Feasibility Assessments of Combined Cooling, Heating, and Power (CCHP) Systems for Commercial Buildings PDF Download

Author: Hyeunguk Ahn
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
Distributed energy systems produce energy on-site considerably reducing energy loss that would occur when energy is supplied from centralized systems. One of the distributed energy technologies is a combined cooling, heating, and power (CCHP) system. In a CCHP system, electricity is generated near end-users and the recovered heat from a power generation unit is utilized for cooling and heating in a building. Therefore, CCHP systems can increase primary energy utilization efficiency and energy reliability while reducing adverse environmental impacts. CCHP systems can be applicable from a building to community level. However, the feasibility of CCHP systems can largely vary with building type and location as well as other integrated sub-systems such as hybrid chiller and solar photovoltaic (PV) systems. This dissertation focuses on feasibility assessments of CCHP systems integrated with hybrid chiller and PV systems. Specifically, the work in this dissertation consists of investigations of energy, environmental, and economic performances of CCHP systems applied to various commercial building types in different climatic regions in the U.S.The first investigation evaluates the energy and environmental performances of CCHP systems operating with two distinct cooling systems (i.e., absorption chiller vs. hybrid chiller) based on primary energy consumption and carbon dioxide emission. This study focuses on a hospital and an office building in San Francisco, CA and Long Island, NY. The results show that CCHP hybrid chiller systems can reduce a significant amount of primary energy consumption than traditional CCHP systems that utilize only an absorption chiller, especially when the systems are applied to a hospital building. The significant reduction of the primary energy consumption is mainly because a hybrid chiller system can minimize undesirable boiler operations for absorption cooling. The reduced primary energy consumption can also lead to a decrease in carbon dioxide emissions although regionally-varying emission factors of the grid electricity notably influence the environmental performance of CCHP hybrid chiller systems.The second investigation focuses on the economic feasibility of different-sized CCHP hybrid chiller systems for large office buildings considering realistic electricity tariff structures in different geographic regions including San Francisco, CA; Boston, MA; and Miami, FL. The results show that CCHP hybrid chiller systems can be economically justifiable for regions with relatively high electricity price and low natural gas price such as San Francisco and Boston. The cost savings are mainly attributed to electricity cost savings. Specifically, if a local electricity tariff estimates demand charges as high as energy charges (e.g., a tariff structure in San Francisco), demand charges can contribute to about 40% of the electricity cost savings; thus, using simplified tariff structures that neglect demand charges can result in a noticeable discrepancy in economic analyses of CCHP systems or other analogous distributed energy systems. However, for regions with relatively high natural gas price and low electricity price (e.g., Miami), the operation cost of CCHP hybrid chiller systems is higher up to $0.4 million per year compared to that of a conventional separate heat and power (SHP) system.The third investigation integrates solar PV panels with CCHP hybrid chiller (CCHP+PV) systems as applied to a large office building in San Francisco, CA and examines the impacts of variabilities in energy demands and solar irradiance on the energy and economic performances of CCHP+PV systems. According to the results obtained in this study, the associated uncertainties marginally influence the energy performance of CCHP+PV systems whereas they can increase the operation cost by up to $75,000 per year. Such a great increase in the operation cost is mainly attributed to demand charges that tend to increase as the uncertainties are considered. This result implies that a deterministic model of a CCHP+PV system may significantly underestimate its operation costs and overestimate economic savings, thereby leading to overly optimistic economic viability.

Author: Masood Ebrahimi
Publisher: Elsevier
ISBN: 0080999921
Category : Technology & Engineering
Languages : en
Pages : 219

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Book Description
A professional reference title written primarily for researchers in thermal engineering, Combined Cooling, Heating and Power: Decision-Making, Design and Optimization summarizes current research on decision-making and optimization in combined cooling, heating, and power (CCHP) systems. The authors provide examples of using these decision-making tools with five examples that run throughout the book. Offers a unique emphasis on newer techniques in decision-making Provides examples of decision-making tools with five examples that run throughout the book

Author: Anh-Tuan Vu Do
Publisher:
ISBN: 9781303034350
Category :
Languages : en
Pages : 349

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Combined cooling, heating and power (CCHP) systems are power generation stations designed for maximum waste heat recovery and energy sustainability. In a conventional CCHP system, a gas turbine provides the electrical generation and the waste heat is recovered for cooling and heating. Traditionally, utility-scale CCHP plants of 100 MW or more were commissioned to support large industrial processing plants. Light industry, commercial, and institutional applications have adopted smaller CCHP systems to realize economic savings and environmental benefits. Besides facing operating constraints such as smaller foot-print, shorter reaction time and shorter control tolerances, these plants also encounter low energy demands because of diurnal or seasonal variations, forcing them to operate at part-load. Coupled with relatively high capital and O & M costs, compact CCHP stations then become uneconomical for end-users. From flexibilities in operation, however, there are ample opportunities for favorable economic dispatch by operating the plant under demand response programs and ancillary services. The small-scaled CCHP systems fall under the distributed generation (DG) category of many regulatory policies and electricity rate tariffs of utilities. Several typical rate structures applicable to CCHP systems were evaluated, including standby and non-standby time-of-use (TOU), and critical peak pricing (CPP). The economic analysis produced insights on novel and preferred chiller dispatch strategies for energy and demand charge reduction. The increased variability and uncertainty of renewable generation add to the balancing duties of grid regulators whom previously had to deal with such behaviors in system load. The situation is becoming direr for California, as the state mandates 33% renewable resource generation by 2020 along with a plethora of stringent environmental legislation that would displace 18,000 MW of traditional base-load plants by 2020. Therefore, ancillary services will become more valuable as grid balancing authorities such as CAISO seek to address the uncertainty and variability in renewable generation. A gas turbine-driven CCHP system is one example of an ancillary service provider capable of complementing the increased renewable penetration. This dissertation seeks to elucidate the feasibility of implementing CCHP technology to light industrial and commercial applications for favorable economic dispatch to complement demand response services and renewable integration.

Author: Yang Shi
Publisher: John Wiley & Sons
ISBN: 1119283353
Category : Technology & Engineering
Languages : en
Pages : 195

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Book Description
A comprehensive review of state-of-the-art CCHP modeling, optimization, and operation theory and practice This book was written by an international author team at the forefront of combined cooling, heating, and power (CCHP) systems R&D. It offers systematic coverage of state-of-the-art mathematical modeling, structure optimization, and CCHP system operation, supplemented with numerous illustrative case studies and examples. CCHP systems are an exciting emerging energy technology offering significant economic and environmental benefits. Combined Cooling, Heating, and Power Systems: Modelling, Optimization, and Operation is a timely response to ongoing efforts to maximize the efficiency of that technology. It begins with a survey of CCHP systems from the technological and societal perspectives, offering readers a broad and stimulating overview of the field. It then digs down into topics crucial for optimal CCHP operation. Discussions of each topic are carefully structured, walking readers from introduction and background to technical details. A set of new methodologies for the modeling, optimization and control of CCHP systems are presented within a unified framework. And the authors demonstrate innovative solutions to a variety of CCHP systems problems using new approaches to optimal power flow, load forecasting, and system operation design. Provides a comprehensive review of state-of-the-art of CCHP system development Presents new methodologies for mathematical modeling, optimization, and advanced control Combines theoretical rigor with real-world application perspectives Features numerous examples demonstrating an array of new design strategies Reflects the combined experience of veteran researchers in the field whose contributions are well recognized within the energy community Offers excellent background reading for students currently enrolled in the growing number of courses on energy systems at universities worldwide Timely, authoritative, and offering a balanced presentation of theory and practice, Combined Cooling, Heating, and Power Systems: Modelling, Optimization, and Operation is a valuable resource forresearchers, design practitioners, and graduate students in the areas of control theory, energy management, and energy systems design.

Author: Mingxi Liu
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
Combined cooling, heating and power (CCHP) systems are known as trigeneration systems, designed to provide electricity, cooling and heating simultaneously. The CCHP system has become a hot topic for its high system efficiency, high economic efficiency and less greenhouse gas (GHG) emissions in recent years. The efficiency of the CCHP system depends on the appropriate system configuration, operation strategy and facility size. Due to the inherent and inevitable energy waste of the traditional operation strategies, i.e., following the electric load (FEL) and following the thermal load (FTL), more efficient operation strategy should be designed. To achieve the highest system efficiency, facilities in the system should be sized to match with the corresponding operation strategy. In order to reduce the energy waste in traditional operation strategies and improve the system efficiency, two operation strategy design methods and sizing problems are studied (In Chapter 2 and Chapter 3). Most of the improved operation strategies in the literature are based on the ''balance'' plane, which implies the match of the electric demands and thermal demands. However, in more than 95% energy demand patterns, the demands cannot match with each other at this exact ''balance'' plane. To continuously use the ''balance'' concept, in Chapter 2, the system configuration is modified from the one with single absorption chiller to be the one with hybrid chillers and expand the ''balance'' plane to be a ''balance'' space by tuning the electric cooling to cool load ratio. With this new ''balance'' space, an operation strategy is designed and the power generation unit (PGU) capacity is optimized according to the proposed operation strategy to reduce the energy waste and improve the system efficiency. A case study is conducted to verify the feasibility and effectiveness of the proposed operation strategy. In Chapter 3, a more mathematical approach to schedule the energy input and power flow is proposed. By using the concept of energy hub, the CCHP system is modelled in a matrix form. As a result, the whole CCHP system is an input-output model. Setting the objective function to be a weighted summation of primary energy savings (PESs), hourly total cost savings (HTCs) and carbon dioxide emissions reduction (CDER), the optimization problem, constrained by equality and inequality constraints, is solved by the sequential quadratic programming (SQP). The PGU capacity is also sized under the proposed optimal operation strategy. In the case study, compared to FEL and FTL, the proposed optimal operation strategy saves more primary energy and annual total cost, and can be more environmental friendly. Finally, the conclusions of this thesis is summarized and some future work is discussed.

Author: Eugenio Arbizzani
Publisher: Springer Nature
ISBN: 3031295153
Category : Architecture
Languages : en
Pages : 1027

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Book Description
This open access book addresses the pressing need for sustainability in urban development and the use of technology, with cities to serve as the main stage for strategies that seek to meet the targets and the cross-sector priorities indicated in the EU’s Next Generation program, all in pursuit of a solid recovery on the part of the European economy, along lines of ecological transition, digitalization, competitiveness, training, and inclusion to overcome social, territorial, and gender differences. The international study encounter is meant to promote visions shared by architectural technology and other disciplines, which, though they may appear to differ, are closely interconnected, with the aim of achieving an open, interdisciplinary integration capable of proposing concrete projects regarding topics held to be of strategic importance to the future of the built environment. These are identified to draw up evolving scenarios of architecture and cities suited to reflection, at various levels, on innovative models of process and product.

Author:
Publisher:
ISBN:
Category : Buildings
Languages : en
Pages :

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Combined Cooling Heating and Power (CCHP) systems have been recognized as a viable alternative to conventional electrical and thermal energy generation in buildings because of their high efficiency, low environmental impact, and power grid independence. Many researchers have presented models for comparing CCHP systems to conventional systems and for optimizing CCHP systems. However, many of the errors and uncertainties that affect these modeling efforts have not been adequately addressed in the literature. This dissertation will focus on the following key issues related to errors and uncertainty in CCHP system modeling: (a) detailed uncertainty analysis of a CCHP system model with novel characterization of weather patterns, fuel prices and component efficiencies; (b) sensitivity analysis of a method for estimating the hourly energy demands of a building using Department of Energy (DOE) reference building models in combination with monthly utility bills; (c) development of a practical technique for selecting the optimal Power Generation Unit (PGU) for a given building that is robust with respect to fuel cost and weather uncertainty; (d) development of a systematic method for integrated calibration and parameter estimation of thermal system models. The results from the detailed uncertainty analysis show that CCHP operational strategies can effectively be assessed using steady state models with typical year weather data. The results of the sensitivity analysis reveal that the DOE reference buildings can be adjusted using monthly utility bills to represent the hourly energy demands of actual buildings. The optimal PGU sizing study illustrates that the PGU can be selected for a given building in consideration of weather and fuel cost uncertainty. The results of the integrated parameter estimation study reveal that using the integrated approach can reduce the effect of measurement error on the accuracy of predictive thermal system models.

Author:
Publisher:
ISBN:
Category : Cogeneration of electric power and heat
Languages : en
Pages : 7

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Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 32

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This report analyzes the current economic and environmental performance of combined heat and power (CHP) systems in power interruption intolerant commercial facilities. Through a series of three case studies, key trade-offs are analyzed with regard to the provision of black-out ridethrough capability with the CHP systems and the resutling ability to avoid the need for at least some diesel backup generator capacity located at the case study sites. Each of the selected sites currently have a CHP or combined heating, cooling, and power (CCHP) system in addition to diesel backup generators. In all cases the CHP/CCHP system have a small fraction of the electrical capacity of the diesel generators. Although none of the selected sites currently have the ability to run the CHP systems as emergency backup power, all could be retrofitted to provide this blackout ride-through capability, and new CHP systems can be installed with this capability. The following three sites/systems were used for this analysis: (1) Sierra Nevada Brewery - Using 1MW of installed Molten Carbonate Fuel Cells operating on a combination of digestor gas (from the beer brewing process) and natural gas, this facility can produce electricty and heat for the brewery and attached bottling plant. The major thermal load on-site is to keep the brewing tanks at appropriate temperatures. (2) NetApp Data Center - Using 1.125 MW of Hess Microgen natural gas fired reciprocating engine-generators, with exhaust gas and jacket water heat recovery attached to over 300 tons of of adsorption chillers, this combined cooling and power system provides electricity and cooling to a data center with a 1,200 kW peak electrical load. (3) Kaiser Permanente Hayward Hospital - With 180kW of Tecogen natural gas fired reciprocating engine-generators this CHP system generates steam for space heating, and hot water for a city hospital. For all sites, similar assumptions are made about the economic and technological constraints of the power generation system. Using the Distributed Energy Resource Customer Adoption Model (DER-CAM) developed at the Lawrence Berkeley National Laboratory, we model three representative scenarios and find the optimal operation scheduling, yearly energy cost, and energy technology investments for each scenario below: Scenario 1 - Diesel generators and CHP/CCHP equipment as installed in the current facility. Scenario 1 represents a baseline forced investment in currently installed energy equipment. Scenario 2 - Existing CHP equipment installed with blackout ride-through capability to replace approximately the same capacity of diesel generators. In Scenario 2 the cost of the replaced diesel units is saved, however additional capital cost for the controls and switchgear for blackout ride-through capability is necessary. Scenario 3 - Fully optimized site analysis, allowing DER-CAM to specify the number of diesel and CHP/CCHP units (with blackout ride-through capability) that should be installed ignoring any constraints on backup generation. Scenario 3 allows DER-CAM to optimize scheduling and number of generation units from the currently available technologies at a particular site. The results of this analysis, using real data to model the optimal schedulding of hypothetical and actual CHP systems for a brewery, data center, and hospital, lead to some interesting conclusions. First, facilities with high heating loads will typically prove to be the most appropriate for CHP installation from a purely economic standpoint. Second, absorption/adsorption cooling systems may only be economically feasible if the technology for these chillers can increase above current best system efficiency. At a coefficient of performance (COP) of 0.8, for instance, an adsorption chiller paired with a natural gas generator with waste heat recovery at a facility with large cooling loads, like a data center, will cost no less on a yearly basis than purchasing electricity and natural gas directly from a utility. Third, at marginal additional cost, if the reliability of CHP systems proves to be at least as high as diesel generators (which we expect to be the case), the CHP system could replace the diesel generator at little or no additional cost. This is true if the thermal to electric (relative) load of those facilities was already high enough to economically justify a CHP system. Last, in terms of greenhouse gas emissions, the modeled CHP and CCHP systems provide some degree of decreased emissions relative to systems with less CHP installed. The emission reduction can be up to 10% in the optimized case (Scenario 3) in the application with the highest relative thermal load, in this case the hospital. Although these results should be qualified because they are only based on the three case studies, the general results and lessons learned are expected to be applicable across a broad range of potential and existing CCHP systems.

Author: CB. Oland
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
Combined heat and power (CHP) or cogeneration is the sequential production of two forms of useful energy from a single fuel source. In most CHP applications, chemical energy in fuel is converted to both mechanical and thermal energy. The mechanical energy is generally used to generate electricity, while the thermal energy or heat is used to produce steam, hot water, or hot air. Depending on the application, CHP is referred to by various names including Building Cooling, Heating, and Power (BCHP); Cooling, Heating, and Power for Buildings (CHPB); Combined Cooling, Heating, and Power (CCHP); Integrated Energy Systems (IES), or Distributed Energy Resources (DER). The principal technical advantage of a CHP system is its ability to extract more useful energy from fuel compared to traditional energy systems such as conventional power plants that only generate electricity and industrial boiler systems that only produce steam or hot water for process applications. By using fuel energy for both power and heat production, CHP systems can be very energy efficient and have the potential to produce electricity below the price charged by the local power provider. Another important incentive for applying cogeneration technology is to reduce or eliminate dependency on the electrical grid. For some industrial processes, the consequences of losing power for even a short period of time are unacceptable. The primary objective of the guide is to present information needed to evaluate the viability of cogeneration for new or existing industrial, commercial, and institutional (ICI) boiler installations and to make informed CHP equipment selection decisions. Information presented is meant to help boiler owners and operators understand the potential benefits derived from implementing a CHP project and recognize opportunities for successful application of cogeneration technology. Topics covered in the guide follow: (1) an overview of cogeneration technology with discussions about benefits of applying cogeneration technology and barriers to implementing cogeneration technology; (2) applicable federal regulations and permitting issues; (3) descriptions of prime movers commonly used in CHP applications, including discussions about design characteristics, heat-recovery options and equipment, fuels and emissions, efficiency, maintenance, availability, and capital cost; (4) electrical generators and electrical interconnection equipment; (5) cooling and dehumidification equipment; (6) thermodynamic cycle options and configurations; (7) steps for evaluating the technical and economic feasibility of applying cogeneration technology; and (8) information sources.