A new model for predicting boiling points of alkanes

A general perception among researchers is that boiling points, which is a key property in the optimization of lubricant performance, are difficult to predict successfully using a single-parameter model. In this contribution, we propose a new graph parameter which we call, for lack of better terminology, the conduction of a graph. We exploit the conduction of a graph to develop a single-parameter model for predicting the boiling point of any given alkane. The model was used to predict the boiling points for three sets of test data and predicted with a coefficient of determination, $$R^2=0.7516,~0.7898$$ R 2 = 0.7516 , 0.7898 and 0.6488, respectively. The accuracy of our model compares favourably to the accuracy of experimental data in the literature. Our results have significant implications on the estimation of boiling points of chemical compounds in the absence of experimental data.

A New Model For Predicting Boiling Points of Alkanes

A general perception among researchers is that boiling points, which is a key property in the optimization of lubricant performance, are difficult to predict successfully using a single-parameter model [5, 6]. In this contribution, we propose a new graph parameter which we call, for lack of better terminology , the conduction of a graph. We exploit the conduction of a graph to develop a single-parameter model for predicting the boiling point of any given alkane. The accuracy of our model compares favourably to the accuracy of experimental data in literature. Our results have significant implications on the estimation of boiling points of chemical compounds in the absence of experimental data.

Subsea Chemical Storage and Injection- Qualification of HAMPRO 70V Pump

The development of Subsea Chemical Storage & Injection (SCS&I) technology is a continuation of the trend to move more of the hydrocarbon production systems subsea. This is driven by a need to make exploitation of remote resources profitable; unlock single-line long tie-backs and subsea to shore architectures, and to enable tie-ins with otherwise constrained topside infrastructure. The SCS&I System is also a significant contributor to the development of "All-Electric" subsea architecture where the umbilical is reduced to a power and communication cable only. TechnipFMC https://www.technipfmc.com/ and Total https://www.total.com/en are collaborating to develop and qualify the SCS&I technology components and system. In order to make the SCS&I technology competitive and field developments profitable, the reliability of the equipment is paramount. The HAMPRO 70V injection pump is one key component in the system for which high reliability must be ensured. The objective of the qualification program is to confirm the adequate performance of the HAMPRO 70V pump in the following areas: The reliability of the chemically exposed parts and the impact of chemical fluid cleanliness The reliability of the pump and motor rotating parts and the impact of lubricant performance The reliability of the electrical components The impact of transient behaviour on the pressure compensation system, rotating parts and electrical components Due to the similarity of design, smaller versions of the HAMPRO pump will also be qualified by the activities in the program.

Effect of the Geometric Profile of Top Ring on the Tribological Characteristics of a Low-Displacement Diesel Engine

The present study aims to analyze the influence of the geometric profile of the compression ring on the tribological properties of the lubricant. Additionally, the influence of the rotation speed and the engine load on the state of the lubricant is evaluated. For this study, a single-cylinder diesel engine is taken as the basis, from which a CAD model of the combustion chamber-piston assembly was made. In addition, the conditions in the cylinder chamber were analyzed when the engine operates at a rotation speed of 3000, 3300, 3600, and 3900 rpm, and a load of 1.5, 3.0, 4.5, and 6.0 N. The calculations were developed using the OpenFOAM® simulation software. The results obtained show that changes in the geometric profile of the ring can contribute to reducing the hydrodynamic friction force by 13% and the friction force caused by roughness by 61%. This implies a decrease in the power lost by friction. In general, the modification of the geometric profile allowed a reduction of 21% in the lost power associated with friction. Additionally, it was observed that the shape of the profile allows to reduce the pressure in the lubricant by 65% and obtain a greater thickness of the lubrication film. On average, an increase of 300 rpm and 1.5 N in the speed and load of the engine causes the friction force and power losses to increase by 45% and 10%. The above results imply that the geometric profile of the compression ring can improve tribological performance in the engine, allowing a reduction in fuel and better lubricant performance.

High Temperature Microtribological Studies of MoS2 Lubrication for Low Earth Orbit

Molybdenum disulfide is one of the most common lubricant coatings for space systems but it displays enormous susceptibility to environmental conditions making it hard to predict performance throughout the entire lifetime. The majority of mechanisms for space operate in low Earth orbit where temperatures typically reach 120 °C along with exposure to highly reactive atomic oxygen which can be detrimental to lubricant performance. In the present study, a MoS2 lubricant coating is tested using friction force microscopy under different environmental conditions including air and dry nitrogen environments with temperatures ranging from 25 °C to 120 °C. The increased temperature was found to be beneficial for friction behaviour in air up to 100 °C as ambient humidity is removed from the contact, but higher temperatures become detrimental as increased reactivity leads to oxidation. These competing effects resulted in a minimum coefficient of friction at 110 °C in the air environment. The high temperature also increases the wear of the coatings as the intrinsic shear strength decreases with thermal energy which in turn disrupts tribofilm formation leading to increased friction. The run-in duration and magnitude are both found to decrease with temperature as the energy barrier to optimal reconfiguration is reduced. Finally, contextualization of the present findings for mechanisms operating in low earth orbit is discussed.