2022年2月19日星期六
[AC][EL][Rnew./Inno.] 乜嘢係Cogeneration CHP? 乜嘢係Trigeneration CCHP?
CHP = Combined Heat and Power (Cogeneration)
CCHP = Combined Cooling, Heat and Power (Trigeneration)
要搞清係啲乜嚟之前，先要回顧返前文<做Genset房通風及散熱設計有啲乜地方要留意？>。睇明咗一部發電機嘅化學能係點轉為電能、唔同部份嘅廢熱係點帶走後，我地就可以用嚟類比CHP或CCHP.
以下我會直接用CCHP做講解，因為CHP可以簡單理解成係CCHP嘅閹割版，即係做少一樣制冷。
理解咗平時我地見開嘅一柴油發電機運作後，可睇下表嘅類比﹕
可以簡單理解成CCHP係一部發電機，但用CCHP有啲乜好處？由上表可以見到燃料方面，CCHP係用一啲廢氣或碳排放較少嘅氣體；而生產嘅廢熱都冇嘥到，低位能嘅熱用嚟煲水；而高位能嘅熱攞嚟制冷(Absorption chiller原理見<Chiller有邊幾種>)。
香港那打素醫院有用過CHP, 可參考WSP網站﹕https://www.wsp.com/en-CN/news/2019/wsp-landfill-gas-combined-heat-and-power-project-in-hong-kong-wins-more-awards
2020年5月10日星期日
[AC] [PD] [Renew./Inno.] 問﹕除咗渠之外，BS仲有啲乜嘢係要submit比BD？
答﹕
入BA13嗰陣除咗堆UG Drain Test Report 外 (見 http://elvissharing.blogspot.com/2020/05/pd-bsstatutory-submission-drainage.html) 仲有兩樣嘢要預備﹕
一樣係PNAP APP-13既Fire Resistance Materials, BS嘢包括Fire Damper, Fire Shutter, Lift Landing Door, Cast Iron Pipe;
另一樣係Framework相關 (唔係用minor works嚟入)，舉例有Fiberglass Tank, Solar Panel, Cooling Tower, External AC Hanger etc.;
Fiberglass Tank 深過2m 或大過9
m³
就要入；其他則冇指定。個過程都幾麻煩，先要預備好晒呢啲Framework Drawing and Calculation, 之後比RSE簽，跟住比BD Approval先開工，再之後預備一堆Welding/Anchor/Mill Cert等文件响BA13嗰陣入埋。
仲有樣嘢係BS關BD事，係OTTV submission related, see http://elvissharing.blogspot.com/2020/04/ac-cooling-load.html
2020年5月9日星期六
2020年4月27日星期一
[Renew./Inno.] 問﹕火神山醫院响工程上有啲乜亮點？
答﹕
响建築Layout上既規劃，令醫護人員逗留既地方及出入通道唔會同病人嗰啲唔會交疊。亦係唔可以隨便徵用酒店/旅館既原因。
應用Design for Manufacturing and Assembly DfMA 及 Modular Integrated Construction MiC (外國有啲叫Prefabricated Prefinished Volumetric Construction PPVC), 詳見 https://elvissharing.blogspot.com/2020/04/renewinno-dfma-prefabrication.html
重點係加大重複構件數量，減少特殊構件數量，咁先容易高效批量生產。
Site Formation 整層HDPE, 再用鋼管墊起，一嚟防水二嚟可以下面走風火水電
逐級負壓系統，見 https://elvissharing.blogspot.com/2020/03/ac-isolation-room-mvac.html
(Source: BIMBOX https://bimbox.top/4914.html)
响建築Layout上既規劃，令醫護人員逗留既地方及出入通道唔會同病人嗰啲唔會交疊。亦係唔可以隨便徵用酒店/旅館既原因。
應用Design for Manufacturing and Assembly DfMA 及 Modular Integrated Construction MiC (外國有啲叫Prefabricated Prefinished Volumetric Construction PPVC), 詳見 https://elvissharing.blogspot.com/2020/04/renewinno-dfma-prefabrication.html
重點係加大重複構件數量，減少特殊構件數量，咁先容易高效批量生產。
Site Formation 整層HDPE, 再用鋼管墊起，一嚟防水二嚟可以下面走風火水電
逐級負壓系統，見 https://elvissharing.blogspot.com/2020/03/ac-isolation-room-mvac.html
(Source: BIMBOX https://bimbox.top/4914.html)
[Renew./Inno.] 問﹕DfMA / Prefabrication Components / MiC 分別係啲乜嚟？
Design for Manufacturing and Assembly DfMA 係一個概念嚟，顧名思義，著重考慮組件製造及裝配過程，以便响廠房完成預製再去地盤安裝，減少現場施工工序。Prefabrication Components and MiC 係兩個做法去實現DfMA呢個概念。
就好似Apps Store係一個概念，但就有N種實現方式，如Google Play Store, Apple Store etc.
响工場做好舊嘢先一口氣掟落地盤度裝有諸多好處，做過地盤就知，地盤立立亂，做好先掟落嚟响地盤工序少咗，House keeping又好咗，又唔洗咁多人同時响地盤安全度都高咗，工場做質量控制亦都易，成本/時間效益都好咗因為批量式生產。但都有難題，首先係運過嚟個Trasportation, Tower Crane等要配合到，仲有啲Alignment要好精準，砌過Facade就知件事既難度，更何況如果係成個MiC module咁砌。
Prefabrication Components - e.g. Prefabricated Facades / Staircases / Manhole etc., 只係某少部份用Prefabrication, 其餘大部份都係using conventional construction methods
Modular Integrated Construction - 一件頭過成個Modules咁响地盤度砌，包括風火水電都係包埋响個Module入面，再睇下Module之間啲風火水電等點接駁
電接駁
渠接駁
有啲Project 既DfMA用上述以外既方式嚟實現，如淨係做一組Cooling Tower Modularization. 用BIM做好設計圖後成組掟落地盤。
就好似Apps Store係一個概念，但就有N種實現方式，如Google Play Store, Apple Store etc.
响工場做好舊嘢先一口氣掟落地盤度裝有諸多好處，做過地盤就知，地盤立立亂，做好先掟落嚟响地盤工序少咗，House keeping又好咗，又唔洗咁多人同時响地盤安全度都高咗，工場做質量控制亦都易，成本/時間效益都好咗因為批量式生產。但都有難題，首先係運過嚟個Trasportation, Tower Crane等要配合到，仲有啲Alignment要好精準，砌過Facade就知件事既難度，更何況如果係成個MiC module咁砌。
Prefabrication Components - e.g. Prefabricated Facades / Staircases / Manhole etc., 只係某少部份用Prefabrication, 其餘大部份都係using conventional construction methods
Modular Integrated Construction - 一件頭過成個Modules咁响地盤度砌，包括風火水電都係包埋响個Module入面，再睇下Module之間啲風火水電等點接駁
電接駁
有啲Project 既DfMA用上述以外既方式嚟實現，如淨係做一組Cooling Tower Modularization. 用BIM做好設計圖後成組掟落地盤。
關於BS嘅MiMEP/emMiC, CIC網頁有好好嘅參考 https://mic.cic.hk/en/UsefulInfo/5
(Source: CIC; https://www.bca.gov.sg/Professionals/Technology/others/PPVC_Guidebook.pdf)
(Source: CIC; https://www.bca.gov.sg/Professionals/Technology/others/PPVC_Guidebook.pdf)
2020年4月6日星期一
[Renew./Inno.] [AC] [EL] [PD] 問﹕有啲乜Innovative / Environmental Friendly Building Services Design?
答﹕
Heat Recovery Chiller
我地平時Cooling Tower嗰Loop會帶走廢熱，但Heat Recovery Chiller 就利用呢啲廢熱嚟用，如Hot water storage.
但要注意既係，呢啲Low Temperature heat 好多時用途不太大，要Series 咁駁住Heat Pump 將呢啲Heat 升溫嚟變成啲更有用既熱，大概係37度升到45度；此外要留意埋個Condenser散熱，因為散熱唔會會影响個Chiller performance, 解決方案一係連埋個Cooling Tower 一齊用；解決方案二係散熱既水可能係Constant Flow嚟Ensure Chiller performance.
之後要加Carbon Filter, Sand Filter, Ultraviolet Sterilizer 嚟加工啲水
Wind Turbine
詳細接Grid等注意事項please refer: https://elvissharing.blogspot.com/2020/03/renewinno-solar-related-system-with.html
Biomass
香港冇乜機會用，得個知字。原理大概係燒木碎或廢木點著個Gas Engine生熱或做熱水。
Fuel Cells
香港冇乜聽過，都係得個知字。原理係同電池類似係用Chemical Energy，一頭用Hydrogen。電池當然係做直流電出嚟再轉AC，生產出嚟既廢熱可用於煲水或Absorption Chiller.
Ground Source System / Ground Source Heat Pumps
都係得個知字。原理係利用地底嚟取冷/暖
Heat Recovery Chiller
我地平時Cooling Tower嗰Loop會帶走廢熱，但Heat Recovery Chiller 就利用呢啲廢熱嚟用，如Hot water storage.
但要注意既係，呢啲Low Temperature heat 好多時用途不太大，要Series 咁駁住Heat Pump 將呢啲Heat 升溫嚟變成啲更有用既熱，大概係37度升到45度；此外要留意埋個Condenser散熱，因為散熱唔會會影响個Chiller performance, 解決方案一係連埋個Cooling Tower 一齊用；解決方案二係散熱既水可能係Constant Flow嚟Ensure Chiller performance.
咁Heat Recovery Chiller 同 Heat Pump 有乜分別？兩者都係一頭比凍一頭熱。
佢地最大分別係
Heat Recovery Chiller designed to CHILLED WATER;
Heat Pump designed to Hot Water.
前者Condense Loop uncontrolled, 為咗chilled water 穩定，所以會配合埋Cooling Tower 用；
後者Evaporative Loop uncontrolled;
佢地最大分別係
Heat Recovery Chiller designed to CHILLED WATER;
Heat Pump designed to Hot Water.
前者Condense Loop uncontrolled, 為咗chilled water 穩定，所以會配合埋Cooling Tower 用；
後者Evaporative Loop uncontrolled;
Ice Storage System
Lighting (Digital & Addressable Lighting Interface DALI, Occupancy Sensors, Photocell Sensors)
呢篇裡面有講，唔重複﹕
https://elvissharing.blogspot.com/2020/03/el.html
Tubular Daylighting System
攞條導管從室外引入自然光
Nano Reflector / Mirro Reflector
T5管個反射，由於T5管啲光四散效率唔高，所以加個好既反射器(納米)嚟聚光，LED冇呢個問題。光管長線都係被淘汰，得個知字。
High Effieiency Motor & VSD
EMSD BEEO有講要求
Grey Water / Rain Water Recovery
收集啲雨水嚟淋花，或Cooling Tower 啲Bleed-off用嚟沖廁。
有單香港JOB用過前者，原理大概係收集兩水後，响地下挖一個大石矢缸放隻潛水泵入去。
用台Dual Mode Chiller 响夜晚做冰嚟Shift Load, 要配合Ice Storage Tank使用
通常係受惠電費政策先會用，因為Ice making, Ice melt 都會有energy loss, 兼且Dual Mode Chiller Ice Making Mode個COP都唔會太高，大概3.5
一般運作會係
夜晚﹕行Normal Chiller + Ice Making Mode
日頭﹕1. 行Normal Chiller; 2. Melting Ice; 3. Peak到都頂唔晒嗰陣先係Dual Mode Chiller, 因為Dual Mode Chiller 個COP就算係佢Normal Condition COP 都係比普通Chiller低
Sea Water Cooling
响個Condenser嗰 Loop用海水冷却而唔係用Cooling Tower, 分為Direct Sea Water Cooling & Indirector Sea Water Cooling, 後者多個Heat Exchanger冇咁易積垃圾或海洋生物，但效率當然會低咗。但Heat Exchanger 都好，一樣會有垃圾或微生物積响條管度降低效率，可彩取以下方法﹕
- Mesh Screen
- Electro-Chlorination, 大概就係利用電解海水後一系列化學反應殺微生物；
- Biocides, 即係殺蟲劑
仲有種叫Surface Water Cooling, 唔用Chiller進一步降溫直接經Heat Exchanger用，大前提都係，要有合適水源
Chiller Single Loop with VSD
呢篇裡面有講，唔重複﹕
VAV with VSD
呢篇裡面有講，唔重複﹕
Indirect Evaporating Pre-cooling of Primary Air
一Loop用類似Cooling Tower原理整凍條管，再經Heat Exchanger pre-terat outdoor air
Absorption Chiller
呢篇裡面有講，唔重複﹕
Combined Cooling, Heat and Power CCHP (Trigeneration) or Combined Heat and Power CHP (Cogeneration)
Displacement Ventilation
平時啲冷氣係放得高，凍+相對高風速；但Displayment Ventilation 就放得低啲，及改以相對高溫及低風速派冷氣，再利用熱空氣向上升原理Return.
咁做可以增加supply chilled water temperature 及減細啲把Return Fan風速，Louver出風風速低又可以降低System Pressure, 從而達到節能。經Temperature/Humidity Sensor控制個Modulating Volume Control Damper大細嚟調節。
Heat Recovery Wheel / Disiccant Wheel / Heat Pipe / Liquid Desiccant
Radiant Ceiling / Chilled Beam / Chilled Ceiling
室內熱量通過Natural Convection & Radiation 由Ceiling Chilled Beam吸收，再冷空氣向下沉，慳返啲Ventilation Fan，再以Dehumidification Air control humidity
District Cooling
All Variable Speed Chilled Water Plant Control
將Chillers, Chilled Water Pumps, Condensing Water Pumps, Cooling Tower Fans 都配VSD, 再做個Central 統一控制去optimize
Fuzzy (音﹕花時) Logic Control Algorithms
Traditional Logic: 唔係1 就係 0, 溫度低過某水平，就開盡冷氣；一夠凍就熄機，會成日又開又關做成耗能。
Fuzzy Logic Control: 考慮多個因素諸如濕度、溫度等因素再做一個加權平均數嚟做調整。
舉個比喻，就好似一個要控制體重响68-70kg既人，如果佢一重過呢個數，就即刻唔食嘢，跟住可能唔食嘢一下子輕過68kg好多，跟住又暴飲暴食追返上去。咁就會時而過飽時而唔食。
Fuzzy Logic 就放多好多考慮參數入去，例如呢期有冇好嘢食，心情如何，運動量如何等等，最後得出一個參數再決定食定唔食。
响冷氣系統度，呢啲參數可能係溫度、溫度、Occupancy Patterns etc.
Physical Scale Prevention Technologies
- Electromagnetic Induction Device
Chiller防水垢，响Condense Loop嗰度加個Electromagnetic Induction Device
咁做可以改變雜質既化學特性令其更加Soluble in water insteat of form hard scale.
- Automatic Tube Cleansing System
射啲波波入去刷水垢再接返，主要洗個Chiller Condenser
Central Control & Monitoring System CCMS or Building Management System BMS
Computer software program, usually configured in a hierarchical manner, to control, monitor and manage all the equipment installed in the building.
Oil Free Chiller
Solid State Refrigeration
即係制冷片，COP不高，暫時只係用响啲冷熱水機度，當然有可能有朝一日好似Heat Pump咁成為主流。呢種嘢最大特點係唔洗好似普通Chiller Plant咁要compressor特mechanical moving parts, low maintenance fee, 但同一時間都係要散熱，如果廢熱可以好似Heat Pump咁有效運用就好得多。
Power Factor Correction Device
BEEO有講Power Lagging要求，Impedance load 用到
Harmonic Filter
首先要知乜嘢係Linear Load乜嘢係Non Linear Load
Linear Load - 好似一隻普通摩打咁，比Voltage落去，個Impedance係Constant, Voltage同Current係Proportional;
Non Linear Load - Impedance not constant, Current is not proportion to voltage, 但都會顯示週期特性。VSD, Electronic / IT Devices are example.
呢啲Non Linear Load 會制造unwanted current to electrical system, 可以加Harmonic Filter 解決，分別係Passive & Passive. 顧名思義，一種係做個類似Air Filter, 另一種係造一種同佢完全反方向既Current進行抵消。BEEO有講Total Harmonic Distortion THD 要求。
Services on Demand Escalator
電梯前個Sensor同重力感應啟動。空載期間一般係會極慢行而唔會停晒，即使停晒慳電啲，但選擇慢行係因為唔想啲人以為部電梯壞咗。
Hall Call Allocation, Double Deck, Energy Reclaim, VVVF
呢篇裡面有講，唔重複﹕
Light Emitting Capacitor (LEC) Exit Sign
特點﹕輕薄，慳電，High visibility in darkness & smoke, 唔洗點維護
同LED一樣，都係慳電。左圖係LEC, 右圖係LED
Tritium Self-Luminous Exit Sign
一條熒光管，裡面入啲氚，再通過Beta衰變打啲電子落磷度從而發光。有十年以上壽命。
但呢隻輻射嘢嚟要過Radiation Board of Hong Kong
呢篇裡面有講，唔重複﹕
https://elvissharing.blogspot.com/2020/03/el.html
Tubular Daylighting System
攞條導管從室外引入自然光
Nano Reflector / Mirro Reflector
T5管個反射，由於T5管啲光四散效率唔高，所以加個好既反射器(納米)嚟聚光，LED冇呢個問題。光管長線都係被淘汰，得個知字。
EMSD BEEO有講要求
Grey Water / Rain Water Recovery
收集啲雨水嚟淋花，或Cooling Tower 啲Bleed-off用嚟沖廁。
有單香港JOB用過前者，原理大概係收集兩水後，响地下挖一個大石矢缸放隻潛水泵入去。
之後要加Carbon Filter, Sand Filter, Ultraviolet Sterilizer 嚟加工啲水
Water Tap / Urinal / WC Infra Red Sensor, Dual Volume Flushing
仲有啲慳水既出水咀，WC大細水沖廁etc.詳細接Grid等注意事項please refer: https://elvissharing.blogspot.com/2020/03/renewinno-solar-related-system-with.html
Biomass
香港冇乜機會用，得個知字。原理大概係燒木碎或廢木點著個Gas Engine生熱或做熱水。
Fuel Cells
香港冇乜聽過，都係得個知字。原理係同電池類似係用Chemical Energy，一頭用Hydrogen。電池當然係做直流電出嚟再轉AC，生產出嚟既廢熱可用於煲水或Absorption Chiller.
Ground Source System / Ground Source Heat Pumps
都係得個知字。原理係利用地底嚟取冷/暖
(Source: EMSD, BSRIA)
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