Heat Recovery Systems and CHP最新文献

{"title":"Analysis of modified counter-flow cooling towers","authors":"M.P. Maiya","doi":"10.1016/0890-4332(95)90013-6","DOIUrl":"10.1016/0890-4332(95)90013-6","url":null,"abstract":"<div><p>Evaporative air cooling for human comfort and other applications, whenever possible and feasible, is less expensive than conventional air conditioning. A cooling tower is used in the centralised evaporative air cooling system. In the present study, the counter-flow cooling tower is modified to pre-cool the air at the tower inlet, either by the water after the cooling load, or the tower exit air. These two modified cooling towers are modelled and their thermal performances are compared with the conventional counter-flow cooling tower. For generality, the results are presented in terms of number of transfer units (<em>NTU</em>), a dimensionless number for a cooling tower indicating its size. The modified cooling towers are found to be better than the conventional one in lowering the tower approaches below about 2°C. These cooling towers seem to be distinctly advantageous when operating at low approaches, small ranges and large wet-bulb depressions, thus making them quite useful in evaporative air cooling applications.</p></div>","PeriodicalId":100603,"journal":{"name":"Heat Recovery Systems and CHP","volume":"15 3","pages":"Pages 293-303"},"PeriodicalIF":0.0,"publicationDate":"1995-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0890-4332(95)90013-6","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79932233","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Rigorous investigation of heat pump assisted distillation","authors":"Omar Annakou,&nbsp;Peter Mizsey","doi":"10.1016/0890-4332(95)90008-X","DOIUrl":"10.1016/0890-4332(95)90008-X","url":null,"abstract":"<div><p>In this work a propylene-propane splitter assisted by a heat pump of the vapour recompression type is investigated by rigorous methods. Two schemes, a single compressor scheme and a double compressor scheme in parallel arrangement, are scrutinised and compared to the conventional stand alone column. The investigation includes parametric study, operability assessment and an estimation of the role of heat pump in minimising flue gas emissions. The parametric study of the influences of the column top pressure and the pressure lift of the heat pump on the economics shows, for both schemes at the optimal conditions, practically the same annual total cost, which is about 37% cheaper than the conventional stand alone column.</p><p>The operability of the system is investigated by degrees of freedom analysis and steady state controllability parameters. The operability considerations show that in the case of the double compressor scheme, the column pressure can be independent of the threshold temperature of the condenser. Thus the column pressure can be determined to satisfy the optimum separation parameters. Due to this operability reason, the double compressor scheme is preferred to the single compressor scheme. The heat pump share in reducing flue gas emissions is estimated. It is found that about 60% of the flue gas emissions can be minimised when using a heat pump.</p></div>","PeriodicalId":100603,"journal":{"name":"Heat Recovery Systems and CHP","volume":"15 3","pages":"Pages 241-247"},"PeriodicalIF":0.0,"publicationDate":"1995-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0890-4332(95)90008-X","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89565106","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Alternative heat pump working fluids to CFCs","authors":"Sukumar Devotta","doi":"10.1016/0890-4332(95)90011-X","DOIUrl":"10.1016/0890-4332(95)90011-X","url":null,"abstract":"<div><p>CFC-11, CFC-12, CFC-114 and HCFC-22 are used as mechanical vapour compression heat pump working fluids for low and high temperature applications. Because of the Montreal Protocol, alternative heat pump working fluids to CFCs have to be identified and developed. This paper discusses the various potential alternatives screened from various families of compounds.</p><p>HFC-134a is the most popular choice as an alternative to CFC-12, although HFC-152a appears to be a better alternative. Among the HFEs, HFE-134 is a potential long-term alternative. HFC-143 and HFE-134 appear to be attractive as substitutes for CFC-114 for high temperature applications. For centrifugal compressor applications, HCFC-123 is currently the most popular choice as an interim alternative to CFC-11. HFC-245ca and HFC-143 are also potential long-term substitutes for CFC-11. The various implications with respect to these alternatives are discussed.</p></div>","PeriodicalId":100603,"journal":{"name":"Heat Recovery Systems and CHP","volume":"15 3","pages":"Pages 273-279"},"PeriodicalIF":0.0,"publicationDate":"1995-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0890-4332(95)90011-X","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89881326","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"HRSGs for combined cycle power plants","authors":"Nvrss Subrahmanyam,&nbsp;S. Rajaram,&nbsp;N. Kamalanathan","doi":"10.1016/0890-4332(95)90022-5","DOIUrl":"10.1016/0890-4332(95)90022-5","url":null,"abstract":"","PeriodicalId":100603,"journal":{"name":"Heat Recovery Systems and CHP","volume":"15 2","pages":"Pages 155-161"},"PeriodicalIF":0.0,"publicationDate":"1995-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0890-4332(95)90022-5","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82116637","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Combined cycle heat recovery steam generators optimum capabilities and selection criteria","authors":"Akber Pasha,&nbsp;Sanjeev Jolly","doi":"10.1016/0890-4332(95)90021-7","DOIUrl":"10.1016/0890-4332(95)90021-7","url":null,"abstract":"<div><p>The Heat Recovery Steam Generator is an integral and critical component of the Combined Cycle Power Plant. In the conceptual stage of the project it is very difficult to select the steam conditions for the optimized plant configuration. At this point most of the parameters are not well defined and since they are interdependent on each other, it is hard to optimize.</p><p>The paper presents discussion of what parameters are influenced by the type of circulation and how the selection should be made. The user can evaluate the critical parameters and select the circulation most advantageous for that particular plant.</p><p>This paper presents a method and an example of how the steam output of Heat Recovery System changes with the change in the steam conditions. The effect of auxiliary or supplementary firing in the boiler is also discussed.</p><p>Another dilemma these days is to determine whether a forced or natural circulation boiler is the best alternative.</p></div>","PeriodicalId":100603,"journal":{"name":"Heat Recovery Systems and CHP","volume":"15 2","pages":"Pages 147-154"},"PeriodicalIF":0.0,"publicationDate":"1995-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0890-4332(95)90021-7","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84481967","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hot-gas cleanup−sulfur recovery technical, environmental, and economic issues","authors":"S. Gangwal, R. Gupta, W. McMichael","doi":"10.1016/0890-4332(95)90028-4","DOIUrl":"https://doi.org/10.1016/0890-4332(95)90028-4","url":null,"abstract":"","PeriodicalId":100603,"journal":{"name":"Heat Recovery Systems and CHP","volume":"3 1","pages":"205-214"},"PeriodicalIF":0.0,"publicationDate":"1995-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88559194","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparison of chemical solvents for mitigating CO2 emissions from coal-fired power plants","authors":"A. Chakma,&nbsp;A.K. Mehrotra,&nbsp;B. Nielsen","doi":"10.1016/0890-4332(95)90030-6","DOIUrl":"https://doi.org/10.1016/0890-4332(95)90030-6","url":null,"abstract":"<div><p>There is a growing concern about the effect of greenhouse gases on global warming. Among the many greenhouse gases, CO₂ produced from burning fossil fuels is a major contributor due to the huge volumes emitted into the atmosphere. According to the estimates of the Intergovernmental Panel on Climate Change (IPCC), a worldwide reduction in the emission of greenhouse gases by more than 60% is necessary to avert significant global climate changes.</p><p>This paper examines the key issues involved in greenhouse gas emissions from coal-fired power plants. At the present time, absorption by chemical solvents appears to be best option for the separation of CO₂ from low pressure flue gas streams. The costs of separation and disposal of CO₂ from existing coal fired, air blown boilers are estimated to increase the cost of electricity by about 75%. Therefore, there is a need to optimize the selection of processing solvents and operating parameters to minimize the cost of separation. Increasing the inlet flue gas pressure did not improve mass transfer rates sufficiently to compensate for the higher compression costs. The effects of other process variables were also examined.</p><p>In this work, we have examined the cost effectiveness of six ethanolamine-based solvents. Overall, monoethanolamine (MEA) was found to be the best solvent.</p></div>","PeriodicalId":100603,"journal":{"name":"Heat Recovery Systems and CHP","volume":"15 2","pages":"Pages 231-240"},"PeriodicalIF":0.0,"publicationDate":"1995-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0890-4332(95)90030-6","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91726238","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A computational, modular approach to the simulation of powerplants","authors":"Marco Francesco Falcetta,&nbsp;Enrico Sciubba","doi":"10.1016/0890-4332(95)90020-9","DOIUrl":"10.1016/0890-4332(95)90020-9","url":null,"abstract":"<div><p>The paper describes the development, the implementation and the practical application of a new modular procedure for the numerical simulation of thermal powerplants. The procedure has resulted in a <strong>FORTRAN</strong> code, named <strong>“CAMEL”</strong> (Italian acronym for “Modular Elemental Plant Calculation), which is also described in detail. The plant -any plant, but application of the procedure is presently limited to thermal powerplant- is described in terms of three matrices, named the Interconnection matrix <strong>IM</strong>, the plant matrix <strong>PM</strong> and the Topographic matrix <strong>TM</strong>, which contain in an orderly fashion all of the design data and the6“topological” description of the plant configuration. The Interconnection matrix is equivalent to a structured list of the flows (of matter and energy) which are fed to or extracted from any of the “n” plant components; the plant matrix is a table of the design values of all the fluxes in the plant, and the Topographic matrix is a reference table which allows the logical location of any component to be found both in <strong>PM</strong> and in <strong>IM</strong>.</p><p>Starting from a set of design input data, <strong>CAMEL</strong> calculates, component bby component, all the values of the thermodynamic variables of interest which do not already appear in <strong>PM</strong>; more precisely, <strong>CAMEL</strong> can calculate the numerical value of all the parameters needed to uniquely determine the thermodynamic and/or energetic state of whatsoever flux in the plant by calling for each component the corresponding routine, which returns the numerical value of all the variables it can calculate at the “present” stage of the simulation. It is important to underscore that these routines can calculate a component not as whole machine but equation by equation, i.e., the routine must not necessarily calculate all of the operating parameters of the component at the same stage of the simulation, but only those which can be calculated with the data known at the current stage of the simulation and that are involved in the same physical event described by one of the equations included in the set which pertains to that component.</p><p><strong>CAMEL</strong> can perform, at the user's request, either a single plant simulation or a sensitivity analysis of the behaviour of the plant. At present, <strong>CAMEL</strong> is only capable of performing sensitivity analysis of plants at design conditions and in a limited number of (steady state) off-design conditions (i.e., the analysis is aimed at the optimization of the design operating conditions of the plant): in principle it is possible to implement a transient computation, but this has not yet been done. <strong>CAMEL</strong> has been implemented for powerplant simulation, but the core has been structured to allow the code to handle with any kind of processor-plant, provided the code's component library is larg","PeriodicalId":100603,"journal":{"name":"Heat Recovery Systems and CHP","volume":"15 2","pages":"Pages 131-145"},"PeriodicalIF":0.0,"publicationDate":"1995-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0890-4332(95)90020-9","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84673168","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hot-gas cleanup—sulfur recovery technical, environmental, and economic issues","authors":"S.K. Gangwal,&nbsp;R. Gupta,&nbsp;W.J. McMichael","doi":"10.1016/0890-4332(95)90028-4","DOIUrl":"https://doi.org/10.1016/0890-4332(95)90028-4","url":null,"abstract":"<div><p>Advanced high-efficiency integrated gasification combined cycle (IGCC) power systems employing hot-gas cleanup are being developed to produce electric power from coal. Hot-gas cleanup consists of hot particulate removal and hot-gas desulfurization (HGD) technologies that match or nearly match the temperature and pressure of the gasifier and turbine generator. HGD is carried out using solid regenerable metal oxide sorbents that can remove the sulfur down to low parts per million and can be regenerated with air for multicycle operation. Economic studies have shown that HGD results in lower capital and operating costs than conventional cold gas desulfurization. Development of efficient sorbent desulfurization-regeneration reactor and tailgas treatment subsystems properly integrated with the overall IGCC systems is a key requirement for successful commercialization of HGD.</p></div>","PeriodicalId":100603,"journal":{"name":"Heat Recovery Systems and CHP","volume":"15 2","pages":"Pages 205-214"},"PeriodicalIF":0.0,"publicationDate":"1995-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0890-4332(95)90028-4","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91760394","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The cyclone separators performances under high temperature in PFBC unit","authors":"Shi Mingxian, Liu Junren, Li Guorong, Jin Youhai, Yao Zhibiao, Liu Qianxin","doi":"10.1016/0890-4332(95)90026-8","DOIUrl":"https://doi.org/10.1016/0890-4332(95)90026-8","url":null,"abstract":"","PeriodicalId":100603,"journal":{"name":"Heat Recovery Systems and CHP","volume":"5 1","pages":"191-198"},"PeriodicalIF":0.0,"publicationDate":"1995-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74392893","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}