초록 ▼

A storage tank leak detection system, including a quartz crystal type pressure transducer held at a constant temperature, a bubbler-based pressure sensor for reporting tank bottom pressure measurements to the transducer, a fluid surface measurement apparatus to report liquid surface pressure to the

A storage tank leak detection system, including a quartz crystal type pressure transducer held at a constant temperature, a bubbler-based pressure sensor for reporting tank bottom pressure measurements to the transducer, a fluid surface measurement apparatus to report liquid surface pressure to the transducer, atmospheric pressure measuring apparatus, and a computing system for, based on data reported by all components, effecting data correction (corrected for atmospheric and container physical variations during data gathering) and regression techniques to yield data indicative of changes, if any, in mass content of a liquid storage container, such as a surface storage tank for petroleum and other chemicals.

대표청구항 ▼

We claim: 1. A system for detecting and quantifying changes in the mass content of liquid storage containers comprising: differential pressure sensor means configured for receiving input representative of a first and second pressure parameter and for transmitting data representative of differential

We claim: 1. A system for detecting and quantifying changes in the mass content of liquid storage containers comprising: differential pressure sensor means configured for receiving input representative of a first and second pressure parameter and for transmitting data representative of differential between said first and second pressure parameters to a computing means; high pressure measurement means configured for measuring a first pressure parameter in a liquid medium residing within a container, and engaged with said differential pressure sensor means for facilitating the sensing of said first pressure parameter by said differential pressure sensor means; low pressure measurement means configured, when positioned substantially at the surface of said liquid medium, for measuring said second pressure parameter at said surface of said liquid medium and for facilitating the sensing of said second pressure parameter by said differential pressure sensor means; and ambient temperature measurement means for measuring ambient temperature near said container and reporting data indicative of said ambient temperature to said computing means; wherein said computing means is configured for recording in a time continuum basis data from said differential pressure sensor means, said high pressure measurement means, said low pressure measurement means, and said ambient temperature measurement means, and for deriving data indicative of changes over time of the mass of said liquid medium within said container. 2. The system of claim 1 further comprising barometric pressure measuring means configured for measuring atmospheric pressure near said container and reporting data indicative of said atmospheric pressure to said computing means, and wherein said computing means is further configured for deriving said data indicative of changes over time of the mass of said liquid medium within said container, basing such derivation, in part, on said date indicative of said atmospheric pressure. 3. The system of claim 2 wherein said high pressure measurement means is a bubbler pressure measurement means. 4. The system of claim 3 wherein said bubbler is in sealed fluid communication with a source of substantially constant pressure, inert gas. 5. The system of claim 3 further comprising temperature management means configured for maintaining the temperature of said differential pressure sensor means at a substantially constant level. 6. The system of claim 2 further comprising temperature management means configured for maintaining the temperature of said differential pressure sensor means at a substantially constant level. 7. The system of claim 1 wherein said high pressure measurement means is a bubbler pressure measurement means. 8. The system of claim 7 wherein said bubbler is in sealed fluid communication with a source of substantially constant pressure, inert gas. 9. The system of claim 7 further comprising temperature management means configured for maintaining the temperature of said differential pressure sensor means at a substantially constant level. 10. The system of claim 1 further comprising temperature management means configured for maintaining the temperature of said differential pressure sensor means at a substantially constant level. 11. A system for detecting leaks in a liquid storage tank comprising: differential pressure sensor means having a bubbler-based low pressure measurement component and a high pressure measurement component, said high pressure measurement component being configured for measuring tank bottom pressure within a liquid in which a bubbler is immersed, and said low pressure measurement component being configured for receiving data indicative of atmospheric and vapor pressure substantially at the surface of said liquid; barometric pressure measuring means configured for measuring atmospheric pressure substantially at the surface of said liquid; barometric pressure and differential pressure calculation means configured for receiving first and second data reflecting, respectively, said tank bottom pressure and of said barometric pressure substantially at said surface of said liquid, and for adjusting said first data to substantially eliminate variations upon said measurements of said tank bottom pressure caused solely from atmospheric pressure variations to yield an atmospheric pressure adjusted tank bottom pressure; ambient temperature measurement means for measuring ambient temperature near said storage tank; tank dynamic and barometric pressure adjusted tank bottom pressure calculation means configured for receiving third data indicative of said atmospheric pressure adjusted tank bottom pressure, for receiving fourth data indicative of ambient temperature measurements by said ambient temperature measurement means, for receiving fifth data indicative of expansion characteristics of said storage tank, and for adjusting said third data with reference to said fourth and fifth data to substantially eliminate variations upon measurements and calculations of said barometric pressure adjusted tank bottom pressure, caused solely by dimensional changes in said storage tank resulting from atmospheric temperature variations, to yield a tank dynamic adjusted tank bottom pressure; and tank content mass calculation means for calculating mass contents of said storage tank substantially based on said tank dynamic adjusted tank bottom pressure and operator input data reflecting physical characteristics of said contents of said storage tank. 12. The system of claim 11 further comprising temperature management means configured for maintaining the temperature of said differential pressure sensor means substantially at an operator-specified temperature. 13. A method for detecting leaks in a storage receptacle; comprising the steps of: selecting a mass detection system comprising: differential pressure sensor means having a bubbler-based low pressure measurement component and a high pressure measurement component, said high pressure measurement component being configured for measuring receptacle bottom pressure within a liquid in which a bubbler is immersed, and said low pressure measurement component being configured for receiving data indicative of atmospheric and vapor pressure substantially at the surface of said liquid; barometric pressure measuring means configured for measuring atmospheric pressure substantially at the surface of said liquid; barometric pressure and differential pressure calculation means configured for receiving first and second data reflecting, respectively, said receptacle bottom pressure and of said barometric pressure substantially at said surface of said liquid, and for adjusting said first data to substantially eliminate variations upon said measurements of said receptacle bottom pressure caused solely from atmospheric pressure variations to yield an atmospheric pressure adjusted receptacle bottom pressure; ambient temperature measurement means for measuring ambient temperature near said storage receptacle; receptacle dynamic and barometric pressure adjusted receptacle bottom pressure calculation means configured for receiving third data indicative of said atmospheric pressure adjusted receptacle bottom pressure, for receiving fourth data indicative of ambient temperature measurements by said ambient temperature measurement means, for receiving fifth data indicative of expansion characteristics of said storage receptacle, and for adjusting said third data with reference to said fourth and fifth data to substantially eliminate variations upon measurements and calculations of said barometric pressure adjusted receptacle bottom pressure, caused solely by dimensional changes in said storage receptacle resulting from atmospheric temperature variations, to yield a receptacle dynamic adjusted receptacle bottom pressure; and receptacle content mass calculation means for calculating mass content data representative of the contents of said storage receptacle substantially based on said receptacle dynamic adjusted receptacle bottom pressure and operator input data reflecting physical characteristics of said contents of said storage receptacle; selecting data storage means for collecting a plurality of mass content data as generated by said receptacle content mass calculation means over a plurality of points in time; selecting computing means configured for generating a human perceptible indication of changes in said mass content data between a plurality of said points in time; actuating said mass detection system; and recording data indicative of changes in said mass content data attributable to leakage of said storage receptacle to detect such leakage. 14. The method of claim 13 further comprising the steps of: securing all input and outflow orifices of said storage receptacle before said actuation of said mass detection system; and substantially selectively processing said mass content data which were generated approximately between sunset and sunrise at an installation site of said system.