Designs for enhanced reliability and calibration of landfill gas measurement and control devices
An apparatus for sampling landfill gas from a landfill flowing through a pipe. The apparatus may comprise: an enclosure configured to receive a section of the pipe; a gas sampling port in the section of the pipe; at least one sensor device disposed in a region of the enclosure, the at least one sensor being coupled to the section of the pipe through the gas sampling port; and thermal insulation positioned to retain heat from the section of the pipe in the region of the enclosure. A method of operating a landfill gas recovery system. The method may comprise: flowing gas from a well riser pipe through a sampling subsystem to a collection system; and heating a portion of the sampling subsystem with the gas flowing from the well riser pipe to the collection system.
1. An apparatus for sampling landfill gas flowing through a pipe, the apparatus comprising:
an enclosure configured for coupling to a section of the pipe, the section of the pipe having at least one gas sampling port;
at least one sensor device disposed in a region of the enclosure, the at least one sensor device being coupled to the section of the pipe through the at least one gas sampling port; and
at least one controller configured to:
adjust a frequency of landfill gas sampling based at least in part on an available battery charge and/or an available power supply voltage of the apparatus, wherein adjusting the frequency of landfill gas sampling comprises adjusting a frequency of operation of at least one pump for pumping landfill gas from the pipe to the region of the enclosure having the at least one sensor device such that the at least one pump continues to pump the landfill gas into the region of the enclosure, but at a reduced frequency.
2. The apparatus of claim 1 , wherein the enclosure comprises an hermetic seal.
3. The apparatus of claim 1 , further comprising:
thermal insulation positioned to retain heat from the section of the pipe.
4. The apparatus of claim 3 , further comprising:
at least one thermal conductivity component configured for enhancing a thermal conductivity of the section of the pipe.
5. The apparatus of claim 4 , wherein the thermal conductivity component comprises a corrosion resistant metal heat sink.
6. The apparatus of claim 3 , further comprising:
at least one active heating element configured to emit heat within the enclosure wherein
the at least one controller is configured to control the at least one active heating element.
7. The apparatus of claim 1 , wherein the at least one sensor device comprises:
a sensor configured to measure flow of the landfill gas through the pipe and a sensor configured to measure characteristics of a gas sample.
8. The apparatus of claim 1 , wherein the at least one sensor device comprises:
a sensor configured to measure humidity of the landfill gas.
9. The apparatus of claim 1 , comprising:
a sampling subsystem comprising:
a gas inlet port and a gas outlet port, wherein the at least one sensor device is coupled to the gas outlet port;
the region of the enclosure, the region of the enclosure further being configured to be coupled to the section of the pipe having the at least one gas sampling port;
a thermoelectric condenser;
and
a gas flow passage from the gas inlet port, over the at least one sensor device, and to the gas outlet port, the gas flow passage passing adjacent to and in thermal contact with the thermoelectric condenser.
10. The apparatus of claim 9 , wherein:
the thermoelectric condenser comprises at least one channel at a surface of a block.
11. The apparatus of claim 10 , wherein:
the thermoelectric condenser is covered by at least one chilled plate, and
the at least one channel is configured to direct a gas sample across the at least one chilled plate.
12. The apparatus of claim 9 , wherein:
the at least one sensor device is a gas sensor disposed in the region of the enclosure and coupled to the section of the pipe through the at least one gas sampling port; and
the apparatus further comprises thermal insulation positioned to retain heat from the section of the pipe in the region of the enclosure.
13. The apparatus of claim 9 , wherein:
the sampling subsystem comprises an orifice block and a filter for at least one of a particulate and a corrosive gas, and
the gas flow passage comprises at least one fluid knock-out.
14. The apparatus of claim 9 , wherein:
the at least one sensor device comprises a pressure sensor and a sensor configured to measure an amount of gas of a predetermined type.
15. The apparatus of claim 1 , wherein the enclosure is configured to receive the section of the pipe.
16. The apparatus of claim 1 , further comprising a wireless transmitter.
17. A method performed by an apparatus for sampling landfill gas flowing through a pipe, the apparatus comprising an enclosure for coupling to a section of the pipe, the section of the pipe having at least one gas sampling port, at least one sensor device disposed in the enclosure and coupled to the section of the pipe through the at least one gas sampling port, a wireless transmitter, and a controller, the method comprising:
obtaining at least one measurement, using the at least one sensor device, of a concentration of at least one constituent gas in the landfill gas flowing through the pipe;
transmitting, using the wireless transmitter, the at least one measurement obtained by the at least one sensor device to an external device; and
adjusting a frequency of landfill gas sampling based at least on an available battery charge and/or an available power supply voltage of the apparatus, wherein adjusting the frequency of landfill gas sampling comprises adjusting a frequency of operation of at least one pump for pumping landfill gas from the pipe to a region of the enclosure having the at least one sensor device such that the at least one pump continues to pump the landfill gas into the region of the enclosure, but at a reduced frequency.
18. The method of claim 17 , wherein the enclosure is configured to receive the section of the pipe.
19. An apparatus for sampling landfill gas flowing through a pipe, the apparatus comprising:
an enclosure configured for coupling to a section of the pipe, the section of the pipe having at least one gas sampling port;
at least one sensor device disposed in a region of the enclosure, the at least one sensor device being coupled to the section of the pipe through the at least one gas sampling port; and
at least one controller configured to:
adjust a frequency of landfill gas sampling based at least in part on a temperature inside the enclosure and/or landfill gas temperature, wherein adjusting the frequency of landfill gas sampling comprises adjusting a frequency of operation of the at least one sensor device such that the at least one sensor device continues to perform the landfill gas sampling, but at a reduced frequency.
20. The apparatus of claim 19 , wherein the at least one controller is configured to adjust the frequency of landfill gas sampling at least in part by decreasing the frequency of landfill gas sampling in response to a decrease in the temperature inside the enclosure.