Development of a 150kW Microturbine System Which Applies the Humid Air Turbine Cycle

2007 ◽  
Author(s):  
Susumu Nakano ◽  
Tadaharu Kishibe ◽  
Hidefumi Araki ◽  
Manabu Yagi ◽  
Kuniyoshi Tsubouchi ◽  
...  
Keyword(s):  
Flow Rate ◽  
Air Flow ◽  
Laboratory Evaluation ◽  
Air Cooling ◽  
Performance Tests ◽  
Air Flow Rate ◽  
Humid Air ◽  
Electrical Efficiency ◽  
Air Turbine ◽  
Electrical Output

A prototype machine for a next generation microturbine system incorporating a simplified humid air turbine cycle has been developed for laboratory evaluation. Design targets of electrical output were 150 kW and of electrical efficiency, 35% LHV. The main feature of this microturbine system was utilization of water for improved electrical output, as lubricant for bearings and as coolant for the cooling system of the generator and the power conversion system Design specifications without WAC (Water Atomizing inlet air Cooling) and HAT (Humid Air Turbine) were rated output of 129 kW and efficiency of 32.5% LHV. Performance tests without WAC and HAT were done successfully. Electrical output of 135 kW with an efficiency of more than 33% was obtained in the rated load test. Operation tests for WAC and HAT were carried out under the partial load condition as preliminary tests. Water flow rates of WAC were about 0.43 weight % of inlet air flow rate of the compressor and of HAT, about 2.0 weight %. Effects of WAC and HAT were promptly reflected on electrical output power. Electrical outputs were increased 6 kW by WAC and 11kW by HAT, and efficiencies were increased 1.0 pt % by WAC and 2.0 pt % by HAT. Results of WAC and HAT performance tests showed significant effects on the electrical efficiency with an increase of 3.0 point % and electrical output with an increase of 20% by supplying just 2.4 weight % water as the inlet air flow rate of the compressor.

Development of an Advanced Microturbine System Using Humid Air Turbine Cycle

2004 ◽  
Author(s):  
Satoshi Dodo ◽  
Susumu Nakano ◽  
Tomoaki Inoue ◽  
Masaya Ichinose ◽  
Manabu Yagi ◽  
...  
Keyword(s):  
High Efficiency ◽  
Load Test ◽  
Laboratory Evaluation ◽  
Air Cooling ◽  
Humid Air ◽  
Electrical Efficiency ◽  
Speed Test ◽  
Partial Load ◽  
Air Turbine ◽  
Load Tests

A prototype machine for a next generation microturbine system applying a simple humid air turbine system (design target of electrical output: 150 kW, electrical efficiency: 35% LHV) was developed for its laboratory evaluation. A low NOx combustor which applied a lean-lean zone combustion concept and water lubricated bearings were developed for the prototype machine. Operation using two water lines for the humid air turbine (HAT) was proposed as an effective way to obtain rated electric output to ambient temperature of 40 deg C. Tests for the main components were done successfully. Motoring tests, full speed test with no load, 50% load and 70% load tests as preliminary tests for rated load tests were also carried out successfully. Low NOx emission of 7.6 ppm and high efficiency of 95.6% for the power conversion system were achieved in the partial load tests. At the first rated load test without HAT and Water atomizing inlet air cooling (WAC) that followed those partial load tests, 150.3 kW electric output with electrical efficiency of 32% was obtained.

Measurement of Air Flow Rate Sensitivity to the Differential Pressure Across a Server Rack in a Data Center

2015 ◽  
Vol 137 (4) ◽  
Author(s):  
Vaibhav K. Arghode ◽  
Yogendra Joshi
Keyword(s):  
Flow Rate ◽  
Data Center ◽  
Air Flow ◽  
Rate Sensitivity ◽  
Differential Pressure ◽  
Air Cooling ◽  
Air Flow Rate ◽  
Hot Air ◽  
Fan Speed ◽  
Measured Sensitivity

Presently, air cooling is the most common method of thermal management in data centers. In a data center, multiple servers are housed in a rack, and the racks are arranged in rows to allow cold air entry from the front (cold aisle) and hot air exit from the back (hot aisle), in what is referred as hot-aisle-cold-aisle (HACA) arrangement. If the racks are kept in an open room space, the differential pressure between the front and back of the rack is zero. However, this may not be true for some scenarios, such as, in the case of cold aisle containment, where the cold aisle is physically separated from the hot data center room space to minimize cold and hot air mixing. For an under-provisioned case (total supplied tile air flow rate < total rack air flow rate) the pressure in the cold aisle (front of the rack) will be lower than the data center room space (back of the rack). For this case, the rack air flow rate will be lower than the case without the containment. In this paper, we will present a methodology to measure the rack air flow rate sensitivity to differential pressure across the rack. Here, we use perforated covers at the back of the racks, which results in higher back pressure (and lower rack air flow rate) and the corresponding sensitivity of rack air flow rate to the differential pressure is obtained. The influence of variation and nonuniformity in the server fan speed is investigated, and it is observed that with consideration of fan laws, one can obtain results for different average fan speeds with reasonable accuracy. The measured sensitivity can be used to determine the rack air flow rate with variation in the cold aisle pressure, which can then be used as a boundary condition in computational fluid dynamics (CFD)/rapid models for data center air flow modeling. The measured sensitivity can also be used to determine the change in rack air flow rate with the use of different types of front/back perforated doors at the rack. Here, the rack air flow rate is measured using an array of thermal anemometers, pressure is measured using a micromanometer, and the fan speed is measured using an optical tachometer.

scholarly journals An Advanced Microturbine System with Water-Lubricated Bearings

2009 ◽  
Vol 2009 ◽  
pp. 1-12 ◽  
Author(s):  
Susumu Nakano ◽  
Tadaharu Kishibe ◽  
Tomoaki Inoue ◽  
Hiroyuki Shiraiwa
Keyword(s):  
Gas Turbines ◽  
High Performance ◽  
Unique Feature ◽  
Laboratory Evaluation ◽  
Air Cooling ◽  
Test Results ◽  
Air Turbine ◽  
Operation Test ◽  
Load Tests ◽  
Electrical Output

A prototype of the next-generation, high-performance microturbine system was developed for laboratory evaluation. Its unique feature is its utilization of water. Water is the lubricant for the bearings in this first reported application of water-lubricated bearings in gas turbines. Bearing losses and limitations under usage conditions were found from component tests done on the bearings and load tests done on the prototype microturbine. The rotor system using the water-lubricated bearings achieved stable rotating conditions at a rated rotational speed of 51,000 rpm. An electrical output of 135 kW with an efficiency of more than 33% was obtained. Water was also utilized to improve electrical output and efficiency through water atomizing inlet air cooling (WAC) and a humid air turbine (HAT). The operation test results for the WAC and HAT revealed the WAC and HAT operations had significant effects on both electrical output and electrical efficiency.

scholarly journals COMPUTATIONAL SIMULATION OF THE EVAPORTIVE AIR COOLING PROCESS IN A SUBWAY TUNNEL

2021 ◽  
Vol 2 (3) ◽  
pp. 115-122
Author(s):  
Elena L. Alferova
Keyword(s):  
Flow Rate ◽  
Air Flow ◽  
Computational Simulation ◽  
Evaporative Cooling ◽  
Water Flow Rate ◽  
Air Cooling ◽  
Air Flow Rate ◽  
Subway Tunnel ◽  
Pump Equipment ◽  
Metro Tunnel

The paper shows the possibility of using evaporative cooling of air by spraying water directly in the tunnel. The solution of the problem of modeling the process of removing heat excess from the air during the phase transition of water from the liquid state to the gaseous in the conditions of the metro tunnel is carried out. It is shown that using method significantly reduces the requirements for ventilation equipment in comparison with the method of removing heat surpluses only by mechanical ventilation. When using evaporative cooling method of removing heat surpluses in a subway tunnel, the maximum air flow rate of one fan will be 67.5 m/s with 104 kW power, the power of the pump equipment will be nearly 50 kW, with a water flow rate 1.5 m per hour. When removing heat surpluses only by ventilation, the air flow rate of one fan (with two fans in parallel work) will be up to 269 m/s, and the power will be 727 kW.

scholarly journals CFD-modeling of the temperature field of the radiator casing of the transmitting module of the active phased antenna arrays with air cooling

2019 ◽  
pp. 27-33 ◽  
Author(s):  
Yu. E. Nikolaenko ◽  
A. V. Baranyuk ◽  
S. A. Reva ◽  
V. A. Rohachov
Keyword(s):  
Output Power ◽  
Flow Rate ◽  
Antenna Arrays ◽  
Air Flow ◽  
Cfd Modeling ◽  
Maximum Temperature ◽  
Technical Solution ◽  
Air Cooling ◽  
Air Flow Rate ◽  
Phased Antenna Arrays

Modern radar stations are widely used to obtain images of earth surface with high spatial resolution, to identify moving objects in the air, on sea and on the ground, and allow determining the coordinates and movement parameters accurately. Active phased antenna arrays with large number of transmitting modules are widely used as antenna systems in radar stations. The heat generated by the active microwave elements of the output amplifiers of the transmitting module, leads to an increase in their temperature and to decrease in reliability. In this regard, the task of increasing the cooling efficiency of active microwave elements of the output power amplifiers is important. The aim of this study is to assess the possibilities of air cooling of the active elements of the output power amplifier in relation to the transition from gallium arsenide to gallium nitride element base with increased heat generation. This paper presents the results of computer simulation for the temperature filed of the mounting base of the radiator casing, on which 8 heat-generating elements with a local heat release of 28 W each are installed. Cooling fins are made on the opposite base of the radiator casing. The finned surface of the radiator casing is blown by an air stream with an inlet air temperature of 40°C. The simulation was carried out for three values of the air flow rate in the interfin channels: 1, 6 and 10 m/s. It is shown that the maximum temperature of the mounting base of the radiator casing is 90.1°C and is observed at an air flow rate of 1 m/s inside the interfin channels. Increasing the air speed up to 10 m/s makes it possible to reduce the temperature at the installation site of the microwave elements down to 72.1°C. A new technical solution was proposed to further improve the efficiency of the applied cooling system and to reduce the temperature of the mounting surface of the radiator casing.

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