Advanced LNG vehicle fuel system and standardizations of fueling process and interface
Tank System prototypes
SAG delivered tank system prototypes to the project partners MAN (Tank system with low pressure pump) and Iveco (Tank system with medium pressure pump). Both tank systems consist of the following components: (1) Base tank: Double walled stainless steel tank with Vacuum Multi-Layer Insulation and a specially designed pump socket to provide the possibility to mount a cryogenic pump (2) Cryogenic Pump: Cryogenic Pump including drive and Control system (3) Plumbing: Heat Exchanger, valves, couplings and piping to ensure sufficient fluid flow and preparation acc. To the engine specifications. All components are directly mounted on the tank system The tank system with low pressure pump is using a Cryogenic Piston pump driven by a linear electric drive. The complete system including the electrical control unit was developed specifically for the HDGAS requirements. The pump is designed to realize a differential pressure of 12 bar with a mass flow of 75kg/h. The tank system with medium pressure pump is using a cryogenic piston pump driven by a hydraulic piston. The design of the LNG pump including the hydraulic drive was developed specifically for the HDGAS requirements. The pump is designed to realize a differential pressure of 65bars with a mass flow of 100kg/h. Both systems were tested on the SAG pump test bench, where the functionality of the pump systems could be confirmed. These tests were done with liquid nitrogen. The systems are designed in a way to meet the requirements of ECE R110, however they do not have the certificate due to the need of using non certificated components in the plumbing system and for the pumps. To ensure that an ECE certification could be achieved for the tank system, SAG performed a drop test and a bonfire test according to the ECE R110 guidelines. Furthermore there was done a shake test with measured vibration signals to ensure that the life length strength of the tank system is sufficient.
read here more on how SAG designed and delivered the pumps.
Volvo received a Westport High pressure LNG pump prototype. For this pump prototype development, Westport relied on its long standing experience in submerged high pressure LNG pumps for heavy duty and high horsepower mobile applications. The starting point and baseline was the Westport™ HPDI 2.0 truck system and more particularly its P20 LNG pump. Expected technology achievements in the HDGAS project are in increased pump lifetime and a path to a high pressure LNG system where the system is capable of reducing tank pressure during operation when it is above a certain level. Like the P20 LNG pump, the new high pressure pump is a hydraulically driven, linear piston pump. The developments performed within the HDGAS project were primarily focused on the cryogenic section of the pump to improve pump durability and impact on tank conditions. LNG pump improvements for the HDGAS pump prototype included pump intake, discharge line, hydraulic piston and valve and prototype shaft. Development, component sourcing, assembly and testing of the new prototype pump were performed for the HDGAS project using internal design tools, assembly and testing capabilities. The performance tests were run on LNG as the test fluid, using a harsh test cycle based on a steep route with a high load factor. Testing was completed with the HDGAS pump as well as a baseline pump. Under these controlled testing conditions, the enhanced pump developed for the HDGAS project has shown promising results when compared against the baseline Westport™ HPDI 2.0 LNG pump. Reductions in tank pressure rise or better yet, reductions in tank pressure during operation were observed. Further evaluation remains to be performed during and after completion of the road tests on the Volvo truck in order to confirm that the expected technology improvements of the new pump are achieved.