• New & Renewable Energy
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• v.19 no.4
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• pp.72-83
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• 2023

Only ground source heat pump units certified according to the regulations in Korea can be adopted in ground source heat pump systems. In this study, domestic and international standards and regulations for ground source heat pump units were investigated. Unlike ISO 13256-1~2, which is the international standard, KS B 8292~8294 for ground source heat pump unit only included rated test conditions. Therefore, it is necessary to supplement various test conditions to the KS B series, because its performance data, which is required to calculate the system's design capacity, is dependent on the change in entering water temperature. The difference between the coefficient of performance of the certified ground source heat pump units and the certified criteria changed significantly according to the operating mode, heat source, and load type, because the criteria increased by about 5% for all. Thus, it is highly suggested that the certification standards be revised while considering the product performance level and various conditions.

• Proceedings of the KSME Conference
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• 2007.05a
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• pp.102-107
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• 2007

The steel impeller placed in a water pump has been studied with the aim to understand corrosion phenomena on the surface responsible for reducing the pumping efficiency of water inside cooling system. This preliminary experiment includes a period (around 1 month) observation with a powered microscope and weight measurements. The experiments are carried out at different conditions of water and mixtures of water and coolants, based on the water contents of 25%, 50%, 75%, and 100% water (pure tap water). From the visual results of microscopy, most of the steel surface is fitted and clear rusty or corrosion phenomena are noticeable as time goes. In addition, the weight loss of the sample specimen submerged in the water is linearly increased, whereas those in the mixtures of water initially gain weight and become almost constant.

• Transactions of the Korean Society of Automotive Engineers
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• v.20 no.3
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• pp.83-87
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• 2012

Computational Fluid Dynamics (CFD) method has been used to investigate the axial force of automotive water pump. As the excessive axial force can make some unexpected problems like impeller interference and coolant leakage we have focused on finding the cause of axial force and its reduction in this paper. First, we have tested the closed type water pump with and without balance hole by the calculation methods. By examining the pressure contour around the impeller, we have found that the axial force arises not only from the pressure difference around shroud but also from the pressure difference around hub. So we have tested two impellers - one is normal open type impeller and the other is open type impeller with modified hub. The results show that the axial force reduction is about 150~200N for normal one and 700N@3000RPM for modified impeller. And the hydraulic efficiency which is important in aspect of engine fuel efficiency is reduced about 6.5% for normal one but increased 4%@3000RPM for modified impeller.

• The KSFM Journal of Fluid Machinery
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• v.2 no.2 s.3
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• pp.64-73
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• 1999

The three-dimensional numerical study of a water jet pump was carried out to investigate the relationship between performance and the geometric variables of nozzle space, area ratio, and throat length. Because of the complex geometry, the multiblock technique was adopted for numerical analysis and a special treatment for transferring data from each of the block interfaces was implemented in order to maintain the conserved properties. To validate the present code, flow passing through a square duct with a 90-deg bend was computed, our results show good accordance with other experimental and computational results. The numerical simulation was done with the flow of the water jet pump having a 180-deg bend in order to calculate the performance at different operating conditions. The performance of the water jet pump can be improved by study of parameters which clarify the relations between the geometric variables and the flow characteristics of vortex strength and location.

• Transactions of the Korean Society of Automotive Engineers
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• v.16 no.3
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• pp.111-117
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• 2008

The aim of this paper was to investigate the fluid dynamic behavior of the automotive closed type water pump with balance hole in order to evaluate and justify its overall hydraulic performance and, in particular to analyze the effects of the balance hole on the reduction of hydraulic flow force of it. The analysis has been peformed by applying the commercial computational fluid dynamics (CFD) code, Fluent, to the solution of the 3-D turbulent flow fields of automotive closed type water pump. The reliability of the employed analysis was demonstrated by the comparison between numerical result and experimental data. Although, hydraulic head of the closed type water pump with 3mm diameter of balance hole decreased by 1.1%, axial flow force was effectively reduced by 13.3%, comparison of it with no hole at design point.

• Proceedings of the SAREK Conference
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• 2008.06a
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• pp.1099-1104
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• 2008

Recent year, mean energy consumptions of a people are higher than other country. And international oil price became over 120 dollar. This energy environment as well as energy war. Maybe, the Meteorological Administration is going to enforce scorching heatwave special report system from that come summer. Besides, 2008 summer, maximum demand power is expected by 64,240,000kW. The electric power equipment reserve rate appeared in to keep 12.5% level. Chilled water storage system witch is one of electric load administration system. Heat pump system used cooling tower heat recovery is advantage that use is possible to summer in small a public bath building. In this paper, we suggest that heat pump system by heat recovery using cooling tower when it is heating operation of ambient air temperature. To apply cooling tower heat recovery heat pump to chilled water heat storage type and achieved performance evaluation about operation. As a result, performance of heat pump system that about 121% in cooling mode, 138% in heating mode higher than KEPCO standard. And heating operation possible to ambient air temperature about $23^{\circ}C$, which of appear cooling tower outlet temperature about $13^{\circ}C$.

• Design & Manufacturing
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• v.16 no.2
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• pp.46-52
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• 2022

As the consumer market in the eco-friendly vehicle industry grows, the demand for water pump in a electric car parts market. This study intend to propose a mathematical model that can verify the effect of improving thermal properties when a non-conductive cooling filler liquid is introduced into an electric vehicle water pump. Also, the pros and cons of the immersion cooling method and future development way were suggested by analyzing the cooling characteristics using on the derived analysis solution. Thermal characteristics analysis of electric water pump applied with non-conductive filler liquid was carried out, and the diffusion boundary condition in the motor body and the boundary condition the inside pump were expressed as a geometric model. As a result of analyzing the temperature change for the heat source of the natural convection method and the heat conduction method, the natural convection method has difficulty in dissipating heat because no decrease in temperature due to heat release was found even after 300 sec. Also, it can be seen that the heat dissipation effect was obtained even though the non-conductive filling liquid was applied at the 120 sec and 180 sec in the heat conduction method. It has proposed to minimize thermal embrittlement and lower motor torque by injecting a non-conductive filler liquid into the motor body and designing a partition wall thickness of 2.5 mm or less.

• Journal of the Korean Society of Marine Environment & Safety
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• v.20 no.6
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• pp.788-793
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• 2014

In this study, the electrical power consumption saving effect is studied through installing an inverter which is able to control the R.P.M. of marine sea water pump by effective flow control. The study looks at how sea water pump's flow control influences on the system without the Marine Growths Protection System(MGPS). Auxiliary sea water pump and refrigerator sea water pump in training ships, which are always operated not only in harbor but also in navigation, was used in the experiment and the experiment was conducted by dividing into harbor and navigation. As a result of research, in the case the sea water temperature is under $18^{\circ}C$, the operation was possible with a 58.3 % decrease in pump R.P.M. and electric power consumption was saved by 50 %. In spite of the sea water temperature increasing upto $34^{\circ}C$, pump R.P.M. at 91.6 % was sufficient to operate with a 20 % electric power consumption saving effect. In the pipelines without MGPS, lowering R.P.M. along with lowering pressure results in the attachment of various marine growths.

• Journal of the Korean Society for Geothermal and Hydrothermal Energy
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• v.11 no.4
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• pp.7-13
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• 2015

The efficiency, reliability and performance of any heat pump unit can only be ascertained after it has been tested and rated. For this reason, specific facilities, equiped with testing plants are built. Heat pump calorimeter is the facilities used by most of these testing facilities in their rating and certification process. The ultimate function of calorimeters is to, control and maintain the constant standard test conditions (indoor/outdoor entering temperatures and flow rate etc) during testing period. In this study, the test standards of heat pump unit and the structure of the calorimeter are surveyed. In addition, this study analyzes the total energy consumption of a water to water heat pump calorimeter. Heat pump calorimeter consumed much energy to excute the heat pump tests. The energy consumption of the calorimeter was higher than the heat pump unit, and it was increased as the heat pump unit capacity decreased.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.11 no.3
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• pp.391-400
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• 1999

The efficiency and capacity of an air source heat pump system decrease as the ambient temperature drops. One strategy of avoiding the decrease of the efficiency and capacity in air source heat pump system is to switch to another thermal energy source. Water can be a good candidate for the heat source. This paper presents the results of the performance analysis of heat pump system with a single unit dual source(SUDS) evaporator The heat exchanger combines two separated evaporators into a single evaporator and the object of the SUDS evaporator is to recover energy from dual heat sources, i.e. air and water. Simulation program is developed for the dual source heat pump system with a SUDS evaporator and experimental data are obtained and compared with the simulation results. Differences in heating capacity and COP are 7% and 8% respectively. Simulation results are in good agreement with the test results. Therefore, the developed program is effectively used for the design and performance prediction of the dual source heat pump system with a SUDS evaporator.