Combined Heat Power Plant Research Articles

METHODICAL APPROACH TO ESTIMATING THE POTENTIAL OF THERMAL ENERGY PRODUCTION BY HEAT PUMP PLANTS IN CASE OF THEIR IMPLEMENTATION IN REGIONAL DISTRICT HEATING SYSTEMS

The results of the estimation of the annual potential for thermal energy production using heat pumps (HPs) in district heating systems (DHS) for the regions of Ukraine and the country as a whole are given. This study is relevant due to the high level of DHS development in Ukraine, which reaches 52 %. Today, the outdated equipment of DHSs in Ukraine needs significant technological modernization. Also, in the near future, it will be necessary to restore DHSs destroyed as a result of the total destruction of the civil infrastructure by the russian aggressor. The post-war reconstruction of Ukrainian cities has a unique chance to radically update DHSs using renewable energy sources and innovative technologies, including HPs. The authors propose a new methodical approach for the regional determination of the forecast implementation scope of HPs in DHSs. Using this approach, the economically available energy potential of thermal energy production by HPs in DHSs from various low-potential heat sources (LPHS) was determined, both for the regions of Ukraine and for the country as a whole. As of 2020, this energy potential for DHSs of Ukraine is 62.601 million Gcal/year (262.1 PJ/year): 22.2 % is provided by natural LPHS (heat of air (2.2 %), river water (16.9 %), ground and groundwater (3.1 %)) and 77.8 % is provided by anthropogenic LPHS (heat of ventilation emissions of buildings connected to the DHS (43.0%), sewage water (9.7 %), flue gases from boilers and combined heat power plants (14.3 %), cooling water of technological processes (10.8 %)). The calculated energy potentials for the thermal energy production by HPs from various LPHSs for DHSs of 24 regions of Ukraine are presented also. Information from scientific publications, regulatory documents, annual reports of the State Statistical Service of Ukraine and other government agencies used as the initial data for calculations. Approved methods of heat engineering calculations, methods of statistical and calculation-comparative analysis using Microsoft Excel computer software used to calculate and visualize the results. Methodical recommendations for determining the priority and locations for the implementation of HPs in regional DHSs of Ukraine, which developed by the authors of the article, are presented. Bibl. 48, Fig. 2, Tab. 4.

Membrane Cascade Type of «Continuous Membrane Column» for Power Plant Post-Combustion Carbon Dioxide Capture Part 1: Simulation of the Binary Gas Mixture Separation

The present paper deals with the complex study of CO2 capture from combined heat power plant flue gases using the efficient technological design of a membrane cascade type of «Continuous Membrane Column» for binary gas mixture separation. In contrast to well-known multi-step or multi-stage process designs, the cascade type of separation unit provides several advantages. Here, the separation process is implemented in it by creating two counter current flows. In one of them is depleted by the high-permeable component in a continuous mode, meanwhile the other one is enriched. Taking into account that the circulating flows rate overcomes the withdrawn one, there is a multiplicative increase in separation efficiency. A comprehensive study of CO2 capture using the membrane cascade type of «Continuous Membrane Column» includes the determination of the optimal membrane material characteristics, the sensitivity study of the process, and a feasibility evaluation. It was clearly demonstrated that the proposed process achieves efficient CO2 capture, which meets the modern requirements in terms of the CO2 content (≥95 mol.%), recovery rate (≥90%), and residual CO2 concentration (≤2 mol.%). Moreover, it was observed that it is possible to process CO2 with a purity of up to 99.8 mol.% at the same recovery rate. This enables the use of this specific process design in CO2 pretreatment operations for the production of high-purity carbon dioxide.

Design of Energy Storage for Assisting Extraction Condensing Unit to Peak Regulation and Frequency Modulation

Abstract Coupling energy storage system is one of the potential ways to improve the peak regulation and frequency modulation performance for the existing combined heat power plant. Based on the characteristics of energy storage types, achieving the accurate parameter design for multiple energy storage has been a necessary step to coordinate regulation. In this work, heat storage tank for peak regulation and flywheel energy storage for frequency modulation have been carried out, including the parameters design and performance evaluation for their charging (or discharging) rate and capacity, and the collaborative optimization of dual energy storage systems has been realized. First, the effects of increasing peak depth, load change rate (frequency modulation) range, and energy storage parameters are further analyzed. It is worth noting that the power curves of regional thermal and electrical loads would be adjusted according to the set requirements. Results showed that, the set rate of charge and discharge as well as the capacity of energy storage is conducive to improving the peak regulation depth of the system, and the peak regulation depth would reach its limit at 96.35 MW and 40.83 MWh in the calculation cases, respectively. On this basis, the cooperative regulation of dual energy storage can further increase the capability of peak regulation and frequency modulation. The extreme point is that when the charge and discharge rates are both 3 MW, and meanwhile the peak clipping coefficient, a self-defined parameter, reaches 22.34 MW. Furthermore, an example calculation is carried out to verify the reliability of the design method of energy storage parameter. The specific parameters set include the charging and discharging rate of energy storage tank equipment is 61.67 MW, and its capacity is 10.64 MWh, and the charging and discharging rate of flywheel energy storage equipment is 3 MW. The example results confirmed that there was only a very small error between the set results and the calculation results. Finally, the thermal-electric load region has been drawn to contrast the key roles of dual energy storage systems, which indicates that the heat storage tank can be used for peak regulation and flywheel energy storage for frequency modulation. Overall, the parameter design method for dual energy storage can meet the engineering requirements and provide a new direction for the subsequent parameter design of thermal power unit coupled energy storage system.

Development of the concept of environmentally friendly CHPP and TPP with the active use of photosynthetic processes

The article considers the possibility of applying the concept of a “transition link” from hydrocarbon to “green” energy. The entire world industry uses hydrocarbons as fuel. The share of “green” energy is growing, but it cannot completely replace oil, gas and coal at this stage. In many production processes, due to technology, a significant amount of heat is lost. Thus, the anthropogenic impact is doubled both due to fuel combustion and due to heat losses into the environment. Traditional methods of reducing harmful emissions, as a rule, are focused only on a specific type of treatment and are capital treatment facilities. The authors' approach to the problem differs from the generally accepted one. The developed method makes it possible to obtain an additional product due to waste heat, while reducing emissions of carbon monoxide into the atmosphere. The authors have chosen Combined heat power plant (CHPP), thermal power plant (TPP) as the object of research. Their role as a source of heat, light and hot water supply can hardly be overestimated. But thermal power plants and thermal power plants are also sources of greenhouse gases generated during fuel combustion, sources of heat loss with exhaust gases and thermal pollution of water bodies with cooling liquid. Thermal pollution of water bodies leads to their overgrowth with algae, and as a result, deterioration of water quality. The method presented by the authors is based on the integrated use of waste heat generated in large volumes in algae cooling ponds and the production of bioethanol. Studies were carried out on a mass spectrometer of the chemical composition of algae formed in various media (sea, tap and purified water). During the experiments, legumes were grown on purified water, tap water, and distilled water. According to the calculations, the cost of 1 L of the resulting bioethanol will be about 28 rubles/l, which is 3 times cheaper than what is currently produced. It is concluded that the polluted water of a thermal power plant or thermal power plant has a negligible effect on the bioethanol yield. A 17.8-fold decrease in sodium was shown due to the use of biofilters. During the experiments, legumes were grown on purified water, tap water, and distilled water.The conclusion is made about the significant adsorption capacity of Zn, Mg, Fe, Al, Si, Pb ions. The resulting water after passing through the algae was tested according to SanPiN 2.1.4.1074-01, and fully complied with the standard, which allows it to be used for technological and technical purposes and, moreover, to be returned to the natural environment without consequences.The work is planned within the framework of an international project to create devices and industrial technology that provides for the production of synthesis gas in a fuel processor and hydrogen for generating electrical energy using a fuel cell.

Increasing the energy efficiency of combined heat power plants by reducing the temperature of the additional feed water of power boilers

The article discusses a fundamentally new technology for increasing the specific generation of electricity based on thermal consumption, and also calculates the effectiveness of the proposed solution. The main distinguishing feature of this solution is a decrease in the temperature of the additional feed water of the boilers of thermal power plants. As a result, a method was developed to increase the specific power generation based on heat consumption by reducing the temperature of the additional feed water of power boilers. The authors have developed a technical solution for the use of gas entering the burners to cool additional feed water through a heat exchanger-cooler; a study of the economic and energy efficiency of the proposed technical solution has been carried out.

Research on Down-Regulation Cost of Flexible Combined Heat Power Plants Participating in Real-Time Deep Down-Regulation Market

The issue of real-time deep down-regulation ancillary service has received increasing attention in the Northeast of China. Participation of combined heat and power plants with multitype units and flexible heating devices in the market is investigated. This paper establishes a model of feasible operating region and the coal consumption function for the combined heat and power plant. An internal optimal dispatch model and the minimum overall electric power output model for the plant satisfying a given heat load are presented. Furthermore, the models of total cost for down-regulation and average cost for deep down-regulation in two levels are established. These models are validated based on the realistic data of the plant in the Northeast of China. In case studies, the influence factors and change rules of the minimum electric power output, the total cost, and the average cost of plants are analyzed.

Optimal Municipal Energy System Design and Operation Using Cumulative Exergy Consumption Minimisation

In developed countries like Austria the renewable energy potential might outpace the demand. This requires primary energy efficiency measures as well as an energy system design that enables the integration of variable renewable energy sources. Municipal energy systems, which supply customers with heat and electricity, will play an important role in this task. The cumulative exergy consumption methodology considers resource consumption from the raw material to the final product. It includes the exergetic expenses for imported energy as well as for building the energy infrastructure. In this paper, we determine the exergy optimal energy system design of an exemplary municipal energy system by using cumulative exergy consumption minimisation. The results of a case study show that well a linked electricity and heat system using heat pumps, combined heat power plants and battery and thermal storages is necessary. This enables an efficient supply and also provides the necessary flexibilities for integrating variable renewable energy sources.

Improving urban district heating systems and assessing the efficiency of the energy usage therein

The report describes issues in connection with improving urban district heating systems from combined heat power plants (CHPs), to propose the ways for improving the reliability and the efficiency of the energy usage (often referred to as “energy efficiency”) in such systems. The main direction of such urban district heating systems improvement suggests transition to combined heating systems that include structural elements of both centralized and decentralized systems. Such systems provide the basic part of thermal power via highly efficient methods for extracting thermal power plants turbines steam, while peak loads are covered by decentralized peak thermal power sources to be mounted at consumers’ locations, with the peak sources being also reserve thermal power sources. The methodology was developed for assessing energy efficiency of the combined district heating systems, implemented as a computer software product capable of comparatively calculating saving on reference fuel for the system.

Economic efficiency of a gas-turbine topping for steam reheating at heating turbo-installations

The article considers the ways to improve the operating efficiency of conventional combined heat power plants using gas-turbine topping scheme allowing heat utilization of flue gases for steam reheating in the waste-heat steam boiler. The calculating analysis was performed for a steam-turbine power generating unit with a turbine of the Т-110/120-130 brand name intended for various modes of operation.

열병합발전소 플라이애시와 순환잔골재를 사용한 무시멘트 모르타르의 공학적 특성

본 연구는 순환골재의 재활용 방안 및 시멘트를 대체할 수 있는 결합재에 대한 연구가 필요한 실정으로 고로슬래그, 플라이애시, 열병합플라이애시 등을 시멘트 대체재로 활용하여 무시멘트 모르타르를 제조하고자 하였다. 기초 실험에서는 결합재의 비율 및 알칼리 자극제의 선정을 위한 실험을 실시하였으며, 실험결과 결합재는 플라이애시 20%, 열병합플라이애시 40%를 치환한 경우 가장 높은 강도 값을 나타내었으며 알칼리 자극제로 NaOH 2.5%, <TEX>$Ca(OH)_2$</TEX> 7.5%를 혼합하여 사용할 경우 가장 높은 강도 값을 나타내었다. 따라서 본 실험에서는 기초 실험에서 얻어진 최적 배합을 토대로 순환 잔골재의 치환율에 따른 무시멘트 모르타르의 특성을 검토하여 열병합플라이애시와 순환 잔골재를 사용한 모르타르의 공학적 특성을 분석하고자 하였다. 실험결과, 순환 잔골재의 적정 치환율은 75%인 것으로 나타났다. In this study, to suggest the application method of recycled fine aggregate, the non-cement mortar was prepared and studied with the binders of blast furnace slag, fly ash, and fly ash from combined heat power plant. As a basic experiment, a series of tests was conducted to determine the potions of the binders and types of activator. When the binder was consisted with 20% of fly ash and 40% of fly ash from combined heat power plant, the highest strength of the mortar was obtained, and as an activator, the combination of sodium hydroxide 2.5%, and calcium hydroxide 7.5% showed the highest strength of the mortar. Therefore, this study focuses on engineering properties of mortar contains fly ash from combined heat power plant and recycled fine aggregate according to replacement ratio of recycled fine aggregate based on the optimum mix from the basic experiment. As a result, the best replacement ratio of recycled fine aggregate is 75%.

Methodology for consideration of specific features of combined-cycle plants with the optimal sharing of the thermal and the electric loads at combined heat power plants with equipment of a complex configuration

When a combined-cycle power plant operates as part of a combined heat power plant, the optimal load-sharing among the power-generating units of the station is complicated owing to specific features of operating a combined-cycle power plant, viz., the dependence of its adjustment range values on the outdoor air temperature, degradation of the ecological and economic performance figures under underloading conditions, possibility of load-sharing between the gas turbines, and a high flexibility. A method for optimal sharing of the load among the power-generating plants of combined heat power plants is proposed that takes into consideration the above features of the combined-cycle power plants. The combined heat power plant is divided into “equivalent” units according to the group power supply points. The first step is the intra-unit optimization over the entire variation range of the thermal and electric loads to achieve the best energy performance of the “equivalent” unit. The second step is the optimization of the load-sharing among the “equivalent” units.

Anaerobic treatment of palm oil mill effluents: potential contribution to net energy yield and reduction of greenhouse gas emissions from biodiesel production

Abstract The effluents from palm oil mills for biodiesel production are generally treated in open ponds, causing large amounts of greenhouse gas (GHG) emissions. This study assesses the use of palm oil mill effluents (POME) as feedstock to produce biogas via anaerobic digestion. Biogas from POME can be converted into electricity and heat to eventually reduce the greenhouse gas (GHG) emissions of biodiesel production from palm oil. This study is using two system boundaries, firstly, system a “gate-to-gate” concerning the POME treatments, and secondly a “cradle-to-gate/total combustion” when we assess the impact of varying POME treatments within the biodiesel chain. The research draws on field and experimental data from palm oil and biogas production in Sumatra, Indonesia. The findings show that the energy output from the conversion of POME to methane via anaerobic digestion and the subsequent combustion of the methane in a combined heat-power plant exceeds the energy consumption of the palm oil milling process. Treating POME in an anaerobic digester and using the biogas to generate electricity and heat has the potential to significantly reduce the GHG emissions of biodiesel production from palm oil. In the studied case, the energy output from the conversion of POME to electricity and heat is 0.44 MJ kg−1 biodiesel and the net energy yield is 0.42 MJ kg−1 biodiesel. The ratio of energy output to energy input of the conversion process is about 23.1. The potential reduction of GHG emissions is 658 g CO2-eq kg−1 biodiesel or 15.96 g CO2-eq MJ−1. This is equivalent to about 33% of the total GHG emissions of biodiesel production from palm oil. Against this background we recommend to further develop and implement the treatment of POME in anaerobic digestion combined with the purposeful use of the methane, electricity and heat produced from the POME. This can make a significant contribution toward meeting international targets of emissions reduction for biodiesel production.

Analysis of Competitiveness and Support Instruments for Heat and Electricity Production from Wood Biomass in Latvia

Analysis of Competitiveness and Support Instruments for Heat and Electricity Production from Wood Biomass in Latvia Utilisation of renewable energy sources is one of the key factors in a search for efficient ways of reducing the emissions of greenhouse gases and improving the energy supply security. So far, the district heating supply in Latvia has been based on natural gas, with the wood fuel playing a minor role; the same is true for decentralised combined heat-power (CHP) production. The paper describes a method for evaluation of the economic feasibility of heat and electricity production from wood biomass under the competition between different fuel types and taking into account the electricity market. For the simulation, a cost estimation model is applied. The results demonstrate that wood biomass can successfully be utilised for competitive heat production by boiler houses, while for electricity production by CHP utilities it cannot compete on the market (even despite the low prices on wood biomass fuel) unless particular financial support instruments are applied. The authors evaluate the necessary support level and the impact of two main support instruments - the investment subsidies and the feed-in tariff - on the economic viability of wood-fuelled CHP plants, and show that the feed-in tariff could be considered as an instrument strongly affecting the competitiveness of such type CHP. Regarding the feed-in tariff determination, a compromise should be found between the economy-dictated requirement to develop CHP projects concerning capacities above 5 MWel - on the one hand, and the relatively small heat loads in many Latvian towns - on the other.

98/02253 Modernization of the OP-230p steam boiler and machine room of block No. 2 in the Lodz III combined heat power plant

98/02253 Modernization of the OP-230p steam boiler and machine room of block No. 2 in the Lodz III combined heat power plant

98/02255 Operation of an OP-230 boiler equipped with low-emission swirl burners at the Gdansk II Combined Heat Power Plant Installation and operational experience

98/02255 Operation of an OP-230 boiler equipped with low-emission swirl burners at the Gdansk II Combined Heat Power Plant Installation and operational experience