Engine Cogeneration Research Articles

3639 200kW級のガスエンジンコージェネレーションシステムの性能評価と最適化研究(G08-2 エネルギ有効利用,G08 動力エネルギーシステム)

From the viewpoint of effective use of energy, a Co-generation system (here after CGS) is considered as one of the significant strategies to achieve energy conservation. In recent year, CGS is introduced to low capacity and low heat to power ratio object such as household use and business place. However, Along with this, the total efficiency through the year become low because of low generating efficiency and low exhaust heat-using efficiency. So, it is necessary to find the problem by evaluating the influence of low capacity and low heat to power ratio on effective use of energy. In this study, we evaluate the effective use of energy using heat quantity and exergy for 200kW gas engine cogeneration system introducing to Energy Conversion Research Center in Doshisha University. As the result, we clear up the factor that influence on effective use of energy.

439 ガスエンジンコージェネレーションシステムによるオフィスビルの省エネルギー効果(CGS II,環境保全型エネルギー技術)

439 ガスエンジンコージェネレーションシステムによるオフィスビルの省エネルギー効果(CGS II,環境保全型エネルギー技術)

440 ガスエンジンコージェネレーション排熱の有効利用に関する研究(CGS II,環境保全型エネルギー技術)

440 ガスエンジンコージェネレーション排熱の有効利用に関する研究(CGS II,環境保全型エネルギー技術)

OS4-02 バイオガス混焼高効率ガスエンジンコージェネレーションシステムの開発(OS4 省エネルギー・小型分散電源コジェネ技術)

OS4-02 バイオガス混焼高効率ガスエンジンコージェネレーションシステムの開発(OS4 省エネルギー・小型分散電源コジェネ技術)

ガスエンジンオイルの黒色化に関する実験研究

Gas engines are increasingly coming into use in Japan as cogeneration engines. In some cases, the lubricating oil of such engines is replaced very often because it turns black in a short time. The authors, therefore, conducted experiments to obtain information on overcoming the rapid blackening. The results show that the black lubricating oil in gas engines may be caused by the high temperatures of these engines. It therefore may not be difficult to cope with the problem.

エネルギーフローに基づく電力·熱供給システムのCO<sub>2</sub>排出量評価

It is required for the energy systems to satisfy simultaneous solutions to the problems, such as cost reduction, global warming, assurance of energy security, and resource conservation. To evaluate optimal end-use energy systems from the stand point of CO2 emissions, we apply a comprehensive approach based on the life cycle assessment. Several combinations of electricity and heat supplying systems are compared. They include the electricity driven heat pump, gas engine co-generation, absorption refrigeration and so on. Calculations represent total CO2 emission by energy consumption of several operation patterns, based on the actual data of energy demand, CO2 intensity of the grid electricity and the equipment specifications. The results indicate that CO2 emissions can be minimized by maximum utilization of electricity from the grid.

エネルギー自由化時代における経営資源の選択と集中について

Osaka Gas has cultivated its core technologies through research and development based on a wealth of technological expertise accumulated since the days when gas was manufactured from coal. Research and development have been positioned as an important means for enhancing competitiveness in both the energy and non-energy businesses, and constant innovation has been pursued while maintaining speed and flexibility in its implementation. We are selective in the fields of R&D and are focusing on those areas that enhance the Osaka Gas Group's market position. Using our core technologies and product development capabilities, we aim to strengthen technological development capabilities that contribute to better safety, services, efficiency and sales in the energy business. In the gas business, Osaka Gas is advancing research and development that contributes to higher sales in gas operations, such as the commercialization of residential and industrial gas engine cogeneration systems, higher efficiency in cogeneration systems, and higher efficiency in gas heat pumps (GHP). In areas related to the electric power business, Osaka Gas is focusing efforts on the development of an electricity supply control system to comprehensively manage distributed power sources, including the power generation facilities of LNG terminals and cogeneration facilities installed at customers whose excess power is subject to retailing.

Deodorization for Fermentation Gas of Livestock Composting Facility Using Diesel Engine Co-generation System

Deodorization for Fermentation Gas of Livestock Composting Facility Using Diesel Engine Co-generation System

森林バイオマスによるガス化発電実証試験設備(バイオマス利用への機械工学的アプローチ-前処理技術から(バイオマス利用への機械工学的アプローチ-前処理技術から廃棄物発電まで-(2),バイオマス利用への着小合工学的アプローチ-前処理技術から廃棄物発電まで-)

森林バイオマスによるガス化発電実証試験設備(バイオマス利用への機械工学的アプローチ-前処理技術から(バイオマス利用への機械工学的アプローチ-前処理技術から廃棄物発電まで-(2),バイオマス利用への着小合工学的アプローチ-前処理技術から廃棄物発電まで-)

Adoption and Diffusion of Decentralised Energy Conversion Technologies: The Success of Engine Co-Generation in Germany

Energy market liberalisation, concerns about environmental pollution and climate change, and the dependence on fossil fuel imports render the adoption and diffusion of distributed generation technologies a field of research increasingly recognised as important. This paper contains a brief overview of both commercially available and close-to-market distributed co-generation (CHP) technologies and fields of application. It also provides a thorough investigation on the adoption and diffusion of engine-based CHP systems in the German market since 1960. The empirical analysis is mainly based on a detailed data set of nearly 5,000 such systems installed in Germany until 1998. It makes use of descriptive data analysis, net present value calculations, and micro-econometric (hazard rate) modelling. We further assess market diffusion from 1998 until today and future diffusion prospects, and discuss impacts on the development that stem from liberalisation-driven energy market transformation processes. The results show that economic considerations alone do not suffice to explain the adoption decisions taken by investors, and also present some new insights with regard to the use of hazard rate models in the context of energy conversion technology adoption.

船舶からの大気汚染物質の排出実態と規制動向 ４ストローク中速機関の対応

On September 1997, the Conference of Parties to the International Convention for the Prevention of Pollution from Ships adopted the Technical Code on Control of Emission of Nitrogen Oxides from Marine Diesel Engines. The purpose of this Code is to specify the requirements for the testing, survey and certification of marine diesel engines to ensure they comply with NOx limits. This paper describes the proposal for amend-ments to NOx Code on test condition fa submitted by Japan, the research conducted by the authors on“Follow-up Survey on NOx Concentration from Cogeneration Engines”, and the countermeasures of 4 stroke medium speed diesel engine for IMO regulation on NOx.

3304 エネルギー供給システムの大規模最適設備容量計画における一効率的近似解法

An efficient approximate method for large scale optimal unit sizing of energy supply systems is proposed based on the following two intuitive hypotheses : (a) optimal equipment capacities exist between minimum and maximum ones obtained by solving partial problems, and (b) for a certain sampling time, if on-off status of equipment for the minimum capacity is equal to one for the maximum capacity, on-off status of equipment for the optimal capacity is equal to those states. By solving small scale problems plural times based on these hypotheses, equipment capacities and utility contract demands as well as systems' operational strategies are efficiently determined to minimize the annual total cost and to satisfy energy demand requirements. Numerical studies on gas engine cogeneration systems installed in a hotel are carried out to ascertain the validity and the effectiveness of the proposed method.

The evaluation of small cogeneration for residential heating

The decision whether or not to install small cogeneration for residential purposes mainly depends on individual economic considerations, combined with ecological awareness. Since in most cases, the economic balance is still unfavourable, government grants are considered in order to bridge this economic barrier. It is however still unclear how these grants are best spent to obtain an optimal environmental benefit. In the case of cogeneration, mainly static and simplified methods are used, completely neglecting the dynamic interaction between the cogeneration systems and the central power system and the dynamic response of the cogeneration units themselves. In this paper, these issues are discussed in two parts. The first part clarifies how an actual cogeneration unit, if necessary in combination with a back-up boiler and heat storage, will respond to a certain demand. For this purpose, experiments were performed to establish the transient and stationary behaviour of the system. It is shown that the transient heating of the cogeneration engine is rather slow (e.g. half an hour after cold start, the engine only produced 65% of the heat it would have in stationary regime) where the electric transient behaviour is negligible. In the second part of the paper, dynamic simulations are performed to quantify the impact (primary energy saving and reduction in greenhouse-gas emissions) of the massive installation of cogeneration for residential heating. Two important parameters are isolated. First, the interaction with the expansion of the central power system is very important. If the installation of cogeneration prevents the commissioning of new power plants, the potential energy saving and (especially) emission reduction are reduced. The second parameter is the annual use of the cogeneration units. Here, the potential energy saving and emission reduction increase with increasing annual use. Copyright © 2002 John Wiley & Sons, Ltd.

Distributed generation and distribution utilities

Distributed (co)generation (DG) represents an alternative paradigm of energy supply and the opportunity for significant CO 2 emission reductions. This paper investigates the adoption of the DG technology of internal combustion (IC) engine cogeneration in the Netherlands and UK from 1985–1998. This detailed comparison was motivated to understand why the Netherlands installed 20 times as many units and 40 times as much DG capacity (per capita) compared to the UK. The primary finding of this study emphasizes the win–win partnerships between DG adopters and utilities. While both governments promoted DG as part of their CO 2 reduction goals, only distribution utilities in the Netherlands were primed to support greater DG penetration. Crucially, Netherlands utilities offered high electricity buy-back rates which enabled innovative utilization of DG. Flexible operation modes allowed investment in larger units, benefiting from economies of scale due to fixed components in maintenance costs, and extended DG use to the much larger set of sites with limited electricity base-loads. The win–win partnerships between distribution utilities and DG adopters for cost savings also facilitated improved management of the electricity network. A final consequence was a virtuous circle of maintenance cost reductions from geographic concentration of DG units, resulting in improved returns and hence more DG unit sales.

Separation of hydrocarbons from natural gas using silicalite membranes

Abstract The removal of heavy hydrocarbons from natural gas becomes necessary to facilitate its pipeline transport and distribution, and for applications in conventional gas burners and co-generation engines. This work presents the use of silicalite membranes for this separation process. It was found that n-butane permeates preferentially over methane, due to its strong adsorption on the membrane, which hinders methane permeation. The influence of the operating conditions (temperature, sweep gas flow, gas composition, etc.) was studied experimentally. Several membranes prepared by different methods are compared. The best separations are obtained with the same pressure at both sides of the membrane and with the use of a sweep gas. Pretreatment of the support before the zeolite synthesis improves the separation performance.

S02 家庭用ガスエンジンの開発状況(家庭用コージェネレーションシステム)

S02 家庭用ガスエンジンの開発状況(家庭用コージェネレーションシステム)

Optimal Operation of a Gas Engine Exhaust Heat Recovery System in Consideration of Temperature Effect on Refrigerator Performance.

The optimal operation of an exhaust heat recovery system in a gas engine cogeneration is investigated in consideration of the influence of chilled and cooling water temperatures on the performance characteristics of exhaust heat and gas fired absorption refrigerators. First, a simulation calculation is carried out to evaluate the performance characteristics of absorption refrigerators. Second, an optimization calculation based on the mixed-integer linear programming is carried out to determine the on/off status of operation and energy flow rates of equipment. In a case study, it is clarified how the strategies for controlling the load of the gas fired absorption refrigerator affect the optimal operation and running cost of the system, and how the optimal operation is advantageous as compared with a conventional one.

Comparative study of cogeneration systems in a chemical industry

With the large penetration of the natural gas into the Brazilian energy structure, industries such as paper mills and chemical plants are analyzing the feasibility of implementing cogeneration schemes appropriate to this fuel. The analysis of the energy demand patterns of a chemical company from the photographic sector revealed the possibility of using combined cycles or diesel engine cogeneration schemes keeping the existing compression refrigeration units and steam or gas cycle cogeneration systems with absorption refrigeration units. In terms of economic attractiveness, an analysis based on the method of the internal rate of return was performed. The results indicated that the schemes composed by reciprocating engines and combined cycle with compression chillers, as well as the gas cycle scheme with absorption chiller, present return periods of up to 3 years, showing that the investment in cogeneration could be of interest for this plant.

Exhaust Oxidation of Unburned Hydrocarbons from Lean-Burn Natural Gas Engines

Post cylinder oxidation of unburned hydrocarbons (UHC) was studied using a 35 kW lest engine. The engine was equipped with an insulated exhaust reactor to extend the residence time. The exhaust reactor performance has been characterised under the basic engine operating conditions, and under conditions where temperature and composition (NOx level) of the exhaust were modified independent of engine settings. The experiments studied spanned a wide range of moderately lean-bum conditions. The composition at the exhaust port was as follows: O2 5-9% (engine excess air ratios of 1.28-1.75), UHC 1000-7000 ppm, CO 550 ppm, NOx0-1400 ppm. The temperature varied from 600 to 700°C, In addition, experiments with injection of hydrogen peroxide to promote UHC oxidation in the exhaust system were conducted. The amount of UHC oxidised in the exhaust system depended closely on the exhaust temperature, residence time and concentration of nitrogen oxides in the exhaust gas. The increased reaction time in the exhaust reactor caused an oxidation of the exhaust hydrocarbons of up to 90% with CO as the major oxidation product, but the reactor efficiency decreased as the engine was operated at leaner conditions, due to lower temperatures and lower NO, levels. Levels of nitrogen oxides above 300 ppm were shown to strongly promote the extent of UHC oxidation. Injection of hydrogen peroxide increased the degree of exhaust reactor oxidation and extended the oxidation further into the lean operation range. A field engine was tested at increased NOx levels, obtained by addition of ammonia to the air intake. No physical modifications of the engine or the settings were performed. The ammonia addition resulted in a reduction of unburned hydrocarbons by approximately 30% with CO2 as the major product. Due to the comparatively low temperature and short residence time of the field engine exhaust system, as well as the absence of CO production, the UHC reduction was attributed to processes occurring in the cylinder or exhaust port, rather than in the exhaust system. Similar levels of UHC reduction prior to the exhaust reactor were observed in the test engine. A detailed chemical kinetic model was used for simulation of the exhaust oxidation experiments. The modelling predictions were in fairly good agreement with the observations, confirming the catalytic role of NOx in the oxidation of hydrocarbons. The model was used to extrapolate the test engine results to conditions representative of co-generation engines and the practical implications are discussed.

中速ディーゼル機関のNOx変動因子

This paper describes the results of the combustion test by controlling the absolute humidity and the cylinder inlet air temperature in air in order to confirm the NOx variations in the medium speed single cylinder diesel engine with 200mm in bore.The absolute humidity is controlled by varying the quantity of water injected into the suction port. These findings show a close proximity to the result of research conducted by the authors on “Follow-up Survey on NOx Concentration from Cogeneration Engines”