scholarly journals Investigating Solid and Liquid Desiccant Dehumidification Options for Room Air-Conditioning and Drying Applications

2020 ◽  
Vol 12 (24) ◽  
pp. 10582
Author(s):  
B. Kiran Naik ◽  
Mullapudi Joshi ◽  
Palanisamy Muthukumar ◽  
Muhammad Sultan ◽  
Takahiko Miyazaki ◽  
...  
Keyword(s):  
Air Conditioning ◽  
Climatic Conditions ◽  
System Capacity ◽  
Inlet Temperature ◽  
Outlet Temperature ◽  
Performance Parameters ◽  
Liquid Desiccant ◽  
Two Stage ◽  
Air Inlet ◽  
Liquid Desiccant Dehumidification

This study reports on the investigation of the performance of single and two-stage liquid and solid desiccant dehumidification systems and two-stage combined liquid and solid desiccant dehumidification systems with reference to humid climates. The research focus is on a dehumidification system capacity of 25 kW designed for room air conditioning application using the thermal models reported in the literature. RD-type silica gel and LiCl are used as solid and liquid desiccant materials, respectively. In this study, the application of proposed system for deep drying application is also explored. Condensation rate and moisture removal efficiency are chosen as performance parameters for room air conditioning application, whereas air outlet temperature is chosen as performance parameter for deep drying application. Further, for a given range of operating parameters, influences of air inlet humidity ratio, flow rate, and inlet temperature on performance parameters of the systems are investigated. In humid climatic conditions, it has been observed that a two-stage liquid desiccant dehumidification system is more effective for room air conditioning application, and two-stage solid desiccant dehumidification system is more suitable for deep drying application in the temperature range of 50 to 70 °C, while single-stage solid desiccant and two-stage combined liquid and solid desiccant dehumidification systems are more effective for low temperature, i.e., 30 to 50 °C deep drying application.

The Influence of Coal Slurry Fuel Properties on the Performance of a Bench Scale Two-Stage Slagging Combustor

1992 ◽  
Author(s):  
L. H. Cowell ◽  
C. S. Wen ◽  
R. T. LeCren
Keyword(s):  
Pollutant Emissions ◽  
Test Facility ◽  
Inlet Temperature ◽  
Coal Slurry ◽  
Particulate Emissions ◽  
Two Stage ◽  
Bench Scale ◽  
Air Inlet ◽  
Primary Zone ◽  
Secondary Zone

Fuel specifications for a coal-fueled industrial gas turbine are being determined through bench scale testing of a two-stage slagging combustor with coal water mixtures (CWM) possessing different properties. Twelve CWMs have been formulated with variations in coal loading, ash concentration, fuel additives, coal particle size, and coal type. The test combustor is operated at 7 bars with a 600 K air inlet temperature in a high pressure test facility. The two-stage slagging combustor (TSSC) features a rich burning, slagging primary zone and a lean secondary zone. Combustor performance is characterized by measurements of pollutant emissions, slag capture, particulate emissions, and coal utilization. The combustor has demonstrated a high degree of fuel property flexibility with performance remaining above goals in most tests. The properties of the CWMs and the test results are discussed.

Performance Analysis on the Internally Cooled Dehumidifier Using Two Liquid Desiccant Solutions

2012 ◽  
Author(s):  
I. P. Koronaki ◽  
R. I. Christodoulaki ◽  
V. D. Papaefthimiou ◽  
E. D. Rogdakis
Keyword(s):  
Mass Transfer ◽  
Theoretical Model ◽  
Heat And Mass Transfer ◽  
Flow Rate ◽  
Air Conditioning ◽  
Cooling Water ◽  
Operating Conditions ◽  
Inlet Temperature ◽  
Liquid Desiccant ◽  
Internally Cooled

Liquid desiccant air conditioning systems have recently been attracting attention due to their capability of handling the latent load without super-cooling and then reheating the air, as happens in a conventional compression-type air conditioning system. This paper presents the results from a study of the performance of an internally cooled liquid desiccant dehumidifier. A plate heat exchanger is proposed as the internally cooled element of the dehumidifier and water as the cooling fluid. The desiccant solution is sprayed into the internally cooled dehumidifier from the top and flows down by gravity. At the same time, fresh humid air is blown from the bottom or top, counter-flowing or co-flowing with the desiccant solution. The desiccant is in direct contact with the air, allowing for heat and mass transfer. The cooling water, flowing inside the plates of the dehumidifier, carries out the heat of the crossed air and solution. A heat and mass transfer theoretical model has been developed, based on the Runge-Kutta fixed step method, to predict the performance of the device under various operating conditions. Experimental data from previous literature have been used to validate the model. Excellent agreement has been found between experimental tests and the theoretical model, with the deviation not exceeding ±4.1% for outlet air temperature and ±4.0% for outlet humidity ratio. Following the validation of the mathematical model, the dominating effects on the absorption process have been discussed in detail. Namely, effects of flow configuration, air inlet temperature, humidity and flow rate, as well as desiccant inlet temperature, concentration and flow rate have been investigated against the dehumidification rate and the cooling efficiency. The two most commonly used liquid desiccant solutions, namely LiCl and LiBr have been also evaluated against each other. The results suggested that high dehumidification mass rate can be achieved under counter flow between air and solution, low air mass flow rates, low cooling water temperature, low desiccant temperature and LiCl as the desiccant solution.

scholarly journals ПІДВИЩЕННЯ ЕФЕКТИВНОСТІ СИСТЕМ КОНДИЦІЮВАННЯ ПОВІТРЯ ШЛЯХОМ РОЗПОДІЛУ ТЕПЛОВОГО НАВАНТАЖЕННЯ ЗА СТУПЕНЕВИМ ПРИНЦИПОМ

2019 ◽  
pp. 49-53
Author(s):  
Євген Іванович Трушляков ◽  
Микола Іванович Радченко ◽  
Андрій Миколайович Радченко ◽  
Сергій Георгійович Фордуй ◽  
Сергій Анатолійович Кантор ◽  
...  
Keyword(s):  
Thermal Load ◽  
Air Conditioning ◽  
Rational Design ◽  
Ambient Air ◽  
Cooling Capacity ◽  
Climatic Conditions ◽  
Outlet Temperature ◽  
Thermal Loads ◽  
Air Conditioning System ◽  
Air Conditioning Systems

Maintaining the operation of refrigeration compressors in nominal or close modes by selecting a rational design thermal load and distributing it in response to the behavior of the current thermal load according to the current climatic conditions is one of the promising reserves for improving the energy efficiency of air conditioning systems, which implementation ensures maximum or close to it in the annual cooling production according to air conditioning duties. In general case, the total range of current thermal loads of any air-conditioning system includes a range of unstable loads caused by precooling of ambient air with significant fluctuations in the cooling capacity according to current climatic conditions, and a range of relatively stable cooling capacity expended for further lowering the air temperature from a certain threshold temperature to the final outlet temperature. If a range of stable thermal load can be provided within operating a conventional compressor in a mode close to nominal, then precooling the ambient air with significant fluctuations in thermal load requires adjusting the cooling capacity by using a variable speed compressor or using the excess of heat accumulated at reduced load. Such a stage principle of cooling ensures the operation of refrigerating machines matching the behavior of current thermal loads of any air-conditioning system, whether the central air conditioning system with ambient air procession in the central air conditioner or its combination with the local indoors recirculation air conditioning systems in the air-conditioning system. in essence, as combinations of subsystems – precooling of ambient air with the regulation of cooling capacity and subsequent cooling air to the mouth of the set point temperature under relatively stable thermal load.

Research on Biological Materials with Optimization of Spray Drying Walnut Antioxidant Polypeptide Using Response Surface Methodology

2014 ◽  
Vol 540 ◽  
pp. 326-330
Author(s):  
Yan Ma ◽  
Shuai Wu ◽  
Chu Yu Guan ◽  
Guo Hui Huang
Keyword(s):  
Response Surface Methodology ◽  
Response Surface ◽  
Spray Drying ◽  
Inlet Temperature ◽  
Outlet Temperature ◽  
Scavenging Activity ◽  
Feed Concentration ◽  
Air Inlet ◽  
Dpph Scavenging Activity ◽  
Dpph Scavenging

Response surface methodology (RSM) was employed to optimize the spray drying process for walnut polypeptide, which were hydrolyzed by papain and trypsin. Air inlet temperature, air outlet temperature and feed concentration as well as cross-interaction among these factors exhibited a significant effect on collection rate and DPPH scavenging activity of walnut polypeptide powder. Results showed that the optimal drying parameters were air inlet temperature of 172℃, air outlet temperature of 88℃ and feed concentration of 23 %. The observed collection rate and DPPH scavenging activity of polypeptide powder under the optimal conditions was up to 91.28 % and 76.33 %, respectively, which was consistent with the predicted result.

Performance Analysis and Simulation of Automotive Air Conditioning Systems

2012 ◽  
Vol 260-261 ◽  
pp. 357-361
Author(s):  
Zhi Zhang ◽  
Peng Du ◽  
Pei Zhang
Keyword(s):  
Simulation Model ◽  
Air Conditioning ◽  
Inlet Temperature ◽  
Refrigeration Cycle ◽  
Cycle System ◽  
Air Inlet ◽  
Automotive Air Conditioning ◽  
Air Conditioning Systems ◽  
The Mathematical Model ◽  
Performance Analysis And Simulation

This paper analyzes the automotive air conditioning refrigeration cycle system, to establish the mathematical model of the compressor, condenser and evaporator. Using the Matlab to build a simulation model of the automotive air conditioning and refrigeration systems. by the simulation model of automobile air conditioning compressor, condenser and evaporator match the condensing temperature, evaporating temperature, air inlet temperature ,it is shown this model is reasonable

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