scholarly journals STUDY ON ARRANGEMENT OF COOLING WATER PIPE TO CONTROL HYDRATION HEAT OF CONCRETE IN BEAM OF CABLE-STAYED BRIDGE

2021 ◽  
Vol 30 (2) ◽  
Author(s):  
Long Liu ◽  
Saisai Yu ◽  
Wentao Xu ◽  
Zhilong Wang
Keyword(s):  
Finite Element ◽  
Flow Rate ◽  
Water Flow Rate ◽  
Cooling Water ◽  
Hydration Heat ◽  
Inlet Temperature ◽  
Mass Concrete ◽  
Water Pipe ◽  
Finite Element Software ◽  
Joint Section

The box girder joint section of the Yangtze River Highway Bridge is taken as the research background, and the finite element software MIDAS/FEA is used to simulate the hydration heat of concrete to the layout of cooling water pipe in building mass concrete. The finite element calculation results are in well agreement with the measured data. On this basis, the influence of changing the diameter and distance of the cooling water pipe, the inlet temperature and the flow rate on the temperature of hydration heat is studied. The results show diameter of the cooling water pipe and inlet temperature have a significant effect on the temperature of hydration heat. The change of water flow rate has little effect on the temperature of hydration heat. It provides a reference for the layout of the same concrete cooling water pipe arrangement.

Analisis Efektivitas Kondensor Di PLTU PT. Semen Tonasa Btg Unit I 2×25 MW

PoliGrid ◽  
2021 ◽  
Vol 2 (1) ◽  
pp. 20
Author(s):  
Jamal Chandra Bhuana ◽  
Irfan Muh ◽  
Aqsha Maulana
Keyword(s):  
Flow Rate ◽  
Water Flow Rate ◽  
Cooling Water ◽  
Steam Pressure ◽  
Inlet Temperature ◽  
Outlet Temperature ◽  
Steam Temperature ◽  
Control Room ◽  
Steam Power ◽  
Cooling Water Flow Rate

Abstract: This research was conducted to determine the effect of fouling on the effectiveness of condensers in the Steam Power Plant (PLTU) PT. Semen Tonasa. The research method used is data collection in the central control room PLTU PT. Semen Tonasa. Steam temperature inlet condenser (Thin), temperature of condensate water  (Thout), steam pressure inlet condenser (Ps), pressure of cooling water (Pcw), inlet temperature (Tcin) and outlet temperature of cooling water (Tcout), steam flow rate ( and cooling water flow rate () is the data needed in this research. Data were analyzed to get the value of effectiveness, number transfer of units (NTU), capacity ratio (C), log mean temperature different (LMTD) of the condenser. The results of the analysis showed that the decrease in condenser performance was influenced by the effect of fouling. Overhaul is done every 2 years. There was a decrease in NTU's value of 31.69% and an effective value of 22.29% in the period April 2016 to March 2018.

Experimental Research on Heat Transfer of Closed Cooling Tower with Packing

2014 ◽  
Vol 960-961 ◽  
pp. 614-620 ◽  
Author(s):  
Ya Su Zhou ◽  
Xiao Ding ◽  
Wei Xie
Keyword(s):  
Water Flow ◽  
Flow Rate ◽  
Cooling Tower ◽  
Water Flow Rate ◽  
Cooling Water ◽  
Cocurrent Flow ◽  
Inlet Temperature ◽  
Cooling Performance ◽  
Cooling Water Flow Rate ◽  
Better Than

Three different structural types of closed cooling tower (CCT) and two cooling water flow directions were considered. The experimental study were done on the cooling performance of influences of inlet air dry and wet bulb temperature, cooling water flow rate and inlet temperature, air flow rate and spray density. The experimental results show that the cooling performance of CCT with packing is obviously better than non-packing cooling tower in 7%~18.4%. And the cooling performance of CCT with packing on top and coil underneath is slightly better than CCT with coil on top and packing underneath in 4.9%. In the same conditions the cooling performance of CCT with packing under cooling water cocurrent-flow is better than that cooling water countercurrent-flow in 3.2%~9.6%. Therefore, the closed cooling tower structure with the cooling water path in bottom and out top, and with packing on top and coil underneath is recommended.

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.

Experimental Investigation of a Pilot Compression Chiller With Alternatives Refrigerants R401a and R134a

2005 ◽  
Author(s):  
M. Fatouh
Keyword(s):  
Experimental Investigation ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Water Mass ◽  
Cooling Water ◽  
Cooling Capacity ◽  
Inlet Temperature ◽  
Chilled Water ◽  
Water Mass Flow Rate

This paper reports the results of an experimental investigation on a pilot compression chiller (4 kW cooling capacity) working with R401a and R134a as R12 alternatives. Experiments are conducted on a single-stage vapor compression refrigeration system using water as a secondary working fluid through both evaporator and condenser. Influences of cooling water mass flow rate (170–1900 kg/h), cooling water inlet temperature (27–43°C) and chilled water mass flow rate (240–1150 kg/h) on performance characteristics of chillers are evaluated for R401a, R134a and R12. Increasing cooling water mass flow rate or decreasing its inlet temperature causes the operating pressures and electric input power to reduce while the cooling capacity and coefficient of performance (COP) to increase. Pressure ratio is inversely proportional while actual loads and COP are directly proportional to chilled water mass flow rate. The effect of cooling water inlet temperature, on the system performance, is more significant than the effects of cooling and chilled water mass flow rates. Comparison between R12, R134a and R401a under identical operating conditions revealed that R401a can be used as a drop-in refrigerant to replace R12 in water-cooled chillers.

Effective Fuel Consumption by Improving Cooling Water Flow Rate in IC Engine

2015 ◽  
Vol 812 ◽  
pp. 112-117
Author(s):  
K.M. Kumar ◽  
P. Venkateswaran ◽  
P. Suresh
Keyword(s):  
Flow Rate ◽  
Cooling System ◽  
Water Flow Rate ◽  
Research Work ◽  
Cooling Water ◽  
Major Change ◽  
Clear Understanding ◽  
Water Pump ◽  
Ic Engine ◽  
Cooling Water Flow Rate

The coolant (water) pump assumes an important role of cooling system in IC engines. With upgrading of the engine power by turbocharging and turbo inter cooling, the water pump capacity needs to be increased corresponding to the power. This capacity enhancement has to be achieved without calling for a major change in the existing water pump, envelop and related fitment details. This requires a clear understanding of centrifugal pump for its performance parameter. One such engine is upgraded by turbocharging from 195PS to 240PS @2200 rpm. Improving water pump flow by changing the impeller dimensions, impeller casing, increase the suction, delivery pipe diameter had been done. Validation of the water pump in its actual engine installation was taken up as a part of the research work. Flow rate comparison of the new pump with the existing pump was made and the results were analyzed. The new water pump gives better flow rates for the engine speeds up to1800 rpm, beyond which the flow rate is slightly lesser than the existing pump.

Effect of the cooling water flow rate to control self-heating of coal in a cylindrical reactor heated by a hot plate heater

2020 ◽  
Author(s):  
Sofi Hesti Fathia ◽  
Inkasandra Faranisa Kolang ◽  
Ricky Putro Satrio Wicaksono ◽  
Achmad Riadi ◽  
Yulianto Sulistyo Nugroho
Keyword(s):  
Water Flow ◽  
Flow Rate ◽  
Water Flow Rate ◽  
Cooling Water ◽  
Hot Plate ◽  
Self Heating ◽  
Cooling Water Flow Rate ◽  
Cylindrical Reactor ◽  
Plate Heater

High Performance and Sub-Ambient Silicon Microchannel Cooling

2006 ◽  
Author(s):  
E. G. Colgan ◽  
B. Furman ◽  
M. Gaynes ◽  
N. LaBianca ◽  
J. H. Magerlein ◽  
...  
Keyword(s):  
Thermal Resistance ◽  
High Performance ◽  
Water Flow Rate ◽  
Cooling Water ◽  
Interface Layer ◽  
Inlet Temperature ◽  
Chip Surface ◽  
Thermal Interface ◽  
Performance Improvements ◽  
Average Unit

High performance single-phase Si microchannel coolers have been designed and characterized in single chip modules in a laboratory environment using either water at 22°C or a fluorinated fluid at temperatures between 20 and −40°C as the coolant. Compared to our previous work, key performance improvements were achieved through reduced channel pitch (from 75 to 60 microns), thinned channel bases (from 425 to 200 microns of Si), improved thermal interface materials, and a thinned thermal test chip (from 725 to 400 microns of Si). With multiple heat exchanger zones and 60 micron pitch microchannels with a water flow rate of 1.25 lpm, an average unit thermal resistance of 15.9 C-mm2/W between the chip surface and the inlet cooling water was demonstrated for a Si microchannel cooler attached to a chip with Ag epoxy. Replacing the Ag epoxy layer with an In solder layer reduced the unit thermal resistance to 12.0 C-mm2/W. Using a fluorinated fluid with an inlet temperature of −30°C and 60 micron pitch microchannels with an Ag epoxy thermal interface layer, the average unit thermal resistance was 25.6 C-mm2/W. This fell to 22.6 C-mm2/W with an In thermal interface layer. Cooling >500 W/cm2 was demonstrated with water. Using a fluorinated fluid with an inlet temperature of −30°C, a chip with a power density of 270 W/cm2 was cooled to an average chip surface temperature of 35°C. Results using both water and a fluorinated fluid are presented for a range of Si microchannel designs with a channel pitch from 60 to 100 microns.

Effect of Non-Condensible Gas on the Subcooled Water Critical Flow in a Safety Valve

2002 ◽  
Author(s):  
Se Won Kim ◽  
Sang Kyoon Lee ◽  
Hee Cheon No
Keyword(s):  
Flow Rate ◽  
Critical Pressure ◽  
Safety Valve ◽  
Pressure Ratio ◽  
Water Flow Rate ◽  
Critical Flow ◽  
Inlet Temperature ◽  
Nitrogen Gas ◽  
Critical Flow Rate ◽  
Subcooled Water

The effect of non-condensable gas on the subcooled water critical flow in a safety valve is investigated experimentally at various subcoolings with 3 different disk lifts. To evaluate its effect on the critical pressure ratio and critical flow rate, three parameters are considered: the ratios of outlet pressure to inlet pressure, the subcooling to inlet temperature, and the gas volumetric flow to water volumetric flow are 0.15–0.23, 0.07–0.12, and 0–0.8, respectively. It turns out that the critical pressure ratio is mainly dependent on the subcooling, and its dependency on the gas fraction and the pressure drop is relatively small. When the ratio of nitrogen gas volumetric flow to water volumetric flow becomes lower than 20%, the subcooled water critical flow rate is decreased about 10% compare to the water flow rate of without non-condensable gas. However, it maintains a constant value after the ratio of gas volumetric flow to water volumetric flow becomes higher than 20%. The subcooled water critical flow correlation, which considers subcooling, disc lift, backpressure, and non-condensable gas, shows good agreement with the total present experimental data with the root mean square error 8.17%.

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