3+300CMH=4800CMH）,为了保持风量平衡，房间综合排风和送风量变为：
Three fume hoods are opened so the fume hood flow is now 4800 CMH. In order to
maintain air balance the general exhaust and supply air change to:
Fume hoods + General exhaust - Offset = Supply air
4800CMH + 0 CMH– 360CMH= 4440CMH
控制环路将持续保持房间的风量平衡、房间压力和温度控制满足要求。
The control loop continuously keeps the room balance, room pressure, and temperature control satisfied.
