Maciej Błaszkowski, Antoni Litwinowicz, Aleksandra Matyja
Neutralization of alkaline wastewater with carbon dioxide
Alkaline wastewater formation is one of the technological and environmental problems related to contemporary conventional power generation. Alkaline wastewater neutralization with hydrochloric or sulphuric acid increases the content of chlorides or sulphates in total wastewater balance of the power plant. Other methods of neutralization are not commonly applied. The article indicates the sources of alkaline wastewater from conventional power plants and discusses the method of its neutralization with gaseous carbon dioxide (CO2). Moreover, the preliminary test results are presented. The method enables reduction of pH value of wastewater without any inputs of additional pollutants such as chlorides and sulphates.
Keywords: carbon dioxide, wastewater neutralization, alkaline wastewater, landfill, waste
Piotr Plis, Bartłomiej Dziubek
Secondary capacity market – will there be anyone interested?
The article provides analysis of the system of penalties and bonuses related to performance of the capacity obligation and also identifies technical potential broken down into capital groups which is available on the secondary capacity market. Moreover, the article evaluates economic justification for participation in the secondary market as regards the process of volume reallocation. This is preceded by a synthetic description of the present situation on the capacity market after four main auctions and first additional auctions.
Keywords: capacity market, secondary capacity market, technical potential, volume reallocation
Łukasz Kot
Wastewater without ammonia – waste-free technology of ammonium ion removal from FGD wastewater
The article describes the method of ammonium ion removal from wastewater generated by wet FGD plants which has been prepared by „ENERGOPOMIAR” Sp. z o.o. In 2020 the method was patented thanks to its innovation. A key solution which enhances effectiveness of this method and enables a treatment process at conditions less severe to the environment is the use of steam as a released ammonia carrier. A quick response of the system to the change in process parameters and its modular character make it possible to use it both in the existing as well as the designed wastewater treatment plants.
Keywords: FGD wastewater treatment plant, ammonium ion, ammonia, stripping column, steam, thermal degassing, alkalinisation, pH
Andrzej Kochaniewicz
ORC technologies – an overview of solutions and applicability in combined heat and power generation
The article presents an overview of solutions and applicability of the ORC (Organic Rankine Cycle) technology in combined heat and power generation. The ORC technology is based on the same principles of operation as in the classic Clausius Rankine cycle, i.e.: the same thermodynamic transformations occur. The only difference is the application of a low-boiling agent. The article mainly focuses on the ready and proven solutions used by suppliers of systems like that. A comparison is made of configurations for this type of systems and, moreover, their possible use to optimize electric power and heat generation is presented. The basic advantage of the ORC technology is possibility of its application in various sectors of the economy. The commercial technology offered on the market is generally based on ORC systems supplied by biomass-fired boilers. The article provides a synthetic list of ready solutions for this technology, including types of available electric and thermal power in combined systems and, additionally, of electric power and electric efficiency in condensing systems. Besides, the article mentions an economic aspect related to capital expenditures for the presented solutions and provides the corresponding cost estimates.
Keywords: ORC technology, power efficiency, combined heat and power generation, thermal cycles
Rafał Czekalski
Mathematical modelling to support measurements and conceptual work
The article presents the application of mathematical modelling as a tool to support projects performed by „ENERGOPOMIAR” Sp. z o.o. Three examples of the use of Thermoflex program in modelling thermodynamic cycles are discussed. The first example refers to analysis of operation of the 200 MW power unit below its technical minimum based on a model developed using measurement data at the rated load. The next example describes ‘a digital twin’ which is a virtual model of the power unit in operation. This model allows for continuous diagnostics of condition of the power unit using the current measurement and model data. The third example refers to the application of mathematical modelling in desk study research. This model can provide a number of necessary data related to the future system which are required at this stage of work.
Keywords: mathematical modelling, technical minimum of the power unit, digital twin, feasibility study, Thermoflex®, PI SystemTM
Robert Cholewa
Online monitoring of auxiliary consumption in the power plant – experiences from the implementation of applications supporting the advanced control of auxiliary consumption
Monitoring of auxiliary power consumption understood as reporting on electrical energy consumption by particular auxiliaries and determination of key performance indicators (KPI) which enable the assessment and optimization of operation of the auxiliaries is a crucial element of IT systems supporting electrical energy and heat generation. The article points out problems and constraints related to online monitoring of auxiliary power consumption and presents examples of practical applications of online detailed analysis of operation of the basic auxiliaries. An essential problem for the power plant operation staff is reporting and analysis of heat consumption by the auxiliaries. The lack of a proper metering system frequently imposes the use of available data – operating time and rated capacity of equipment (e.g. dust blowers) or its performance parameters (e.g. steam demand during commissioning of the power unit). Moreover, if there is no metering system for heat consumption by the auxiliaries, it is necessary to make theoretical calculations of heat losses in the steam collector and determine auxiliary heat consumption based on the balance of the whole collector. The article indicates that IT systems can present a substantial support in reporting on heat consumption by the auxiliaries and, thus, enable their monitoring and optimization.
Keywords: monitoring of auxiliary power and heat consumption in the power plant, optimization of operation of the auxiliaries
Rafał Szymanowicz
Balancing of energy generated in thermal waste treatment plants
The article presents issues related to performance of tasks associated with preparation of waste/fuel supply systems in thermal waste treatment plants and proper balancing and metering of energy generated from RES. Besides, the article discusses the corresponding legal requirements and provides some examples of fuel systems for thermal waste treatment plants.
Keywords: thermal waste treatment plants, energy generation from RES, balancing and metering of energy from RES
Łukasz Kot, Janusz Skwara
Optimization of FGD wastewater treatment plants as a response to the requirements under the BAT conclusions
The article presents more stringent requirements resulting from the BAT conclusions as regards the quality of wastewater from flue gas desulphurization plants and also possibilities of their fulfilment by the existing wastewater treatment plants. The adaptation of the existing treatment plants is associated with capital expenditures for their extension. As an effective way to reduce capital expenditures (CAPEX) and operating expenditures (OPEX), the article indicates a technological audit and optimization tests of operation of the wastewater treatment plant which enable the determination of the scope of modernization and calculations of the actual financial outlays for adapting to the requirements under the BAT conclusions.
Keywords: BAT conclusions, FGD wastewater treatment plant, optimization, modernization, wastewater, heavy metals, alkaline precipitation
Robert Cholewa
Aspects related to metering consumption of chemical energy of fuel for electrical energy and heat generation in CCGT systems
The article brings up the aspects connected with metering consumption of chemical energy of fuel for electrical energy and heat generation in CCGT power plants. Attention has been paid that for CCGT units the uncertainty of determining consumption of chemical energy of fuel by direct method is about 1% and is significantly lower than for coal-fired power units. As regards CCGT units, the indirect method therefore aims at interpreting the obtained indicators, including determination of deviations of the power unit efficiency which demonstrate the influence of performance parameters on the obtained value of indicators, and at determining limitations of electrical energy and useful heat production for various atmospheric conditions and various thermal loads of the power unit. What can be also crucial is optimization of process steam and useful heat consumption by the power unit, optimization of operation of fan cooling towers and cooling water pumps, assessment of operation of feed water pumps and online calculation of electrical energy and heat production costs. The article discusses ways of dividing consumption of chemical energy of fuel into electrical energy and heat generation and offers practical measures of adapting the methods applied for coal-fired power units to CCGT units.
Keywords: combined cycle gas turbine (CCGT) unit, metering consumption of chemical energy of fuel, optimization of operation of the CCGT unit
Wieńczysław Wasik
Control capability of combined cycle gas turbine power plants in relation to balancing, defence and restoration of the power system
The article describes control properties of combined cycle gas turbine (CCGT) power plants. Based on the exemplary results of grid code tests performed by „ENERGOPOMIAR” Sp. z o.o., the assessment is made of possible use of these generating units for active power and frequency control in the National Power System and also for participation in defence and restoration of the power supply system in case of its failure. Moreover, the article provides a comparison of control properties of CCGT power plants and coal-fired power plants.
Keywords: combined cycle gas turbine (CCGT) power plant, control capability, balancing of the National Power System, restoration of the National Power System, grid code tests
Kazimierz Zamorowski
Energy losses during operation of rotary regenerative air heaters
The article discusses some issues related to leakage of rotary regenerative air heaters (RRAH) and presents the corresponding leak analysis. The particular leak components have been broken down into a leak due to air transfer in the heating baskets to flue gas and a direct leak divided into leaks at the hot outlet or cold inlet of the RRAH. The article provides analysis of the losses of heat and electrical energy resulting from leakage. Based on the adopted model of leaks, overall effects of sealing modernization have been determined for the OP-650 boiler. The article points out the guarantee fulfilment conditions which should be included in a contract for modernization of the RRAH.
Keywords: rotary regenerative air heater (RRAH), leakage, leak, energy losses
Łukasz Tomczak
Effects of repair of the rotary regenerative heater confirmed by measurements
Although the history of rotary regenerative air heaters (RRAHs) goes back 100 years, they are still successfully applied in the existing generating units. The construction of RRAHs has been improved over the years, yet its idea and principle of operation remain unchanged. RRAHs are key elements of the boiler installation as they are responsible for about 10% of total energy exchange in the boiler, however, they require proper control. Neglecting their technical condition can lead to many disadvantageous phenomena like combustion deterioration, a decrease in the mill efficiency, increased consumption of electrical energy by fans and dust removal equipment, and in extreme cases, can bring about a decrease in thermal capacity of the boiler.
Keywords: rotary regenerative air heater (RRAH), repair and modernization of RRAHs, energy losses, auxiliary consumption
Jacek Lepich
Tests of fans and boilers in accordance with the ecodesign requirements
The article presents the genesis of ecology-oriented directives and regulations for equipment and activities in power industry. Moreover, the article includes the requirements for fans and heating boilers specified in these directives as well as the test results according to the ecodesign requirements. Exemplary tests of the fan and the heating boiler are given to illustrate the procedure of measurements performed at the devices and a list of the required parameters for ecodesigns is also included. The examples demonstrate whether the specific product (fan/heating boiler) fulfils the criteria of ecological requirements and energy efficiency included in the EU regulations.
Keywords: ecodesign, Ecodesign Directive, fan testing, boiler testing, energy efficiency, ecodesign emission requirements
Artur Jasiński
Damage and diagnostics of gate valves of HP installations
Gate valves are elements commonly mounted in industrial installations and general purpose pipelines. Their objective is to deliver or cut off the flow of media, for example, water and wastewater, water vapour, petroleum, gas, oil, flue gas and others. Depending on the construction of the installation, operating parameters and medium, gate valves are mounted in a horizontal or vertical position by means of flange / socket / threaded or welded connections. Gate valves can have manual, electrical, pneumatic or hydraulic actuators. They can be operated manually or automatically. Their proper production, assembly and use should not cause any danger to people or the environment. However, if gate valves are used in an improper way or contain manufacturing defects, in extreme cases, they can create a huge hazard. The article focuses on the most common damage to gate valves.
Keywords: material diagnostics, gate valves, cut-off fittings, steam pipelines, water pipelines, power installations, damage mechanisms
Michał Kwiecień
Boiler operation safety in relation to heating surface wear-out
The article presents basic threats to operation of boilers in relation to heating surface wear-out and gives examples of failure connected with high-temperature corrosion processes and the exceeded cycle medium temperature. The article provides the corresponding results of testing and analysis of pipes whose heating surfaces have been subject to failure. It is pointed out that operational staff should monitor cycle medium temperature. Some preventive measures are offered to reduce failure rate of boilers.
Keywords: high-temperature corrosion, erosion, damage processes, biomass, sludge, creeping
Elżbieta Janigacz, Agnieszka Stachura-Węgierek
Industrial waste discharge into rivers under the requirements of the Water Framework Directive
The article points out the guidelines for fulfilment of the requirements of the Water Framework Directive (WFD) related to wastewater discharge into surface water. Special attention is drawn to the necessity of taking account of environmental objectives determined for surface water bodies (SWB) in analysis of the water use impact assessment and when obtaining the relevant permits. Omitting or underestimating the aspects connected with water protection and incomplete or improper assessment of possible influence of the investment project/installation on water environment presents a serious risk to the investment process and the process of obtaining proper permits.
Keywords: Water Framework Directive (WFD), environmental objectives, surface water bodies (SWB), mixing zone, condition assessment, industrial wastewater
Magdalena Malara
An overview of waste legislation – legal obligations and testing required for combustion waste management
The issue of waste in the national legislation appears in many acts and implementing regulations. The most important legal documents include The Act on Waste of 14 December 2012, The Act of 27 April 2001: Environmental Protection Law and their corresponding regulations. As regards professional waste management, the Polish legislation comprises several permits/licenses, e.g. integrated permit, waste generation permit, waste treatment permit and waste collection permit. At present on the Polish market there are three types of waste: hazardous, neutral and other than hazardous and neutral. Combustion wastes generated in conventional power plants/CHP plants fall into Category 10, Sub-category 10 01 of the Waste Catalogue. If these wastes are to be stored at landfills (D5 process), two types of testing are required: basic characteristics of waste, including the so-called compliance test, and structure and composition of the stored waste.
Keywords: waste management, waste landfilling, waste recovery, integrated permit, waste generation permit, waste treatment permit, environmental monitoring, waste testing