scholarly journals Performance Improvement of KCS (Kalina Cycle System) 34 by Replacing Throttle Valve With Single-Screw Expander

2021 ◽  
Vol 9 ◽  
Author(s):  
Xinxin Zhang ◽  
Zhenlei Li ◽  
Jingfu Wang ◽  
Yuting Wu ◽  
Chongfang Ma
Keyword(s):  
Water Concentration ◽  
Exergy Efficiency ◽  
Water Mixture ◽  
Two Phase ◽  
Kalina Cycle ◽  
Ammonia Water ◽  
Single Screw ◽  
Cycle System ◽  
Throttle Valve ◽  
The Difference

In order to recover the energy loss due to the throttling in the path of ammonia-lean solution in the Kalina Cycle System (KCS) 34, two redesigned cycles, in which single-screw expanders that can perform two-phase expansion are used to replace the throttle valve, are proposed in this paper. The results show that the thermal efficiency and net work of two redesigned cycles are higher than those of the original KCS 34. With the concentration increase of ammonia-water mixture, the work produced by the single-screw expander B in two redesigned cycles gradually decreases, and the difference between the work produced in two redesigned cycles also gradually decreases. The original KCS 34 and two redesigned cycles have high exergy efficiency. The highest cycle exergy efficiency of 56.59% can be obtained in the II-redesigned cycle when the evaporation pressure is 3.0 MPa and ammonia-water concentration is 0.75.

scholarly journals Modification of KCS (Kalina Cycle System) 34g by replacing throttle valve with single-screw expander

2021 ◽  
pp. 295-295
Author(s):  
Xinxin Zhang ◽  
Zhenlei Li
Keyword(s):  
Water Concentration ◽  
Work Output ◽  
Positive Role ◽  
Kalina Cycle ◽  
Ammonia Water ◽  
Single Screw ◽  
Cycle System ◽  
Throttle Valve ◽  
Thermodynamic Performance ◽  
Better Than

Recovery of the energy loss caused by throttling plays an important role in improving the performance of a cycle. Based on the original Kalina Cycle System 34g, two redesigned cycles, which have different placement of single-screw expanders used to replace the throttle valve, are proposed in this paper. The thermodynamic performance of two redesigned cycles is analyzed and compared with the original Kalina Cycle System 34g. The results show that the thermodynamic performance of each redesigned cycle is better than that of the original Kalina Cycle System 34g and the I?-redesigned cycle performs best. At a low and moderate evaporation pressure, there is an optimal ammonia-water concentration and it increases with the increase of evaporation pressure. With the concentration increases of ammonia-water, the performance advantage of the redesigned cycle system over the original Kalina Cycle System 34g gradually decreases. When the ammonia-water concentration is much lower than the optimal concentration, the single-screw expander produces much work and plays a positive role in net work output of cycle system. The highest cycle exergy efficiency of 54.14% can be obtained in the II-redesigned cycle when the evaporation pressure is 3.0MPa and ammonia-water concentration is 0.85.

Exergy Analysis of a Combined Power and Refrigeration Thermodynamic Cycle Driven by a Solar Heat Source

2003 ◽  
Vol 125 (1) ◽  
pp. 55-60 ◽  
Author(s):  
Afif Akel Hasan ◽  
D. Y. Goswami
Keyword(s):  
Heat Source ◽  
Exergy Analysis ◽  
Thermodynamic Cycle ◽  
Exergy Efficiency ◽  
Operating Conditions ◽  
Optimum Operating ◽  
Water Mixture ◽  
Exergy Destruction ◽  
Ammonia Water ◽  
Solar Heat

Exergy thermodynamics is employed to analyze a binary ammonia water mixture thermodynamic cycle that produces both power and refrigeration. The analysis includes exergy destruction for each component in the cycle as well as the first law and exergy efficiencies of the cycle. The optimum operating conditions are established by maximizing the cycle exergy efficiency for the case of a solar heat source. Performance of the cycle over a range of heat source temperatures of 320–460°K was investigated. It is found that increasing the heat source temperature does not necessarily produce higher exergy efficiency, as is the case for first law efficiency. The largest exergy destruction occurs in the absorber, while little exergy destruction takes place in the boiler.

scholarly journals Energy and Cost Analysis and Optimization of a Geothermal-Based Cogeneration Cycle Using an Ammonia-Water Solution: Thermodynamic and Thermoeconomic Viewpoints

2020 ◽  
Vol 12 (2) ◽  
pp. 484 ◽  
Author(s):  
Nima Javanshir ◽  
Seyed Mahmoudi S. M. ◽  
M. Akbari Kordlar ◽  
Marc A. Rosen
Keyword(s):  
Water Solution ◽  
Unit Cost ◽  
Exergy Efficiency ◽  
Hot Water ◽  
Cycle Performance ◽  
Working Fluid ◽  
Kalina Cycle ◽  
Ammonia Water ◽  
Total Product ◽  
Cogeneration Cycle

A cogeneration cycle for electric power and refrigeration, using an ammonia-water solution as a working fluid and the geothermal hot water as a heat source, is proposed and investigated. The system is a combination of a modified Kalina cycle (KC) which produces power and an absorption refrigeration cycle (ARC) that generates cooling. Geothermal water is supplied to both the KC boiler and the ARC generator. The system is analyzed from thermodynamic and economic viewpoints, utilizing Engineering Equation Solver (EES) software. In addition, a parametric study is carried out to evaluate the effects of decision parameters on the cycle performance. Furthermore, the system performance is optimized for either maximizing the exergy efficiency (EOD case) or minimizing the total product unit cost (COD case). In the EOD case the exergy efficiency and total product unit cost, respectively, are calculated as 34.7% and 15.8$/GJ. In the COD case the exergy efficiency and total product unit cost are calculated as 29.8% and 15.0$/GJ. In this case, the cooling unit cost, c p , c o o l i n g , and power unit cost, c p , p o w e r , are achieved as 3.9 and 11.1$/GJ. These values are 20.4% and 13.2% less than those obtained when the two products are produced separately by the ARC and KC, respectively. The thermoeconomic analysis identifies the more important components, such as the turbine and absorbers, for modification to improve the cost-effectiveness of the system.

scholarly journals Evaluation and Optimization of the Annual Performance of a Novel Tri-Generation System Driven by Geothermal Brine in Off-Design Conditions

2020 ◽  
Vol 10 (18) ◽  
pp. 6532
Author(s):  
Mehri Akbari Kordlar ◽  
Florian Heberle ◽  
Dieter Brüggemann
Keyword(s):  
Exergy Efficiency ◽  
Working Fluid ◽  
Exergy Destruction ◽  
Operational Parameters ◽  
Generation System ◽  
Geothermal Resources ◽  
Kalina Cycle ◽  
Destruction Rate ◽  
Heating And Cooling ◽  
The Difference

The difference in heating or cooling to power ratio between required demands for district networks and the proposed tri-generation system is the most challenging issue of the system configuration and design. In this work, an adjustable, novel tri-generation system driven by geothermal resources is proposed to supply the thermal energies of a specific district network depending on ambient temperature in Germany. The tri-generation system is a combination of a modified absorption refrigeration cycle and a Kalina cycle using NH3-H2O mixture as a working fluid for the whole tri-generation system. A sensitive analysis of off-design conditions is carried out to study the effect of operational parameters on the system performances prior to optimizing its performance. The simulation show that the system is able to cover required heating and cooling demands. The optimization is applied considering the maximum exergy efficiency (scenario 1) and minimum total exergy destruction rate (scenario 2). The optimization results show that the maximum mean exergy efficiency in scenario 1 is achieved as 44.67% at the expense of 14.52% increase in the total exergy destruction rate in scenario 2. The minimum mean total exergy destruction rate in scenario 2 is calculated as 2980 kW at the expense of 8.32% decrease in the exergy efficiency in scenario 1.

Experimental Investigations of Oscillatory Fluctuation in an Ammonia-Water Mixture Turbine System

2005 ◽  
Author(s):  
Yoshiharu Amano ◽  
Keisuke Kawanishi ◽  
Takumi Hashizume
Keyword(s):  
Low Temperature ◽  
Heat Source ◽  
Flow Rate ◽  
Mass Fraction ◽  
Working Fluid ◽  
Experimental Investigations ◽  
Water Mixture ◽  
Kalina Cycle ◽  
Ammonia Water ◽  
Temperature Heat

This paper reports results from experimental investigations of the dynamics of an ammonia-water mixture turbine system. The mixture turbine system features Kalina Cycle technology [1]. The working fluid is an ammonia-water mixture (AWM), which enhances the power production recovered from the low-temperature heat source [2], [3]. The Kalina Cycle is superior to the Rankine Cycle for a low temperature heat source [4], [5]. The ammonia-water mixture turbine system has distillation-condensation processes. The subsystem produces ammonia-rich vapor and a lean solution at the separator, and the vapor and the solution converge at the condenser. The mass balance of ammonia and water is maintained by a level control at the separator and reservoirs at the condensers. Since the ammonia mass fraction in the cycle has a high sensitivity to the evaporation/condensation pressure and vapor flow rate in the cycle, the pressure change gives rise to a flow rate change and then level changes in the separators and reservoirs and vice versa. From the experimental investigation of the ammonia-water mixture turbine system, it was observed that the sensitivity of the evaporating flow rate and solution liquid density in the cycle is very high, and those sensitivity factors are affected by the ammonia-mass fraction. This paper presents the experimental results of a study on the dynamics of the distillation process of the ammonia-water mixture turbine system and uses the results of investigation to explain the mechanism of the unstable fluctuation in the system.

THERMOPHYSICAL PROPERTIES ANALYSIS FOR AMMONIA-WATER MIXTURE OF AN ORGANIC RANKINE CYCLE

2015 ◽  
Vol 75 (8) ◽  
Author(s):  
N.H. Mohd Razif ◽  
A.M.I Mamat ◽  
I. Lias ◽  
W.A.N.W Mohamed
Keyword(s):  
Thermal Conductivity ◽  
Dynamic Viscosity ◽  
Organic Rankine Cycle ◽  
Water Concentration ◽  
Thermodynamic Characteristics ◽  
Rankine Cycle ◽  
Low Grade ◽  
Water Mixture ◽  
Ammonia Water ◽  
Optimum Energy

In an Organic Rankine Cycle (ORC), the thermofluid properties of the organic fluid are key parameters to achieve an optimum energy recovery. Non-azeotrapic fluid, such as ammonia-water mixture is suitable for applications in low grade heat source because of the thermodynamic characteristics of this fluid. This paper reports experimental data of thermal conductivity and dynamic viscosity of ammonia-water mixtures that will be used for ORC application. Five ratios of ammonia to water concentration were tested which are; (1) 25:75, (2) 20:80, (3) 15:85, (4) 10:90 and (5) 5:95. These five mixtures are characterized at a temperature range from 25ºC to 40ºC. The result shows that the thermal conductivity increases as the concentration of the ammonia reduces. The thermal conductivity also increases as the mixture temperature increases. The ammonia-water mixture at the ratio of 5:95 gives the highest thermal conductivity at 40ºC which is 30% better than the other concentrations at similar temperature. The dynamic viscosity,   and heat capacity,   of these mixtures shows a linear relationship to ammonia molar concentration.  

Numerical Simulation Study on Characteristics of Vertical Gravity Separator in a Kalina Cycle System

2015 ◽  
Author(s):  
Ya Zheng ◽  
Saili Li ◽  
Dongshuai Hu ◽  
Yiping Dai
Keyword(s):  
Structure Design ◽  
Separation Performance ◽  
Initial Structure ◽  
Water Mixture ◽  
Plant Design ◽  
Operational Parameters ◽  
Kalina Cycle ◽  
Ammonia Water ◽  
Gravity Separator ◽  
Vertical Gravity

In various novel thermodynamic cycles which utilize waste heat and geothermal resources, the Kalina cycle is the most significant improvement in thermal power plant design and it has been considered as an ambitious competitor against the Organic Rankine Cycle. However, the kalina cycle faces the complicated separate process and the design of separators still depends on the experience empirical formulae. Therefore, the vertical gravity separator used for separating ammonia-water mixture plays a vital important role in this system. The separator should keep high separation performance and enable the system to operate with stability. In this paper, we propose the initial structure design of a vertical gravity separator according to the separation theories. Based on the initial structure design of separator, conventional separator has been improved by changing the structure and operational parameters, including the ammonia concentration, inlet velocity, diameter, angle and height of inlet, and that has been numerically simulated by the means of CFX in computational fluid dynamics. In-depth estimating the separating performance of vertical gravity separator, different structural and operational parameters of vertical gravity separator are simulated and discussed. The separation performance and the distribution of ammonia-water mixture are estimated including flow field, trajectories of motion of particles, pressure drop, separation efficiency and so on. The results can be expected to be of great technical interest as basis for the design of vertical gravity separators.

scholarly journals Optimasi Siklus Kalina KCS34 Pada Pemanfaatan Sumber Air Panas (Natural Hot Spring) Sebagai Pembangkit Listrik

2018 ◽  
Vol 1 (1) ◽  
Author(s):  
Muhammad Pramuda N.S ◽  
Muhammad Ridwan ◽  
Iqbal Iqbal Maulana
Keyword(s):  
Power Plant ◽  
Low Temperature ◽  
Electric Power ◽  
Hot Spring ◽  
Electric Power Plant ◽  
Water Mixture ◽  
System Efficiency ◽  
West Java ◽  
Kalina Cycle ◽  
Ammonia Water

ABSTRAK Indonesia memiliki potensi panas bumi yang besar. Daerah potensi panas bumi seperti di daerah Cimanggu, Provinsi Jawa Barat umumnya memiliki sumber air panas. Sumber air panas selain dimanfaatkan untuk pariwisata, dapat pula dimanfaatkan sebagai pembangkit tenaga listrik. Temperatur sumber air panas yang relatif rendah antara 60° - 90°C membutuhkan teknologi khusus agar dapat dimanfaatkan sebagai pembangkit tenaga listrik. Siklus Kalina KCS34 merupakan siklus yang memanfaatkan campuran ammonia-air sebagai fluida kerja untuk menyerap energi kalor dari sumber panas bertemperatur rendah karena sifat dari campuran ammonia-air yang memiliki titik didih yang rendah. Fraksi campuran ammonia-air dan tekanan kondensor dapat mempengaruhi daya turbin dan efisiensi dari siklus Kalina KCS34. Simulasi optimasi fraksi campuran ammonia-air dan tekanan kondensor dilakukan untuk mengetahui besarnya fraksi campuran ammonia-air dan tekanan kondensor yang sesuai untuk digunakan sebagai pembangkit tenaga listrik di daerah Cimanngu, Provinsi Jawa Barat. Berdasarkan hasil simulasi, untuk mendapatkan kondisi pembangkit yang optimum di lokasi tersebut diperlukan fraksi campuran ammonia-air sebesar 87% dengan tekanan kondensor 7.6 bar sehingga akan dihasilkan daya turbin sebesar 73.57 kW dengan efisiensi sistem 14.85%. Kata kunci: Siklus Kalina, optimasi, campuran ammonia-air.  ABSTRACT Indonesia have a large potential of geothermal resources. Geothermal resource area such as Cimanggu area, West Java Province has natural hot spring resources. These natural hot spring resource can be utilized for eco tourism and electric power plant. Natural hot spring have relatively low water temperature between 60° - 90°C and it need special technology to be utilized as electric power plant. Kalina cycle KCS34 is a cycle that utilize ammonia-water mixture to absorb energy from low temperature natural hot spring source because of the properties of ammonia-water mixture that can boiled at low temperature. The fraction of ammonia-water mixture and the condensor pressure of the Kalina cycle KCS34 can affect the turbine output power and system efficiency. Optimization simulation was held to discover the required fraction of ammonia-water mixture and condenser pressure that suitable for generating electricity on Cimanggu area, West Java Province. According to the simulation results, the optimum fraction of ammonia-water mixture is 87% and the condensor pressure at 7.6 bar which will generate 73.57 kW of turbine power with 14.85% system efficiency. Keywords: Kalina cycle, optimization, ammonia-water mixture.

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