MULTIDISCIPLINARY TECHNOVATION Efficiency Analysis of the Turbine using Calorific Value Parameters for a 10 Megawatt Gas Turbine

This research is based on the analyzed thermodynamics of a gas turbine energy plant. It considered the differing operating states, i.e. the ambient temperature, the compressor outlet temperature, pressure ratio, etc. and their affective modes on thermal efficiency, turbine work, compressor work, etc. which were derived and analyzed. The Gross (higher) calorific values at constant pressure (Δh(liq)) heat of combustion in a flow process from state 1 to state 2 was considered and used to analyze our thermal efficiency. Ambient temperature cum air/ fuel ratio affected the turbine work, compressor work and system efficiency. In addition, the thermal efficiency nd power decreases linearly with increase of the ambient temperature. However, the efficiency analyzed when the calorific parameters were considered was higher than the efficiency when the basic thermodynamic theories (first and second law principles) were used. The first ranges between 31% to 33, while the second ranges between 28% to 32% under the same ambient temperature conditions.


Introduction
With the improvement in industrialization and people, there has been an extending interest for electrical energy in Nigeria. Power age in Nigeria is transcendently from three hydro-electric power stations, steam and gas warm stations. An enormous bit of these workplaces are being directed by the Nigerian Electricity Regulatory Commission (NERC), an organization guaranteed administration association that co-ordinates all activities of the power region be it creation, transmission, movement, or exhibiting and bargains. The free regulatory office, as given in the Electric Power Sector Reform Act of 2005 was depended with checking and coordinating the Nigerian power industry, with offering licenses to exhibit individuals, and with ensuring consistence with market oversees and working guidelines. Oyedepo & Kalinko (2014) [1] did Thermodynamic examination of a gas turbine power plant exhibited with an evaporative cooler. in their dissemination the show improvement of gas turbine power plants by cooling the blower utilization air with an evaporative cooler is thought of. This assessment investigated the effect of bay air cooling structure on the introduction of a current gas turbine power plant in Nigeria. The results show that for each 5 o C decay of delta air temperature, net yield power increases around 5 -10% and warm usefulness increases around 2-5%. It is shown that the proportion of this development is higher when the squeezing factor extent is high and the turbine channel temperature is low. The results of this assessment shows that the retrofitting of the current gas turbine plant with channel air cooling structure gives a predominant system execution and may wind up being an engaging endeavor opportunity to the Nigerian government and accomplices of the plant. Kotowicz et.al., (2016) [2], made on the system out of the gas turbine convenience evaluation. An evaluation thinking for isentropic effectiveness of a blower and turbine in a gas turbine establishment reliant upon polytropic sufficiency qualities was introduced. A gas turbine model was outlined into programming projects for power plant age. The evaluation depended upon assessments from iterative models for isentropic ampleness of the blower and the isentropic ability of the base on the turbine inlet temperature.
The isentropic value credits of the blower and the turbine and made through the as of late referred to assessments. The gas turbine improvement for the high blower degrees was the focal basic role for this Int. Res. J. Multidiscip. Technovation, 3(4) (2021) 59-66 | 60 assessment. The got gas electric handiness qualities show that an improvement of pressing variable degree in excess of 50 isn't protected because of the slight expansion in the ability with an essential increase of turbine bay combustor outlet and temperature. Rahman et.al., (2011) survey thermodynamic execution examination of gas-turbine power plant. The variety of working conditions (pressure proportion, turbine bay and fumes temperature, air to fuel proportion, isentropic blower and turbine proficiency and encompassing temperature) on the exhibition of gas turbine (warm productivity, blower work, power, explicit fuel utilization, heat rate) were researched. The scientific recipe for the particular work and proficiency were inferred and dissected [3].
The outcomes showed that the pressure proportions, encompassing temperature, air to fuel proportion just as the isentropic efficiencies are firmly impacted on the warm productivity. What's more, the warm proficiency and force yield diminishes directly with increment of the encompassing temperature and air to fuel proportion. In any case, the particular fuel utilization and warmth rate increments straightly with expansion in both encompassing temperature and air to fuel proportion. Hence, the thermodynamic boundaries on cycle execution are monetarily possible and gainful for the gas turbine tasks.
The poor performance of these thermal plants has contributed immensely to incessant power outages and economic loss. [4] revealed that only 15 out of the 55 units were available for power generation as at 1994. The 'then Minister of Power and Steel in [5] put the record at 20 out of 55 units (25.6%) were functional before 1999 and by 2001 the percentage had moved to 43.8% with the additional 2 units added while 17 units were under rehabilitation.
For greatest economic benefit, the availability of the most efficient and modem plant must be high. Agbauduta (1998), reported that Nigeria's economic losses from unreliable power generation and supply was put at a staggering N66 billion (equivalent to $0.55 billion). He identified thy lack of qualified maintenance engineers, non-availability of required spare parts and the instability of the national grid among other factors as being responsible for the poor performance of these power stations [6].
Hart (1992) revealed that the improvement of force age and dissemination in Nigeria didn't at first include a public matrix framework and accordingly, the producing plants were not arranged as for such a framework. The foundation of the framework was made essential on the grounds that an enormous piece of the nation didn't have producing stations situated inside them [7].

Energy Analysis of Power Plants
Obodeb & Ugwuoke (2013) did Time-Dependent energy examination of a 120MW steam turbine unit of Sapele Power Plant. The work by and large showed that energy misfortune expanded with expanded activity time. It was seen that disintegration and oldness might be the serious issues and that plant restoration is a possible arrangement [8].
Kwak et al., (2010), checked exergetic and thermo-economic analyses on a 500-MW Power plant running a combined cycle system. In the analysis, they contemplated the protection of mass and energy of every part in the framework [9]. They likewise consider the quantitative equilibrium of exergy and exergetic cost (exergoeconornics) related with every part, and for the framework all in all. In an exergoeconomic model, they addressed the useful construction of the framework to imagine the expense related with the arrangement cycle and the useful connection between parts. Kwak fostered a PC program to decide the creation expenses of force plants using gas or steam turbines, or a blend of the two (cogeneration plant). The prom could likewise be utilized to consider plant qualities, especially thermodynamic execution and framework affectability change. The kind of changes inferred here are in measure and additionally segment plan factors.
Vundela et al. (2010) inspected on energy investigation of nuclear energy stations. They surveyed a thermodynamic examination of a coal based nuclear energy station and gas-based cogeneration power plant as far as energy for the various segments of the force plants in sub-basic reach. They presumed that, the significant energy misfortune was found to happen in condenser. The energy investigation showed that ignition chamber in both steam and gas turbine nuclear energy stations is primary wellspring of irreversibility. The irreversibility in condenser is inconsequential as the bad quality energy is lost in the condenser [10].
Egware and Obanor (2013) investigated energy examination of Omotosho stage 1 gas nuclear energy station. In their examination, they saw that exergy effectiveness diminishes and exergy annihilation productivity increments as surrounding temperature expansions in the plant and its parts [11]. demonstrates wise. The exergy obliteration is attributed to the irreversibility's related with the burning response and the warmth move across huge temperature contrasts between the lighted gases and the functioning liquid. Besides, the exergoeconomic examination recognizes the ignition chamber as having the best expense related with exergy annihilation, everything being equal. It is additionally confirmed that expanding the Gas Turbine Inlet Temperature (GTIT), adequately diminishes the proficiency of the turbine [12].

Calorific Value Analysis
Ordinarily stated, the calorific value of a fuel is the amount of heat liberated when a kilogram mass of fuel is assuredly burnt (synonymous to heat of combustion). However, it is defined with reference to the state (temperature, pressure and volume).

Four types of calorific values are defined
For non-flow process: If the fuel is a gas with the water of the product in the vapour phase

Heat of Combustion
Applying first law of thermodynamics to combustion results in heat of combustion.
Two types of heat of combustion are defined.  Some thermal process (addition of heat) some thermal process cooling The total change of internal energy between state 1 and 2 may be written as: Where mi is the mass of the various constituents and cvi is the mean specific heat at constant volume for the appropriate temperature ranges T0 to T2 and T0 to T1.
(b) Enthalpy of (constant pressure heat of) combustion is the heat of combustion generated in a flow process.
Considering combustion in a flow process from state 1 to state 2, from Total change of enthalpy between states 1 and 2 may be written as:  Generally for gaseous fuels Where ht1 and ht0 are obtained from gas tables at temperature t1 and t0 respectively and ni = mole of each constituent.

Enthalpy of Formation
Enthalpy of formation of a compound is the heat-transfer obtained as change in enthalpy between the product and reactants when the enthalpy of the all the elements (reactants) are made zero at standard condition of 25 o C and 1 bar.
= h at any other pressure and temperature.
Where  h change in enthalpy between 25 o C(298K), 1bar and the required temperature and

Results and Discussion
Following the procedurals and equations adopted, the outcome of the performance improvement of thermal power systems through energy efficiency analysis was presented. The plant energy efficiency of the gas turbine components has been evaluated.

Presentation of Input Data
Appropriate assumptions have been made for the power plant and stated in table 1 such that the results obtained will closely approximate actual data from the gas turbines.    figure 1, the results show a significant decrease in turbine load as inlet temperature increases just as its efficiency is affected when ambient temperature increases. This is due to the density of air reducing at increase in ambient temperature.   Increased ambient temperature lowers the density of the inlet air, thus reducing the mass flow through the turbine and therefore reduces the efficiency. At constant speed, where the volume flow remains approximately constant, the mass flow will increase with decreasing temperature and will increase with increasing temperature. Fig 5 and table 4 considering just the parameters under the calorific efficiency shows the results of the efficiency of the gas turbine with respect to its temperature. There's as well a decrease in efficiency of about 2% as the ambient temperature rises.
The figures 2 and 3 compare the efficiency of the turbine. The comparison is between efficiencies when calorific parameters are considered and when they are not at different ambient temperatures. We could see from the above figures that when the calorific parameters are used the efficiency ranges between 31% and 33%, while when calorific parameters are not considered the efficiency ranges between 28% to 32%. Hence, at higher ambient temperatures the efficiencies are lower when the nature of heat of combustion is not put into consideration. This could also be due to some forms of energy losses in the different components.

Comparison with Work of Past Researchers
In the work of Rahman and Thamir (2011) carried out analysis of the effect of ambient temperature, compression ratio and air to fuel ratio, etc. on the thermal efficiency. The present research having analyzed various operational conditions of Dave Energy Power Plant exposed the shortcomings of energy analysis when the Gross Ethalpy of (Constant pressure heat of) combustion is not put into consideration.
However, both analyses are relevant in the performance analysis of a power plant.
While in the work of Kotowicz (2016) carried out analysis on the methodology of the gas turbine efficiency calculation even when the Gross efficiency is considered. The efficiency of the turbine was around 22% while this research ranges from 31%. However, both analysis are still relevant in the performance analysis of gas turbine.

Conclusion
The result from the modeling of the influence of parameter showed that ambient temperature, air fuel ratio and turbine outlet temperature effect on performance of gas turbine power plant. The results were summarized as follows: (i) The thermal efficiency and power output decreases linearly with increased of ambient temperature as well as the air to fuel ratio.
(ii) The variation of thermal efficiency at higher compression ratio, turbine outlet temperature and ambient temperature are very important.
(iii) The nature of the heat of combustion in the turbine with its effect on the turbine efficiency is important and necessary to consider while analyzing.
(iv) The thermal efficiency and power output decreases linearly with increase in ambient temperature.
(v) The peak efficiency and power occur at lower ambient temperature.