Existing Building Energy Saving

Transcription

1 Existing Building Energy Saving Ir Cary Chan Executive Director, HK Green Building Council

2 Aviation industry s

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7 7 A big gap to fill

8 Convincing responses to your boss! Deliver!

9 Energy Management Process Implementation of energy management POLICY OBJECTIVE & TARGET ACT Knowledge-based AUDIT DATABASE ANALYSIS ACTION PLAN PLAN IMPLEMENTATION DIAGNOSIS (Retro-Cx) DO MEASUREMENT & VERIFICATION REVIEW MEETING & REPORT CHECK BENCHMARKING

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11 Design parameters Load calculation System design Equipment selection Testing and commissioning

12 Idea of ACT-Shop Groups of representatives from buildings going through a retro-commissioning process Buildings as living laboratories HKGBC as facilitator Learning from peers Building up knowledge Together

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14 In participating in the ACT-Shop programme : Actively supporting HK gov s energy saving plan Building up the competence for the industry on retrocommissioning through developing the data/knowledge base developing a systematic approach for retro-commissioning demonstrating the value of retro-commissioning transferring the knowledge and skills to the industry establishing a practical operation & management system Promoting the adoption of best practices to the industry

15 Initial findings

16 Different types of building, system design, age.. Bldg A Bldg B Bldg C Bldg D Bldg E Type Composite Hotel Composite (Podium+ Towers) Composite (Office +Education) Office (Industrial Building Renovation) Age (Yrs) IFA (sqm) ~20,000 ~36,000 ~150,000 ~4,500 ~45,000 Chiller Cooling Tower Control 4x320TR Water-Cooled (new) 4x180TR Water-cooled 4x190TR Air-cooled (new) 7x1000TR Water-cooled. 2x400TR Water-cooled(Night) 1x150TR Air-cooled 1x150TR Air-cooled (new) 4x400TR Air-cooled N/A N/A Differential Pressure Bypass Pumps 4+1 Features Variable Speed Chiller Differential Pressure Bypass Water-cooled: 4 Air-cooled: TR Heat Pump for hot water Differential Pressure Bypass (Office Tower) Heat Exchanger for high rise office tower Differential Pressure Bypass Differential Pressure Bypass natural ventilation allowed Fresh air treated by FCU

17 Availability of data and information varies!

18 Has to consider : Practicality Minimum provision of instrument Availability of data and information Approach and Method

19 1. Re-tune 1.1 Valve authority 1.2 Set-point 1.3 Equipment operation Valve Authority %load Re-tune: 1. DT CHWS 2. DT A 3. DSP 1.3 Re-tune: Discharge valve Double regulating valve, etc. Cooling load 4. DP WS 5. T APP,C 6. T APP,C T 100% ACT-Shop Data Analysis Method (retro-cx) Loading Peak Demand 0: Outdoor Ambient Temperature summer winter 24:00 2. Performance line evaluation 3. Peak demand shedding 4. Set-point reset Control Set-point 6 Outdoor Ambient Temperature Cooling Load 19

20 ACT-Shop Data Analysis Method (retro-cx) DTCHW summer DTCHW winter TCHWS summer TCHWS winter Bldg A Bldg B Bldg C Bldg D Bldg E 5.0 C 2.5 C 7.8 C 10 C 5.0 C 3.2 C 7 C 11 C 5.0 C 3.0 C 8 C 9.5 C 2.5 C 0.75 C 9.5 C 14 C 3.4 C 2.0 C 8.5 C 10 C Low DTCH W TCHWS reset at winter COP,CH summer 6.3 COP,Ch winter 13 EUI(Chiller) 60 kwh/m 2 /year kwh/m 2 /year kwh/m 2 /year kwh/m 2 /year Low CO P 48.3 kwh/m 2 /year 20

21 1. Re-tune Chiller Operation Percentage of Full Load Ampere (%FLA) 100% Full Load 1 Chiller Zone 2 Chillers Zone Extra chiller More FLA Less FLA 3 Chillers Zone Cooling Load/m 2 Good operation Poor operation (high % full load ampere due to deterioration of chiller capacity) 21

22 1. Re-tune Chiller operation (cont d) % Full Load Ampere issue Percentage of Full Load Amp 100% 80% 60% 40% 20% 0% Bldg C Cooling Load Intensity 1 Chiller 2 Chiller 3 Chiller 4 Chiller 5 Chiller Percentage of Full Load Amp 100% 80% 60% 40% 20% 0% Bldg E Chiller operate at high % FLA Cooling Load Intensity 1 Chiller 2 Chiller 3 Chiller 4 Chiller Extra chiller in operation 22

23 1. Re-tune Chiller Operation (cont d) Delta T of Chilled Water issue Delta T of Chilled Water Design Value Large Delta -T Delta T of Chilled Water 1 Chiller Zone 2 Chillers Zone Small Delta-T 3 Chillers Zone Cooling Load/m 2 Good operation Poor operation (narrow delta T due to excessive flow through chillers or bypass pipe) 23

24 Delta T of Chilled Water ( C) Re-tune Chiller Operation (cont d) Bldg C Extra flow through bypass pipe Cooling Load Intensity 1 Chiller 2 Chiller 3 Chiller 4 Chiller 5 Chiller Delta T of Chilled Water ( C) Delta T of Chilled Water issue Bldg B One chiller capacity but two pumps Cooling Load Intensity 1 WCC 0.5ACC + 0.5WCC Delta T of Chilled Water ( C) Bldg E Extra flow through chiller Cooling Load Intensity 1 Chiller 2 Chiller 3 Chiller 4 Chiller 24

25 1. Re-tune Chiller Operation (cont d) %Bypass Flow issue 25

26 1. Re-tune Chiller Operation (cont d) %Bypass Flow issue Bldg C Percentage of Bypass Flow Rate 250% 200% 150% 100% 50% 0% Extra flow through bypass pipe Cooling Load Intensity 1 Chiller 2 Chiller 3 Chiller 4 Chiller 5 Chiller 26

27 2. Performance line evaluation Using thermal & electricity performance line Consumption/Load Intensity COP keeps constant Consumption/Load Intensity COP increases at part load Outdoor Temperature Outdoor Temperature COP decreases at part load Consumption/Load Intensity Outdoor Temperature 27

28 2. Performance line evaluation (cont d) Using Coefficient of Performance line Coefficient of Performance (COP) COP = constant Cooling Load Intensity 28

29 2. Performance line evaluation (cont d) 14 Bldg D 15 Bldg A COP COP 9 VSD Air-cooled 4 CSD Air-cooled Cooling Load Intensity new chiller Old Chiller Bldg C CSD Water-cooled Cooling Load Intensity Note: Not sufficient data for Building B (No COP data), COP COP VSD Water-cooled Cooling Load Intensity Bldg E CSD Air-cooled Cooling Load Intensity

30 1. Summary of Common Problems on Chiller Plant Systems Common Problems on Chiller Plant Systems Bld A Bld B Bld C Bld D Bld E Chillers Improper chiller sequencing * Serious chiller deterioration Pumps (chilled water flow) Low/improper bypass valve setting Deviation on chilled water flow rates across each chiller Primary variable flow design but not fully in operation Cooling towers N/A N/A N/A High approach temp N/A N/A *One chiller is sufficient to provide cooling over a year 30

31 1. Summary of Re-tuning Work Suggested Re-tuning Work Bld A Bld B Bld C Bld D Bld E Chillers Reduce chiller operation (N-1) to achieve higher overall COP Increase Tcws Max. demand shedding Pumps (chilled water flow) Re-tune bypass valve setting Install differential pressure sensors at the critical path Install VSD on the existing chilled water pumps N/A Cooling towers Reactive cooling tower (CT) optimisation N/A N/A N/A *1 *2 *2 *2 N/A *1 One chiller is sufficient to provide cooling over a year *2 Serious chiller deterioration limited improvement 31

32 1. Saving Summary of Re-tuning Work Suggested Re-tuning Work Bld A Bld B Bld C Bld D Bld E Chillers Reduce chiller operation (N-1) to achieve higher overall COP Increase Tcws Max. demand shedding Pumps (chilled water flow) Re-tune bypass valve setting Install differential pressure sensors at the critical path Install VSD on the existing chilled water pumps Cooling towers % (Actual) 1-3% (Potential) 0-1% (Potential) 1-3% (Potential) Reactive cooling tower (CT) optimisation N/A N/A *1 One chiller is sufficient to provide cooling over a year *2 Serious chiller deterioration limited improvement N/A *1 3-5% (Potential) 1-3% (Potential) 3-5% (Potential) 1-3% (Potential) 0-1% (Potential) 1-3% (Potential) 3-5% (Potential) 1-3% (Potential) *2 3-5% (Potential) *2 1-3% (Potential) 1-2% (Potential) 1-3% (Potential) *2 N/A 0-1% (Potential) 1-3% (Potential) 1-3% (Potential) N/A 1-3% (Potential)

33 1. Payback Summary of Re-tuning Work Suggested Re-tuning Work Bld A Bld B Bld C Bld D Bld E Chillers Reduce chiller operation (N-1) to achieve higher overall COP <1 year *1 3-5 year Increase Tcws <1 year <1 year *2 *2 <1 year <1 year Max. demand shedding <1 year <1 year <1 year <1 year <1 year Pumps (chilled water flow) Re-tune bypass valve setting <1 year <1 year <1 year Install differential pressure sensors at the critical path <1 year <1 year Install VSD on the existing chilled water pumps N/A 3-5 year 3-5 year Cooling towers Reactive cooling tower (CT) optimisation N/A N/A <1 year N/A <1 year *2 N/A *1 One chiller is sufficient to provide cooling over a year *2 Serious chiller deterioration limited improvement 33

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35 make the most out of the next Energy Audit Review and identify improvements needed from last audit : Quality of measurement, methodology, robustness of data, value of data, readiness of building operators and REA..etc Learn where to focus Setting a foundation for the future : New requirements for data and information for future management, tracking and analysis ( for buildings, industry and government) Useful O&M manual Benchmarking Building capacity ( building provisions, knowledge, specially trained REA.. ) Central data center Setting up energy management systems

36 Performance Assessment Development of KPI (Air conditioning)

37 Performance Assessment - KPI benchmarking

38 Performance Assessment -KPI benchmarking

39 Performance Assessment - KPI benchmarking

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41 Case Study: Problem in Air Handling Unit

42 Are our systems working? Diagnosis Always open Always close

43 How do we compare with others? Opportunities Benchmarking (50th%) Existing Bldg A Commercial Bldgs New Development Hotels

44 Can we have a 10-year plan? Long Term Planning

45 How much can you save? Saving Estimation ANALYSIS Saving = 9,858kWh/year

46 Knowledge-Based Energy Management Data Bank Data Transmission BMS Sensors Long Term Planning Analysis Saving Estimation Fault Diagnosis Useful Information Always close Utilise Information Facilitate Research Implement Initiatives M&V Method Opportunities

47 Characteristic Action Research Sources: Swire Properties Ltd

48 Difficulties BUSINESS Knowledge - Why Operating Data Not Commonly Used? Lack of market drives Not aware benefit of using data Lack of support Not much demand High investment Cost not directly justified Product upgrade Staff training DATA Data missing Massive data transmission and storage problem Inaccurate data Sensor malfunction/ improper location & error Inconsistent data format Bldg. Mgt. Systems & power metering systems not interoperable ACT-shop FACILITIES Inadequate hardware Power meter / Flow meter / DP sensors on equipment/ system base Software not user friendly Proprietary product Lack of Specification There is no any requirement and standards for reference

49 Owner Barriers Collaboration issues within the Industry Designer ACT-shop Lacks BMS/PMS/DMS expertise Lacks O&M experiences Inadequate drives for knowledge based management Focus on project cost only Manufacturer Operator Contractor Focus on functional operation needs only Value of information management not emphasis Lacks of interest in O&M market Emphasis on cost competitiveness Focus on services reliability for tenants Lack of interest and capabilities in performance analysis Shortage of construction time Inadequate T&C and re-commissioning concept

50 How Efficient is Our Plant? Key Performance Indicators DATA INFORMATION Efficiency = Output Input

51 Technical Challenges BMS BMS BMS BMS BMS BMS BMS BMS BMS BMS BMS BMS Quality of Data Accuracy Right Form Accessibility BMS BMS BMS BMS BMS BMS BMS BMS BMS BMS BMS BMS BMS BMS BMS BMS BMS BMS BMS BMS BMS BMS Problems: Missing data Incorrect BMS BMS form BMS of data BMS Huge data volume and scale Incompetence in analysis BMS BMS BMS BMS BMS BMS BMS

52 Transformation of the Current Industry Knowledge-Based Practice Adopt Best Practice Maintenance Requirement Basic Need Continuous Improvement. Lift Modernization Chiller O&M Manual Routine Inspection Work with stakeholders Knowledge transfer Retro-Cx Metering Optimization Saving >24% Advanced Control. Air-cool Water-cool Retrofit. Lighting Early Replacement Saving ~17% Mandatory Audit General Practices & Regulatory Compliance Routine Maintenance House keeping Run to Life

53 Establish Knowledge Sharing Platform Building Operator ACT SHOP Government Private Sector Services Provider Business Saving In-house Competence e-o&m Manual Develop & drive the products / services markets Beyond Standard Industry HKIE BSOMES ASHRAE RICS knowledge Education VTC/IVE Universities Detailed databank Develop competence within the industry Standardise energy analysing method / format Raise next energy audit standard Robust benchmarking system

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55 Analysis & Benchmarking (Opportunities?) How Data Helps Fault detection Tool Time series analysis Expert rules

56 Diagnosis (Any fault?) How Data Helps Fault detection Tool Time series analysis Expert rules

57 Case Study: Problem in Air Handling Unit

58 Case Study: Problem in Air Handling Unit Problem Verification

59 Case Study: Problem in Air Handling Unit After problem solving

60 Re-tune (Implementation) How Data Helps Optimise operation Tool Engineering Approach

61 Any Deviation? ΔT Real Operation 7 C Data of ΔT high condensing differential temperature ΔT, design = 5 C Design Underflow

62 Problem Identification & Rectification Underflow Increase pressure Reduce resistance More consumption To BMS collector P 1m P T Entering Flow con Cooling Tower T Leaving 7 C lower 4.5 C to remove the flow-con: higher water flow rate lower condensation temperature higher chiller efficiency

63 Any Deviation? Riser A Riser B Riser C Riser D Riser E Riser F ΔP ΔP ΔP ΔP ΔP ΔP Return Supply Design Vs. Real Operation kpa Riser A B C D E F Critical AHU Target

64 Problem Identification & verification Renovation of undersized AUHs P reset Summer time exercise Over pressurized A B C D E F Original Step Restricted by under-sized AUHs Step Step Winter time??

65 Saving Estimation, Measurement & Verification Conversion from IGV to VSD control How Data Helps Saving Estimation Tool Regression model + BIN Method

66 Retrofit Saving Estimation

67 Retrofit Measurement & Verification Performance indicator to be verified against % loading at particular range of impact factor(s) Manufacturer claimed saving cannot be identified

68 Energy Management Long term Plan (Are we achieving our target?) How Data Helps Energy management reporting Tool Cumulative frequency plot

69 Buildings in HK account for: 90% Total Electricity Consumption 60% Greenhouse Gas Emission Existing Buildings account for 90% of HK Building Stock

70 Achievement and Target

71 Cost and Benefit

72 Database

73 Did it work? Condition 1 Condition 2 Condition 3 Measurement and Verification