Abstract
In the study of natural gas hydrates, the maintenance of the low-temperature and high-pressure state of the core sample under in situ conditions is highly important for cutting, transferring, and subsequent analysis. The pressure maintenance and temperature control device (PMTCD) for natural gas hydrate core samples described in this paper is a subsystem of the pressure-retaining and transfer device. The device consists of a water tank, seawater chillers, a plunger pump and a thermoelectrical refrigeration device. The device cools the seawater to 2 °C, and then pressurizes it to inject it into the sample cylinder. Due to the inevitable heat generated by the pressurization and heat exchange with environment, there is a thermoelectrical refrigeration device to compensate for temperature rise. Finally, the seawater temperature entering the sample cylinder is no higher than 3 °C, effectively preventing the decomposition and deterioration of the natural gas hydrate core in the sample cylinder. In this paper, the temperature increase of the device and its compensation capacity are analyzed in detail on the basis of calculation and simulation. On the basis of testing with the device, it is verified that even at the ambient temperature, the water temperature can still be maintained at 3 °C.
Highlights
At present, a large amount of natural gas hydrate (NGH) resources have been explored all over the world
This paper considers the pressure maintenance and temperature control device (PMTCD), a part of new generation NGH core sample pressure-retaining and transfer devices, and analyzes the causes of temperature increase during the pressure maintenance of the sample
This paper describes a PMTCD placed on shipboard that can be used in the pressure-retaining and transfer process of natural gas hydrate core samples
Summary
A large amount of natural gas hydrate (NGH) resources have been explored all over the world. This paper considers the PMTCD, a part of new generation NGH core sample pressure-retaining and transfer devices, and analyzes the causes of temperature increase during the pressure maintenance of the sample. By designing a chiller and a thermoelectrical refrigeration device, the seawater flowing into the sample cylinder is cooled separately before and after being pressurized, and the temperature control effect is explored, effectively preventing the decomposition and deterioration of the NGH sample due to temperature increase during the transfer process. The segmented core sample is pushed into the sub-sample cylinder (not shown in Figure 1) connected to the right side of the system and transported to the laboratory for further analysis All these process in situ conditions realized by PMTCD.
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
