Cryosat Cold Gas System and Component Development

The formation of sodium disulfite by the heterogeneous reaction of solid active sodium sulfite with gaseous sulfur dioxide in the presence of water vapour was investigated over the temperature range of 293 to 393 K at SO2. H2O and O2 partial pressures of 1.2-7.4, 1.2-6.4 and 0-11.3 kPa, respectively. The effect of the reaction time was also examined. Kinetic measurements were supplemented with the determination of the equilibrium dissociation pressure of SO2 in contact with sodium sulfite at 373.15 K. The major aim of the work was to establish the optimum conditions for attaining the maximum degree of conversion of the solid reactant to sodium disulfite. The conditions for the formation of virtually pure sodium disulfite were found.

Download Full-text

Insights into the physics when modelling cold gas clouds in a hot plasma

Monthly Notices of the Royal Astronomical Society Letters ◽

10.1093/mnrasl/slz144 ◽

2019 ◽

Vol 490 (1) ◽

pp. L52-L56

Author(s):

Bastian Sander ◽

Gerhard Hensler

Keyword(s):

Adaptive Mesh Refinement ◽

Adaptive Mesh ◽

Careful Consideration ◽

Necessary Condition ◽

Interstellar Clouds ◽

Hot Plasma ◽

Magnetic Dipole Field ◽

Set Up ◽

Self Gravity ◽

Cold Gas

ABSTRACT This paper aims at studying the reliability of a few frequently raised, but not proven, arguments for the modelling of cold gas clouds embedded in or moving through a hot plasma and at sensitizing modellers to a more careful consideration of unavoidable acting physical processes and their relevance. At first, by numerical simulations we demonstrate the growing effect of self-gravity on interstellar clouds and, by this, moreover argue against their initial set-up as homogeneous. We apply the adaptive-mesh refinement code flash with extensions to metal-dependent radiative cooling and external heating of the gas, self-gravity, mass diffusion, and semi-analytic dissociation of molecules, and ionization of atoms. We show that the criterion of Jeans mass or Bonnor–Ebert mass, respectively, provides only a sufficient but not a necessary condition for self-gravity to be effective, because even low-mass clouds are affected on reasonable dynamical time-scales. The second part of this paper is dedicated to analytically study the reduction of heat conduction by a magnetic dipole field. We demonstrate that in this configuration, the effective heat flow, i.e. integrated over the cloud surface, is suppressed by only 32 per cent by magnetic fields in energy equipartition and still insignificantly for even higher field strengths.

Download Full-text

Optimal Planning of Electricity-Natural Gas Coupling System Considering Power to Gas Facilities

Energies ◽

10.3390/en14123400 ◽

2021 ◽

Vol 14 (12) ◽

pp. 3400

Author(s):

Jie Xing ◽

Peng Wu

Keyword(s):

Natural Gas ◽

Energy Systems ◽

Optimal Planning ◽

Planning Model ◽

Operation Costs ◽

Coupling System ◽

Gas System ◽

Different Types ◽

Power To Gas ◽

Natural Gas System

Bidirectional coupling systems for electricity and natural gas composed of gas units and power-to-gas (P2G) facilities improve the interactions between different energy systems. In this paper, a combined optimization planning method for an electricity-natural gas coupling system with P2G was studied. Firstly, the characteristics of the component model of the electricity-natural gas coupling system were analyzed. The optimization planning model for the electricity-natural gas coupling system was established with the goal of minimizing the sum of the annual investment costs and the annual operation costs. Based on the established model, the construction statuses for different types of units, power lines, and pipelines and the output distribution values for gas units and P2G stations were optimized. Then, the immune algorithm was proposed to solve the optimization planning model. Finally, an electricity-natural gas coupling system composed of a seven-node natural gas system and a nine-node power system was taken as an example to verify the rationality and effectiveness of the model under different scenarios.

Download Full-text