نشریه انرژی ایران
سال پانزدهم شماره 1 (پیاپی 54، بهار 1391)

In this article the application of a turbo expander in a gas well has been studied technically economically and thermodynamically for the purpose of recycling the wasted exergy in a chock valve, reducing the gas pressure as well as generating huge amount of electrical power through a generator are among the advantages of applying an expansion turbine instead of chock valve. On the other hand this method is a clean method of energy production since no fuel is consumed for and no environmental pollution is caused through this method. In this thesis two software HYSYS and GAMS have been applied to calculate the productivity power in various pressure ranges and mass flow rate in different years of extractions when expansion turbine are used. Considering the necessary power of an infrastructure this system of calculation helps to determine the maximum life span of an expansion turbine in a gas well. This project is aimed at technical and economical planning and optimization of a mechanical package to recycle the pressure exergy of a gas well inlet chock valve in order to generate the electrical power both for the consumption of the infrastructure itself and for selling the extra amount.In administrating this project not only would the gas wells of the country become needless of electrical power but also the super flues amount at electricity could be sold to the national electricity network. Financial studies indicate that the capital returning period in this project for pressure range of 1850 – 4850 psig and mass flow rate of 21.2 kg/s at prices of 1600 $ per kilowatt hour and 0.12 $ per kilowatt hour for constructing a power station and the value of generated electricity respectively is estimated almost 3.5 years which economically appears really fascinating for the purpose of investment.

Iran as a developing and growing country and the vast resources of energy and large oil and gas reservoirs, is among the countries with the growth pattern of the pressure on natural resources. Therefore plan to consume of energy is very important and must be done carefully. It is clear that to accomplish this, must have accurate knowledge of the relationship between energy consumption and production. This paper investigates the effect of long term subsidies elimination of energy carriers oil, gas and electricity on the production level and inflation in the period 1352-1387 with use of Vector Error Correction Model (VECM) in Iran.The results of Johansson test indicate that there are 3 long-term relationship in the 95% significant level and 2 in the 99% significant level between variables. According to the impulse response analysis, removal of energy carriers subsidies cause to reduced consumption of these carriers in the short, medium and long term, thus it reducing GDP in the short, medium and long term. With removal of energy carriers subsidies, price of these carriers are increased in short, medium and long term, and this price increase, cause to reduce consumption of energy carriers too. Hence government should develop optimal pattern of consumption of all carriers in all sections and take additional tax of consumption, who those don’t observe this pattern.

Motorized shades have a considerable impact on energy demand reduction of building, combining it with lighting systems and PV panels will make it more effective. In this article, three shade design, two lighting control system (on/off, dimming) and the option of using PV cells in shades have been investigated. The best combination of above cases which maximizes annual electrical energy saving and minimizes return on investment’s time is found. Annual saving is calculated using hourly simulation of lighting, solar heat flux and electricity generation. Results showed that the optimum combination have the saving potential of 792kwh annually.