Showing papers on "Gas compressor published in 2017"
TL;DR: In this paper, an integrated model is developed for the integrated solar power tower (SPT) system including the heliostat field, the molten salt solar receiver, the thermal storage, and the S-CO2 recompression Brayton cycle with reheating.
251 citations
TL;DR: In this article, the performance of S-CO 2 Brayton cycle layouts is compared for applications in molten salt solar power tower (SPT) systems from the aspects of the efficiency, specific work, and the incorporation ability with the thermal energy storage indicated by the molten salt temperature difference across the solar receiver.
234 citations
TL;DR: In this paper, the authors apply new techniques for control of dynamic gas flows on pipeline networks to examine day-ahead scheduling of electric generator dispatch and gas compressor operation for different levels of integration, spanning from separate forecasting, and simulation to combined optimal control.
Abstract: The extensive installation of gas-fired power plants in many parts of the world has led electric systems to depend heavily on reliable gas supplies. The use of gas-fired generators for peak load and reserve provision causes high intraday variability in withdrawals from high-pressure gas transmission systems. Such variability can lead to gas price fluctuations and supply disruptions that affect electric generator dispatch, electricity prices, and threaten the security of power systems and gas pipelines. These infrastructures function on vastly different spatio-temporal scales, which prevents current practices for separate operations and market clearing from being coordinated. In this paper, we apply new techniques for control of dynamic gas flows on pipeline networks to examine day-ahead scheduling of electric generator dispatch and gas compressor operation for different levels of integration, spanning from separate forecasting, and simulation to combined optimal control. We formulate multiple coordination scenarios and develop tractable physically accurate computational implementations. These scenarios are compared using an integrated model of test networks for power and gas systems with 24 nodes and 24 pipes, respectively, which are coupled through gas-fired generators. The analysis quantifies the economic efficiency and security benefits of gas-electric coordination and dynamic gas system operation.
167 citations
TL;DR: In this article, a combined cooling, heating and power-based compressed air energy storage system is proposed, which combines a gas engine, supplemental heat exchangers and an ammonia-water absorption refrigeration system.
155 citations
01 Jun 2017
TL;DR: New techniques for control of dynamic gas flows on pipeline networks are applied to examine day-ahead scheduling of electric generator dispatch and gas compressor operation for different levels of integration, spanning from separate forecasting, and simulation to combined optimal control.
Abstract: The extensive installation of gas-fired power plants in many parts of the world has led electric systems to depend heavily on reliable gas supplies. The use of gas-fired generators for peak load and reserve provision causes high intra-day variability in withdrawals from high pressure gas transmission systems. Such variability can lead to gas price fluctuations and supply disruptions that affect electric generator dispatch, electricity prices, and threaten the security of power systems and gas pipelines. These infrastructures function on vastly different spatiotemporal scales, which prevents current practices for separate operations and market clearing from being coordinated. In this paper, we apply new techniques for control of dynamic gas flows on pipeline networks to examine day-ahead scheduling of electric generator dispatch and gas compressor operation for different levels of integration, spanning from separate forecasting and simulation to combined optimal control. We formulate multiple coordination scenarios and develop tractable, physically accurate computational implementations. These scenarios are compared using an integrated model of test networks for power and gas systems with 24 nodes and 24 pipes, respectively, which are coupled through gas-fired generators. The analysis quantifies the economic efficiency and security benefits of gas-electric coordination and dynamic gas system operation.
104 citations
TL;DR: In this paper, an energy and exergy analysis of an adiabatic CAES system is presented, where the heat of compression is stored and subsequently used during the expansion process in the turbine.
101 citations
TL;DR: In this paper, the authors used the first and second law of thermodynamics to construct a model for the gas turbine power plant, and calculated the exergy flow rate for the compressor, the combustion chamber, and the GT inlet and outlet.
101 citations
TL;DR: A review of linear compressors for domestic refrigeration and electronics cooling is presented in this article, where the challenges associated with the linear compressor are also discussed to provide a comprehensive review of the technology for research and development in future.
Abstract: Linear compressor has no crank mechanism compared with conventional reciprocating compressor. This allows higher efficiency, oil-free operation, lower cost and smaller size when linear compressors are used for vapour compression refrigeration (VCR) system. Typically, a linear compressor consists of a linear motor (connected to a piston) and suspension springs, operated at resonant frequency. This paper presents a review of linear compressors for refrigeration system. Different designs and modelling of linear compressors for both domestic refrigeration and electronics cooling (miniature VCR system) are discussed. Key characteristics of linear compressor are also described, including motor type, compressor loss, piston sensing and control, piston drift and resonance. The challenges associated with the linear compressors are also discussed to provide a comprehensive review of the technology for research and development in future.
88 citations
TL;DR: In this article, the authors present the modelling and analysis of a waste-heat-recovery system (WHRS) using supercritical carbon dioxide (SC-CO2) based regenerative recompression Brayton cycle (RRCBC) for shipboard applications following energy and exergy analyses.
Abstract: This communication presents the modelling and analysis of a waste-heat-recovery-system (WHRS) using supercritical carbon dioxide (SC-CO2) based regenerative recompression Brayton cycle (RRCBC) for shipboard applications following energy and exergy analyses. The influence of key operating parameters such as, the gas compositions, turbine and compressor inlet temperatures, pressure drop irreversibility, pressure ratio etc., on the overall performance of the system including the exergy destruction rate has been investigated. The results show that the proposed integration improves the overall efficiency of the system by 10% while the net power is found to be increasing up to 25% of the rated power. It is also found that the topping gas turbine exhaust gas compositions and temperatures have a significant influence on the WHRS performance. The results are also found in good agreement with those already available in the published literature.
87 citations
TL;DR: The requirements set by the compressor on the electrical machine design are presented and the design solutions aimed to satisfy these requirements are discussed.
Abstract: Two-stage oil-free centrifugal air compressors can bring significant advantages and open new market opportunities for compressor manufacturers. One of the core technologies behind this compressor type is the high-speed electrical machine supported by active magnetic bearings. In this paper, the requirements set by the compressor on the electrical machine design are presented. The design solutions aimed to satisfy these requirements are discussed. Two case studies illustrate possible design approaches for the target application with examples of a 120-kW, 60 000-r/min induction machine with a solid rotor and a 225-kW, 50 000-r/min permanent-magnet synchronous machine (PMSM) with a full cylindrical magnet. The system design and simulation results are confirmed by measurements of a PMSM prototype.
82 citations
TL;DR: In this paper, a process knowledge-inspired decision-making method was exploited for optimizing the single mixed refrigerant (SMR) natural gas liquefaction process and the results showed that the proposed optimization methodology is simple and effective in determining the optimal operating conditions and could save up to 30.6% in terms of the compressor duty compared to the base case.
TL;DR: In this article, the authors analyzed H2 compression and pipeline transportation processes with safety issues related to water electrolysis and H2 production for different values of the hydrogen mass flow rate: 02, 05, 10, 20, and 28 kg/s.
TL;DR: In this article, the performance of a 20kW vehicular proton exchange membrane fuel cell power system incorporating a fuel cell stack and an air compressor was investigated through the cathode operating pressure optimization.
01 Jan 2017
TL;DR: In this article, the performance of an automotive air conditioning system (AAC) was evaluated by determining the heat absorb, compressor work and coefficient of performance (COP), and the results found that the maximum increase and the average COP enhancement for SiO2/PAG nanolubricants are 24% and 10.5%, respectively.
Abstract: The performance of an automotive air conditioning system (AAC) needs to be enhanced in order to minimize its environment impact and reduce global fuel consumption. Implementing nanofluid technology using nanolubricants inside compressors can improve its performance. Therefore, this paper presents the development of an AAC system performance test rig. The SiO2/PAG nanolubricant was prepared in a prior performance experiment and the stability of the colloidal was also attained. The experiment was conducted with initial refrigerant charge ranging from 95 to 125 gram and compressor speeds of 900 to 2100 RPM. The performance of the AAC system was evaluated by determining the heat absorb, compressor work and coefficient of performance (COP). The results found that the maximum increase and the average COP enhancement for SiO2/PAG nanolubricants are 24% and 10.5%, respectively. It can be concluded that the COP was highest at 0.05% volume concentration for all compressor speeds.
TL;DR: In this article, a transcritical CO2 refrigeration cycle combined with a thermoelectric (TE) subcooler and an expander (TES+EXPHM and TES+EXPML) is proposed.
TL;DR: In this article, a directexpansion solar-assisted heat pump (DX-SAHP) system by using R410A as refrigerant is described, which can supply domestic hot water during the whole year.
Abstract: A direct-expansion solar-assisted heat pump (DX-SAHP) system by using R410A as refrigerant is described, which can supply domestic hot water during the whole year. Based on the distributed parameter and homogeneous flow models of collector/evaporator and condenser, the lumped parameter models of compressor and electronic expansion valve, and the refrigerant charge model, a numerical model is developed to estimate the thermal performance of the system. Given the structure parameters, meteorological parameters, initial and final water temperatures, for a fixed superheat degree, the effects of the refrigerant charge quantity on the performance parameters of the system are analyzed, such as compressor power, heat gain of collector, heating time, collector efficiency and system COP. Furthermore, for a fixed refrigerant charge quantity, the effects of various parameters, including solar radiation, ambient temperature, compressor speed and initial water temperature, have been simulated and analyzed on the thermal performance of the system.
TL;DR: The proposed multiplier is used in image processing applications, where the peak signal to noise ratio of the image is measured and results show that the proposed multiplier performs better than existing approximate multiplier.
Abstract: This paper presents the design of approximate 15-4 compressor using 5-3 compressors as basic module. Four different types of approximate 5-3 compressors are used in a 15-4 compressor for less power consumption and high pass rate. We have analysed the results in all the cases. A $16 \times 16$ bit multiplier is simulated using the proposed 15-4 compressor. Simulation results show that the multipliers with proposed approximate compressors achieve significant improvement in power as compared to the multipliers with accurate 15-4 compressor. Pass rate of the proposed multipliers are high as compared to other existing approximate multipliers. Finally, the proposed multiplier is used in image processing applications, where the peak signal to noise ratio of the image is measured. Quality of the image is compared with an accurate multiplier and the obtained results show that our proposed multiplier performs better than existing approximate multiplier.
TL;DR: A multi-objective optimization model in optimizing the operation of natural gas pipeline networks is presented and a set of Pareto optimal points from which a decision maker can select a specific preferred solution is obtained.
TL;DR: In this article, a model reference adaptive control (MRAC) is introduced, to avoid compressor surge during the dynamic operation of a fuel cell system, and the adaptive control was compared with the nominal feedback control in the air management system of an automotive fuel cell operating within normal conditions.
TL;DR: In this paper, a semi-physical modeling method is adopted to analyze the operating property of a centrifugal compressor, which is more suitable for automotive fuel cells because of its compactness, and a dynamic feedforward controller is proposed based on the load torque to control the air mass flow, eliminating the disturbance produced by the compressor load in transient.
TL;DR: In this article, the authors proposed sensitivity analysis of several parameters and global parameter optimization for the supercritical carbon dioxide (S-CO2) Brayton cycle and showed that the optimal split ratio and split ratio could maximize the cycle efficiency.
TL;DR: In this paper, a novel trigeneration system, which integrates the organic Rankine cycle and vapor compression-absorption cascade refrigeration cycle, is proposed, which combines the advantages of the conventional stand-alone vapor compression system and vapor absorption refrigeration system.
TL;DR: In this paper, the impact of different inlet geometries on the compressor performance, including compressor efficiency, noise emission and surge margin, was studied in an engine test bench with a centrifugal compressor.
TL;DR: In this article, an analytical solution for a novel Compressed Air Energy Storage (CAES) system, Supercritical compressed air energy storage (SC-CAES), was conducted in order to explore the evolution and its reason of roundtrip efficiency varying with system key parameters in depth.
TL;DR: In this paper, a down-scaled industrial organic Rankine cycle (ORC) for low-grade waste heat recovery was investigated, and the experimental results were used to evaluate the influence of the expander performance on the behavior of the ORC system at nominal and part-load conditions.
TL;DR: In this article, a thermodynamic study of newly suggested supercritical carbon dioxide (s-CO2) cycle layouts using an isothermal compressor is presented, and the calculations highlight that it reduces the compression work significantly over other representative working fluids.
TL;DR: In this paper, a model of a pipeline network for gas distribution is developed considering supply of gas, either from external gas networks or as injected biogas or gasified liquefied natural gas (LNG) at terminals.
Patent•
22 Mar 2017
TL;DR: In this paper, an air conditioner control method and device is presented, which consists of determining a preset refrigeration mode, setting temperature and setting the wind power level, and judging whether the pipe temperature of the indoor unit is within a preset range, wherein the minimum value of the preset range is the difference between the target pipe temperature and second adjustment temperature.
Abstract: The invention discloses an air conditioner control method and device and an air conditioner. The method comprises the steps of determining a preset refrigeration mode, setting temperature and setting the wind power level; looking for the target pipe temperature of an indoor unit corresponding to the preset refrigeration mode and the set wind power level according to preset correspondence; starting a compressor, controlling an external fan to operate at the highest wind power level, and controlling an inner fan to be started and operate at the set wind power level when the pipe temperature of the indoor unit is reduced to first temperature, wherein the first temperature is the sum of the target pipe temperature and first adjustment temperature; judging whether the pipe temperature of the indoor unit is within a preset range, wherein the minimum value of the preset range is the difference between the target pipe temperature and second adjustment temperature, and the maximum value of the preset range is the sum of the target pipe temperature and second adjustment temperature; controlling the compressor to operate continuously at the current operation frequency if yes; adjusting the operation frequency of the compressor till the pipe temperature of the indoor unit is within the preset range if not. By the adoption of the technical scheme, the temperature of air provided by the air conditioner can be adjusted by users, so that user experience is effectively improved.
TL;DR: In this article, the authors proposed a control strategy for cascade air source heat pump water heater to adjust the load variation, where the principle that two stage compression ratio is approximately same is used to determine the intermediate pressure.
TL;DR: In this paper, the authors investigated the effects of various ejector geometries on the performance of a small-sized household refrigeration cycle by using the refrigerant R600a under various operating conditions.