On August 15, the first 6G60MEC10.5-LGIP cylinder head exhaust valve assembly produced by Hengli Engine (Dalian) successfully passed airtightness testing at Dalian Haiyue Marine Equipment. This milestone technical breakthrough not only solidifies Dalian Haiyue Marine Equipment’s robust testing capabilities across all engines but also marks the complete overcoming of core technical barriers to large-scale commercial application.
As is well known, the cylinder head of a marine main engine is the “ceiling” of the combustion chamber, withstanding extreme high temperatures, high pressures and intense thermal stress cycles. The cylinder head assembly tested this time is a core component of the LPG dual-fuel main engine, responsible for high-pressure fuel injection, combustion sealing and thermal management.
In LPG dual-fuel mode, the engine operates in a demanding environment:
- First, it needs to seamlessly switch between the high burst pressure of diesel mode and the unique combustion characteristics of LPG mode (such as lower combustion temperature and different flame propagation characteristics) to ensure structural integrity and sealing;
- Second, LPG has a strong endothermic effect during vaporization, and the sudden drop in cylinder head temperature during cold start can easily induce thermal stress fatigue;
- Third, LPG is weakly acidic, which puts forward special anti-corrosion requirements for materials and seals;
- Fourth, the switching between diesel and LPG under dynamic operating conditions must ensure that the cylinder head-related channels (injector/LPG gas valve seat, distribution block) respond accurately, eliminate the risk of leakage, and achieve the reliability of fuel switching.
Functional test data fully demonstrate that the finely assembled cylinder head of the LPG dual-fuel main engine, under high-pressure working conditions, shows perfect performance at all sealed interfaces, meeting the “zero leakage” standard and ensuring high-pressure sealing is secure. Moreover, the channels operate stably independently, with reliable interface sealing, successfully withstanding rigorous tests. It fully complies with relevant domestic and international standards as well as the actual usage requirements of Hengli Engine (Dalian), and has been highly recognized by customers, laying a solid foundation for subsequent mass production and market promotion.
The successful functional testing of this LPG dual-fuel main engine cylinder head has significance far beyond the verification of a single component. It paves the way for the overall integration of marine main engines, subsequent bench testing and on-board testing, significantly reduceing the shipping risks of LPG-powered ships.
At a critical juncture as the global shipping industry accelerates toward a low-carbon future, the successful functional testing of the dual-fuel main engine cylinder head is a key link in the technological chain for LPG-powered ships. With continued breakthroughs and verification of core component technologies, the commercialization of LPG as a clean and sustainable alternative marine fuel is accelerating significantly.
According to public information, Hengli Engine (Dalian) was established on July 20, 2022, with a registered capital of RMB 100 million. It is a wholly-owned core subsidiary of Hengli Group, headquartered in Changxing Island Economic Zone, Dalian, Liaoning Province.
On July 31, 2023, Hengli Engine (Dalian), a subsidiary of Hengli Group, signed a patent license agreement with German engine manufacturer MAN Energy Solutions, officially launching its engine manufacturing business. By the end of the same year, Hengli Engine (Dalian) had obtained a quality management system certification certificate from the China Classification Society, officially entering the marine engine manufacturing market. To date, it has secured orders for over 140 engines. In March 2024, construction of the first engine commenced.