Fig 1 - uploaded by Mohammad Altamush Siddiqui
Content may be subject to copyright.
Source publication
A performance study and economic analysis of the combined absorption/compression cycle using NH3–NaSCN solution have been performed and compared with pure ammonia in the compression cycle under various operating conditions. The performance index, specific compressor displacement, cost of electricity (per year) required for running the compressor an...
Contexts in source publication
Context 1
... Vapour compression cycle Fig. 1(a) shows a schematic diagram of a vapour compression system having dierent components and state points. The high pressure refrigerant, ammonia vapour, leaving the compressor in the superheated state is taken to the condenser where it gets condensed. The condensate from the condenser is subcooled in the precooler and then throttled to the ...
Context 2
... energy balances on each component, as a control volume, lead to the following equations (see Fig. 1(b) for state ...
Similar publications
The paper mainly deals with performance evaluation (Energy analysis) of hybrid cold storage using solar & exhaust heat of biomass gasifier. The paper mainly focuses on the solar biomass hybridization for cold storage. During day time, the system will run on solar thermal energy and during night time, biomass gasifier will be used for the same purpo...
Mass selective deposition of C7H3(+) (m/z = 87) into solid neon reveals the (1)A1 ← (1)A1 electronic absorption system of hepta-1,2,3,4,5,6-heptahexaenylium cation (+) [H2CCCCCCCH](+) with an origin band at 441.3 nm, (1)A' ← (1)A' transition of 2,4-pentadiynylium,1-ethynyl cation (+) [HCCCHCCCCH](+) starting at 414.6 nm and the (1)A1 ← (1)A1 one of...
The milk processing and preservation is a fast growing business in developing
countries and it is facing problems due to high energy cost and environmental
concerns in using conventional energy sources. Since the selection of feedstock and
conversion technologies, appropriate research must implement renewable energybased
technologies to promote a c...
In this report, poly(sodium styrene sulfonate)-functionalized graphene nanosheets (PSS-GN) with good water dispersibility were prepared and for the first time proposed as a peroxidase-like mimic. The intrinsic catalytic activity of PSS-GN nanocomposites was investigated and the results showed that PSS-GN nanocomposites had higher mimetic enzyme cat...
Precision medicine aims to use patient genomic, epigenomic, specific drug dose and other data to define disease patterns that may potentially lead to an improved treatment outcome. Personalized dosing regimens based on tumor drug penetration can play a critical role in this approach. State-of-the-art techniques to measure tumor drug penetration foc...
Citations
... If 200 °C is still possible at the sink with a vapor pressure below 25 bar, 200 °C is assumed to be the upper limit. (10) , MeOH (9) , TEGDME (11) 65/200 [96] −35/160 [86] Hannl (Austria) 2015 X NH 3 ...
... They stated inconsistent results regarding the improvement potential and recommended further investigations. Tarique and Siddiqui (1999) [86] and Hannl (2015) [87] investigated NH 3 paired with salts to increase the amount of refrigerant in the gas phase, eliminating the separation that may be required at increased source temperatures to reduce the water content in the vapor phase. Conducted experiments demonstrated the general functionality of this approach, although further research is required to establish prototypes and applications. ...
... They stated inconsistent results regarding the improvement potential and recommended further investigations. Tarique and Siddiqui (1999) [86] and Hannl (2015) [87] investigated NH 3 paired with salts to increase the amount of refrigerant in the gas phase, eliminating the separation that may be required at increased source temperatures to reduce the water content in the vapor phase. Conducted experiments demonstrated the general functionality of this approach, although further research is required to establish prototypes and applications. ...
Decarbonization of the industrial sector is one of the most important keys to reducing global warming. Energy demands and associated emissions in the industrial sector are continuously increasing. The utilization of high temperature heat pumps (HTHPs) operating with natural fluids presents an environmentally friendly solution with great potential to increase energy efficiency and reduce emissions in industrial processes. Ammonia-water absorption–compression heat pumps (ACHPs) combine the technologies of an absorption and vapor compression heat pump using a zeotropic mixture of ammonia and water as working fluid. The given characteristics, such as the ability to achieve high sink temperatures with comparably large temperature lifts and high coefficient of performance (COP) make the ACHP interesting for utilization in various industrial high temperature applications. This work reviews the state of technology and identifies existing challenges based on conducted experimental investigations. In this context, 23 references with capacities ranging from 1.4 kW to 4500 kW are evaluated, achieving sink outlet temperatures from 45 °C to 115 °C and COPs from 1.4 to 11.3. Existing challenges are identified for the compressor concerning discharge temperature and lubrication, for the absorber and desorber design for operation and liquid–vapor mixing and distribution and the choice of solution pump. Recent developments and promising solutions are then highlighted and presented in a comprehensive overview. Finally, future trends for further studies are discussed. The purpose of this study is to serve as a starting point for further research by connecting theoretical approaches, possible solutions and experimental results as a resource for further developments of ammonia-water ACHP systems at high temperature operation.
... Tarique and Siddiqui [1] compared a conventional vapor-compression cycle using ammonia with a combined refrigeration-cycle using NH 3 and NaSCN. The capital and operation costs were reduced significantly for the combined cycle. ...
Advanced exergy analysis was carried out for absorption-compression refrigeration-cycles with a working fluid selection and parametric analysis. The exergy-destruction was split into endogenous-exogenous and avoidable-unavoidable-parts to reveal the interdependency within the components and determine the improvement potential. The results show that the largest exergy-destruction occurs in the generator, accounting for 53.8% of the total destruction. The largest irreversibility occurs for R507a/NH3–H2O while the lowest destruction occurs for R152a/NH3–H2O with an approximate reduction of 0.62 kW. The largest irreversibility occurs in the azeotropic-fluids while the lowest occurs in wet fluids. More than one-half of overall exergy-destruction rates of the systems falls into the part of the avoidable-destruction with 52.5% of overall irreversibility. The major part of the avoidable-destruction occurs in the generator with 11.47 kW and it accounts for 57.8% of the total avoidable part, meaning that it has the highest improvement potential. The parametric analysis of the advanced exergy shows that the avoidable-part of the exergy-destruction can be minimized to a considerable extent employing a temperature of the condenser below 40 °C and generator temperature larger from 100 °C.
... where h 7 is determined by the generation pressure and generated vapor temperature, which is treated as the average temperature of the beginning and ending equilibrium temperatures; h 8, i is the ideal enthalpy at the compressor outlet determined by an isentropic process ( s 8 ,i = s 7 ); all the refrigerant properties are calculated by Refprop ( NIST, 2013 ). The isentropic efficiency is expressed as a function of the pressure ratio ( P r = p a / p g ) ( Tarique and Siddiqui, 1999 ): ...
Geothermal energy is becoming increasingly attractive to mitigate global energy and environment crisis. Various hybrid heat pump systems were introduced for increasing the utilization of geothermal energy, and then the absorption–compression heat pump (ACHP) using novel NH3/IL (ionic liquid) mixtures was analyzed. The property model of NH3/IL mixtures and the thermodynamic model of the ACHP cycle were established. Parameter studies showed that there was an optimal pressure ratio to achieve the highest coefficient of performance (COP). The optimal pressure ratio increased and the highest COP decreased as the allowed absorption pressure decreased. In addition, a higher pressure ratio was needed to produce a larger temperature lift. A higher absorber temperature (heat sink) led to a lower COP, while a higher generation temperature (heat source) was beneficial to a higher absorber temperature. Among the investigated ILs, [OMIM][BF4] (1-octyl-3-methylimidazolium tetrafluoroborate) yielded the highest heating COP with the lowest pressure ratio.
... The results showed that the ACHP using NH 3 -H 2 O as working fluids can cover the whole working domain of the high temperature (80-120°C) heat pumps with performance levels comparable. The absorption-compression heat pumps using NH 3 -NaSCN solutions was studied in Tarique et al. [18], and the results indicated that the initial investment and running costs of the compressors were reduced greatly compared to that of the pure ammonia cycle. A single-stage absorption-compression heat pump using ternary working fluid was studied by Bourouis et al. [19]. ...
An absorption-compression heat pump is a promising way to recover low-temperature waste heat efficiently in industrial applications. In this paper, an advanced ammonia-water absorption-compression heat pump is proposed to recover the sensible heat of flue gas below 150 °C to generate saturated steam at 0.5 MPa (151.8 °C). The sensible heat is cascade utilized in the hybrid heat pump system. The high-temperature waste heat is recovered to generate pure ammonia vapor in the rectifier, and the low-temperature heat is used to evaporate the ammonia liquid. In the ammonia vapor compression process, the gas compression process is combined with a liquid compression process, leading to the clear decrease in power consumption. The simulation results indicate that the coefficient of performance and exergy efficiency of the proposed system reaches 5.49 and 27.62%, which is almost two times and 4.69% higher than that of the reference system, respectively. Subsequently, a sensitivity analysis is conducted to optimizing the key parameters, and the optimums values are obtained. Finally, an economic analysis is adopted to evaluate the economic performance of the proposed system. The payback period of the proposed system is 6.26 years compared to the reference system. This study may provide a new way to produce saturated steam by efficiently using the low-temperature waste heat.
... Kiss et al. 13 and Jana 14 have provided excellent reviews on the various heat pump assisted distillation (HPAD) techniques for binary as well as multicomponent systems. Among them, the ones suitable for the C2 splitter include mechanical vapor recompression (MVR), bottom flashing (BF), and heat integrated distillation (HIDiC). ...
Ethylene is a platform chemical, and its production process includes energy intensive ethylene-ethane separation via cryogenic distillation. As potential avenues for energy reduction, in this study we have explored four distillation process configurations based on the concepts of mechanical vapor recompression (MVR) of the top product and throttling of the bottom product i.e., bottom flashing (BF). Each of these configurations is optimized in MATLAB using the genetic algorithm to minimize the total annualized cost (TAC) of separation. Our results show that both MVR and BF reduce energy as well as cost of separation compared to the conventional distillation configuration. However, BF outperforms MVR, and together with a prethrottling cooler it provides the minimum TAC configuration for ethylene-ethane separation. The proposed heat pump assisted distillation configuration has the potential to reduce the total energy requirement by 57% and the separation cost by 44% over the conventional distillation process.
... In this manner, higher-temperature hot water can be produced efficiently with appropriate operation pressures, which would be very high for normal vapor-compression cycles [29]. Tariquea and Siddiqui [30] analyzed an NH 3 -NaSCN absorption-assisted cycle which achieved efficiencies 30-60% higher compared to the vapor-compression cycle. Hultén and Berntsson [31] studied the impact of different temperature lifts and glides on an NH 3 -H 2 O absorption-assisted cycle for various heating applications. ...
... where p c and p e are the condensation and evaporation pressures, kPa; v p and ρ p are the specific volume (m 3 kg −1 ) and density (kg m −3 ) at the solution pump inlet; m r is the total refrigerant mass flow rate, kg s −1 ; η p is the solution pump efficiency, which is set to 0.65 [30]; f is the circulation ratio of the absorption sub-cycle, which is calculated by Eq. (7): ...
... where h cp in , and h cp out , are the compressor inlet and outlet refrigerant enthalpies, kJ kg −1 ; h cp out i , , is the ideal outlet refrigerant enthalpy with an isentropic compression, kJ kg −1 ; η i is the isentropic efficiency, which is calculated by Eq. (10) [30]: ...
... The simulation should be an improved COP by comparison of anywhere between 37% and 54%. Tarique and Siddiqui (1999) analyzed the performance of a combined cycle using NH 3 -NaSCN. The COP of NH 3 -NaSCN in the combined cycle is nearly 30-60% higher than that in the pure ammonia compression cycle. ...
This study proposes a simulation that incorporates energy, exergy, and economic factors into the development of an absorption-compression cycle for air-conditioning that makes use of heat sources available in Algeria. The springs have been used on record range in temperature between 60 and 94 °C. LiBr-H2O and LiCl-H2O have been used in the absorption section and low global warming potential fluids including R1234yf, R1234ze (E), and R1233zd (E) in the vapor compression section. In using these combinations of fluids, a recorded (51.36–54.16%) decrease in electricity consumption has been documented in comparison with conventional cycles. Furthermore, the coefficient of performance (COP) values for all of the combinations used ranged between (0.432 and 0.659). Enhanced performance was noted in the systems that used (LiBr-H2O/R1234yf). Economically, the use of geothermal energy is more financially sound in comparison to the use of solar energy in depth of well's less than 16 m.
... Heard and Holland (1997) simulated NH 3 -Li-nitrate absorption/compression refrigeration system for 0-100% range of mechanical vapour compression and concluded that NH 3 -Linitrate combined absorption/compression refrigeration system is increases overall efficiency up to 10%. Tarique and Siddiqui (1999) carried out the comparison of combined compression-absorption cycle using NH 3 -NaSCN working pair and conventional compression cycle using pure NH 3 . The result showed that the combined compressionabsorption cycle using NH 3 -NaSCN solution gives a better performance compared to the conventional compression cycle using NH 3 and reduces the operating cost. ...
... Below 70 K temperature lifts vapour compression cycle with single-stage solution, gives more COP and capacity at a lower pressure ratio, while above 70 K temperature lifts cycles with a desorber/absorber heat exchanger and gives a better performance than the vapour compression cycles with single-stage solution Combine compression and absorption refrigeration cycle Heard and Holland (1997) Combination of NH 3 -Li-nitrate absorption/compression refrigeration system NH 3 -Li-nitrate combine absorption/compression refrigeration system increases overall efficiency up to 10% Combine compression and absorption refrigeration cycle Tarique and Siddiqui (1999) Combination of compression using NH 3 and absorption cycle using NH 3 -NaSCN ...
The vapour absorption refrigeration system is not so much used commercially because of its low performance. The performance of an absorption refrigeration system is required to make it an efficient alternative of vapour compression refrigeration systems. This paper reviews different research on modification of absorption systems contributing to enhance the performance of absorption refrigeration systems. This study suggests that the performance of absorption refrigeration is improved by using double-effect and semi-generator absorber solution heat exchanger arrangement. The coefficient of performance of absorption refrigeration is also improved by the combination of different refrigeration cycles (hybrid refrigeration cycle) such as compression–absorption and ejector–absorption.
Abbreviations: COP: coefficient of performance; GAX: generator absorber solution heat exchanger; ARS: absorption refrigeration system; ECOP: ecological coefficient of performance; CAHP: compression-assisted absorption heat pump
... Kim et al., 2013a). Some other mixtures have been tested for a HACHP by (Bourouis et al., 2000; Tarique & Siddiqui, 1999). ...
The use of high temperature heat pumps (HTHPs) operating with natural fluids has been shown to be a potential environmentally friendly solution to increase energy efficiency in industrial processes. Industrial processes release a significant amount of energy as low quality waste heat to the environment. This paper reviews the research and development of efficient and cost effective HTHP technology that can utilize this waste heat. Natural fluids are of focus with consideration given to the comparable technologies using synthetic fluids. This review reveals the different challenges from fluid selection, component development to system optimization. The various innovative solutions to these challenges and promising technologies for further studies are discussed. The purpose of this paper is to serve as a start point for research by bringing together ideas, simulations and experimental results as a resource or reference tool for future development in HTHP using natural working fluids.
... The CAHP systems are suitable for large temperature lifts and high temperature applications, operated at much lower pressures compared with vapor-compression heat pumps [16]. Tariquea and Siddiqui [39] analyzed an NH 3 -NaSCN CAHP system and compared it with that of an NH 3 compression cycle under various operating conditions. The capital and operating costs of the NH 3 -NaSCN CAHP system were highly reduced compared with those of the compression cycle. ...
