DDC Sequencing and Redundancy

Transcription

1 DDC Sequencing and Redundancy

2 Presenter

3 Sequencing Importance of sequencing Essen%al piece to designing and delivering a successful project Defines how disparate components interact to make up a system The fundamentals to sequencing Mechanical designers intent How it should operate How to control to meet both Simplicity is key Clear, concise and complete Overview of process Analyze mechanical design Outline SOO Fill in details Op%mize system

4 Sequencing approach to developing SOO s. Map out en%re system, compartmentalize components if possible, analyze system on a component level Define instrumenta%on on a component level Develop I/O list for components including hardwired points and data connec%ons Define Instrumenta%on on the system level Develop I/O list for system Iden%fy set points, alarms, schedules and trends

5 Example System Chilled Water Plant Series water- side economizer Primary- secondary chilled water pumping Variable speed condenser water pumping Dual piping loops

6 Sequencing Systema%c approach to developing SOO s. Map out system, compartmentalize components if possible, analyze system on a component level Define instrumenta%on on a component level Develop I/O list for components including hardwired points and data connec%ons Define Instrumenta%on on the system level Develop I/O list for system Iden%fy set points, alarms, schedules and trends

7 Map Out System Define system by it s disparate components N+1 component redundancy One- to- one rela%onships

8 Compartmentalized Components Compartmentalize system as best as possible. Create Line- ups of equipment

9 Chiller Plant System Component Level Break down system to the individual component level

10 Sequencing Systema%c approach to developing SOO s. Map out en%re system, compartmentalize components if possible, analyze system on a component level Define instrumenta@on on a component level Develop I/O list for components including hardwired points and data connec%ons Define Instrumenta%on on the system level Develop I/O list for system Iden%fy set points, alarms, schedules and trends

11 Component Level Defining As laid out by the mechanical designer What instrumenta%on is required to meet intent and opera%on? Enable/Disable

12 Component Level Defining Unit Mounted Controller What instrumenta%on is required to meet intent and opera%on? Enable/Disable

13 Component Level Defining Unit Mounted Controller Shut- off/isola%on Valves What instrumenta%on is required to meet intent and opera%on? Enable/Disable

14 Component Level Defining Unit Mounted Controller Shut- off/isola%on Valves What instrumenta%on is required to meet intent and opera%on? Enable/Disable Capacity Control

15 Component Level Defining Unit Mounted Controller Shut- off/isola%on Valves Temperature Sensor What instrumenta%on is required to meet intent and opera%on? Enable/Disable Capacity Control

16 Component Level Defining Unit Mounted Controller Shut- off/isola%on Valves Temperature Sensor What instrumenta%on is required to meet intent and opera%on? Enable/Disable Capacity Control Opera%ng Restraints

17 Component Level Defining Unit Mounted Controller Shut- off/isola%on Valves Temperature Sensor Head Pressure Control What instrumenta%on is required to meet intent and opera%on? Enable/Disable Capacity Control Opera%ng Restraints

18 Component Level Defining Unit Mounted Controller Shut- off/isola%on Valves Temperature Sensor Head Pressure Control What instrumenta%on is required to meet intent and opera%on? Enable/Disable Capacity Control Opera%ng Restraints Op%miza%on

19 Component Level Defining Unit Mounted Controller Shut- off/isola%on Valves Temperature Sensor Head Pressure Control Addi%onal Sensors What instrumenta%on is required to meet intent and opera%on? Enable/Disable Capacity Control Opera%ng Restraints Op%miza%on

20 Sequencing Systema%c approach to developing SOO s. Map out en%re system, compartmentalize components if possible, analyze system on a component level Define instrumenta%on on a component level Develop I/O list for components including hardwired points and data connec@ons Define Instrumenta%on on the system level Develop I/O list for system Iden%fy set points, alarms, schedules and trends

21 Develop I/O List for Components

22 Develop I/O List for Components

23 Repeat and I/O for other components Cooling Tower Condenser Water Pump Primary Chilled Water Pump Secondary Chilled Water Pump

24 Sequencing Systema%c approach to developing SOO s. Map out en%re system, compartmentalize components if possible, analyze system on a component level Define instrumenta%on on a component level Develop I/O list for components including hardwired points and data connec%ons Define Instrumenta@on on the system level Develop I/O list for system Iden%fy set points, alarms, schedules and trends

25 System Level Defining How do the disparate components interact with the system?

26 System Level Defining System Valves

27 System Level Defining System Valves Flow Meters

28 System Level Defining System Valves Flow Meters System Temp Sensors

29 System Level Defining System Valves Flow Meters System Temp Sensors Differen%al Pressure Sensors

30 Sequencing Systema%c approach to developing SOO s. Map out en%re system, compartmentalize components if possible, analyze system on a component level Define instrumenta%on on a component level Develop I/O list for components including hardwired points and data connec%ons Define instrumenta%on on the system level Develop I/O list for system Iden%fy set points, alarms, schedules and trends

31 Develop I/O List for System

32 Sequencing Systema%c approach to developing SOO s. Map out en%re system, compartmentalize components if possible, analyze system on a component level Define instrumenta%on on a component level Develop I/O list for components including hardwired points and data connec%ons Define instrumenta%on on the system level Develop I/O list for system Iden@fy set points, alarms, schedules and trends

33 Set Points, schedules, alarms, trends Avoid exact set points, baselines are recommended Typically done by Cx agent along with the balancing contractor Define schedules Alarms can be addressed as virtual points in points list as well as safe%es that typically take the form of hardware Define trends

34 Sequencing Understand the importance of sequencing Become in%mate with the fundamentals of the design Define your systema%c approach to developing sequences Keep it simple!

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36 Redundancy in DDC Where and why redundancy in DDC is required Redundant systems within a facility DDC System Redundancies Redundant Instrumenta%on Redundancy in system architecture Physical separa%on of installed control components Dual power supplies with separate feeds to each control panel Network Redundancy Separate supervisory networks Redundant Servers PLC Systems

37 Redundancy in DDC Where: Mission Cri%cal Facili%es (MCF) What it means to be a Mission Cri%cal Facili%es that require 100% up%me 24 hours a day 7 days a week for normal business opera%on Redundancy provides maximum reliability but also generates maximum cost and complexity Examples: Data Centers, Hospitals, Laboratories

38 Redundancy in DDC Why: Enables con%nuous opera%on during cri%cal system failures Meets owner s requirements for minimized down%me Designing for redundancy in all building systems, including the DDC system may be required Site- wide control coordina%on Example coordina%on types: Temperature Control, Power restart, Load Shedding, Humidity Control, Pressuriza%on

39 Redundant Systems

40 Redundant Systems N+1 component redundancy Dual piping loops

41 Redundant Systems DDC system redundancy isn t addressed by Up%me Redundant mechanical equipment s%ll needs DDC to func%on properly Fault Tolerant Control Systems any single controller or communica%on network Redundancy in DDC is necessary to ensure any malfunc%on or loss of power within the control system will not affect cri%cal equipment opera%on

42 DDC System Redundancies Redundant Redundancy in system architecture Physical separa%on of installed control components Dual power supplies with separate feeds to each control panel Network Redundancy Separate supervisory networks Redundant Servers

43 Redundant System Valves Flow Meters System Temp Sensors Differen%al Pressure Sensors

44 DDC System Redundancies Redundant Instrumenta%on Redundancy in system architecture Physical separa%on of installed control components Dual power supplies with separate feeds to each control panel Network Redundancy Separate supervisory networks Redundant Servers

45 Redundancy in System Architecture DDC system architecture depends on the make- up of the mechanical and electrical systems DDC system architecture designs to achieve redundancy: Primary- Redundant Managers (True Primary/Redundant) Distributed Control (Line- Up Configura%on) Hybrid (Line- Up Configura%on with PR Managers) How to find the right design for your applica%on Compartmentalize the systems as best as possible

46 Redundancy in System Architecture Primary- Redundant Managers (True Primary/Redundant)

47 Redundancy in System Architecture Distributed Control (Line- Up Configura%on)

48 Redundancy in System Architecture Hybrid (Line- Up Configura%on with PR Managers)

49 DDC System Redundancies Redundant Instrumenta%on Redundancy in system architecture Physical of installed control components Dual power supplies with separate feeds to each control panel Network Redundancy Separate supervisory networks Redundant Servers

50 Physical of Components DDC Controllers Variable Frequency Drives Redundant Sensors Control Valves Wiring

51 DDC System Redundancies Redundant Instrumenta%on Redundancy in system architecture Physical separa%on of installed control components Power redundancy Network Redundancy Separate supervisory networks Redundant Servers

52 Power Redundancy Control panels need to be powered at all %mes to properly func%on Examples: UPS power from two sources with a local ATS UPS power from electrical system with back- up generator and local UPS

54 Network Redundancy Concept of self- healing communica%on busses Redundant topologies (network s virtual shape or structure) Ethernet Topologies Bus Topology Classic Star Topology Tree Topology (combina%on of bus and star) Ring Topology Redundancy through ring topology is becoming the most popular for the BMS market Wireless Mesh

55 Network Redundancy Bus Topology Uses a common backbone to connect all devices. Failure of one node or link affects the rest of network Works best with a limited number of devices due to the broadcast traffic it generates

56 Network Redundancy Star Topology Most common network setup If the central hub fails, all devices connected to that hub would be disconnected Performance of the network is dependent on the capacity of central hub (router or switch)

57 Network Redundancy Tree Topology Integrates mul%ple star topologies together onto a bus. This hybrid approach supports future expandability of the network much beier than a bus

58 Network Redundancy Ring Topology N+1 U%lizing industrial switches Redundant rings is becoming the most popular for the BMS market Ethernet rings will cause broadcast storms and can ul%mately cause the network to stop working How to fix this? - Spanning Tree Protocol

59 Network Redundancy Spanning Tree Protocol (STP) Although two cable paths exist, messages can only travel in one direc%on STP solves problems in a ring topology including broadcast storms STP does for an Ethernet network what a router does for an IP network Typically provides network recovery %mes of seconds Rapid Spanning Tree Protocol (RSTP) Provides faster spanning tree convergence aler a topology change

60 Network Redundancy Wireless Mesh Topology Can take any of several possible paths from source to des%na%on. Devices are connected with many redundant interconnec%ons between network nodes In a true mesh topology every node has a connec%on to every other node in the network.

61 Network Redundancy The most common problems in any fieldbus or high speed digital communica%ons system are: Cabling and wiring faults: Reflec%ons, interference, cable rou%ng and grounding faults etc. Poor design and installa%on: Lack of awareness of avoidable issues at design stage, poor rou%ng, layout, untrained installers, inaccurate or insufficient system documenta%on Device and wiring failures: Rare but can lead to communica%ons faults or peripheral faults

63 Separate Supervisory Networks SNMP monitoring on equipment back to a separate owner network and server Other secondary monitoring methods such as web based services

65 Redundant Servers Servers are also at risk for being a single point of failure Server redundancy minimizes down%me caused by: Planned Maintenance Hardware Failure Redundancy Methods Two separate servers passive synchroniza%on rou%ne Two separate servers with an ac%ve synchroniza%on rou%ne Clustering and/or VM s (Virtual Machines)

66 Redundant Servers Two separate servers would have some manual back up and a passive synchroniza%on rou%ne Two separate servers with an ac%ve synchroniza%on rou%ne Two computers using separate network between them that buffers and replicates the data going into one machine Poten%ally lose the buffer as data is being passed between the two.

67 Redundant Servers Clustering and/or VM s (Virtual Machines) Two different things but from controls perspec%ve doesn t maier Server Clustering combining two or more servers that are interconnected to appear as one Load balanced clustering/fail over clustering Need clustering solware that monitors the ac%ve nodes in a server cluster and transi%ons a failed server s workload to the secondary node Virtual Machines maintain an exact mirror copy on a second physical server

68 PLC Systems PLC systems are more robust, have higher performance, faster networks and more flexible programming capability PLC s have the capability to have Hot Standby Processors (no PID tuning required): the scans of the primary and standby controllers are synchronized Redundant Power Supplies separate power supplies can be provided for PLC controllers. Redundant Networks Difference in costs between PLC and DDC control - up to 5:1 cost

69 Redundancy in DDC Where and why redundancy in DDC is required Redundant systems within a facility DDC System Redundancies Redundant Instrumenta%on Redundancy in system architecture Physical separa%on of installed control components Dual power supplies with separate feeds to each control panel Network Redundancy Separate supervisory networks Redundant Servers PLC Systems

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