# US 12,761,201 B2 · Calculation device, calculation method, and program > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,761,201 B2 - Document ID: US12761201B2 - Status: Granted - Kind: B2 - Application number: 18/287,137 - Filed: 2021-04-19 - Published: 2024-06-27 - Granted: 2026-10-13 - Earliest claimed: 2021-04-19 - Assignees: Riken Keiki Co., Ltd. - Applicants: Riken Keiki Co., Ltd. - Inventors: Tomoo Ishiguro - Web page: https://patentgrep.com/patent/US12761201B2 ## CPC - G01N 33/225: {Gaseous fuels, e.g. natural gas} - G01N 21/45: using interferometric methods; using Schlieren methods - G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q) ## Abstract A calculation device is configured to calculate a value relating to a combustible target gas containing miscellaneous gas components. The calculation device includes: a heating value calculation unit configured to calculate a heating value of the target gas on the basis of converted heating values obtained from a refractive index and a density of the target gas, respectively; a miscellaneous gas total approximate-concentration calculation unit configured to calculate an approximate concentration of the miscellaneous gas components on the basis of the converted heating values; and a virtual basic-heating-value calculation unit configured to calculate, on the basis of the heating value and the approximate concentration, a virtual basic heating value of the target gas when the miscellaneous gas components are assumed to be removed. ## Claims ### Claim 1 A calculation device configured to calculate a value relating to a combustible target gas containing miscellaneous gas components, the calculation device comprising: a heating value calculation unit configured to calculate a heating value of the target gas on a basis of converted heating values obtained from a refractive index and a density of the target gas, respectively; a miscellaneous gas total approximate-concentration calculation unit configured to calculate a total approximate concentration of the miscellaneous gas components on a basis of the converted heating values; and a virtual basic-heating-value calculation unit configured to calculate, on a basis of the heating value and the approximate concentration, a virtual basic heating value of the target gas when the miscellaneous gas components are assumed to be removed. ### Claim 2 (depends on 1) The calculation device according to claim 1, further comprising: a refractive index-converted heating value acquisition unit capable of acquiring the converted heating value obtained from the refractive index of the target gas; and a density-converted heating value acquisition unit capable of acquiring the converted heating value obtained from the density of the target gas. ### Claim 3 (depends on 1) The calculation device according to claim 1, wherein the target gas is a natural gas, and the miscellaneous gas components mainly include nitrogen and carbon dioxide. ### Claim 4 (depends on 1) The calculation device according to claim 1, further comprising a physical property value calculation unit configured to calculate a physical property value of the target gas using the virtual basic heating value. ### Claim 5 (depends on 4) The calculation device according to claim 4, wherein the physical property value calculation unit performs error correction corresponding to the miscellaneous gas components. ### Claim 6 (depends on 4) The calculation device according to claim 4, wherein the physical property value is a compression factor. ### Claim 7 (depends on 6) The calculation device according to claim 6, wherein the compression factor is calculated on a basis of a normalized compression factor. ### Claim 8 (depends on 4) The calculation device according to claim 4, wherein the physical property value is a combustion speed. ### Claim 9 A calculation method for causing a computer to execute a program to calculate a value relating to a combustible target gas containing miscellaneous gas components, the calculation method comprising executing on the computer the steps of: a step of acquiring converted heating values obtained from a refractive index and a density of the target gas, respectively; a step of calculating a heating value of the target gas on a basis of the converted heating values; a step of calculating a total approximate concentration of the miscellaneous gas components on a basis of the converted heating values; and a step of calculating, on a basis of the heating value and the total approximate concentration, a virtual basic heating value of the target gas when the miscellaneous gas components are assumed to be removed. ### Claim 10 (depends on 9) The calculation method according to claim 9, further comprising: a step of acquiring the converted heating value obtained from the refractive index of the target gas; and a step of acquiring the converted heating value obtained from the density of the target gas. ### Claim 11 (depends on 9) The calculation method according to claim 9, wherein the target gas is a natural gas, and the miscellaneous gas components mainly include nitrogen and carbon dioxide. ### Claim 12 (depends on 9) The calculation method according to claim 9, further comprising a step of calculating a physical property value of the target gas using the virtual basic heating value. ### Claim 13 (depends on 12) The calculation method according to claim 12, wherein, when the physical property value is calculated, error correction corresponding to the miscellaneous gas components is performed. ### Claim 14 (depends on 12) The calculation method according to claim 12, wherein the physical property value is a compression factor. ### Claim 15 (depends on 14) The calculation method according to claim 14, wherein the compression factor is calculated after a normalized compression factor is calculated. ### Claim 16 (depends on 12) The calculation method according to claim 12, wherein the physical property value is a combustion speed. ### Claim 17 (depends on 9) A non-transitory computer readable medium storing the program for causing the computer to execute the calculation method according to claim 9. ### Claim 18 (depends on 5) The calculation device according to claim 5, wherein the physical property value is a compression factor. ### Claim 19 (depends on 18) The calculation device according to claim 18, wherein the compression factor is calculated on a basis of a normalized compression factor. ### Claim 20 (depends on 5) The calculation device according to claim 5, wherein the physical property value is a combustion speed.