National Grid. Prescriptive Variable Speed Drive Worksheet Development 6/9/2006. Demand Management Institute. 450 Lexington St, Newton, MA 02466

Transcription

1 National Grid Prescriptive Variable Speed Drive Worksheet Development 6/9/2006 Demand Management Institute 450 Lexington St, Newton, MA

2 Executive Summary This document presents information to support adding a simplified and expanded prescriptive Variable Speed Drive worksheet to National Grid s menu of Energy Efficiency programs for its customers. DMI provided a draft list of applications for variable speed drives in late Savings parameters were finalized in 2004 for use by National Grid in the 2005 program year. A list of likely installation types was developed in consultation with National Grid staff. For each measure, a representative installation scenario was selected. The representative scenario included details of typical air or water flow, pressures and operating conditions that are commonly found in National Grid customer installations. Where feasible a corresponding fan or pump curve was utilized. For each scenario a base case and proposed case were developed, both for a retrofit installation and new construction. Simplified savings calculations were performed incorporating the variety of operating conditions and associated operating hours for each representative scenario. The savings results were allocated among onpeak, offpeak, and superpeak, as defined in 2004, to correspond with National Grid s method of recording energy efficiency installations. The resulting savings were normalized by dividing by nominal horsepower, using a 75% oversizing motor selection factor. The normalized results are presented in the two summary tables, one for Design 2000plus, the other for Energy Initiative. The summary tables include a simple average of all installation scenarios, without weighting according to frequency of installation. DMI prepared an initial starting point for the design of the Application Worksheets. DMI also made a preliminary estimate of installation cost for a wide range of sizes of VSDs, using budget prices from a quality vendor and estimating labor costs for installation and controls. National Grid used that cost estimate in conjunction with other cost sources to determine incentive levels. The initial worksheet design is included in an appendix to this report. Following the summary tables, the first appendix presents the measures individually. For each measure, there is a page of description, followed by two pages of savings calculations for the retrofit and new construction scenarios. The second appendix contains information that assisted National Grid in designing the program and the application worksheets. DMI 450 Lexington Street, Newton, MA Ph: (617) FAX: (617)

3 List of measure descriptions Following is a description of each measure for which calculations were performed. Supply Fan or Supply Air Handlers This measure is to install a variable speed drive on an air handling unit supply fan that serves a single zone. The VSD will vary the fan speed based on indoor or outdoor temperature compared to a base case of constant airflow. Supply Fan on VAV Packaged or Rooftop Unit This measure is to install a variable speed drive on VAV packaged rooftop unit or supply air fan. The VSD will vary the fan speed to provide the required supply airflow compared to the base case, which varies airflow using inlet guide vanes or discharge dampers. Return Fans or Return Air Handler This measure is to install a variable speed drive on a return air fan that serves a single zone. The VSD will vary the fan speed based on indoor or outdoor temperature compared to a base case of constant airflow. Return Fan on VAV Packaged or Rooftop HVAC unit This measure is to install a variable speed drive on a VAV packaged rooftop unit return fan. The VSD will vary the fan speed to provide the required return airflow compared to the base case, which varies airflow using inlet guide vanes or discharge dampers. Building Exhaust Fan This measure is to install a variable speed drive to control a building general exhaust fan based on a measured condition (temperature, humidity, pressure) in the building. The base case is a constant flow general exhaust fan. Process Exhaust Fan This measure is to install a variable speed drive to control a process exhaust fan based on a process variable such as temperature or production rate. For EI the assumed pre-retrofit case is full speed at all times and for D2 the assumed base case uses automatically controlled inlet guide vanes. Makeup Air Fans and Fume Exhaust Fan This measure is to install a variable speed drive to control make-up air and fume exhaust fans. The VSD will vary the fume exhaust fan speed based on process requirements during occupied hours and reduced setting during third shift or unoccupied periods. Makeup air fan would be controlled similar to fume exhaust fan, or on pressurization control. The base case and preretrofit controls are continuous airflow throughout the day. Chilled water pump This measure is to install a variable speed drive to control a chilled water circulation pump based on differential pressure near the end of the distribution system compared to a pump riding the full speed pump curve DMI 450 Lexington Street, Newton, MA Ph: (617) FAX: (617)

4 Heating Hot Water Pump This measure is to install a variable speed drive to control a heating hot water circulation pump based on differential pressure near the end of the distribution system compared to a pump riding the full speed pump curve. Circulation Pump for Water Source Heat Pump Loop This measure is to install a variable speed drive to control a water source heat pump loop circulation pump based on differential pressure near the end of the distribution system compared to a pump riding the full speed pump curve. Process Cooling Pump This measure is to install a variable speed drive to control a process cooling water circulation pump based on differential pressure near the end of the distribution system compared to a pump riding the full speed pump curve. Boiler Feedwater Pump This measure is to install a variable speed drive to control a boiler feedwater pump based on pressure sensor between the pump and the throttling valve compared to riding the pump curve. Boiler Draft Fan This measure is to install a variable speed drive to control a boiler forced draft fan compared to airflow control using discharge dampers. Water Supply or Wastewater Treatment Pump This measure is to install a variable speed drive to control a city water supply pump or a wastewater treatment pump. The pre-retrofit pump is assumed to be throttled to 75% average flow all of the time along the full speed pump curve compared to VSD control operating the pump at 85% speed continuously. RAS Pump in Wastewater Treatment Plant This measure is to install a variable speed drive to control a return activated sludge (RAS) pump in a wastewater treatment plant compared to the pre-retrofit pump control of an eddy clutch type drive Molding machine Hydraulic Pump This measure proposed to retrofit a constant speed injection molding machine hydraulic pump to variable speed drive control which would be integrated with the molding machine controls. Single Cell Cooling Tower This measure is to retrofit a constant speed single cell cooling tower fan that provides condenser water to a chiller or a year round process load with a variable speed drive. The VSD would control the fan speed to maintain the condenser water temperature setpoint DMI 450 Lexington Street, Newton, MA Ph: (617) FAX: (617)

5 Summary Tables Energy Initiative Summary Table This table presents a summary of the on-peak, off-peak and total energy savings as well as the summer and winter demand savings associated with each Energy Initiative measure. There are seventeen Energy Initiative measures as described in the List of Measure Descriptions. The table includes calculated savings per motor horsepower. The table also includes the savings associated with a 20-horsepower motor, which are calculated by scaling of the savings per horsepower by the motor horsepower. Design 2000 Summary Table This table presents a summary of the on-peak, off-peak and total energy savings as well as the summer and winter demand savings associated with each Design2000plus measure. There are thirteen Design2000plus measures as described in the List of Measure Descriptions. Four of the measures that are included in the Energy Initiative program are not applicable to the Design2000plus program because they are assumed to be standard practice for new construction. The table includes calculated savings per motor horsepower. The table also includes the savings associated with a 20-horsepower motor, which are calculated by scaling of the savings per horsepower by the motor horsepower. Overall Summary Table This summary table combines some of the measures listed in the Energy Initiative and Design2000plus summaries into categories. The following table includes a list of which measures are included in each category. Category Measure HVAC Return or Supply Fan 3, 4, 5 HVAC Supply Fan 1, 2 Process Exhaust and Makeup Air Fan 6, 7 Heating Hot Water Pump 9 Process Cooling Pump 11 WSHP Circulation Pump 10 Boiler Draft Fan 13 Cooling Tower Fan 17 Water Supply or Wastewater Pump 14,15 Chilled Water Distribution Pump 8 Boiler Feed Water Pump 12 The table includes average energy savings per horsepower, average peak kw savings per horsepower, average percent on-peak savings and summer/winter peak kw diversity. DMI 450 Lexington Street, Newton, MA Ph: (617) FAX: (617)

6 Energy Initiative Summary Table EI savings per hp Energy Initiative 20 hp motor savings kwh kwh kwh kw kw kwh kwh kwh kw kw DMI # Measure List On-Peak Off-Peak Total Summer Winter On-Peak Off-Peak Total Summer Winter 1 Supply fan or supply air handler ,693 3,735 18, Supply fan on VAV packaged or rooftop unit ,180 4,759 18, Return fans or return air handler ,693 3,735 18, Return fan on VAV packaged or rooftop HVAC unit ,935 3,812 14, Building exhaust fan ,434 2,255 16, Process exhaust fan , ,718 13,300 29, Makeup air fans and fume exhaust fan 125 2,092 2, ,503 41,844 44, Chilled water pump ,618 1,632 6, Heating hot water pump ,046 11,788 18, Circulation pump for water source heat pump loop 424 1,264 1, ,476 25,273 33, Process cooling pump ,518 1,048 7, Boiler feedwater pump , ,011 18,740 31, Boiler draft fan 1,036 1,493 2, ,728 29,854 50, Water supply or wastewater treatment pump ,902 9,880 15, RAS pump in wastewater treatment plant ,337 10,608 16, Molding machine hydraulic pump , ,892 13,725 24, Single cell cooling tower ,641 1,329 6,

7 Design2000plus Summary Table D2 savings per hp Design hp motor savings kwh kwh kwh kw kw kwh kwh kwh kw kw DMI # Measure List On-Peak Off-Peak Total Summer Winter On-Peak Off-Peak Total Summer Winter 1 Supply fan or supply air handler ,307 3,635 17, Supply fan on VAV packaged or rooftop unit ,807 4,635 18, Return fans or return air handler ,307 3,635 17, Return fan on VAV packaged or rooftop HVAC unit ,640 3,711 14, Building exhaust fan ,092 2,201 16, Process exhaust fan ,650 1,396 3, Makeup air fans and fume exhaust fan 121 2,043 2, ,414 40,854 43, Chilled water pump ,414 1,562 5, Heating hot water pump ,834 11,433 18, Circulation pump for water source heat pump loop 406 1,215 1, ,129 24,305 32, Process cooling pump ,349 1,021 7, Boiler feedwater pump , ,750 18,363 31, Boiler draft fan 1,012 1,457 2, ,232 29,139 49,

8 Overall Summary Table 2005 Design 2000 VSDs kwh/hp kw/hp % on summer winter peak diversity diversity REF HVAC RETURN OR EXHAUST FAN SF HVAC SUPPLY FAN PE PROCESS EXHAUST AND MAKEUP AIR FAN HWP HEATING HOT WATER PUMP PCP PROCESS COOLING PUMP HPP WSHP CIRCULATION PUMP BDF BOILER DRAFT FAN CT COOLING TOWER FAN NA NA NA NA NA WSP WATER SUPPLY OR WASTEWATER PUMP NA NA NA NA NA CWP CHILLED WATER DISTRIBUTION PUMP FWP BOILER FEED WATER PUMP Energy Initiative VSDs kwh/hp kw/hp % on summer winter peak diversity diversity REF HVAC RETURN OR EXHAUST FAN SF HVAC SUPPLY FAN PE PROCESS EXHAUST AND MAKEUP AIR FAN HWP HEATING HOT WATER PUMP PCP PROCESS COOLING PUMP HPP WSHP CIRCULATION PUMP BDF BOILER DRAFT FAN CT COOLING TOWER FAN WSP WATER SUPPLY OR WASTEWATER PUMP CWP CHILLED WATER DISTRIBUTION PUMP FWP BOILER FEED WATER PUMP