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.

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 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.

Common Design Deficiencies in Counterflow Cooling Towers

2004 ◽  
Author(s):  
Hector L. Cruz
Keyword(s):  
Power Plant ◽  
Cooling Tower ◽  
Cold Water ◽  
Industrial Plant ◽  
Project Design ◽  
Minimum Standards ◽  
Operational Design ◽  
Cold Water Temperature ◽  
Design Deficiencies ◽  
Base Load

One of the best methods for insuring a power plant will produce its guaranteed base load is to have an excess of circulating cold water or at least the expected guaranteed cold water temperature throughout the year. Yet, within industry today, numerous mistakes continue to be made when purchasing a cooling tower, by both the Subcontractor, and the Contractor. Only following only normal design criteria established by cooling tower Subcontractors, or an industry association, is not sufficient. Guidelines in the cooling tower industry have been established to set forth minimum standards that have helped to eliminate obvious past deficiencies. They were not established to protect the Subcontractor. Nor were they established to guarantee the Contractor receives what is thermally and mechanically necessary for a given project. Design of a cogeneration or industrial plant does not always consider the necessary requirements on a cooling tower over the range of expected operation. This type of design for a cooling tower is more complicated than the single guarantee point operational design of a power plant that is the current norm. Just as the Contractor needs to consider how to meet the thermal energy requirements over the range of expected operation of the plant, the Subcontractor of the cooling tower must do the same. Contractors must be aware that the cooling tower designer does not consider aspects that are often applicable to cogeneration plants and therefore they must include exceptions to the Subcontractors’ optimized offering in their standard cooling tower specifications. These exceptions in no way disagree with the Codes and Standards adopted by the cooling tower industry or any governing agency. This paper will address exceptions that the power plant and cooling tower designer needs to take into consideration to ensure that a reliable supply of cold water relates to the thermal duty requirements from the plant throughout the year.

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.

scholarly journals Financial Analysis of the Use of Two Horizontal Drain Water Heat Recovery Units

Energies ◽  
2020 ◽  
Vol 13 (16) ◽  
pp. 4113 ◽  
Author(s):  
Kamil Pochwat ◽  
Sabina Kordana-Obuch ◽  
Mariusz Starzec ◽  
Beata Piotrowska
Keyword(s):  
Heat Exchanger ◽  
Water Temperature ◽  
Heat Recovery ◽  
Cold Water ◽  
Financial Analysis ◽  
Global Scale ◽  
Drain Water ◽  
Actual Distribution ◽  
Cold Water Temperature ◽  
The Impact

The growing interest in the use of unconventional energy sources is a stimulus for the development of dedicated devices and technologies. Drain water heat recovery (DWHR) units can be an example of such devices. They allow the recovery of part of the heat energy deposited in grey water. This paper describes the results of research on the assessment of the financial profitability of the use of two horizontal heat exchanger solutions, taking into account the actual distribution of cold water temperature during the operating year in the plumbing and two operating regimes of the premises as the residential and service facilities. The analysis showed that the use of a horizontal heat exchanger with increased efficiency in a dwelling in a 15-year life cycle allowed for achieving more than twice as much savings (reaching up to EUR 1427) compared to a classic horizontal heat exchanger. At the same time, it was shown that the installation of this type of equipment was more profitable the greater the water consumption of the premises. The article also notes the impact of cold water temperature in the installation on the results of the analysis. It was featured that taking temperature on the basis of installation design recommendations led to significant distortions in the financial analysis. On the other hand, comparing the method of averaging the cold water temperature (daily, monthly and yearly), it was determined that averaging the temperature over the annual cycle was an acceptable simplification of the model. The research results presented in the paper have a practical aspect and may constitute guidelines for designers and potential investors. In addition, they can be an incentive to continue research on heat exchangers by other scientific centers, which on a global scale will increase the universality of their use.

Power Recapture and Power Uprate in NPPs With Process Data Reconciliation in Accordance With VDI 2048

2006 ◽  
Author(s):  
Magnus Langenstein
Keyword(s):  
Process Parameters ◽  
Control Volume ◽  
Reactor Power ◽  
Data Reconciliation ◽  
Thermal Reactor ◽  
Process Data ◽  
Pressurized Water ◽  
Statistical Probability ◽  
Water Reactor ◽  
Heat Cycle

The determination of the thermal reactor power is traditionally done by establishing the heat balance: • for a boiling water reactor (BWR) at the interface of reactor control volume and heat cycle; • for a pressurized water reactor (PWR) at the interface of the steam generator control volume and turbine island on the secondary side. The uncertainty of these traditional methods is not easy to determine and it can be in the range of several percent. Technical and legal regulations (e.g. 10CFR50) cover an estimated instrumentation error of up to 2% by increasing the design thermal reactor power for emergency analysis to 102% of the licensed thermal reactor power. Basically, the licensee has the duty to warrant at any time operation inside the analysed region for thermal reactor power. This is normally done by keeping the indicated reactor power at the licensed 100% value. A better way is to use a method which allows a continuous warranty evaluation. The quantification of the level of fulfilment of this warranty is only achievable by a method which: • is independent of single measurements accuracies; • results in a certified quality of single process values and for the total heat cycle analysis; • leads to complete results including 2-sigma deviation especially for thermal reactor power. This method, which is called ‘process data reconciliation based on VDI 2048 guideline’, is presented here [1, 2]. The method allows to determine the true process parameters with a statistical probability of 95%, by considering closed material, mass- and energy balances following the Gaussian correction principle. The amount of redundant process information and complexity of the process improves the final results. This represents the most probable state of the process with minimized uncertainty according to VDI 2048. Hence, calibration and control of the thermal reactor power are possible with low effort but high accuracy and independent of single measurement accuracies. Furthermore, VDI 2048 describes the quality control of important process parameters. Applied to the thermal reactor power, the statistical certainty of warranting the allowable value can be quantified. This quantification allows keeping a safety margin in agreement with the authority. This paper presents the operational application of this method at an operating plant and describes the additional use of process data reconciliation for acceptance tests, power recapture and system and component diagnosis.

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