Bi-Fuel Minimum Specifications.pdf

MINIMUM SPECIFICATIONS

INSTALL, Bi-Fuel/ Dual Fuel/ Blended Fuel System to Emergency Generator at Bldg. P-5

SCOTT AIR FORCE BASE, ILLINOIS

20 AUGUST 2020

1. REQUIREMENTS:

a. Install new bi-fuel/dual fuel/blended fuel system and all associated equipment for the proper operation of existing generator. The bi-fuel/dual fuel/blended fuel contractor shall supply the following requirements to the system:

1) be of the following design principles:

i. gas delivered to diesel engine at a regulated and monitored “zero” or “negative” pressure relative to ambient conditions – inherent level of safety

ii. use of a primarily supervisory control scheme (“gas ON” or “gas OFF”, no primary “active” gas flow control) –inherent level of safety and greater stability

iii. primary gas flow is derived by the direct physical relationship of combustion air flow through a true venture air-gas mixer, thus maintaining a single engine control point for the delivery of both fuels while in bi-fuel mode of operation – inherent level of safety and greater stability

iv. use of dedicated sensors (bi-fuel system supplied) to monitor critical engine parameters related to bi-fuel operation – inherent level of safety and reliability

v. operate autonomously, without any required interface with diesel engine ECM or other control source – inherent level of safety and reliability

2) allow the up-fitted diesel engine to operate on a mixture (blend) of diesel fuel and natural gas, or alternately, on 100% diesel fuel with the ability to be manually or automatically switched between fuel modes with no loss in diesel engine performance or drop / interruption in power output.

3) allow for up to a maximum of 70% gas substitution (diesel replacement) at the engine’s prime rating

4) be of a retrofit technology that allows the diesel engine to be converted on-site, without the need to be taken off-line for any extended time during installation, while allowing for near immediate return to service throughout the complete installation process

5) require that no changes or adjustments be made to the diesel engine, to include but not limited to the engine compression ratio, piston design, valve train, injection timing, diesel injectors, fuel system design, cylinder head design; and further, shall not require removal of valve covers nor cylinder heads

6) require not more than minimally invasive on-site machining of engine intake/exhaust manifolds

7) be able to optionally operate on low or medium gas supply pressure of between .07 psig and .7psig or between 3.0 psig and 15 psig, respectively.

8) meet or exceed diesel transient load performance while operating in bi-fuel mode.

9) meet OEM and site specific requirements for engine operating parameters including:

i. intake manifold temperature

ii. exhaust gas temperature

iii. engine coolant temperature

iv. lube oil temperature

v. compressor inlet restriction

10) include a complete “gas train” consisting of at least the following minimum items:

i. 50 micron in-line gas filter

ii. redundant DC operated, normally closed shut-off valves

iii. “Zero-Governor/Zero-Pressure” type gas regulator

11) utilize materials and component construction suitable to the media, temperatures, vibration and duty cycles which the component is subjected to during normal operation of the diesel engine

12) utilize threaded, JIC type connections between the gas train and air-gas mixers

13) shall include properly rated and sized flexible fuel delivery hoses with female JIC swivel connections between the air-gas mixers and gas train

14) utilize a bi-fuel master control installed in an area adjacent to the diesel engine with the following minimum design features:

i. NEMA 4X rated enclosure

ii. Dual-Microprocessor based controller

iii. option for CSA rated for Class I Div II

iv. 12 or 24 VDC

v. readily visible LED lights showing normal and fault modes

vi. LCD display showing current status of bi-fuel system / monitored channels

vii. hour meter displaying total time accumulated in bi-fuel mode

viii. manual primary-power “on-off” switch

ix. key-pad user interface for selecting monitored channels and entering safety set points and control set points

x. electronically calibrated sensors

xi. selectable RS-232 or RS-485 standards with ASCII of MODBUS RTU

(addressable 01 through 99) protocols communication ports to allow for process system integration

xii. discrete digital inputs to allow for remote/external control, at a minimum, of:

a. Stop – latching, fault level Bi-Fuel off control function

b. Safety – latching, fault level Bi-Fuel off control function

c. Reset – system reset following the “setting” of a latching, fault control

d. Inhibit – non-latching, permissive level Bi-Fuel off control function

xiii. optional interfaces include read-only CAN based SAE J1939, OEM

(Caterpillar, Cummins, …) data links, and IP addressable

15) utilize a control system that monitors at least the following engine / system parameters:

i. exhaust gas temperature for each turbo

ii. manifold air temperature for each operational section

iii. natural gas supply pressure to gas train

iv. natural gas supply pressure from gas train to engine

v. engine manifold air pressure for each operational section

vi. engine vacuum for each air-intake operational section

vii. engine vibration level, minimum of one sensor per cylinder bank

16) monitor critical engine parameters via a system dedicated sensor package; the user shall be able to set the maximum or minimum allowable limits, for both control and safety categories

17) monitor, detect, and record any decrease or increase in values of critical engine/system parameters, to include gas supply pressure, that violate established safety limits

18) monitor and detect a decrease or increase in values of critical engine/system parameters, to include manifold air pressure (turbo boost pressure), that violate established control limits delineating the engine’s window for bi-fuel operation

19) monitor engine vibration level in order to detect multiple conditions of improper combustion and/or elevated vibration to include knock (detonation), misfire, or mechanical failure. User shall be able to set vibration safety limits based on normal engine vibration levels at rated load

2. CLEANUP: The Contractor shall cleanup each work site at the end of each work day to the satisfaction of the Government Representative. All construction equipment and debris shall be removed from the site and the area shall be left in a neat and completely acceptable condition as required by the General Provisions. Contractor must always recycle materials, such as, but not limited to cardboard and paper. The Contractor will use whatever means necessary to store all recyclable materials and is responsible for turning in recyclable materials to an off base center.

3. PATCHING AND REPAIRING: After the work has been completed, holes, cuts, and damages made in the finished surfaces of the work site and adjacent areas shall be properly repaired and restored to match the existing finishes. Any abrasion or disfigurement of the finish work or any portion of the building where any such abrasion or disfigurement is caused by the activities of the Contractor shall be repaired and neatly refinished to match the adjacent work to the satisfaction of the Government Representative. Patching includes but not limited to brick, block, pavements, drywall, vinyl, carpet, etc. Any finished disturbed area needs brought back to its original or NEW look.