Dynamic Analysis of Prime Mover Combined Heat and Power Delivery to Chemical Processing

2011 ◽  
Author(s):  
Michael E. Reed ◽  
Diana K. Grauer
Keyword(s):  
Chemical Process ◽  
Power Input ◽  
Combined Heat And Power ◽  
Power Delivery ◽  
Chemical Plants ◽  
Prime Mover ◽  
Engine Operation ◽  
Unit Operations ◽  
Aspen Custom Modeler ◽  
The Impact

This paper presents a study of the impact of combined heat and power generation from prime mover engines on coupled chemical processes. Medium- and large-bore engines are frequently used in refineries and chemical plants to provide dedicated mechanical power to unit operations. Currently, the prime mover is included in the chemical process design as a single, steady-state power input. This design does not take into account, dynamic engine operation including load changes, start-up, shut-down, and malfunction, all of which have a direct and immediate impact on unit operations. The research team has developed a dynamic model of a “proof of concept” example chemical process in Aspen Custom Modeler to investigate the impact of dynamic operation and integration of a dedicated prime mover unit on an example chemical process.

Optimum Microturbine Sizing in Small Scale CHP Systems

2011 ◽  
Author(s):  
Mehdi Aghaei Meybodi ◽  
Masud Behnia
Keyword(s):  
Power Systems ◽  
Carbon Tax ◽  
Combined Heat And Power ◽  
Small Scale ◽  
Optimum Number ◽  
Prime Mover ◽  
Present Worth ◽  
Prime Movers ◽  
Chp System ◽  
The Impact

Microturbines are ideally suited for distributed generation applications due to their flexibility in connection methods. They can be stacked in parallel for larger loads and provide stable and reliable power generation. One of the main applications of microturbines is operating as the prime mover in a combined heat and power (CHP) system. CHP systems are considered to be one of the best ways to produce heat and power with efficient fossil fuel consumption. Further, these systems emit less pollution compared to separate productions of the same amount of electricity and heat. In order to optimally benefit from combined heat and power systems, the proper sizing of prime movers is of paramount importance. This paper presents a technical-economic method for selecting the optimum number and nominal power as well as planning the operational strategy of microturbines as the prime movers of small scale combined heat and power systems (capacities up to 500 kW) in three modes of operation: one-way connection (OWC) mode, two-way connection (TWC) mode, and heat demand following (HDF) mode. In the proposed sizing procedure both performance characteristics of the prime mover and economic parameters (i.e. capital and maintenance costs) are taken into account. As the criterion for decision making Net Present Worth (NPW) is used. In our analysis we have also considered the impact of carbon tax on the economics of generation. The proposed approach may also be used for other types of prime movers as well as other sizes of CHP system.

Optimum Sizing of the Prime Mover in a Medium Scale Gas Turbine CHP System

2011 ◽  
Vol 133 (11) ◽  
Author(s):  
Mehdi Aghaei Meybodi ◽  
Masud Behnia
Keyword(s):  
Gas Turbine ◽  
Internal Combustion Engines ◽  
Carbon Tax ◽  
Combined Heat And Power ◽  
Prime Mover ◽  
Medium Scale ◽  
Economic Parameters ◽  
Prime Movers ◽  
Chp System ◽  
The Impact

Optimum selection of prime movers in combined heat and power (CHP) systems is of crucial importance due to the fact that inappropriate choices reduce the benefits of CHP systems considerably. In the selection procedure, the performance characteristics of prime movers as well as economic parameters should be taken into account. In this paper, a thermo-economic method for selecting the optimum nominal power and planning the operational strategy of gas turbine as the prime mover of a medium scale (500–5000 kW) CHP system is presented. Appropriate relations for estimating thermodynamic and economic parameters of the system in the context of net annual cost criterion are introduced. Three modes of operation have been considered, namely, two-way connection (TWC) mode, one-way connection (OWC) mode, and heat demand following (HDF) mode. In TWC mode, buying electricity from the grid and selling the excess electricity to the grid are allowed. OWC mode is a situation in which it is only possible to buy electricity from the grid. In HDF mode, buying electricity from the grid and selling electricity to the grid are allowed. HDF mode of operation is considered to have the minimum waste of energy due to the fact that prime movers work in a condition at which the excess produced heat is minimal. As a way of dealing with the environmental concerns, the impact of carbon tax has also been studied. The proposed method has been used for a case study. It was observed that the optimum nominal powers in TWC mode, OWC mode, and HDF mode are 3.5 MW, 3.4 MW, and 0.8 MW, respectively. Furthermore, in order to determine the sensitivity of results to parameters such as cost of electricity, cost of fuel, and carbon tax, a comprehensive sensitivity analysis was conducted. It is noted that the proposed method may be used for other types of prime movers (such as internal combustion engines) as well as various sizes of combined heat and power systems.

scholarly journals A New Method to Determine the Impact of Individual Field Quantities on Cycle-to-Cycle Variations in a Spark-Ignited Gas Engine

Energies ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 4136
Author(s):  
Clemens Gößnitzer ◽  
Shawn Givler
Keyword(s):  
Kinetic Energy ◽  
Flow Field ◽  
Turbulent Kinetic Energy ◽  
Negative Impact ◽  
Operating Conditions ◽  
Engine Operation ◽  
Gas Engine ◽  
Cycle Simulation ◽  
Simulation Results ◽  
The Impact

Cycle-to-cycle variations (CCV) in spark-ignited (SI) engines impose performance limitations and in the extreme limit can lead to very strong, potentially damaging cycles. Thus, CCV force sub-optimal engine operating conditions. A deeper understanding of CCV is key to enabling control strategies, improving engine design and reducing the negative impact of CCV on engine operation. This paper presents a new simulation strategy which allows investigation of the impact of individual physical quantities (e.g., flow field or turbulence quantities) on CCV separately. As a first step, multi-cycle unsteady Reynolds-averaged Navier–Stokes (uRANS) computational fluid dynamics (CFD) simulations of a spark-ignited natural gas engine are performed. For each cycle, simulation results just prior to each spark timing are taken. Next, simulation results from different cycles are combined: one quantity, e.g., the flow field, is extracted from a snapshot of one given cycle, and all other quantities are taken from a snapshot from a different cycle. Such a combination yields a new snapshot. With the combined snapshot, the simulation is continued until the end of combustion. The results obtained with combined snapshots show that the velocity field seems to have the highest impact on CCV. Turbulence intensity, quantified by the turbulent kinetic energy and turbulent kinetic energy dissipation rate, has a similar value for all snapshots. Thus, their impact on CCV is small compared to the flow field. This novel methodology is very flexible and allows investigation of the sources of CCV which have been difficult to investigate in the past.

scholarly journals Risk-Averse Scheduling of Combined Heat and Power-Based Microgrids in Presence of Uncertain Distributed Energy Resources

2021 ◽  
Vol 13 (13) ◽  
pp. 7119
Author(s):  
Abbas Rabiee ◽  
Ali Abdali ◽  
Seyed Masoud Mohseni-Bonab ◽  
Mohsen Hazrati
Keyword(s):  
Electrical Energy ◽  
High Energy ◽  
Combined Heat And Power ◽  
Energy Resources ◽  
Distributed Energy Resources ◽  
Solar Pv ◽  
Distributed Energy ◽  
Robust Scheduling ◽  
Battery Energy ◽  
The Impact

In this paper, a robust scheduling model is proposed for combined heat and power (CHP)-based microgrids using information gap decision theory (IGDT). The microgrid under study consists of conventional power generation as well as boiler units, fuel cells, CHPs, wind turbines, solar PVs, heat storage units, and battery energy storage systems (BESS) as the set of distributed energy resources (DERs). Additionally, a demand response program (DRP) model is considered which has a successful performance in the microgrid hourly scheduling. One of the goals of CHP-based microgrid scheduling is to provide both thermal and electrical energy demands of the consumers. Additionally, the other objective is to benefit from the revenues obtained by selling the surplus electricity to the main grid during the high energy price intervals or purchasing it from the grid when the price of electricity is low at the electric market. Hence, in this paper, a robust scheduling approach is developed with the aim of maximizing the total profit of different energy suppliers in the entire scheduling horizon. The employed IGDT technique aims to handle the impact of uncertainties in the power output of wind and solar PV units on the overall profit.

scholarly journals Performance analysis of the thermoacoustic refrigerator with the standing wave and air as a working fluid

2018 ◽  
Vol 44 ◽  
pp. 00063 ◽  
Author(s):  
Jakub Kajurek ◽  
Artur Rusowicz
Keyword(s):  
Temperature Difference ◽  
High Reliability ◽  
Power Input ◽  
Acoustic Power ◽  
Operating Frequency ◽  
Working Fluid ◽  
Resonator Length ◽  
Environmental Friendliness ◽  
The Impact ◽  
Thermoacoustic Refrigerator

Thermoacoustic refrigerator is a new and emerging technology capable of transporting heat from a low-temperature source to a high-temperature source by utilizing the acoustic power input. These devices, operating without hazardous refrigerants and owning no moving components, show advantages of high reliability and environmental friendliness. However, simple to fabricate, the designing of thermoacoustic refrigerators is very challenging. This paper illustrates the impact of significant factors on the performance of the thermoacoustic refrigerator which was measured in terms of the temperature difference generated across the stack ends. The experimental device driven by a commercial loudspeaker and air at atmospheric pressure as a working fluid was examined under various resonator length and operating frequencies. The results indicate that appropriate resonator’s length and operating frequency lead to an increase in the temperature difference created across the stack. The maximum values were achieved for operating frequency equalled to 200 and 300 Hz whereas resonator length corresponded to the half-length of the acoustic wave for these frequencies. The results of experiment also confirm that relationship between these parameters is strongly affected by the stack spacing, which in this research was equalled to 0.4 mm.

scholarly journals Impacts of New EU and Czech Environmental Legislation on Heat and Electricity Prices of Combined Heat and Power Sources in the Czech Republic

10.14311/1460 ◽  
2011 ◽  
Vol 51 (5) ◽  
Author(s):  
J. Vecka
Keyword(s):  
Combined Heat And Power ◽  
Environmental Legislation ◽  
Industrial Emissions ◽  
Electricity Prices ◽  
Power Sources ◽  
The Czech Republic ◽  
The Future ◽  
Large Heat ◽  
Industrial Emissions Directive ◽  
The Impact

In my economic model I calculate the impact of the new EU ETS Directive, the Industrial Emissions Directive and the new air protection law on future heat and electricity prices for combined heat and power sources. I discover that there will be a significant increase in heat and electricity prices, especially because of the implementation of new so-called benchmark tools for allocating allowances. The main problem of large heat producers in this respect is loss of competitiveness on the heat market due to emerging stricter environmental legislation, which is not applied to competitors on the heat market (smaller heat sources). There is also lack of clarity about the modalities for allocating free allowances, and about the future development of the whole carbon market (the future European allowance price).

scholarly journals Thermodynamic cycles variability of TJI gas engine with different mixture preparation systems

2020 ◽  
Vol 181 (2) ◽  
pp. 46-52
Author(s):  
Filip SZWAJCA ◽  
Krzysztof WISŁOCKI
Keyword(s):  
Fuel Injection ◽  
Combustion Process ◽  
Engine Operation ◽  
Gas Engine ◽  
Part Load ◽  
Mixture Preparation ◽  
Key Factor ◽  
Test Engine ◽  
Operation Stability ◽  
The Impact

Gas engines are a viable source of propulsion due to the ecological indicators of gas fuels and the large amount of the needed natural resources. Combustion of lean homogeneous gas mixtures allows achieving higher thermal efficiency values, which is a key factor in current engine development trends. Using the spark-jet ignition system (also called as Turbulent Jet Ignition or Two-stage combustion) significantly improves the efficiency and stability of the combustion process, especially in the part-load operation on lean or very lean mixtures. This paper presents the impact of using two different fuel injection methods: Port Fuel Injection or Mixer on the operation stability of a gas engine designed for LDVs. Comparative studies of two different mixture preparation systems were carried out on a single-cylinder AVL 5804 test engine. By re-cording the cylinder pressure for a significant number of engine cycles, it became possible to determine the repeatability of engine operation and to correlate the results with the mixture formation system and the air-fuel ratio. In the performed research the beneficial effect of the mixer system application on the engine operation stability in the part-load conditions was found.

scholarly journals An Overview of Difficulties in Controlling Intensified Process

2007 ◽  
Vol 7 (1 & 2) ◽  
pp. 8
Author(s):  
Reza Barzin ◽  
Syamsul Rizal Abd Shukor ◽  
Abdul Latif Ahmad
Keyword(s):  
Chemical Engineering ◽  
Process Intensification ◽  
Dynamic Interaction ◽  
Engineering Industry ◽  
Chemical Plants ◽  
Control Loop ◽  
Process Technology ◽  
Unit Operations ◽  
Potential Problems ◽  
Production Objectives

Process intensification (PI) is currently one of the most significant trends in chemical engineering and process technology. PI is a strategy of making dramatic reductions in the size of unit operations within chemical plants, in order to achieve production objectives. PI technology is able to change dramatically the whole chemical engineering industry pathway to a faster, cleaner and safer industry. Nonetheless, PI technology will be handicapped if such system is not properly controlled. There are some foreseeable problems in order to control such processes for instance, dynamic interaction between components that make up a control loop, response time of the instrumentations, availability of proper sensor and etc. This paper offers an overview and discussion on identifying potential problems of controlling intensified systems.

The impact of marine engine operation and maintenance on emissions

2012 ◽  
Vol 17 (1) ◽  
pp. 54-60 ◽  
Author(s):  
Vanessa Duran ◽  
Zigor Uriondo ◽  
Juan Moreno-Gutiérrez
Keyword(s):  
Engine Operation ◽  
Marine Engine ◽  
Operation And Maintenance ◽  
The Impact

scholarly journals Does Combined Heat and Power Play the Role of a Bridge in Energy Transition? Evidence from a Cross-Country Analysis

2019 ◽  
Vol 11 (4) ◽  
pp. 1035 ◽  
Author(s):  
Hyo-Jin Kim ◽  
Jeong-Joon Yu ◽  
Seung-Hoon Yoo
Keyword(s):  
Power Generation ◽  
Renewable Energy ◽  
Electricity Generation ◽  
Nuclear Power ◽  
Energy Transition ◽  
Parameter Estimate ◽  
Combined Heat And Power ◽  
Cross Country ◽  
The Impact

In an era of energy transition involving an increase in renewable energy and a reduction in coal-fired power generation and nuclear power generation, the role of combined heat and power (CHP) as a bridging energy is highly emphasized. This article attempts to look empirically into the impact of increasing the share of renewable energy in total electricity generation on CHP share in total electricity generation in a cross-country context. Data from 35 countries during the period 2009–2015 were used, and the least absolute deviations estimator was applied to obtain a more robust parameter estimate. The results showed that a 1%p increase in the share of renewable energy significantly increased the CHP share by 0.87%p. Therefore, the hypothesis that CHP serves as bridge energy in the process of energy transition was established.

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