Characteristic Analysis of Francis-Turbine in Cooling Tower

2012 ◽  
Vol 190-191 ◽  
pp. 57-59 ◽  
Author(s):  
Lan Jin Zhang ◽  
Lei Wang ◽  
Yan Ren
Keyword(s):  
Flow Rate ◽  
Cooling Tower ◽  
Water System ◽  
Cooling Water ◽  
Hydraulic Performance ◽  
Francis Turbine ◽  
Characteristic Analysis ◽  
Flow Passage ◽  
Water Power ◽  
Water Turbine

The water turbine stands in the cooling water system and drives the fan in the cooling tower, so its flow rate, head and output is limited to the flow rate of cooling water, saved-energy of pump and input of fan separately. The spiral casing dimension of water turbine is limited to the diameter of tower. All above facts make the water turbine of cooling tower be different to that of water power station. The paper introduces one turbine which flow rate is 0.139m/s. Its characteristic of flow passage and hydraulic performance is analyzed, and some new flow passage to improve hydraulic performance is suggested.

Experimental Research on the Effect of Cross-Wind to Wet-Cooling Tower Performance

2013 ◽  
Vol 860-863 ◽  
pp. 1412-1415
Author(s):  
Qing Yang Wang ◽  
Tian Yu Sun ◽  
Jian Zhang ◽  
Jian Xing Ren
Keyword(s):  
Wind Velocity ◽  
Flow Rate ◽  
Temperature Difference ◽  
Cooling Tower ◽  
Thermal Power ◽  
Water System ◽  
Cooling Water ◽  
Cooling Capacity ◽  
Inlet Temperature ◽  
Circulating Water

Environmental cross-wind has a influence on cooling capacity of wet cooling tower to a great extent in power plant.The variation of circulating-water temperature difference (Δt) and cooling coefficient of efficiency(η) with cross-wind velocity, circulating water inlet temperature and flow rate, are shown under cross-wind conditions, compared with cases without wind. By using experimental platform of cooling water system based on 300MW thermal power unit,it is found that with cross-wind velocity increasing,cooling temperature difference and cooling efficiency decrease first then increase at the knee point when the velocity value is 0.8m/s. In addition, the correlation betweenΔt ,η and parameters,such as circulating-water inlet temperature and flow rate, is derived for cases with windless conditions.

Hydraulic Design of Inlet Guide Vane and its Full Flow Passage Numerical Simulation on Centrifugal Pump

2014 ◽  
Author(s):  
Hucan Hou ◽  
Yongxue Zhang ◽  
Zhenlin Li ◽  
Xin Zhou ◽  
Zizhe Wang
Keyword(s):  
Centrifugal Pump ◽  
Flow Rate ◽  
Guide Vane ◽  
Hydraulic Performance ◽  
Design Flow ◽  
Inlet Guide Vane ◽  
Hydraulic Efficiency ◽  
Flow Passage ◽  
Setting Angle ◽  
Hydraulic Design

In order to effectively improve hydraulic performance of centrifugal pump on off-conditions, the hydraulic design of inlet guide vane (IGV) was completed by adopting two dimensional theory in-house code based on one kind of IS series of centrifugal pump, which can achieve pre-whirl regulation of centrifugal pump. During design process the trailing edge of vane is assumed as equal velocity moment condition, and the distribution of vane setting angle along meridional streamline is also given as a quartic function firstly, the camber line is then drawn by point-by-point integration method and thickened at both sides along circumferential direction. With local vortex dynamics diagnosis theory, the optimal improvement of vane space shape can be finished by adjusting the design parameters of vane setting angle distribution coefficient ap. The full flow passage numerical simulations of centrifugal pump with IGV device are completed to analyze the influence of pre-whirl regulation on hydraulic performance of centrifugal pump under various pre-whirl angles. The results show that the pre-whirl regulation can improve the hydraulic performance of centrifugal pump on off-conditions. Under the positive pre-whirl regulation conditions, the best efficient point shift to small flow rate zone, and under the negative pre-whirl regulation conditions it moves to large flow rate zone. Compared with the pump without IGV device at the same flow rate condition of 0.8Q (Q the design flow rate), the hydraulic efficiency of centrifugal pump with IGV device improves obviously and reaches up to 1.43%. Meanwhile compared with that installed with the straight vanes designed based on the traditional theory, the inner flow field of centrifugal pump with the designed vanes improves and the overall hydraulic efficiency of centrifugal pump is somewhat increased.

Efficient Replacement of Centrifugal With Absorption Chillers Upgrading the Heat Transfer of the Cooling Tower

2001 ◽  
Author(s):  
E. D. Rogdakis ◽  
V. D. Papaefthimiou
Keyword(s):  
Flow Rate ◽  
Cooling Tower ◽  
Water Flow Rate ◽  
Cooling Water ◽  
Double Effect ◽  
Operating Conditions ◽  
Cooling Power ◽  
Absorption Chiller ◽  
Absorption Chillers ◽  
Cooling Water Flow Rate

Abstract It is a general trend today, the old centrifugal machines to be replaced by new absorption machines. The mass flow rate of the cooling water in the centrifugal machines is normally 30% less than that in the two-stage absorption chiller for the same refrigerating capacity. Some absorption chillers manufacturers have updated and improved the double-effect technology increasing the cooling water temperature difference from the typical value of 5.5°C to 7.4°C and reducing the cooling water flow rate by about 30%. Using such a modern double effect absorption unit to replace a centrifugal chiller the same cooling water circuit can be used and the total cost of the retrofit is minimized. In this case a new flow pattern of the cooling tower is developed, and in this paper the design of a new tower fill is predicted taking into account the new factors characterizing the operating conditions and the required performance of the tower. As an example, the operational curves of a modified cooling tower (1500 KW cooling power) used by a 240 RT double-effect absorption chiller are presented.

The Hot Function Flow Characteristics of a Main Cooling Water System for the Nuclear Fuel Test Loop Installed in HANARO

2009 ◽  
Author(s):  
Young-Chul Park ◽  
Young-Seob Lee ◽  
Dae-Young Chi
Keyword(s):  
High Temperature ◽  
Power Reactor ◽  
Water System ◽  
Cooling Water ◽  
Flow Characteristics ◽  
Reaction Heat ◽  
Water Power ◽  
Test Loop ◽  
Air Pockets ◽  
High Temperature Operation

A nuclear fuel test loop (after below, FTL) is installed in IR1 of an irradiation hole in HANARO for testing neutron irradiation characteristics and thermo hydraulic characteristics of a fuel loaded in a light water power reactor or a heavy water power reactor. There is an in-pile section (IPS) and an out-pile section (OPS) in this test loop. When HANARO is normally operated, the fuel loaded in the IPS has a nuclear reaction heat generated by a neutron irradiation. To remove the generated heat and to maintain an operating conditions of the test fuel, a main cooling water system (MCWS) is installed in the OPS of the FTL. The MCWS is composed of a main cooler, a pressurizer, two circulation pumps, a main heater, interconnection pipe line and instruments. The interconnection pipeline is a closed loop which is connected respectively to an inlet and an outlet of the IPS. To absorb the nuclear reaction heat, there is a higher elevation pipeline with a reverse U letter type pipeline installed in upstream of the cooler. And there is another higher elevation pipeline for sucking a fluid by a vertically installed circulation pump with a top suction and a side discharge. Therefore, we predicted that it is difficult to continuously suck a fluid and pressurize the fluid due to air pockets in the two higher elevation pipelines under a high temperature operation. To verify the hot function flow characteristics of the MCWS including air pockets of the higher elevation pipelines, a flow net work analysis has been conducted under a high temperature operation. When the two higher elevation pipelines wholly filled with coolant, it was confirmed through the results that the pump pressurizes the coolant normally. And it was confirmed through the analysis results that the system hot function characteristics met the system design requirements.

Method and Implementation of Energy-Saving Control for Industrial Cooling Water Tower Pump

2012 ◽  
Vol 512-515 ◽  
pp. 1163-1166
Author(s):  
Li Zhong Zhang ◽  
Shu Hong Jia ◽  
Xiao Jun Zhao ◽  
Yan Sun ◽  
Guo Dong Shi
Keyword(s):  
Energy Saving ◽  
Flow Rate ◽  
Control Method ◽  
Water System ◽  
Cooling Water ◽  
Cold Pool ◽  
Pump Flow Rate ◽  
Energy Saving Process ◽  
Energy Saving Control ◽  
And Control

This article introduce a kind of energy-saving control method and implementation for a tower pump in industrial cooling water system (hot tub→ up tower pump→ cooling tower→ cold pool). Under the conditions without changing the original industrial cooling water’s normal operating, the method of temperature control liquid-level under the protection of pressure to regulate and control the energy-saving process of cooling water on tower pump was used. According to the hot tub’s actual temperature and cold pool’s temperature which has process requirements can automatically regulate the hot tub’s liquid height or the height difference between hot tub and cold pool. It can finally automatically control the natural flow rate of the connected overflow hole or connecting pipe, thereby reducing the pump flow rate on tower to ensure the purpose of siginificant energy-saving on the basis of process demand. The comprehensive energy-saving rate can be 40% to 60% or more.

scholarly journals Study on Energy Efficient Operation of Air-Conditioning Cooling Water System

2015 ◽  
Vol 9 (1) ◽  
pp. 53-60 ◽  
Author(s):  
Wang Liang ◽  
Yang Lu-lu ◽  
Tian Ya-bin
Keyword(s):  
Energy Consumption ◽  
Temperature Control ◽  
Cooling Tower ◽  
Operation Mode ◽  
Water System ◽  
Cooling Water ◽  
Outlet Temperature ◽  
Control Logic ◽  
Cooling Water System ◽  
Load Rate

The control logic of frequency adjustment for pump and cooling tower fan has been presented in this paper, based on the operation mode of a chiller with one pump and one cooling tower. Optimum outlet water temperature control of cooing tower has been put forward through analysis and comparison among factors influencing it, based on measured data. A mathematical model of energy consumption has been established under different outdoor wet-bulb temperature and load rate conditions. The optimized controlling strategy has been obtained after the analysis on energy consumption under two different operational strategies with different number of cooling towers in service. In partial load condition, the best operation mode of cooling water system is the optimal water outlet temperature control system, which aims at the lowest comprehensive system energy consumption. Cooling water system can match the best temperature difference and determine the fan frequency according to optimum outlet temperature automatically. Variable frequency control should be applied to fans; meanwhile, routing maintenance and cleaning is also needed for an even distribution of water and effective use of heat exchange area.

scholarly journals The Stafford outbreak of Legionnaires’ disease

1990 ◽  
Vol 104 (3) ◽  
pp. 361-380 ◽  
Author(s):  
M. C. O'Mahony ◽  
R. E. Stanwell-Smith ◽  
H. E. Tillett ◽  
D. Harper ◽  
J. G. P. Hutchison ◽  
...  
Keyword(s):  
Legionella Pneumophila ◽  
Air Conditioning ◽  
Cooling Tower ◽  
Ventilation System ◽  
Water System ◽  
Cooling Water ◽  
District General Hospital ◽  
Control Measures ◽  
Epidemic Strain ◽  
Legionnaires Disease

SUMMARYA large outbreak of Legionnaires’ disease was associated with Stafford District General Hospital. A total of 68 confirmed cases was treated in hospital and 22 of these patients died. A further 35 patients, 14 of whom were treated at home, were suspected cases of Legionnaires’ disease. All these patients had visited the hospital during April 1985. Epidemiological investigations demonstrated that there had been a high risk of acquiring the disease in the out patient department (OPD), but no risk in other parts of the hospital. The epidemic strain ofLegionella pneumophila, serogroup 1, subgroup Pontiac la was isolated from the cooling water system of one of the air conditioning plants. This plant served several departments of the hospital including the OPD. The water in the cooling tower and a chiller unit which cooled the air entering the OPD were contaminated with legionellae. Bacteriological and engineering investigations showed how the chiller unit could have been contaminated and how an aerosol containing legionellae could have been generated in the U–trap below the chiller unit. These results, together with the epidemiological evidence, suggest that the chiller unit was most likely to have been the major source of the outbreak.Nearly one third of hospital staff had legionella antibodies. These staff were likely to have worked in areas of the hospital ventilated by the contaminated air conditioning plant, but not necessarily the OPD. There was evidence that a small proportion of these staff had a mild legionellosis and that these ‘influenza–like’ illnesses had been spread over a 5–month period. A possible explanation of this finding is that small amounts of aerosol from cooling tower sources could have entered the air–intake and been distributed throughout the areas of the hospital served by this ventilation system. Legionellae, subsequently found to be of the epidemic strain, had been found in the cooling tower pond in November 1984 and thus it is possible that staff were exposed to low doses of contaminated aerosol over several months.Control measures are described, but it was later apparent that the outbreak had ended before these interventions were introduced. The investigations revealed faults in the design of the ventilation system.

Experimental Investigation on the Effect of Fill Materials in Cooling Towers

2015 ◽  
Vol 766-767 ◽  
pp. 505-510 ◽  
Author(s):  
J. Jayaprabakar
Keyword(s):  
Corrosion Resistance ◽  
High Efficiency ◽  
Cooling Tower ◽  
Water System ◽  
Cooling Water ◽  
Cross Flow ◽  
Water Source ◽  
Coefficient Of Performance ◽  
Advanced Materials ◽  
Cooling Towers

The cooling water system is the industry’s primary way of conserving water. Modern water cooling towers were invented during the industrial age to dissipate heat when natural cooling water sources were available. The origin of cooling towers made the plant site selection independent of the availability of water source. The development of new, high efficiency film fills produced from light weights, flame retarded PVC reduces the size and weight of cross flow cooling towers. Today’s cooling tower combine the latest advanced materials to achieve the optimum balancing of High corrosion resistance, product durability and cost. Based on their specific functions, cooling tower components are designed using the materials with the best combination of corrosion resistance and physical properties. In this work, the coefficient of performance is determined by using Simpson’s rule and the performance of cooling tower at various L/G ratios is evaluated. The optimum approach of the tower is calculated.

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