QSK50-DPM Fuel System PDG 70.02 Total Document Pages: 11 Cummins Confidential PROJECT GUIDE DOCUMENT Subject QSK50-DPM Fuel System This PGD is for the following applications: PGD Number 70.02 Automotive Industrial Marine G-Drive Genset Date: November 13, 2015 Filtration Emissions Solution Engine Models included: QSK50-DPM Author: Christian Lobo Approver per Procedure VPI-CCE-9695 CHANGE LOG Date Author Description Page(s) Nov 13, 2015 Christian Lobo Updated information in all sections All Dec 3, 2012 Arvind Chandrasekaran Original Publication All
Transcript
QSK50-DPM Fuel System PDG 70.02 Total Document Pages: 11
Cummins Confidential
PROJECT GUIDE DOCUMENT
Subject QSK50-DPM Fuel System
This PGD is for the following applications: PGD Number 70.02 Automotive Industrial Marine G-Drive Genset Date: November 13, 2015 Filtration Emissions Solution Engine Models included: QSK50-DPM Author: Christian Lobo Approver per Procedure VPI-CCE-9695
CHANGE LOG
Date Author Description Page(s)
Nov 13, 2015 Christian Lobo Updated information in all sections
All
Dec 3, 2012 Arvind Chandrasekaran Original Publication All
This document provides a description of the QSK50-DPM engine fuel filtration system. It also provides installations recommendations and requirements to provide the end user with a robust fuel system interface.
INSTALLATION REQUIREMENTS Fuel filters:
• Supply fuel must be filtered with the filters supplied on the power module using the provided plumbing arrangement.
• The entire assembly must be mounted on the OEM’s base skid and should meet the vibration profile shown in Figure 3.
• The water-in-fuel (WIF) sensors should be connected to a power source as per the wiring diagram shown in Figure 4.
Fuel supply:
• The complete fuel supply system, including any optional equipment such as fuel heaters or fuel filter arrangements, must meet the “Maximum Fuel Supply Restriction at Pump Inlet - With Clean Fuel Filter Element(s) at Maximum Fuel Flow” on the engine data sheet per the test procedure outlined in AEB 24.10 Fuel System – Industrial Application Installation Requirements and Recommendations.
• Fuel inlet pressure at the Stage 1 filter head must not exceed 2.5 psi. • Fuel lines should be routed such that fuel could not leak onto hot piping under any operating
conditions. • All fuel line materials must be compatible with fuel oil, capable of continuous operation from -40
°C (-40 °F) to 100 °C (212 °F), does not degrade, swell, or deform under 500 mm Hg (20 in Hg) vacuum, resist kinking when bent, and resist abrasion.
Fuel return:
• The fuel return system must not exceed the “Maximum Fuel Drain Restriction (total head)” on the Engine Data Sheet when tested per the appropriate test procedure outlined in AEB 24.10 Fuel System – Industrial Application Installation Requirements and Recommendations.
• If applicable, separate fuel return lines must be used to return fuel to the day tank for each power module in a multiple-module installation.
• Fuel return lines must not contain a shutoff device. • Flexible lines must be used for connecting between the engine and the stationary fuel lines. • Fuel lines must be supported to restrain movement and prevent chaffing on contact with sharp
edges, electrical wiring and hot exhaust parts. The fuel lines must be routed to maintain a 12.7 mm (0.5 inch) minimum clearance from electrical wiring and a 51 mm (2 inch) minimum clearance from hot exhaust parts.
• All materials used in return lines must be compatible with fuel oil, capable of continuous operation from -40 °C (-40 °F) to 120 °C (250 °F), does not degrade or deform up to 2500 mm Hg (100 in Hg) internal pressure, resist kinking when bent, and resist abrasion. The line material must not degrade after long term exposure to fuel oil, engine oil, and water.
• The main fuel tank must meet all legal requirements. • The fuel tank must have provisions to periodically drain water and sediment from the tank. • The fuel supply and return location must be separated by a minimum of 305 mm (12 in). • There must be a minimum of 5% expansion space above the full level of the tank. • A 10 micron or better vent filter must be installed on the fuel tank.
Day tank:
• Valves must be used to control and shut off make-up flow to prevent overfilling of day tanks. • Suitable alarms and redundant components should be used to guard against the day tank
overflowing if a component fails. • Fuel filters must be used in transfer lines between the main tank and the day tanks. • Transfer piping must not be capable of siphoning fuel from the day tanks.
APPLICABLE AEBs AEB 24.10 Fuel System – Industrial Application Installation Requirements and Recommendations
SYSTEM OVERVIEW This document details the features of the Cummins high pressure fuel pump and Modular Common Rail System (MCRS) used on the QSK50 Tier 2 engine. The fuel pump, solenoid controlled electronic injectors, and engine electronic control module provide full authority electronic control for fuel delivery, allowing both injection pressure and timing to be accurately controlled.
1. Operation The component life of the MCRS fuel system is maximized by supplying fuel to the engine via a Cummins two stage fuel filtration system which meets an ISO 18/16/13 particle count level or better per ISO Standard 11171. An electric priming pump is integrated with the off-engine fuel filter head (Stage 1) and is controlled and powered by the engine ECM. The fuel supply strategy includes OEM-installed fuel tank air vents filtered to at least a 10 micron level to avoid adding suspended, hard, fine particles to the fuel. During start-up, the priming pump pulls fuel from the tank through the Stage 1 fuel filters. The priming pump pressurizes the inlet to the mechanically driven gerotor pump. After the engine starts, the electric lift pump is shut off and bypassed, requiring the gerotor to draw fuel directly from the tank through the Stage 1 filter. The gerotor pump on the rear of the high pressure pump supplies approximately 100 psi of fuel pressure through the Stage 2 fuel filter and to the high pressure pump. The pump pressurizes the fuel to the desired injection pressure, as defined by the software calibration and controlled by the inlet metering valve (IMV). Pressure at the outlet of the pump can be as high as 1,600 bar (23,200 psi). The fuel is then delivered to the fuel injectors. Double wall fuel lines deliver fuel from the fuel pump and to each of the 16 injectors, which are plumbed in series. NOTE: External fuel shutoff valves are not required because the injectors are electronically actuated. The injectors will not deliver fuel if the emergency stop or the run/stop switch is in the stop position.
The high pressure fuel pump has five cylinders to deliver fuel to the electronic injectors at very high pressures up to 1,600 bar. The pressure is controlled by an electronic actuator at the pump inlet
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called the inlet metering valve (IMV) and is measured by a special pressure sensor mounted on the top of the pump. The pump, lubricated by engine oil for long durability, has a mechanically driven gerotor pump on the rear that feeds fuel into the high pressure pumping section. The gerotor pump has been designed to operate in a low pressure system and cannot accept any overpressure above atmospheric at the pump inlet.
1.2. Fuel filters
In order to protect the precision fuel system components, the QSK50-DPM require 2 stages of fuel filtration. The first stage of filtration utilizes triplex style 7 micron Cummins Filtration Sea Pro™ 5 filters with integrated priming pump located on the suction side of the gear pump, while the second stage uses 3 micron dual pass FF5644 filter cans located on the pressure side of the gear pump. To ensure consistent filtration efficiency at the 4 micron level, the recommended filter change interval is at 500 hours.
Stage 1 Stage 2
Location Suction side Pressure side
Element Fleetguard FH23471 assembly Fleetguard FS19841 filters
Fleetguard FF5644 filters
Filtration 7 micron 3 micron
Service Life 500 hours 500 hours
Mounting OEM base skid (brackets provided) Power unit base rails
Water Separation Included N/A
Table 1. QSK50-DPM fuel filters
The Stage 1 Sea Pro™ provides water separation capacity adequate for handling a fuel supply containing up to 200 ppm water. The filter assembly, which includes the filter housing, mounting brackets, and water-in-fuel (WIF) sensor is provided as a kitted option along with the 9.8 ft. (3 m) wiring harness. The entire assembly must be mounted on the OEM’s base skid and should meet the vibration profile shown in Figure 3. Literature and technical data for the FH234 series Sea Pro™ filters can be found on the Cummins Filtration website (http://www.cumminsfiltration.com).
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Figure 3. Stage 1 filter vibration profile
1.3. Water-in-fuel (WIF) sensor
The WIF sensor provided on the filter assembly should be connected to a power source as per the wiring diagram shown in Figure 4. The engine Warning Lamp on the PowerCommand® controller will be illuminated when water is detected in the fuel and the ECM will register a Severity Level 2 fault. The WIF LED light is optional and may be provided on the OEM panel as an additional means of warning the operator of the WIF sensor fault condition.
Figure 4. WIF sensor wiring
2. Fuel supply system The fuel supply system transfers fuel from the fuel tank(s) to the engine fuel system inlet. This system generally includes a fuel pickup in the fuel tank, and lines and fittings connecting to the engine. Also included in fuel restriction considerations are any shutoff valves, fuel filters, fuel warmers, and water separators that may be part of the system. External fuel shutoff valves are not required with the MCRS fuel system because the injectors are electronically actuated; they will not deliver fuel if the power or the key switch is turned off.
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The complete fuel supply system, including any optional equipment such as fuel heaters or fuel filter arrangements, must meet the “Maximum Fuel Supply Restriction at Pump Inlet - With Clean Fuel Filter Element(s) at Maximum Fuel Flow” on the engine data sheet per the test procedure outlined in AEB 24.10 Fuel System – Industrial Application Installation Requirements and Recommendations. Excessive fuel inlet restriction will result in reduced fuel filter service life, low power, surging, dump valve faults and/or engine fueling control faults. Refer AEB 24.10 for additional guidelines and recommendations to help minimize fuel system supply restriction. Pressure drop across the Sea Pro™ filter assembly used on the QSK50-DPM is designed to be 2.5 in-Hg (1.2 psi) maximum with clean filters. Sea Pro® filters special considerations: While the Sea Pro® filters are designed to be operated in a low pressure system, typically OEM installations use a pressurized fuel supply system to deliver fuel from the day tank (or main tank) to the power modules. However, the pressure at the filter inlet must not exceed 2.5 psi. Introducing the filter to higher inlet pressures at any time can cause unit failure or give false information regarding filter life.
2.1 Fuel supply line size, routing and support
Fuel supply lines should be routed on the installation to protect them from hazards, and supported to allow sufficient flexibility so that the motion of the engine in the mounts does not kink or damage the line or fittings. Lines should be routed such that fuel could not leak onto hot piping under any operating conditions. Supply lines should be routed as directly as possible from the tank to the engine, avoiding both upward and downward loops. Upward loops can act as air traps, which can cause erratic engine operation, and downward loops can act as water traps, which can freeze and block fuel flow. The fuel supply connection on the QSK50 engine is a 1 ⅟16 – 12 UNF elbow union located on the fuel filter head on the left bank of the engine. A No. 8 flex hose may be used for the return line (if length < 10 ft.). The Sea Pro 5 triplex inlet and outlet connection types and sizes can be found in the figure below.
Figure 5. Sea Pro 5 Triplex with Pump Mounting and Dimensions
2.2 Fuel supply line material
All fuel line materials must be compatible with fuel oil, capable of continuous operation from -40 °C (-40 °F) to 100 °C (212 °F), does not degrade, swell, or deform under 500 mm Hg (20 in Hg) vacuum, resist kinking when bent, and resist abrasion. It is recommended that all fuel wetted O-rings and seals used in fuel hoses, lines, and fittings be of a fluorocarbon FKM material as defined in ASTM D1418 to ensure a
leak-free system. Exposure to fuels with different aromatic content may cause the non-fluorocarbon O-rings and seals to shrink, which might result in air intrusion and a minor fuel leak. An example is exposing such O-rings and seals to low sulfur fuel and then changing to ultra-low sulfur fuel (which has a lower aromatic content). See AEB 24.20 Hose Material and Hose Connection Design Requirements and Recommendations for more information on fuel line selection. Zinc in the form of galvanized or passivate coatings should not be used on any fuel lines, tanks or fittings. The zinc reacts with the fuel to form flakes, which may clog injectors and fuel filters. Copper tube should not be used for fuel lines as it work-hardens and age-hardens, and is then prone to cracking, creating fuel or air leaks. Fuel lines that are resistant to electrostatic discharge are required. Electrostatic discharge may cause fuel leaks under certain conditions. Fuel lines with a braided outer covering that do not have a braided inner lining are not accepted. The following recommendations are from CES 98148:3
• All steel braided hose that shall conform to SAE J517, 100R14 Type B. This type of hose has a conductive inner lining, and prevents fuel leaks from the hose due to pinholes caused by static discharge.
• Acceptable nylon materials are PA 11-PHLY and PA 12- PHLY (reference DIN 73378). This material is advised for suction side fuel systems and where the peak operating temperatures are below 115 °C (240 °F). The nylon lines should have a 1 mm wall thickness. A 2 mm thick Santoprene coating should then be applied to the lines, which provides a flame retardant coating and also provides abrasion resistance. Always seek supplier recommendations for temperature and environmental considerations. This material shall only be used on the suction side of the fuel system.
3. Fuel return system The fuel return system transfers the fuel from the return fitting on the engine to the fuel tank. This system generally includes the line from the return fitting to the fuel tank. This system may also include a fuel cooler, fuel shutoff valve(s), a check valve, and a drop tube in the tank. The complete fuel return system, including any optional hardware, must meet the “Maximum Fuel Drain Restriction (total head)” on the engine data sheet. To make a valid measurement for fuel return restriction, the engine must run at maximum attainable speed at low or no load. This test point creates a maximum return fuel flow condition. The fuel return restriction for high horsepower engines should be measured using the test procedure in AEB 24.10 Fuel System – Industrial Application Installation Requirements and Recommendations.
3.1 Fuel return line size, routing and support
Separate fuel return lines must be used to return fuel to the day or supply tank for each power module in a multiple-module installation to prevent return lines of idle units from being pressurized (See 4.3 for additional information on main tank/day tank layout considerations). The fuel return connection on the QSK50 engine is a 1 ⅟16 – 12 UNF elbow union integrated into the fuel pump plumbing located on the left side of the engine. A No.10 flex hose may be used for the return line (if length < 10 ft.). For the Sea Pro 5 triplex inlet and outlet connection types and sizes reference Figure 5. Fuel return lines must not contain a shutoff device. Engine damage occurs if the engine is run with the return fuel lines blocked or restricted. Flexible lines for connecting between the engine and the stationary fuel lines are supplied as standard equipment. Any additional connections between the engine fuel system and the supply/return lines should use flexible hoses in order to protect the fuel system from damage caused by vibration, expansion and contraction.
Fuel lines must be supported to restrain movement and prevent chaffing on contact with sharp edges, electrical wiring and hot exhaust parts. The fuel lines must be routed to maintain a 12.7mm (0.5 inch) minimum clearance from electrical wiring and a 51mm (2 inch) minimum clearance from hot exhaust parts.
3.2 Fuel return line construction
All materials used in return lines must be compatible with fuel oil, capable of continuous operation from -40 °C (-40 °F) to 120 °C (250 °F), does not degrade or deform up to 2500 mm Hg (100 in Hg) internal pressure, resist kinking when bent, and resist abrasion. The line material must not degrade after long term exposure to fuel oil, engine oil, and water. It is recommended that all fuel wetted O-rings and seals used in fuel hoses, lines, and fittings be of a fluorocarbon FKM material as defined in ASTM D1418 to ensure a leak-free system. Exposure to fuels with different aromatic content may cause the non-fluorocarbon O-rings and seals to shrink, which may result in air intrusion and a minor fuel leak.
4. Fuel tank system All fuel tank materials must be compatible with fuel oil, capable of continuous operation from -40 °C (-40 °F) to 100 °C (212 °F), and resist abrasion. Aluminum or protected steel (phosphate or terneplate) are acceptable tank materials. Galvanized steels must not be used for the tank or any fittings since the coating reacts with diesel fuel to form flakes which may clog filters and damage fuel system components. If the tank is welded, weld spatter or slag must be cleaned from the tank before machine installation. Refer AEB 24.10 Fuel System – Industrial Application Installation Requirements and Recommendations for features of an acceptable fuel tank design.
4.1 Fuel tank connections
Fuel supply connection: The fuel supply connection is typically located on the side of the tank near the bottom, or on the top of the tank with a drop tube used to pick up fuel near the bottom of the tank. Good design practice is to locate the lowest edge of the pickup tube no less than 25 mm (1 in) above the bottom of the tank to allow space for condensate and dirt to collect. Fuel return connection: The fuel return flow from the MCRS engine may enter the tank at any location. However, the fuel supply and return location must be separated by a minimum of 305 mm (12 in) to aid in regulating fuel temperature.
4.2 Fuel tank expansion space and venting
The fuel filler neck and fuel cap are typically elevated above the surface of the tank to lessen debris entry when the cap is removed. The filler neck is either located slightly below the top of the tank or includes an extension into the tank to provide 5% of the tank volume above the full level for expansion space. If the fuel cap also functions as the vent, a 3 mm (1/8 in) diameter hole must be located in the fill neck extension just below the top of the tank to provide venting of the expansion space. A 10 micron or better vent filter must be installed on the fuel tank. This filter prevents fine airborne particles from contaminating the fuel tank as air is drawn in. The fuel tank venting system must accommodate the fastest rate of fuel fill that the tank will experience.
Drilling applications typically use multiple engines with a common bulk fuel tank (main tank). These systems may also include individual day tanks for each engine. Separate return lines must be provided for each engine in a multiple-engine installation. Also, the return lines must not be plumbed with the return or supply fuel of any other engines. This requirement also helps prevent pressurizing the return line to the point that there is no delta pressure from the engine to the manifold, resulting in no return fuel flow.
Figure 6: Fuel storage tank plumbing layout
The day tank must be installed near the power module below the fuel injection system and within the fuel inlet restriction limit. When the main tank is lower than the engine, a fuel transfer pump must be installed to pump fuel from the main tank to the day tank. A float switch can be used in the day tank to control operation of the auxiliary fuel pump.
• Valves must be used to control and shut off make-up flow to prevent overfilling of day tanks. • Suitable alarms and redundant components should be used to guard against the day tank
overflowing if a component fails. • Fuel filters must be used in transfer lines between the main tank and the day tanks. • Transfer piping must not be capable of siphoning fuel from the day tanks.
5. Fuel quality Fuel compatibility for Cummins engines is documented in Cummins Fuel Service Bulletin 3379001. Note: For fuel with high contaminant levels or fuels other than Diesel #2, additional fuel filtration or additives may be required. Please see your Cummins Application Engineer (AE) to receive and review further details or access www.quickserve.cummins.com. Some Cummins engines may be used with certain light fuels when they incorporate the use of a fuel filter with a lubricity enhancing additive. See AEB 74.14 Slow Release Lubricity Additive Fuel Filter Technical Package for more information.
6. Fuel temperature control A fuel drain heat exchanger is not required on the QSK50-DPM due to efficient heat rejection to the fuel.
Cold weather operation: Wax crystals begin to form in diesel fuel when the fuel reaches the cloud point temperature, and fuel will no longer flow when it reaches the pour point temperature. Wax crystals in cold fuel clog fuel lines, fittings, and filters. A variety of fuel warming devices are available to prevent this problem, including electrically heated fuel filter heads, coolant fuel heaters, and electrically heated fuel lines. These devices are effective at controlling fuel waxing problems by warming fuel in cold weather, but must be disabled so they do not heat the fuel in warm weather and contribute to warm fuel problems. Fuel
supply temperatures above the recommended limit cause engine power loss and may shorten life of injectors and other fuel system components. To avoid problems with fuel heaters warming fuel in warm weather, all fuel heaters used on Cummins engines must be thermostatically controlled, self-regulating, or manually regulated by the heater control. The thermostat or regulating feature must stop heating the fuel when the fuel temperature at the heater reaches a maximum of 30 °C (85 °F). A fuel temperature rise of 1.1 °C (2 °F) or less through the fuel heater at fuel temperatures above 30 °C (85 °F) is acceptable.
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REFERENCES
CEB00070 QSK50 Tier 2 MCRS Mechanical Product Information
AEB 24.10 Fuel System – Industrial Application Installation Requirements and Recommendations
AEB 24.20 Hose Material and Hose Connection Design Requirements and Recommendations
AEB 24.45 Fuel System Modular Common Rail System (MCRS) Application Guidelines
