The Experts below are selected from a list of 327 Experts worldwide ranked by ideXlab platform

Tsuyoshi Wakuda - One of the best experts on this subject based on the ideXlab platform.

  • performance of induction synchronous motor having rm mgb _ 2 cage windings for liquid hydrogen Circulation Pump
    IEEE Transactions on Applied Superconductivity, 2012
    Co-Authors: Taketsune Nakamura, Hiroshi Nishio, Naoyuki Amemiya, Kazuhiro Kajikawa, Tsuyoshi Wakuda
    Abstract:

    We have been developing superconducting induction /synchronous motor incorporated with MgB2 cage windings. Target application of the motor is the liquid hydrogen Circulation Pump. In this paper, the performance of the fabricated motor was estimated based on nonlinear electrical equivalent circuit. It was shown that the experimental results of the motor characteristics such as torque vs. slip curve can be reproduced based upon the theoretical estimation. From this result, we can design the MgB2 Pump motor by means of commonly utilized method of the electrical circuit.

  • Performance of Induction/Synchronous Motor Having ${\rm MgB}_{2}$ Cage Windings for Liquid Hydrogen Circulation Pump
    IEEE Transactions on Applied Superconductivity, 2012
    Co-Authors: Taketsune Nakamura, Hiroshi Nishio, Naoyuki Amemiya, Kazuhiro Kajikawa, Tsuyoshi Wakuda
    Abstract:

    We have been developing superconducting induction /synchronous motor incorporated with MgB2 cage windings. Target application of the motor is the liquid hydrogen Circulation Pump. In this paper, the performance of the fabricated motor was estimated based on nonlinear electrical equivalent circuit. It was shown that the experimental results of the motor characteristics such as torque vs. slip curve can be reproduced based upon the theoretical estimation. From this result, we can design the MgB2 Pump motor by means of commonly utilized method of the electrical circuit.

Shanshan Wang - One of the best experts on this subject based on the ideXlab platform.

  • study on demand side design parameters of solar domestic hot water system in residential buildings
    Energy Procedia, 2015
    Co-Authors: Xilin Chen, Weiye Zhou, Shanshan Wang
    Abstract:

    Abstract Solar domestic hot water system is widely used and developing fast in recent years in China. However many problems occur at the same time, for example more energy consumption by Circulation Pump, water reheating, long investment payback period, and etc. Through analyzing the field-testing data of projects and investigating of different residential consumers, it was found that compared to actual hot water consumption the solar domestic hot water systems were generally designed too large in capacity, which means the designed hot water demand is much greater than actual user consumption. This study compared different specifications and recommended design parameters value of hot water related standards, and analyzed the calculation methodology and design parameter ofhot water quota. Finally problems in the system design are summarized and suggestions are proposed for designers and different stakeholders.

Taketsune Nakamura - One of the best experts on this subject based on the ideXlab platform.

  • performance of induction synchronous motor having rm mgb _ 2 cage windings for liquid hydrogen Circulation Pump
    IEEE Transactions on Applied Superconductivity, 2012
    Co-Authors: Taketsune Nakamura, Hiroshi Nishio, Naoyuki Amemiya, Kazuhiro Kajikawa, Tsuyoshi Wakuda
    Abstract:

    We have been developing superconducting induction /synchronous motor incorporated with MgB2 cage windings. Target application of the motor is the liquid hydrogen Circulation Pump. In this paper, the performance of the fabricated motor was estimated based on nonlinear electrical equivalent circuit. It was shown that the experimental results of the motor characteristics such as torque vs. slip curve can be reproduced based upon the theoretical estimation. From this result, we can design the MgB2 Pump motor by means of commonly utilized method of the electrical circuit.

  • Performance of Induction/Synchronous Motor Having ${\rm MgB}_{2}$ Cage Windings for Liquid Hydrogen Circulation Pump
    IEEE Transactions on Applied Superconductivity, 2012
    Co-Authors: Taketsune Nakamura, Hiroshi Nishio, Naoyuki Amemiya, Kazuhiro Kajikawa, Tsuyoshi Wakuda
    Abstract:

    We have been developing superconducting induction /synchronous motor incorporated with MgB2 cage windings. Target application of the motor is the liquid hydrogen Circulation Pump. In this paper, the performance of the fabricated motor was estimated based on nonlinear electrical equivalent circuit. It was shown that the experimental results of the motor characteristics such as torque vs. slip curve can be reproduced based upon the theoretical estimation. From this result, we can design the MgB2 Pump motor by means of commonly utilized method of the electrical circuit.

S. I. Ryasnyi - One of the best experts on this subject based on the ideXlab platform.

  • Risk Management of NPP Incidents
    Atomic Energy, 2018
    Co-Authors: A. K. Adamenkov, A. A. Sal’nikov, I. N. Veselova, S. I. Ryasnyi
    Abstract:

    A diagnostic model for managing the risk of NPP incidents attending different irregularities of equipment operation is examined for the example of the oil delivery system of the main Circulation Pump. The model includes the construction of a graph of the operation of the oil system and ranking in order to obtain indices of priority for monitoring information flow that reflect the actuation probability of each form of protection. The results of the analysis can used as input data for predicting the duration of a stable state of a technological system in the course of operation on the basis of stochastic extrapolation of the parameters by means of single-channel queuing systems with finite storage – technological protection and blocking.

  • On the possibility of connecting a non-operating main Circulation Pump with three Pumps in operation without preliminary coast-down of power-generating unit No. 5 in the Novovoronezh nuclear power plant
    Thermal Engineering, 2014
    Co-Authors: I. L. Vitkovskii, S. P. Nikonov, S. I. Ryasnyi
    Abstract:

    The subject of this paper is a transient caused by connection of a standby loop to three operating Circulation Pumps at the initial reactor heat rate equal to 70% of the rated value without preliminarily reducing it to 30% of the rated level as required by the safe operation regulations. Failure of the following normal operation systems is supposed: the first- and the second-type warning protection systems, all quick-acting reducing devices releasing steam into the auxiliary manifold, the electric heaters of the pressurizer, the pressurizer injection system, the primary cooling circuit fluid makeup/blow-through systems, and the blocking systems to shut down the main Circulation Pump after the level in the steam generator is exceeded. In addition, it is supposed that, under transient conditions, the valves of the turbine regulation system will be in the position in which they were at the moment of the initial event until generation of the signal for positive closing of the turbine stop valves. The first signal to actuate the reactor emergency protection system (EPS) is skipped. The failure of all quick-acting reducing devices releasing steam into the atmosphere is assumed. In addition to equipment failure, at the moment when the main Circulation Pump is connected, the operator erroneously puts in a new setting to maintain the power allowable for four Pumps in operation-in the calculations it was taken equal to 104% of the rated level at most considering the accuracy of evaluating and maintaining the reactor heat rate-and the working group of the reactor protection and control system (P&CS) starts moving upward. On reaching the set power level, the automatic reactor power regulator stops operating and the P&CS elements remain in the position in which they are at the moment. Compliance with the design safety criteria for the adopted scenario of the transient is demonstrated.

Ji-hyun Shin - One of the best experts on this subject based on the ideXlab platform.

  • Development of Operating Method of Multi-Geothermal Heat Pump Systems Using Variable Water Flow Rate Control and a COP Prediction Model Based on ANN
    Energies, 2019
    Co-Authors: Ji-hyun Shin
    Abstract:

    As the global energy trend continues, the importance of energy savings and efficient use is being emphasized, and the installation and operation of geothermal heat Pump systems is increasing. In many buildings, where an actual geothermal heat Pump system has been installed, problems of efficiency deterioration occur frequently because of the inefficient operation after installation of the heat Pump system. The purpose of this study was to develop and verify the operating method for energy saving and performance improvement of multiple geothermal systems. A coefficient of performance (COP) prediction model using an artificial neural network for real-time COP predictions was developed. The operating method of a multi-geothermal heat Pump system using a variable water flow rate control method and COP prediction model was developed. The geothermal heat Pump system operates sequentially depending on the water flow rate of the Circulation Pump. The COP prediction model enabled real-time performance prediction during system operation. The Circulation water flow rate was reduced by up to 29% compared to the existing operating method. Approximately 23% of the energy was saved. The COP system, including the consumption power of the Circulation Pump, was improved.

  • Development of a Variable Water Flow Rate Control Method for the Circulation Pump in a Geothermal Heat Pump System
    Energies, 2018
    Co-Authors: Ji-hyun Shin
    Abstract:

    This study assessed a variable flow rate control method for a Circulation Pump based on the geothermal water temperature difference in a geothermal heat Pump system. As interest in energy conservation and efficient use is increasing around the world, the development and use of renewable energy is increasing and various related studies are currently underway. Among the renewable energy systems, the interest in geothermal energy system is high because of its efficient year-round operation. Geothermal heat Pump system installations have increased in number, but the systems operate inefficiently. Generally in Korea, geothermal heat Pump system operates under partial load conditions, but the Circulation Pump operates at constant speed and supplies a constant flow rate. Therefore, this study examined the operation of the current problems of a geothermal heat Pump system. A variable flow rate control method of the Circulation Pump is proposed to improve the efficiency of the geothermal heat Pump system and save energy during the cooling operation. As a result, the total energy consumption was reduced by 57,017 kW compared to the existing flow rate control method and the energy consumption of the Circulation Pump system was reduced by 35,209 kW.