Nowadays the refining sector in Mexico needs to increase the quantity and quality of produced fuels by installing new process plants for gasoline and ultra low sulphur diesel. These plants require the provision of electricity and steam, among other services to function properly, which can be supplied by the power plants currently installed in each refinery through an expansion of their generation capacity. These power plants need to increase its production of electricity and steam at levels above their installed capacity, which involves the addition of new power generating equipment (gas or steam turbo-generators) as well as the raise of the electrical loads. Currently, the Mexican Petroleum Company (PEMEX) is planning to restructure their electrical and steam systems in order to optimally supply the required services for the production of high quality fuels. In this paper the present status of the original electrical power systems of the refineries is assessed and the electrical integration of new process plants in the typical schemes is analyzed. Also this paper shows the conceptual schemes proposed to restructure the electrical power system for two refineries and the strategic planning focused on implement the modifications required for the integration of new process plants that will demand about 20 MW for each refinery by 2014. The results of the analysis allowed to identify the current conditions of the electrical power systems in the oil refining industry or National Refining Industry (NRI), and thereby to offer technical solutions that could be useful to engineers facing similar projects.

This paper shows the main results from a technical and economical study for the implementation of new cogeneration systems in Mexican refineries. At least three cogeneration alternatives to match a 50% additional energy requirement (thermal and electric) for a refinery are analyzed. A balance simulator tool developed specially for the electric and steam refinery systems is used in order to obtain the technical parameters for the alternatives, which allows obtaining system performance indicators such as fuel consumption, cooling water requirement, electric and combined efficiency. Standard techniques as net present value, internal rate of return, and payback period are used for the economic analysis. According to the results, the best alternative was a gas turbine-heat recovery steam generator arrangement fueled by natural gas, including the respective adjustments of the refinery electrical and steam systems.

This paper details the design of a Pitot tube used for water flow rate measurements in large pipes. The paper describes first the nowadays commonly used device (simplex pitot), based on standard CTI Code ATC-105 from Cooling Tower Institute [1]. The disadvantages of the simplex pitot are pointed out, and the detailed description of the proposed device (multiport pitot) is explained. The Multiport Pitot, which design is also based on norm ATC-105, is able to perform real-time measurements. The paper also includes the results obtained from the water flow rate measurements made in the cooling system of a thermal power plant in Mexico. These measurement results were compared to simulation results obtained with a computational commercial simulation tool.

Significant decrements in generated power at fossil fuel power plants occur in the few months following annual maintenance which, besides causing economic losses for the power plants, reduce their availability. In order to determine the causes of these decrements, it is a common practice to carry out tests to evaluate the performance of the equipment in which the problem supposedly originates. Because these tests are made individually in the equipment, it is not possible to have an integral vision of the plant operation as a whole and, therefore, the problem related to energy efficiency is not attacked from the root [1]. This paper shows a practical method using in-situ measurements and a commercial simulation computer tool that allows the power plant operators to make an integral thermodynamic assessment. It makes possible to identify the causes of efficiency decrease (for the whole plant and its components) and to quantify the contribution of each equipment to the total power loss. As a result, priorities on the maintenance of the equipment can be determined to tackle the most important energy losses, and obtaining a total solution to the problem of energy decrement. The paper includes the results obtained from the application of this methodology to assess a 158 MW fossil fuel power plant unit in Mexico.