This issue was addressed by developing a novel simulation model with emphasis on the transient operational losses of the CHP units. This chapter started by giving general background information about CHP units and its auxiliary components. Then, the current literature was reviewed. The review was focused on experimental studies (mainly studies which used Annex 42 model) and the design guides which associate with heat networks and the CHP units. In the methodology section, the details of the cogeneration model were explained. The output of the developed model is calculated by multiple procedures. The results section of this study summarised the key outputs of the cogeneration models. Firstly, the outputs of the cogeneration system were discussed on minutely basis. Here, the main principles of the cogeneration model were shown for a sample day. This was followed by showing the variation of the same CHP unit over half-hour slots of a calendar year. In addition to this, key differences between the FTL and FEL strategies were highlighted. The result section showed the proportions of energy supplied by a cogeneration system over the simulated apartment stock. Additionally, the results section discussed the impact of various loss mechanisms over the efficiencies of the CHP units.
Power plants and CHP systems based on internal combustion engines are not a new idea, but there have not been many studies on Diesel engine based ones in literature. Diesel engine based CHP and power plants are the best power production option for local applications in some Asian and South European countries . In the present work, the exergetic and exergoeconomic analysis are performed on the Diesel engine based CHP system considered by Aceves et al.  for combinedpower and heating applications. The system is thermodynamically analyzed through energy and exergy. Then, cost balances and auxiliary equations are applied to subsystems. Moreover, a parametric study is used to show the effect of ambient temperature on important energy, exergy and exergoeconomic parameters and effects of change in compressor pressure ratio and turbine inlet temperature on these parameters in Tehran, the capital city of Iranfor four environmental temperatures, namely: spring temperature (21˚C), summer temperature (29˚C), autumn temperature (14˚C) and winter temperature (6˚C).
CHP is therefore one of the best energy alternatives with higher efficiency compared to the conventional generation. CHP utilises less fuel to generate same energy as that of conventional generation which utilises more fuel to generate same amount of energy. This helps to reduce the greenhouse gas emissions into the atmosphere. CHP has very wide range of cost effective industrial applications. When costanalysis is done, CHP has less cost compared to alternative of buying powerfrom grid and producing the heat using natural gas. The choice of a CHP depends on finance available, site demands in terms of power, heat, environmental compliance to the surrounding and fuel available to run the CHP. Depending on the type of fuel available, a particular CHP can be applied to meet the power and heat demands in different industrial applications.
Abstract. CombinedHeat 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 heatfrompower 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%.
The subject facility has already entered into power purchase agreements for the landfill gas CHP and solar panels installed at the facility . The retail rate for the subject facility is $0.06/kWh which is among the lowest in the country . This makes renewable energy projects difficult to justify economically when compared to buying electricity at as low a rate as it currently is. The cost for natural gas is approximately $4.50/dekatherm ($4.50/MMBtu) . Based on review of the CHP Technologies, it is determined that a reciprocating engine is the best option to use. The electrical output of using a reciprocating engine can be determined using the electrical efficiency of the engine which ranges between 30% for smaller engines to 42% for larger engines. The thermal efficiency of an engine is also important for CHP applications with typical values ranging between 35% and 50% . The remaining energy that does not get converted to electricity or useful heat will be expelled from the system in the form of waste heat. The amount of electricity and thermal energy that can be harnessed with a CHP system can be represented as follows:
SOFC technology is currently at the stage of development, thus its cost information is not well established and very little data are available from the open literature. According to (U.S. Department of Energy -DOE, 2017),  , the current capital cost of a SOFC is estimated about $335.89-$1385.69/kW for 1-5 kW CHP System, and for 10-25 kW CHP System is about $516.58- $1109.42 kW. To calculate the cost and the maintenance cost for the system proposed has to be defined, due the fuel cost is variable. For this reason in this paper, it has been calculated the operating of the system, based on the prices of fuel (CH 4 - natural gas) and
The goal of the project is to upgrade the existing heat production plant CET Timisoara Sud with cogeneration capcity. Electricity consumed internally in the heat production plant and for distribution of district heating water will be covered by the new cogeneration capacity. The project foresees an installation of a steam turbine of about 18 MW in the current district heating plant of CET Timisoara Sud. The project is in an advanced stage of development and expected to be commissioned by the mid of 2006 (beginning of the 2006 – 2007 heating season). The new and improved cycle, utilizing the existing steam boilers in the most efficient way, will produce some excess electricity at certain time periods. Excess electricity will be sold to the national power grid (NPG) or will be used for other internal consumption of the company at other locations in the city. The project would contribute to the mitigation of global warming as well as to sustainable development of the host country by increasing the supply of electricity produced efficiently through cogeneration.
Suitable modification possible in the gas turbine combined cycle such as reheat cycle, heat exchange cycle etc which will improve the efficiency. The captive power plant run as a steam power plant is taken for analysis. The power is produced by means of steam generating boilers and turbo generator. The power requirement in the plant is 10.7 MW and 153 TPH steam is generated in a day. Three boilers at a capacity of 60 TPH are used to generate the steam. The pressure is 110ATA at a temperature of 520 o C.The turbo
Today one major challenge is the enhancement of heat transfer in condensers of modern steam-turbine plants because even in case of off-design behavior of a such a system high values of heat transfer coefficient allow, first of all, to ensure high performance, i.e. maintain the necessary vacuum level in the condenser’ steam space (it is noteworthy to mention that in general impairment of vacuum by 1 kPa leads to a decrease
The apartment preliminary design was prepared initially by the students in discussion with lecturers. To ensure the inclusiveness, the participatory workshop was conducted with Dr. Arina as the future user of the apartment. Incorporating the input from Dr. Arina, the design was later developed. And to create more universal apartment design, additional 2 workshops were conducted with the wheelchair users, blind persons, and deaf persons. The workshops were conducted with the architectural model to explain the apartment design to the PwD. The model was developed with a scale of 1:20 to be easily understood by the participants of the workshops.
Once the user specifies building characteristics, geometry, and other operating parameters in the spreadsheet graphic user interface of the tool, they can also select both a baseline and a proposed HVAC system type. The HePESC can model all eight ASHRAE 90.1 baseline system types and also includes additional all-electric system options. For the proposed systems, the tool supports a variety of air source heat pumps, zonal water source heat pump systems, and single zone or multi-zone VRF heat pumps. The calculations include default heating and cooling equipment sizing factors, but can be easily overridden by the user. For system types whose efficiency requirements vary by size, users can also select from a range of Btu/hr capacity ranges. However, this requires judgment on the user’s part in how to select the representative size of the equipment based on the thermal zoning of the building. Depending on the granularity of the zoning and the application of this tool, the system may be left at a smaller size to represent multiple smaller pieces of equipment. Alternatively, fewer larger units may also be specified depending on the project’s zone configuration. This section of the tool also reports the reference occupant density, a critical value in determining which performance curve to use, and an
According to the Energy Development Strategy of the Ministry of Economy and Trade, the production capacities and transportation infrastructure need urgent modernization. It is necessary to rehabilitate thermal facilities, to introduce low power cogeneration and to install modern and efficient equipment. These measures will contribute to integrating Romanian energy industry into European structures and to ensuring the sustainable development of the energetic sector. According to the National Energy Development Strategy on Long Term (2002-2015) of the Ministry of Economy and Trade, the Romanian energetic safety has been and still is affected by the lack of cash availability for the energetic companies. Actions have already been taken in order to prevent deterioration of the energetic infrastructure and to implement investment and repairing programs in due time.
consumption in Japan. Their failure to operate today can be traced to a single, not obvious, and highly concerning fact: Once a nuclear plant stops producing electrical power it requires continuous auxiliary electrical power to prevent the release of radioactive waste. In the case of three reactors at Fukushima, the March 11, 2011 tsunami washed away the fuel tanks for the backup generators. Thus electrical power could not be provided to the emergency support systems in the plant, highlighting the irony that a plant designed to produce electrical power also requires electrical power in order to function.
The HPWH breakeven cost is the net installed cost that achieves cost neutrality with a current water heating technology. It depends on climate, incentives, local utility rates, and other factors. In the United States, where these factors vary substantially across regions, breakeven costs vary significantly. Breakeven cost was used as the primary metric for economic analysis in this study, because these units are relatively new to the market. Their installation costs are thus not well known and the capital costs could change relatively quickly if their adoption were to rapidly increase. Installation costs may also vary significantly from household to household as some installations may incur additional costs associated with condensate drains, louvered doors, venting, or other site-specific considerations. Additional costs associated with fuel switching (for example, capping a gas line or adding a new circuit for the HPWH) may also be incurred if a gas WH is replaced by an HPWH. Recent estimates for the net installed cost (the cost of the WH plus all installation costs) of HPWHs with this efficiency range from $1300 to $2200; the estimated average net installed cost is about $1500 (U.S. Department of Energy, 2010). The HPWH breakeven cost is defined as the point at which the net present cost (NPC) of the HPWH equals the net present benefit (NPB) realized to its owner—the difference between the NPB and NPC yields the net present value (NPV) of the system. By definition, an HPWH system is at (or better than) breakeven when its net installed cost falls below the breakeven value. For example, in an area with a breakeven cost of $2000, all HPWH systems that have an installed cost of less than $2000 are at—or better than—breakeven. Equations for the NPC, NPB, and breakeven cost are presented in Appendix D.
Energy efficiency improvement of existing plants can be achieved by installing a steam turbine or by installing an additional heat export system to a nearby site if the demand for heat exists. Another way is to co-locate new waste management facilities with heat demand (e.g., food waste treatment or drying of sewage sludge for fuel production) at an existing WtE plant. Reduction in consumption of auxiliary fuels and electricity is also necessary to improve efficiency. However, such measures are appropriate only for plants with excess heat and sufficiently long life-times. According to study by the Korean Ministry of Environment , installing a steam turbine for power generation was economically feasible in nine plants with a capacity larger than 50 t/day and five smaller plants. These plants had over six years of life-time remaining and most had >3 t/h of excess steam not utilized. The energy efficiency of these plants is expected to increase since the government has initiated several projects to install additional energy recovery facilities.