METHANE VALUE MEASURING DEVICE AND METHANE VALUE CALCULATION METHOD

To provide a methane value measuring device and a methane value calculation method that can monitor the fuel property of a natural gas used as a fuel gas directly and in real time and also can obtain a relatively reliable methane value easily regardless of the gas composition and can achieve a small size, a small weight, and a low price enough to be equipped in a vehicle.SOLUTION: A methane value measuring device 10 includes: heat conductivity converted heat amount measuring means 12 for measuring the heat amount obtained from the heat conductivity of a target gas; and methane value calculation means 16 for calculating the methane value of a target gas from the basic heat amount calculated on the basis of the heat amount and from the concentration of the nitrogen gas in the target gas.SELECTED DRAWING: Figure 1 【課題】燃料ガスとして利用される天然ガスの燃料性状の監視を直接且つリアルタイムに行え、一応の信頼性を有するメタン価をガス組成に拘わらず容易に得ることができるとともに、車載に適した小型化・軽量化・低価格化を実現するメタン価測定装置およびメタン価算出方法を提供する。【解決手段】メタン価測定装置１０は、対象ガスの熱伝導率から得られる熱量を測定可能な熱伝導率換算熱量測定手段１２と、熱量に基づいて算出される対象ガスの基礎熱量と対象ガス中の窒素ガス濃度により対象ガスのメタン価を算出するメタン価算出手段１６を備える。【選択図】 図１