Pump Tower Research Articles

Experimental Investigation on Performance of Multi-Stage Dehumidification Heat Pump Tower Corn Drying System in High Cold Regions

In view of the problems of high energy consumption and heavy pollution in the drying process of large-scale multi-stage tower coal-fired corn in Northeast China, combined with the high cold characteristics of the regions, a multi-stage series dehumidification heat pump tower corn drying system was proposed, and a demonstration application project was established. The performance and life-cycle costs of the system were experimentally evaluated and compared to a traditional coal-fired corn drying tower. The results show that the system can achieve a supply air temperature above 68 °C under the ambient temperature of −20 °C. The total energy consumption of the system per hour is 595.5 kWh, and the specific moisture extraction rate reaches 3.39 kg/kWh. Moreover, the coefficient of performance of heat pump units reaches 3.0 − 6.3. Due to the attractive energy-saving potential, the operational cost-effectiveness of the multi-stage series dehumidification heat pump tower corn drying system can contribute to cut-down of life-cycle cost. It has been found that the life-cycle cost of the multi-stage series dehumidification heat pump tower corn drying system is 40.5% lower than that of the traditional coal-fired corn drying tower.

Assessment of Methods for Calculating Liquefied Natural Gas Pump Tower Loads

Abstract This paper presents a comparative numerical study on liquefied natural gas (LNG) pump tower loads, while focusing on two aspects. First, are impact loads relevant for the structural design of LNG pump towers and, second, in which way does fluid–structure interaction influence these loads? Numerical simulations of the multiphase problem were conducted using viscous field methods. First, unsteady Reynolds-averaged Navier–Stokes (URANS) equations, extended by the volume of fluid (VoF) approach, were used to simulate, at model scale, the flow inside a three-dimensional LNG tank without the tower structure. Then, these results were used to validate the numerical method against model test measurements. Afterward, motion periods and amplitudes were systematically varied in the flow simulations. Flow velocities and accelerations along the positions of the main structural members of the pump tower were extracted and used as input data for load approximations based on the Morison equation. Finally, these load approximations were compared with loads determined from solving the delayed detached eddy simulation (DDES). Time histories as well as statistical measures of global loads acting on the entire and the simplified tower structure were of the same order of magnitude. However, their time evolution differed, especially at their peaks, and this was considered significant for structural design.

开式热源塔热泵系统运行特性的模拟分析

开式热源塔热泵系统运行特性的模拟分析

멤브레인형 LNG선박의 리퀴드 돔 체어 구조개발

A membrane type LNG cargo tank is equipped with a pump tower and a liquid dome for loading and unloading of LNG. However, the membrane running continuously on the tank wall to prevent leakage of LNG is interrupted by the liquid dome, hence care should be taken in the design of liquid dome and its substructures. In case of GTT NO96 membrane type cargo containment system, chair structure is arranged along the periphery of the liquid dome targeting to support the membrane which is exposed to the both hull girder and thermal load. This paper proposes a new and simple chair structure, which outperforms traditional design from productivity point of view maintaining same level of structural safety. Strength assessment on the new design was performed to guarantee the structural safety of the new design, which includes strength, fatigue and crack propagation analysis.

LNG FPSO 펌프타워 고장 예지 방안에 관한 연구

The plant equipment usually has a long life cycle. During its O&M (Operation & Maintenance) phase, since the occurrence of an accident of offshore plant equipment causes catastrophic damage, it is necessary to make more efforts for managing critical offshore equipment. Nowadays due to the emerging ICTs (Information Communication Technologies) and sensor technologies, it is possible to gather the health status data of important offshore equipment and their environment data, which leads to much concern on CBM (Condition-Based Maintenance). In this study, we will propose an approach to estimate the remaining lifetime of an offshore plant equipment (pump tower) based on gathered ocean environment data.

A Study on the Development of Maintenance System for Equipment of LNG-FPSO Ship

In this paper, a maintenance system is developed for LNG-FPSO topside and hullside equipment based CBM (Condition Based Maintenance) methodology. First, the development system defined the PWBS(Product Work Breakdown Structure) of major equipment of LNG-FPSO. Second, the development system developed the failure analysis, economic evaluation for optimal maintenance plan and database systems that save and manage information about equipment, failure mode, failure rate and failure cause. Finally, the verification of the development system was applied to the inlet system of topside and the pump tower system of hullside and the system was confirmed the effectiveness of CBMS(Condition Based Maintenance System).

Research for Calculation Model of Allotypic Pumping Unit Load

A research has been developed for calculation models of allotypic pumping units load against a series of problems, which are ubiquitous in the oil field, such as unreasonable selection of the pumping unit type, low capacity factor of the pumping unit load, lacking of computing method of allotypic pumping unit load, etc. In the research, a calcaulation model of polished rod motion parameters has been firstly established according to the architectural feature of offset pumping units, dual horsehead pump units and tower pumping units. Then the load calculation model of allotypic pumping units were built based on the superposition method of each rod string stress. And after validating the load models in the oil field, the results have been indicated that the models have been in good agreement with the polished rod load. Therefore, the load calculation model of allotypic pumping units in this paper will be of some guidance significance to the selection of the pumping unit type and the stress check of the rod string in the oil field.

Experimental and Theoretical Studies on Performance of GSHP Combined with Free Cooling System

Ground-Source Heat Pump systems and tower cooling system have been studied in this paper individually by experiment and simulation using TRNSYS, the influencing factors such as meteorological parameter, cooling tower and subunit construction was analyzed. Results show that the combined system has ability to meet the cooling requirements in II building climate zones, the combined system will have energy-saving and obvious economic benefits by working through the year.

Analysis of the sloshing flows of a LNG cargo tank

The sloshing flows in a LNG cargo tank model (1/50 scale) of a ship are measured by an embedded panoramicPIV system. The measurement system consists of a Nd-Yag laser(120mJ, 15Hz), two cameras(1k x 1k) and a host computer. Four experimental cases were tested for the tank model, in which swaying motions are made by a 6 DOF-motion platform. The amplitudes of swaying are 9.76mm and 29.29mm, and the swaying frequencies are 0.633Hz and 0.828Hz. The measurement regions are the vertical plane 50mm away from the front wall of the tank where a pump tower is installed. It was verified that the flow patterns of the sloshing are similar to each other when the swaying amplitudes are similar.

A Simplified Pump Tower Approach for Realistic CFD Simulation of Sloshing in LNG Tanks

The complexity of the sloshing analysis for liquefied natural gas carriers can be reduced by neglecting the pump tower. The validity of this assumption is examined by studying the effect of the pump tower, located near the aft bulkhead of a typical LNG tank on the sloshing flow evolution. Results are compared for surge-induced sloshing in a rectangular tank with pump tower to that without such an obstruction. A commercial flow solver is used to solve the unsteady Reynolds Averaged Navier Stokes equations for an inhomogeneous multiphase flow. Initial validation of the sloshing flow uses the experimental data of Hinatsu. It was found that a simplified pump tower consisting of a single vertical tube was suitable to capture the effect of the pump tower without the necessity of discretising the fine geometric detail of the pump tower structure. A suitable size for the simplified tower diameter was found using the total fluid force on a real pump tower in a steady flow for a similar range of Reynolds Number. This reduces the required mesh size by an order of magnitude. Although it is found that the effect of the pump tower on the overall force levels is small reductions of local impact pressures of up to 50% are observed and the sloshing flow develops a phase lag compared to the unobstructed tank.

Unstructured Grid Based Reynolds-Averaged Navier-Stokes Method for Liquid Tank Sloshing

The present study is concerned with liquid tank sloshing at low filling level conditions. The volume of fluid method implemented in a Navier–Stokes computational fluid dynamics code is employed to handle the free-surface flow of liquid sloshing. The geometric reconstruction scheme for the interface representation is employed to ensure sharpness at the free surface. The governing equations are discretized by second order accurate schemes on unstructured grids. Several different computational approaches are verified and numerical uncertainties are assessed. The computational results are validated against existing experimental data, showing good agreement. The capability is demonstrated for a generic membrane-type liquefied natural gas carrier tank with a simplified pump tower inside. The validation results suggest that the present computational approach is both easy to apply and accurate enough for more realistic problems.