Hybrid Cooling System Research Articles

The 10 kW Level High Brightness Face-Pumped Slab Nd:YAG Amplifier with a Hybrid Cooling System

We demonstrate a high power, high brightness, slab amplifier based on face-pumped Nd:YAG slab gain modules, having a high efficient hybrid cooling system of the conduction cooling and forced convection cooling. Using a single gain module, a laser output power up to 4.5 kW with a remarkable optical-optical conversion efficiency of 51% is realized, indicating an excellent lasing performance of the Nd:YAG slab module. The amplifier operates at a repetition rate of 700 Hz and delivers a maximum average output power exceeding 10.5 kW with pulse duration of 150 μs. A good beam quality factor is measured to be β = 1.9. To the best of our knowledge, this is the highest brightness for a 10 kW level Nd:YAG slab amplifier.

Off-Design Modeling and Simulation of Solar Absorption-Subcooled Compression Hybrid Cooling System

The solar absorption-subcooled compression hybrid cooling system (SASCHCS) is potentially an economical solution for high-rise buildings. The hybrid system is subjected to off-design operation frequently, owing to the changes in solar irradiance and cooling demand. However, a large amount of iterations and difficult convergence are encountered in the traditional off-design modeling. Hence, our present study contributes to the development of an off-design model that is exact and can be solved conveniently. A novel modeling method based on the combination of an absorption subsystem described by the characteristic equation and a compression subsystem modeled by the lumped parameter method is proposed. A prototype and corresponding experimental system are developed to verify the model. A good agreement between the theoretical result and test data is displayed. The maximum deviation is less than 4%. Subsequently, the performance of the facility for different operating conditions is simulated and analyzed. We found that the subcooling power relies significantly on the compressor speed, i.e., a reduction by 58.6% when the compressor speed reduces by 80%. In addition, a high temperature and low flow rate of cooling water in the compression subsystem is adverse to the performance of the hybrid system. Our study can serve as the foundation for the operational analysis of the solar absorption-subcooled compression hybrid cooling system as well as promote its development.

A hybrid cooling system combining self-adaptive single-phase mechanically pumped fluid loop and gravity-immune two-phase spray module

Although single-phase mechanically pumped fluid loop (MPFL) and two-phase spray cooling technologies have been investigated independently for decades, there is a lack of understanding on the combined operation of these two modules. The MPFL has been extensively utilized in the space thermal control system due to its technological maturity and gravity immunity. The spray cooling, which is characterized by the speciality in thermally dealing with the high heat flux equipment, has not gone that far owing to its complexity in the management of the two-phase flow in the space environment. It is also acknowledged that the MPFL, as an overall cooling strategy in the space thermal control system, will not be replaced completely in the foreseeable future because the primary on-board electronic devices require normal heat dissipation demand and only a few equipment such as on-board laser diode and multi-chip modules demand extreme high heat removal technologies. Therefore, a combination of the MPFL and spray cooling technologies, which constitutes the biggest innovation in this paper, is imperatively needed. A hybrid cooling system (HCS) combining the single-phase self-adaptive MPFL and gravity-immune two-phase spray module which satisfies various cooling demands is proposed in the present study. A validating system as a prototype was established on the basis of the optimal design method. Three test cases were conducted to verify the coordinated operation between the single-phase module and two-phase one and investigate thermal performances of both modules. In all the experiments, the controlled temperature of the cold plate in the MPFL remains within a range between 35.9 °C and 41.9 °C under the heat load from 50 W to 150 W. The highest heat flux acquired by the spray cooling module can be up to 468.8 W/cm2 with the superheat level being 70.0 °C. Results can be drawn that the two modules can be operated simultaneously and independently. Systematic operation efficiency of the proposed HCS is calculated to be 17.7 which displays a high economy of the proposed system.

A Study on Hybrid Cooling System Involving Passive Cooling Techniques with PV Panel Roof

A Study on Hybrid Cooling System Involving Passive Cooling Techniques with PV Panel Roof

Hybrid Cooling System for Electronics Equipment During Power Surge Operation

The performance of a hybrid phase-change material (PCM)-based cooling system is investigated experimentally to meet the requirement of power surge effect in electronics equipment. The normal cooling operation of the electronic equipment for a long period using heat sink is also studied. The thermal performance of the hybrid heat sink is studied with three different PCMs: Eicosane, 1-Hexadecanol, and Paraffin. The hybrid PCM-based heat sink is studied for different orientations of PCM and convective cooling area in the heat sink to protect electronic components from the potentially dangerous and disruptive power surge operations. The performance of the hybrid PCM-based heat sinks is compared with conventional air-based heat sinks with and without a fan. In case of hybrid PCM-based heat sink, the fan is operated at 6 V all the time irrespective of the normal or power surge operation. Whereas, in case of air-based heat sink (without PCM), the fan is operated at 12 V during power surging and at 6 V during normal operation time. It is observed that the hybrid PCM-based heat sink with fan performs better than conventional air-based heat sink with fan during surging operation by reducing the peak temperature of 5.6 °C. However, their performance is comparable during post-surging operation. Thus, the power consumption, as well as the noise, gets reduced using hybrid PCM-based heat sink with fan during surging operation. Besides, the life of fan used in hybrid PCM-based heat sink increases, which in turn increases the service life of electronic components.

Thermodynamic characteristics of thermal power plant with hybrid (dry/wet) cooling system

A hybrid cooling system (HCS) consisting of dry and wet sections is proposed as a means to conserve energy and water by combining the benefits of both dry and wet cooling modes. A thermodynamic model of a 660 MW thermal power plant with HCS is established, and the variations in thermodynamic characteristics with respect to dry bulb temperature (TA) and relative humidity (RH) are investigated using Ebsilon calculating code. Through comparison between the dry cooling system (DCS) and wet cooling system (WCS), HCS performance characteristics under different meteorological parameters are analyzed quantitatively. By comprehensively considering water and energy conservation indicators, the unique operation mode and ratio of the heat load shared by dry or wet sections are determined under various meteorological parameters. When TA exceeds a certain value or RH falls below a certain value, the HCS does not operate in a hybrid cooling mode. Instead, its operation is equivalent to that of a WCS. We suggest that the cooling load of the wet section in the HCS be designed with the peak cooling load of the condenser under the most inhospitable meteorological parameters of the year. The findings reported here may provide guidance for HCS thermodynamic design and operation regulations.

自然通風併用型放射冷房システムに関する研究 : 第2報-高温・多湿気候下での適用可能性の検討

自然通風併用型放射冷房システムに関する研究 : 第2報-高温・多湿気候下での適用可能性の検討

Study on Hybrid Cooling System coupled with Radiation Panel Cooling and Natural Cross Ventilation : Part 1-Comparison between Radiation Panel Cooling System and Under Floor Air-Conditioning System

Study on Hybrid Cooling System coupled with Radiation Panel Cooling and Natural Cross Ventilation : Part 1-Comparison between Radiation Panel Cooling System and Under Floor Air-Conditioning System

A Critical Review on Solid Desiccant-Based Hybrid Cooling Systems

The present review provides scientific and technical support on how solid desiccant-based hybrid cooling can be a supplement to the commonly used vapor compression-based traditional air-conditioning systems to provide the indoor thermal comfort to the occupants. The existing design of standalone vapor compression system needs to be modified by integrating it with the solid desiccant-based dehumidification system to achieve better performance and economic feasibility by handling humidity and temperature separately especially in case of hot humid conditions. The present study is undertaken by considering variety of aspects including background and need for alternative cooling systems, system configuration as well as operational modes and current status of desiccant-based hybrid cooling technology. The review work also indicates that the technology of desiccant-based hybrid cooling has a great potential to provide thermal comfort especially in hot humid climate at the expense of lower energy consumption as compared to traditional cooling systems.

Potential for Hybrid-Cooling System for the CO2 Post-Combustion Capture Technology

Deployment of Carbon Capture and Storage (CCS) technology is one of the implemented methods to reduce the emissions of greenhouse gases. Although this technology has an environmental advantage, it is an energy-intensive process in addition to its massive demand for cooling water. The objective of the paper is to design an efficient cooling system using three alternatives cooling technologies. The results obtained prove the potential of using hybrid cooling for both the lean MEA solvent and in the steam condenser. For the condenser, the utility cost for the hybrid cooling is found to be cheaper than using water cooler and more expensive than using air cooler by a difference of only 30%.

Integrated Energy-Aware Management of Supercomputer Hybrid Cooling Systems

Advanced cooling systems and optimization strategies are critical to operate modern supercomputers and high-performance computing systems in an energy-efficient fashion. Hybrid architectures combining emerging liquid cooling with traditional air cooling are a promising solution. Standard management techniques maintain these systems at fixed operating points, typically without coordination between the diverse cooling knobs. In this paper, we propose an energy-aware optimization strategy exploiting heterogeneous cooling systems in a holistic fashion with the goal of minimizing the overall cooling system power consumption, while at the same time meeting the system thermal constraints. To this purpose, we developed a modeling approach to build a low-order analytical model, which captures the overall thermal behavior of the system. Then, this compact and computationally manageable model is exploited to set and solve a treatable optimization problem, leading to definition of an energy-optimal cooling strategy. The proposed method is presented taking Galileo as real-life case study. Galileo is a high-performance computing system with hybrid cooling architecture recently installed at CINECA (a supercomputing facility located in Italy). The cooling strategy resulting from the proposed approach is compared with common strategies in order to assess the efficiency advantages.

A Techno-Economic Assessment of Hybrid Cooling Systems for Coal- and Natural-Gas-Fired Power Plants with and without Carbon Capture and Storage.

Advanced cooling systems can be deployed to enhance the resilience of thermoelectric power generation systems. This study developed and applied a new power plant modeling option for a hybrid cooling system at coal- or natural-gas-fired power plants with and without amine-based carbon capture and storage (CCS) systems. The results of the plant-level analyses show that the performance and cost of hybrid cooling systems are affected by a range of environmental, technical, and economic parameters. In general, when hot periods last the entire summer, the wet unit of a hybrid cooling system needs to share about 30% of the total plant cooling load in order to minimize the overall system cost. CCS deployment can lead to a significant increase in the water use of hybrid cooling systems, depending on the level of CO2 capture. Compared to wet cooling systems, widespread applications of hybrid cooling systems can substantially reduce water use in the electric power sector with only a moderate increase in the plant-level cost of electricity generation.

Comparative Efficiency of Solar Panel by Utilize DC Water Pump and DC Hybrid Cooling System

The purpose of this paper is discussed about comparative efficiency of solar panel by utilize DC water pump and DC hybrid cooling system. Ambient temperature and solar irradiance are played main role of the efficiency of PV module. When temperature of PV module increase, the efficiency of PV module will decreased and vice versa. When solar irradiance increase, output current and output power will increase with linear and output voltage will increase with marginal and vice versa. A solution is provided to solve problem of low efficiency of PV module which is DC cooling system. DC brushless fan and water pump with inlet/outlet manifold were designed for actively cool the PV module to improve efficiency of PV cells. The PV module with DC water pump cooling system increase 3.52 %, 36.27 %, 38.98 % in term of output voltage, output current, and output power respectively. It decrease 6.36 °C compare than to PV module without DC water pump cooling system. While PV module with DC hybrid cooling system increase 4.99 %, 39.90 %, 42.65 % in term of output voltage, output current, and output power respectively. It decrease 6.79 °C compare to PV module without DC water pump cooling system. The higher efficiency of PV module, the payback period of the system can be shorted and the lifespan of PV module can be longer.

空気熱源式ヒートポンプと燃焼式温風暖房機とのハイブリッドシステムによる冷暖房管理がバラ栽培の収量および品質に及ぼす影響

空気熱源式ヒートポンプと燃焼式温風暖房機とのハイブリッドシステムによる冷暖房管理がバラ栽培の収量および品質に及ぼす影響

Feasibility Study of an Innovative Dry-Cooling System With Phase-Change Material Storage for Concentrated Solar Power Multi-MW Size Power Plant

This work concerns the economic potential assessment of an innovative hybrid-cooling system for steam condensation in concentrated solar power plants. The system consists of an air-cooled condenser (ACC) working in parallel to a latent heat storage with phase-change material (PCM). The purpose of the hybrid system is to store some of the latent heat of steam condensation during the turbine operation and reject it at night, in order to shift a share of the cooling work and exploit the high diurnal temperature range of desert areas. System’s energy and economic performances are assessed by the parametric analysis of a theoretical case study, referred to an existing solar power plant and based on historical meteorological data. The analysis considers an ideal “perfect” PCM storage system, namely with no technological barriers, and different cost scenarios. The simulation campaign outcome indicates how the innovative solution can provide just a slight improvement of the plant performance, which is anyway significant in qualitative terms since the risk of breakdowns of turbine operation during the hottest summer days is avoided. It is remarkable that the introduction of the heat storage allows for a reduction of the ACC installed power. The economic feasibility of the proposed solution follows on mainly from the comparison between the investment cost increase —due to the PCM storage—and savings—due to reduction of the installed ACC modules. The hybrid-cooling system would be an attractive alternative to standard systems if the PCM storage cost could be contained by increasing the conductivity of the PCM material. As an alternative, a cheaper heat storage technology (e.g., a water thermocline) could be coupled to an indirect-cooling system.

Analytical Study on the Performance of Fuel Cell Driven Ground and Compound Source Hybrid Heat Pump Heating and Cooling System of a Resort Building

Analytical Study on the Performance of Fuel Cell Driven Ground and Compound Source Hybrid Heat Pump Heating and Cooling System of a Resort Building

Hybrid Cooling System Installation for the KEPCO HTS Power Cable

In Korea, the KEPCO (Korea Electric Power Corporation) HTS power cable system has been successfully operated for evaluating the technical and economic feasibility as well as accumulating the operation experience since 2006. A cooling system composed of a liquid nitrogen decompression cooling unit and a closed-circulation system of subcooled liquid nitrogen at the KEPCO's Gochang power testing center. As the next step, we adjusted the cooling system for the purpose of testing a different cooling system using a cryocooler unit with cooling capacity of 4 kW at 77 K in the existing cooling system. It was designed to be used as a hybrid cooling system. In other words, it has as an each system of cryocooler unit or decompression pump unit. In this paper, the performance test results are summarized and the outline of the hybrid cooling system is introduced.

Development of Energy Saving Type Hybrid Cooling System for Indoor Mobil Tele-communication Center

Development of Energy Saving Type Hybrid Cooling System for Indoor Mobil Tele-communication Center

Simulation of Solar-Powered Ammonia-Water Integrated Hybrid Cooling System

Simulation of Solar-Powered Ammonia-Water Integrated Hybrid Cooling System

Lake Temperature Dynamics in Hybrid Cooling System

A transient thermal simulation model of a hybrid cooling lake is developed to assess the impact of cooling water withdrawals and cooling tower discharges on the thermal structure of the lake. The model is based on one‐dimensional mechanical and thermal energy balances and includes the physical processes of solar heating, wind stirring, vertical advection, and hypolimnetic diffusion. Temperature data were collected on two small lakes in northern Indiana, and the simulated temperatures are compared with the measured data for the lake stratification seasons of 1976 and 1978. It is shown that cooling water circulations significantly thicken the epilimnion due to vertical advection of heat. The simulation results are examined in terms of the values of the wind Richardson number, the withdrawal densimetric Froude number, and the dimensionless surface buoyancy flux. The sensitivity of the lake thermal structure to the densimetric Froude number is demonstrated.