Gas Engine Fuel Mixing for Mine Ventilation Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Gas engines that use methane gas from coal mines as fuel face challenges in maintaining a stable excess air ratio and controlling the temperature of the gas mixture supplied to the combustion chamber due to variations in methane emissions, leading to potential abnormal combustion and increased NOX emissions.
Innovation Solution
A gas engine configuration that includes a gas mixing unit to combine low-concentration and high-concentration methane gases, a turbocharger, an air mixing part, a mixture ratio adjusting unit, and an intake controller to maintain optimal excess air ratio and temperature control, utilizing VAM gas and CMM gas from coal mines, with a bypass passage and exhaust gas flow rate control to stabilize combustion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If the amount of methane gas from coal mines is used as fuel in a gas engine, then greenhouse gas emissions are reduced and fuel supply is increased, but the variations in methane emissions make it difficult to maintain a stable excess air ratio and optimal combustion temperature
Solution Approach 1:
The system changes the parameters of the fuel gas by mixing low-concentration VAM gas with high-concentration CMM gas or natural gas. This adjustment of gas concentration parameters enables stable combustion and maintains optimal excess air ratio despite variations in methane emissions from the coal mine
Solution Approach 2:
The patent introduces an intermediary mixing system that combines VAM gas with CMM gas or natural gas. This intermediary mixing process acts as a buffer to stabilize the fuel composition, allowing the gas engine to maintain reliable operation despite fluctuations in raw VAM gas quality
2Object-generated harmful factors
If the amount of methane gas from coal mines is used as fuel in a gas engine, then greenhouse gas emissions are reduced and fuel supply is increased, but the variations in methane emissions make it difficult to control the temperature of gas mixture supplied to the combustion chamber
Solution Approach 1:
The system adjusts the temperature parameter of the intake gas by controlling the mixing ratio of VAM gas with CMM gas or natural gas. This parameter change ensures the gas mixture temperature remains within the optimal range of 40-45°C, preventing abnormal combustion while utilizing variable methane emissions
Solution Approach 2:
The mixing system serves as an intermediary that buffers temperature variations in VAM gas. By combining VAM gas with other gas sources through this intermediary process, the system stabilizes the temperature of the gas mixture supplied to the combustion chamber
3Object-generated harmful factors
If VAM gas is used as intake gas for the gas engine, then methane emissions from coal mines are effectively utilized, but the low concentration of methane requires large volumes of gas to be handled
Solution Approach 1:
The patent merges VAM gas with CMM gas or natural gas in a mixing system. This combination allows the low-concentration VAM gas to be effectively utilized while reducing the total volume of gas that needs to be processed by concentrating the methane content through mixing with higher-concentration gas sources
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 solution enables precise control of excess air ratio and gas mixture temperature, reducing NOX emissions and preventing abnormal combustion, while effectively utilizing VAM gas to minimize methane emissions and reduce fuel consumption.
Implementation Method 1
a turbocharger provided in the intake passage upstream of the gas mixing unit
Implementation Method 2
the intake gas having higher pressure and temperature after passing through a turbocharger is kept in a constant temperature range by a charge air cooler (intercooler)
Implementation Method 3
a gas mixing unit mixing a high-concentration methane gas to the low-concentration methane gas midway of the intake passage
Implementation Method 4
a gas mixing unit mixing a high-concentration methane gas to the low-concentration methane gas midway of the intake passage, so that a gas mixture of the low-concentration methane gas and the high-concentration methane gas is supplied to and burnt in a combustion chamber
Data Source
AI summary
A gas engine (10) includes a generator (16) coupled to an output shaft thereof, an intake passage (18) to which a low-concentration methane gas (VAM gas) derived from mine venting is supplied, and a gas mixing unit (54a to 54d) mixing a high-concentration methane gas (CMM gas) to the low-concentration methane gas midway along the intake passage (18), so that a gas mixture of the low-concentration methane gas and the high-concentration methane gas is supplied to and burnt in a combustion chamber. A turbocharger (30) is provided in the intake passage upstream of the gas mixing unit, and in the intake passage upstream of the turbocharger, is provided a mixture ratio adjusting unit (26, 28) adjusting a mixture ratio of the low-concentration methane gas and the air. The temperature or flow rate of intake gas flowing into the turbocharger (30) is kept in a constant range by an intake controller (90A).