Liquid ammonia phase-change cooling type hybrid power thermal management system
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Solution Overview
Problem
Current ammonia fuel engines face challenges such as low volume efficiency, poor combustion, low heat efficiency, and limited energy utilization due to the use of diesel ignition combustion mode, and lack a mature fuel supply and injection system capable of handling low viscosity and low flash point fuels like ammonia, which restricts their widespread adoption in green and low-carbon ship technologies.
Innovation Solution
A liquid ammonia phase-change cooling type hybrid power thermal management system is designed, incorporating a dual-fuel injector for ammonia and diesel, a double-acting heat pump module, and a hydrogen fuel cell system, which improves engine efficiency by enabling ammonia to be used as a fuel, refrigerant, and discharge aftertreatment agent, addressing cold start issues and enhancing energy utilization through phase-change cooling and waste heat utilization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If ammonia fuel is injected into the cylinder in liquid state under high pressure to improve heat efficiency, then the combustion effect is improved, but the cold starting problem under cold condition occurs
Solution Approach 1:
The patent utilizes the phase change characteristics of ammonia fuel. Liquid ammonia is injected into the hot cylinder where it rapidly vaporizes and combusts, providing high heat efficiency. For cold starting, the system switches to diesel fuel injection which can ignite reliably at lower temperatures, once the engine is running ammonia takes over as the primary fuel.
Solution Approach 2:
The system performs preliminary heating or pre-combustion using diesel fuel before transitioning to ammonia fuel injection. This preliminary action ensures the cylinder temperature is sufficient for ammonia vaporization and combustion, solving the cold starting problem while maintaining high heat efficiency during normal operation.
2Device complexity
If a traditional fuel supply system is used for ammonia fuel, then the system structure is simple, but the volume efficiency and energy utilization rate are low
Solution Approach 1:
The patent designs a multi-functional fuel supply system that can handle both liquid ammonia and diesel fuel. The system includes high-pressure pumps, common rail pipes, and injectors that are optimized for ammonia's low viscosity and high vapor pressure characteristics, achieving high volume efficiency and energy utilization while maintaining reasonable structural complexity through component integration.
3Device complexity
If ammonia fuel is used as a single-purpose fuel, then the fuel system is simple, but the energy utilization rate is low
Solution Approach 1:
The patent implements a multi-purpose ammonia utilization system where ammonia serves as: (1) fuel for the engine, (2) refrigerant in the cooling system, and (3) reducing agent in the exhaust aftertreatment system. This multi-functionality dramatically improves overall energy utilization rate by capturing and utilizing ammonia's energy and chemical properties across different system functions.
Solution Approach 2:
The system recovers waste heat from the exhaust gases and cooling system to pre-heat the ammonia fuel or generate electricity, and uses ammonia's chemical properties in the aftertreatment system to reduce NOx emissions. This recovery and reuse of energy streams improves overall energy utilization while managing system complexity through integrated design.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The system effectively addresses the cold start problem, reduces compressor power consumption, improves energy utilization, and enhances emission performance by utilizing ammonia in multiple roles, thereby increasing the efficiency and reducing carbon emissions while maintaining dynamic and economic efficiency.
Implementation Method 1
liquid ammonia phase-change cooling principle
Implementation Method 2
liquid ammonia phase-change cooling
Implementation Method 3
waste heat utilization
Data Source
AI summary
A liquid ammonia phase-change cooling type hybrid power thermal management system. The system comprises an injector, a liquid ammonia hydrogen supply system, a liquid ammonia common rail pipe, a fuel oil common rail pipe and an oil tank, wherein the liquid ammonia hydrogen supply system comprises a liquid ammonia storage tank, an ammonia pumping system, a flow dividing system and an ammonia inlet and outlet system, the fuel oil common rail pipe is respectively connected with the oil tank and a one-way oil inlet of the injector, the liquid ammonia common rail pipe is respectively connected with the ammonia inlet and outlet system and a one-way ammonia inlet of the injector, an ammonia inlet pipe and an ammonia return pipe are arranged in the ammonia inlet and outlet system, the ammonia pumping system comprises a liquid ammonia storage flow divider, a low-pressure pump and a high-pressure pump.