Targeting and design of industrial zone waste heat reuse for combined heat and power generation

Energy ◽  
2012 ◽  
Vol 47 (1) ◽  
pp. 302-313 ◽  
Author(s):  
Vladimir Z. Stijepovic ◽  
Patrick Linke ◽  
Mirko Z. Stijepovic ◽  
Mirjana Lj. Kijevčanin ◽  
Slobodan Šerbanović
Keyword(s):  
Power Generation ◽  
Waste Heat ◽  
Combined Heat And Power ◽  
Industrial Zone ◽  
Waste Heat Reuse

scholarly journals Modified High Back-Pressure Heating System Integrated with Raw Coal Pre-Drying in Combined Heat and Power Unit

Energies ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 2487 ◽  
Author(s):  
Heng Chen ◽  
Zhen Qi ◽  
Qiao Chen ◽  
Yunyun Wu ◽  
Gang Xu ◽  
...  
Keyword(s):  
Power Generation ◽  
Flue Gas ◽  
Waste Heat ◽  
Heating System ◽  
Combined Heat And Power ◽  
Back Pressure ◽  
Coal Consumption ◽  
Heating Capacity ◽  
Boiler Efficiency ◽  
Saving Effect

A conceptual high-back pressure (HBP) heating system cooperating raw coal pre-drying for combined heat and power (CHP) was proposed to improve the performance of the HBP-CHP unit. In the new design, besides of heating the supply-water of the heating network, a portion of the exhaust steam from the turbine is employed to desiccate the raw coal prior to the coal pulverizer, which further recovers the waste heat of the exhaust steam and contributes to raising the overall efficiency of the unit. Thermodynamic and economic analyzes were conducted based on a typical 300 MW coal-fired HBP-CHP unit with the application of the modified configuration. The results showed that the power generation thermal efficiency promotion of the unit reaches 1.7% (absolute value) owing to suggested retrofitting, and meanwhile, the power generation standard coal consumption rate is diminished by 5.8 g/kWh. Due to the raw coal pre-drying, the energy loss of the exhaust flue gas of the boiler is reduced by 19.1% and the boiler efficiency increases from 92.7% to 95.4%. The impacts of the water content of the dried coal and the unit heating capacity on the energy-saving effect of the new concept were also examined.

Thermodynamic and Performance Study of Solar Regenerative Organic Rankine Cycle System for Use in Residential Micro-Combined Heat and Power Generation

2019 ◽  
Author(s):  
Wahiba Yaïci ◽  
Evgueniy Entchev
Keyword(s):  
Power Generation ◽  
Energy Demand ◽  
Waste Heat ◽  
Residential Buildings ◽  
Electrical Power ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Combined Heat And Power ◽  
Energy Sources ◽  
Performance Study

Abstract A continued increase in both energy demand and greenhouse gas emissions (GHGs) call for utilising energy sources effectively. In comparison with traditional energy set-ups, micro-combined heat and power (micro-CHP) generation is viewed as an effective alternative; the aforementioned system’s definite electrical and thermal generation may be attributed to an augmented energy efficiency, decreased capacity as well as GHGs percentage. In this regard, organic Rankine cycle (ORC) has gained increasing recognition as a system, which is capable for generating electrical power from solar-based, waste heat, or thermal energy sources of a lower quality, for instance, below 120 °C. This study focuses on investigating a solar-based micro-CHP system’s performance for use in residential buildings through utilising a regenerative ORC. The analysis will focus on modelling and simulation as well as optimisation of operating condition of several working fluids (WFs) in ORC in order to use a heat source with low-temperature derived from solar thermal collectors for both heat and power generation. A parametric study has been carried out in detail for analysing the effects of different WFs at varying temperatures and flowrates from hot and cold sources on system performance. Significant changes were revealed in the study’s outcomes regarding performance including efficiency as well as power obtained from the expander and generator, taking into account the different temperatures of hot and cold sources for each WF. Work extraction carried out by the expander and electrical power had a range suitable for residential building applications; this range was 0.5–5 kWe with up to 60% electrical isentropic efficiency and up to 8% cycle efficiency for 50–120 °C temperature from a hot source. The operation of WFs will occur in the hot source temperature range, allowing the usage of either solar flat plate or evacuated tube collectors.

Optimal sizing of combined heat and power generation units using of MPSO in the Besat Industrial Zone

2016 ◽  
Vol 04 (01) ◽  
pp. 1650002 ◽  
Author(s):  
Hekmat Latifi ◽  
Meisam Farrokhifar ◽  
Amin Safari ◽  
Siamak Pournasir
Keyword(s):  
Power Generation ◽  
Combined Heat And Power ◽  
Industrial Zone ◽  
Optimal Sizing

Exploiting Waste Heat in Small and Medium-Sized Combined Heat and Power Plants Using Steam Injection

2014 ◽  
Author(s):  
Stephan Arnold ◽  
Markus Schatz
Keyword(s):  
Power Generation ◽  
Electric Power ◽  
Power Output ◽  
Waste Heat ◽  
Cooling Water ◽  
Steam Injection ◽  
Combined Heat And Power ◽  
Heat Demand ◽  
Exhaust Heat ◽  
Ic Engines

Combined heat and power generation (CHP) is a way of providing both electric power and thermal heat for industrial and domestic facilities at high fuel efficiencies. Often small and medium sized gas powered internal combustion (IC) engines, rated at electric power outputs of 50–600 kW, are used for such applications. During the time when the available thermal heat is used, the fuel efficiency of such CHP plants is very high, but it drops to the efficiencies of simple power generation when there is no heat demand, e.g. during summer. In these cases, the exhaust heat is blown off, especially as CHP units are mainly heat-lead, i.e. designed to cover the heat demand rather than the demand for electrical power. Moreover, as the cooling water heat rejection is also more difficult at elevated ambient temperatures, these units are then operated at part load or even switched off, hence having a lower degree of capacity utilization. The approach of the work presented here is to replace the turbocharger system commonly used for IC engines and to use an electric driven compression device instead, while the turbine serves to generate additional electric power from the exhaust gas. Furthermore, for periods with low thermal heat demand, steam is generated from the turbine exhaust heat. The steam is injected in front of the turbine in order to increase the turbine work output further. Thus, at least part of the exhaust heat available is used and the power output as well as the electric efficiency is increased. In the present work, two configurations of the described setup using a medium sized gas powered IC engine CHP unit are modeled in order to assess the impact on plant performance and the characteristics of such a facility. In both cases the engine cooling circuit is integrated. Depending on the configuration used, the plant power output increases by up to 7% only because of the power turbine. Additional steam injection to use the waste heat increases the power output further. The relative electric efficiency increase with steam injection is in the range of 3–5%. Apart from the higher output of electric power, this approach allows longer operating hours to be achieved, as the exhaust heat available is utilized and the heat load for the cooling water circuit is reduced.

Recovering waste heat from diesel generator exhaust; an opportunity for combined heat and power generation in remote Canadian mines

2019 ◽  
Vol 225 ◽  
pp. 785-805 ◽  
Author(s):  
Durjoy Baidya ◽  
Marco Antonio Rodrigues de Brito ◽  
Agus P. Sasmito ◽  
Malcolm Scoble ◽  
Seyed Ali Ghoreishi-Madiseh
Keyword(s):  
Power Generation ◽  
Waste Heat ◽  
Combined Heat And Power ◽  
Diesel Generator

Maximising Utility Savings Through Appropriate Implementation of Combined Heat and Power Scheme

2012 ◽  
Author(s):  
Zainuddin A. Manan ◽  
Fang Yee Lim
Keyword(s):  
Power Generation ◽  
Large Scale ◽  
Waste Heat ◽  
Combined Heat And Power ◽  
Ethyl Benzene ◽  
Pinch Analysis ◽  
Electricity Cost ◽  
Process System ◽  
Composite Curve ◽  
The Right

Skema gabungan haba–kuasa yang juga dikenali sebagai kogenerasi telah diterima secara meluas sebagai salah satu daripada kaedah penjimatan tenaga yang amat berkesan, khususnya bagi loji proses kimia dari kategori industri sederhana dan besar. Terdapat dua kebaikan utama daripada skema gabungan haba–kuasa bagi sesebuah loji kimia: (i) bagi mengurangkan bil elektrik secara mendadak melalui penjanaan kuasa di dalam loji (ii) bagi menjimatkan bil bahan api melalui perolehan semula tenaga haba berkualiti yang terbazir daripada penjanaan kuasa untuk tujuan pemanasan proses. Untuk memastikan keberkesanannya, skema gabungan haba–kuasa perlu diintegrasi pada tahap suhu yang bersesuaian dalam konteks keseluruhan sistem proses. Kegagalan berbuat demikian akan menghasilkan skema gabungan haba–kuasa yang tidak akan mendatangkan sebarang manfaat. Kertas kerja ini menghuraikan kaedah implementasi yang berkesan untuk sebuah skema gabungan haba–kuasa berdasarkan satu kajian kes ke atas proses etil benzena. Sebuah teknik gambaran yang penting daripada kaedah analisis Pinch yang dikenali sebagai lengkuk rencam perdana telah digunakan sebagai panduan utama untuk integrasi optimum skema gabungan haba–kuasa dengan proses. Kajian ini menunjukkan bahawa integrasi bersesuaian di bahagian atas Pinch bagi skema gabungan haba–kuasa dengan proses etil benzena berpotensi menghasilkan penjimatan maksimum sebanyak 87% kos elektrik. Kata kunci: Analisis Pinch, lengkuk rencam, lengkuk rencam perdana, kogenerasi Combined Heat and Power (CHP) scheme, also known as cogeneration is widely accepted as a highly efficient energy saving measure, particularly in medium to large scale chemical process plants. The advantages of a CHP scheme for a chemical plant are two–fold: (i) to drastically reduce electricity bill from on–site power generation (ii) to save on fuel bills through recovery of the quality waste heat from power generation for process heating. In order to be effective, a CHP scheme must be placed at the right temperature level, in the context of an overall process system. Failure to do so might render a CHP venture worthless. This paper describes the procedure for an effective implementation of a CHP scheme using an ethyl benzene process as a case study. A key visualisation tool in Pinch Analysis technique known as the grand composite curve is used to guide CHP integration, and allows it to be optimally placed within the overall process scenario. The study shows that appropriate CHP integration with the ethyl benzene process above the pinch can potentially result in significant savings on electricity cost of up to 87%. Key words: Pinch analysis, composite curves, grand composite curves, cogeneration

Second Generation Integrated Combined Heat and Power Engine Generator and Liquid Desiccant System

2004 ◽  
Author(s):  
Sandeep Nayak ◽  
Sumit Ray ◽  
Reinhard Radermacher
Keyword(s):  
Power Generation ◽  
Thermal Energy ◽  
Second Generation ◽  
Waste Heat ◽  
Water Solution ◽  
Combined Heat And Power ◽  
Total System ◽  
Generation Process ◽  
Liquid Desiccant ◽  
Chp System

The Combined Heat and Power (CHP) concept is aptly suited to improve or eliminate some of the global and local issues concerning electric commercial buildings. CHP involves on-site or near-site generation of electricity by using gas-fired equipment along with utilization of thermal energy available from the power generation process. CHP has the potential of providing a 30% improvement over conventional power plant efficiency and a CO2 emissions reduction of 45% or more. In addition, an overall total system efficiency of 80% can be achieved because of the utilization of thermal energy, that would otherwise be wasted, and the reduction of transmission, distribution and energy conversion losses. CHP technology also makes cost savings possible by reducing high summertime electrical demand charges while at the same time providing necessary space heating and cooling. Savings are further increased in applications where waste heat can replace electric heating. Moreover, CHP has the ability to address indoor air quality issues when utilizing a desiccant dehumidifier by providing direct humidity control and consequently reducing the potential for mold and bacteria development. Because power generation is done on-site, CHP provides control in meeting a building’s electrical needs and also provides an increased level of reliability to ensure high employee productivity. The current research is being carried out in a four–story commercial office building that has been established as the CHP research and demonstration facility on the campus of the University of Maryland in College Park, MD, USA. The 52,700 square feet administrative building includes two heating, ventilating and air-conditioning (HVAC) zones of equal area where zone 1 includes the first and second floors and zone 2 includes the second and third floors. This has facilitated the installation of two different CHP systems for the two zones. The research in this paper discusses about the CHP system catering to zone 1. This paper describes a second generation CHP system involving the integration of a new 75 kW commercial engine generator with the existing liquid desiccant system. The engine generator is connected parallel to the grid for supplying 75 kW of electrical power to the building while the combined waste heat recovered from the exhaust gases as well as the jacket water from the engine is used to heat a 50:50 ethyl glycol–water loop through a packaged heat recovery system. This recovered heat is then used for the regeneration of the lithium chloride solution in a liquid desiccant system and the ethyl glycol–water solution is returned back to the engine. The liquid desiccant system reduces the latent load of the ventilation air entering the roof top unit. Technical challenges concerning electrical and control aspects that were related to modifications of the original CHP system are described and improvements to the original system design and performance are evaluated. The paper then discusses the experimental results obtained with first generation CHP system and its overall performance.

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