Theoretical analysis of an improved adsorption desalination system under different operating conditions

2021 ◽  
pp. 095440892198947
Author(s):  
Amirhossein Amirfakhraei ◽  
Taleb Zarei ◽  
Jamshid Khorshidi
Keyword(s):  
Water Temperature ◽  
Cold Water ◽  
Internal Heat ◽  
Operating Conditions ◽  
Hot Water ◽  
Performance Ratio ◽  
Cold Water Temperature ◽  
Conventional Systems ◽  
Heat And Mass Recovery ◽  
Mass Recovery

This paper presents the development of an advanced adsorption desalination system (ADS) with heat and mass recovery. By means of internal heat and mass recovery, this adsorption desalination system (ADS), offers a significantly higher performance ratio compared to the conventional systems. After vapor desorption, the pressure difference in the hot bed is first transmitted to the cold bed using mass recovery. Then, the heat from the hot bed is transferred into the cold bed and, eventually, to the condenser and evaporator, by means of the cold water. Numerical simulations for this system are compared to a verified experimental model, and then developed to study the effect of the operating parameters. The level of SDWP or specific daily water production for this ADS was found to be 13.48 m^3/ton of silica gel/day at a hot water temperature of 92.5 (°C) and a cold water temperature of 30 (°C). Consequently, in these operating conditions, the SDWP of the advanced ADS was found to be 153% more than the conventional ADS. Also, at the same temperature conditions, the performance ratio of the ADS with heat and mass recovery was 35% higher than the ADS without heat and mass recovery.

scholarly journals Experimental determination of cold water temperature at the inlet to solar water storage tanks

2019 ◽  
Vol 116 ◽  
pp. 00106 ◽  
Author(s):  
Miroslaw Zukowski
Keyword(s):  
Water Temperature ◽  
Cold Water ◽  
Tap Water ◽  
Water System ◽  
District Heating ◽  
Hot Water ◽  
Storage Tanks ◽  
Climate Conditions ◽  
Cold Water Temperature

In the present work, results of experimental research on the mains water temperature supplying the Solar Domestic Hot Water system in the period from 2016 to 2018 are shown. The test object is located in the Hotel for Research Assistants on Bialystok University of Technology campus in Poland. One of the elements that will guarantee the correct energy balance of a hot tap-water system is the exact determination of the cold water temperature. The aim of this study is estimation of the temperature of the mains water flowing into the district heating substation and the water feeding directly the heat storage tanks. The research results showed that the average value of the cold water was 14.09°C during the 3 years of measurements. Moreover, it was shown that this temperature increased by about 0.4°C as a result of heat exchange with the air inside the substation. In the article, the author proposed modifications of coefficients in a commonly used model developed by National Renewable Energy Laboratory for determining the temperature of mains water in energy simulations. The proposed changes allow for accurate modelling of the cold water temperature under the climate conditions of north-eastern Poland.

The Worlds’ First Ever Cooling Tower Acceptance Test Using Process Data Reconciliation

2006 ◽  
Author(s):  
Magnus Langenstein ◽  
Jan Hansen-Schmidt
Keyword(s):  
Water Temperature ◽  
Cooling Tower ◽  
Cold Water ◽  
Single Point ◽  
Operating Conditions ◽  
Data Reconciliation ◽  
Acceptance Test ◽  
Process Data ◽  
Statistical Probability ◽  
Cold Water Temperature

The cooling capacity of cooling towers is influenced by multiple constructive and atmospheric parameters in a very complex way. This leads to strong variations of the measured cold-water temperature and causes unacceptable unreliability of conventional acceptance tests, which are based on single point measurements. In order to overcome this lack of accuracy a new approach to acceptance test based on process data reconciliation has been developed by BTB Jansky and applied at a nuclear power plant. This approach uses process data reconciliation according to VDI 2048 [1, 2] to evaluate datasets over a long period covering different operating conditions of the cooling tower. Data reconciliation is a statistical method to determine the true process parameters with a statistical probability of 95% by considering closed material-, mass- and energy balances. Datasets which are not suitable for the evaluation due to strong transient gradients are excluded beforehand, according to well-defined criteria. The reconciled cold-water temperature is then compared, within a wet bulb temperature range of 5°C to 20°C to the manufacturer’s guaranteed temperature. Finally, if the average deviation between reconciled and guaranteed value over the evaluated period is below zero, the cooling tower guarantee is fulfilled.

scholarly journals Application of Response Surface Methodology (RSM) for Optimization of Operating Parameters and Performance Evaluation of Cooling Tower Cold Water Temperature

2011 ◽  
Vol 2 (1) ◽  
pp. 39-50
Author(s):  
Ramkumar RAMAKRISHNAN ◽  
Ragupathy ARUMUGAM
Keyword(s):  
Response Surface Methodology ◽  
Water Temperature ◽  
Response Surface ◽  
Cold Water ◽  
Hot Water ◽  
Optimum Operating ◽  
Operating Parameters ◽  
Operating Variables ◽  
Cold Water Temperature ◽  
And Performance

Performance  of the coolig tower was analysed with various operating parameters and find the minimum cold water temperature. In this study, optimization of operating parameters was investigated. An experimental design was carried out based on central composite design(CCD) with response surface methodology(RSM). This paper presents optimum operating parameters and   the minimum cold water temperature using RSM method.  The RSM was used to evaluate the effects of operating variables and their interaction towards the attainment of their optimum conditions. Based on statistical analysis, water flow, air flow, hot water temperature and packing height were high significant on cold water temperature, with very low probability values(<0.0001). The optimum operating parameters predicted using  RSM method and confirmed through experiment. 

scholarly journals Fluctuating temperature of the mains water throughout the year and its influence on the consumption of energy for the purposes of DHW preparation

2018 ◽  
Vol 44 ◽  
pp. 00017 ◽  
Author(s):  
Agnieszka Chmielewska
Keyword(s):  
Water Treatment ◽  
Water Temperature ◽  
Cold Water ◽  
Treatment Plant ◽  
Water Treatment Plant ◽  
Monthly Basis ◽  
New Model ◽  
Water Influence ◽  
Family Building ◽  
Cold Water Temperature

The article discusses the influence of the cold water temperature on the amount of energy consumed for the purposes of the DHW preparation in multi-family buildings. The article begins with a presentation of the DHW consumption readings from a multi-family building, recorded on a monthly basis during the period of 4 years. The readings constituted the base for calculating the demand for energy for the purposes of the DHW preparation. Subsequently, basing on the output water temperature readings from the water treatment plant, it was proved that the temperature of the mains water fluctuates throughout the year. The review of the available literature, as well as the measurements, confirmed that it is necessary to develop a new model of the cold water temperature that would take into account the type of intake in a water treatment plant. The final part of the article presents how the accepted assumptions about the temperature of the mains water influence the consumption of energy for the purposes of the DHW preparation.

scholarly journals Evaluation of Legionella spp. Colonization in Residential Buildings Having Solar Thermal System for Hot Water Production

2020 ◽  
Vol 17 (19) ◽  
pp. 7050
Author(s):  
Michele Totaro ◽  
Anna Laura Costa ◽  
Lorenzo Frendo ◽  
Sara Profeti ◽  
Beatrice Casini ◽  
...  
Keyword(s):  
Cold Water ◽  
Disease Risk ◽  
Residential Buildings ◽  
Water Systems ◽  
Hot Water ◽  
Solar Thermal ◽  
Water Production ◽  
Systems Maintenance ◽  
Legionnaires Disease ◽  
Cold Water Temperature

Despite an increase of literature data on Legionella spp. presence in private water systems, epidemiological reports assert a continuing high incidence of Legionnaires’ disease infection in Italy. In this study, we report a survey on Legionella spp. colonization in 58 buildings with solar thermal systems for hot water production (TB). In all buildings, Legionella spp. presence was enumerated in hot and cold water samples. Microbiological potability standards of cold water were also evaluated. Legionella spp. was detected in 40% of the buildings. Moreover, we detected correlations between the count of Legionella spp. and the presence of the optimal temperature for the microorganism growth (less than 40 °C). Our results showed that cold water was free from microbiological hazards, but Legionella spp., was detected when the mean cold water temperature was 19.1 ± 2.2 °C. This may considered close to the suboptimal value for the Legionella growth (more then 20 °C). In conclusion, we observed the presence of a Legionnaires’ disease risk and the need of some strategies aimed to reduce it, such as the application of training programs for all the workers involved in water systems maintenance.

A New Performance Estimate Method for Design of Storage-Type Domestic Electrical Water-Heaters Based on the CFD Simulation

2010 ◽  
Vol 129-131 ◽  
pp. 463-466
Author(s):  
Li Li Zhao ◽  
Zhi Jun Zhang ◽  
Shi Wei Zhang
Keyword(s):  
Water Temperature ◽  
Cfd Simulation ◽  
Cold Water ◽  
Discharge Rate ◽  
Water Discharge ◽  
Hot Water ◽  
New Method ◽  
Dynamics Simulation ◽  
Water Heater ◽  
Water Heaters

The 3D physical model of the electrical water heater was built. The water-heater performance was resolved by computer fluid dynamics simulation (CFD). The heater performance is characterized by a new method rather than that the discharge efficiency, extraction efficiency and fraction of heat recoverable. The new method is based on the constant discharge water temperature and rate for end user, 5L/min and 43°C that include the hot water from EWH and cold water from outside EWH. But the water discharge rate from EWH was variable as the water temperature discharge from EWH was variable. Compared with the traditional method, it is more close to the user using reality condition.

scholarly journals Application research of intelligent monitoring system of longsheng hot spring water temperature based on Internet of Things

2019 ◽  
Vol 23 (5 Part A) ◽  
pp. 2613-2622
Author(s):  
Bi Li ◽  
Shi Zheng
Keyword(s):  
Water Temperature ◽  
Monitoring System ◽  
Hot Springs ◽  
Cold Water ◽  
Hot Spring ◽  
Spring Water ◽  
Temperature Monitoring ◽  
Hot Water ◽  
Single Chip ◽  
Main Station

Guangxi Guilin area, China, is rich in hot spring resources. In this paper, a hot spring water temperature monitoring system is developed for longsheng hot springs. Mainly using the hot water of eye of hot springs as the heat source, designing a set of multi-point temperature monitoring system with single-chip and multi-slave as the core of the single-chip microcomputer and wireless and bi-directional transmission for the main station and multiple slave stations to realize automatic temperature monitoring. The system slave station can exchange geothermal water with high temperature extracted from the eye of hot springs and cold water, and automatically control the temperature of the hot spring pool to reach a set value range by controlling the flow rate of the cold water. At the same time, the main station can complete the tasks of monitoring system by setting control commands such as temperature.

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