“We Bring Engineering to Life” 2014 Agent Training Grant Ellington Nov. 19, 2014

Topics Energy outlook Biomass system update Automatic ventilation controls New curing barn energy assessment – part II Heat recovery system evaluation Modular tray steaming system

Source: U.S. Energy Information Administration (LP Gas – Wholesale/Resale; N.G. – Commercial) LP Gas and Natural Gas Price Outlook $18 / $1.30/gal $9.40 / $0.75/therm

Hurst Boiler Biomass Fired Hot Water Heating System;

Woodchip Biomass System and Automated Controls, 3.4 MMBtu/hr Water to Air Heat Exchanger installed in Return Air Plenum

Greenhouse Heating Applications w/Biomass Unit Curing Barns and Greenhouse Applications Result in Extending System Operation from July - March Harnett Co.

Max Ox Smaller Capacity Biomass Heating System – 11 Barns and 200’ Greenhouse Application (900,000 Btu/hr) Person Co.

Performance Information Summary Hurst (2012)Max Ox (2013) Boiler Capacity 3.4 million Btu/hr1 million Btu/hr per unit Number of Barns 1711 Green Leaf Loading (lbs/barn) 18,00013,000 Cured Leaf Weight per Cure (average, lbs/barn) 3,0002,375 # of Cures Total System Cost $300,000- Fuel Type Dry Wood WasteGreen Chips Season Total Fuel Usage (ton) Fuel Cost ($/ton) $30$25 Fuel Usage per Cure (ton) Fuel Cost per Cure $66*$90 Fuel Cost per lb of Cured Leaf $0.02$0.04 *Includes electricity cost for boiler.

Automated Biomass Fired System Advantages – Reduced fuel cost (70 to 90%) – Abundant renewable fuel – High combustion and thermal efficiency – Automated system (combustion controls, emissions, ash removal) – TSNA NO x mechanism eliminated Disadvantages – High initial investment – More equipment maintenance – Increased management – Limited or no local service technicians

Automatic Ventilation Control – Improving Curing Management and Energy Efficiency Most automatic systems measure relative humidity directly, but display dry-bulb and wet-bulb temperature.

2013 County Agent Survey Data (86,000 acres reported)

Real-time Continuous Monitoring of the Curing Environment Significant time management tool for growers Web-based access to monitoring system Audible alarm conditions to help minimize leaf damage during equipment failures or power loss Data logging capabilities Suretrol or Cureco, Marco Mfg., and Enercorp (Flue-Cured Tobacco Services, LLC.)

New Curing Barn Performance Evaluation

Background Energy usage remains a significant input cost Considerable price fluctuations of petroleum fuels in recent years and continued uncertainty of future prices More growers continue to make energy efficiency improvements to existing infrastructure and replacing older barns Approximately 15,000 to 18,000 operational barns in NC 6 manufacturers made barns for the 2014 season Energy efficiency and energy conservation is the best source of new energy and is a cost-effective solution Research continues to explore energy efficiency improvements and renewable energy technologies that are economically feasible

Primary Objectives New curing barn assessment to provide on-farm independent energy and other performance related information to assist growers with curing infrastructure decisions – Total energy footprint (LP gas and kWh usage) – Green and cured leaf weights – Cure duration – Static pressure (airflow) – Cured leaf quality, barn curing management (user-friendly) Exhaust air heat recovery system evaluation

New Barn Specifications LongLong (10-box) – Long 350,000 Btu/hr World TobaccoWorld Tobacco (15-box) – Evans 500,000+ Btu/hr – 2” insulated panels TytunTytun (14-box, 32T) – Powermatic 400,000 Btu/hr – 4” insulated panels TaylorTaylor (10-box) – Evans 390,000 Btu/hr – 3” insulated panels All fan motors 1-phase, 10 Hp, except Tytun 18-box and Long Prototype (15 Hp) All barn pads insulated Suretrol controllers on all barns Long PrototypeLong Prototype (10-box) – Long 400,000 Btu/hr World Tobacco BasicWorld Tobacco Basic (12-box) – Evans 325,000 Btu/hr – 2” insulated panels TytunTytun (18-box, 32T) – Powermatic 550,000 Btu/hr

Heat Exchanger and Burner Operating Efficiently – set the burner firing rate correctly (325,000 to 425,000 BTU/hr typical range) – burner and all controls properly adjusted

Box Comparison Long, Taylor Tytun (32T) World Tobacco, DeCloet

Total Cured Weight – 10 Cures

Season Average Cure Duration (10 Cures)

Season Average Electrical Energy Usage 15 Hp 10 Hp 7.5 Hp

* No lower-stalk cures 2.3 ¢ / lb Season Average Curing Efficiency Comparisons

Fuel Efficiency (lbs/gal) Fuel Cost ($/unit) $ / lb Cured Energy Efficiency and Estimated Cost per Pound Cured Leaf (fuel only)

Summary Approximately 25% increase in fuel efficiency averaged over the season 6 barn manufacturers made and sold barns in 2014 Energy performance alone is not the single justification for purchasing a given barn make, but remains an important factor – New barn costs – Material handling capacity – Existing barn infrastructure – Existing material handling system – Serviceability and maintenance costs Independent performance information can help manufacturers with developing and implementing technologies to improve overall barn design Demand for used all metal barns ?? Plan to continue work in 2015

Exhaust Air Heat Recovery System Evaluation

FAN Heat Exchanger Tobacco Curing Boxes Tobacco Heated Air Intake Air Exhaust Air Heat Exchanger (recovery coil) Heat Recovery System Schematic Heat Exchanger (preheat coil)

Exhaust Vent Heat Exchanger (recovery coil) Intake Vent Heat Exchanger (preheat coil)

Single Cure Evaluated Diff. = 63 gals (17%)

Cure 7 Daily Fuel Usage Comparison (60 gallons difference)

Exhaust Air Heat Recovery System Average Fuel Savings – 2014 * Last Cure Only

Modular Tray Steaming System

System Specifications Container dimensions; 6’ x 5’ x 10’ Approximately 450 trays Steam generator with fuel oil burner – psi = 100,000 Btu/hr (420,000 Btu/hr max) – 8 to 9 gph water input – T = 210 to 215 o F (steam)

Temperature Profiles vs. Time