Utilities and auxiliary systems

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This post was last edited by 955559 on 2018-9-8 at 15:28. Public Works and Auxiliary Works: Public Works and Auxiliary Works are supporting projects that serve the proper operation of the main project components. Public utilities mainly include water supply and drainage, power supply, communications, heating, ventilation, and other systems. Auxiliary engineering includes maintenance, testing, inspection, warehousing, and other related tasks. I. Water supply and drainage facilities 1. Source selection. The selection of a water source should be subject to comprehensive evaluation based on various factors such as hygiene, technical and economic aspects, and water resources. The following requirements apply to the choice of a water source: (1) Sufficient and reliable water supply: In addition to meeting the current needs for production and daily use, it is also necessary to ensure an adequate water supply for future development. The water withdrawal from underground water sources should not exceed the available reserves. For natural rivers (where water is drawn from without the use of dams), the water withdrawal should not exceed the amount of water that can be taken during the dry season. The reliability rate for the designed water supply flow in cities is determined based on the size of the city and the importance of industrial users; generally, a range of 90% to 97% can be used. For industrial enterprises, according to relevant regulations, the amount of water that can be taken usually accounts for 15% to 25% of the water flow during the dry season. The water volume of the water source should be based on official documents from the local water supply and hydraulic engineering departments or hydrogeological departments. (2) The quality of the raw water meets the requirements: The water quality from the source should satisfy the standards required by the project to be constructed, or it can be brought to the desired water quality standards through simple and cost-effective water treatment methods. Generally, the quality of water used for production depends on the nature of the production process. (3) When selecting underground water sources based on mining and hygiene conditions, springs, confined water (or interlayer water), and phreatic water are generally considered in that order. Underground water sources can be used for production purposes if the amount of water taken is small or if it does not affect the local demand for drinking water; otherwise, surface water should be utilized. Groundwater that meets health standards should be given priority as a source for drinking water. (4) When used in combination with agriculture and water conservancy, comprehensive planning should be carried out, and the relationships with economic sectors related to water supply projects such as agriculture, hydropower generation, shipping, timber transportation, fisheries, tourism, and drainage must be properly managed in order to achieve rational utilization and development of water resources. (5) The water intake, transmission, and purification facilities are safe, economical, and easy to maintain. The selection of water sources should take into account the city’s long-term and short-term plans as well as the overall industrial layout, with comprehensive consideration given to the project itself and various other factors. For ease of maintenance, the water intake point should be located upstream of the town. The water source used for toilets should meet the users’ requirements in terms of both quantity and quality; it is necessary to fully consider the impacts of human industrial activities and various natural factors, and take preventive measures. (6) Have the construction conditions. Such as whether land transportation is convenient, whether construction will affect navigation, and whether the construction methods used meet the required conditions. (7) Favorable water level. Using water sources at higher elevations (such as reservoir water, mountain spring water, and deep artesian groundwater) can reduce regular operating electricity consumption, so they should be considered first. (8) Meets environmental protection requirements. Water sources designated for domestic drinking water must be protected in accordance with the requirements of the \"Sanitary Standards for Domestic Drinking Water.\" Meanwhile, environmental protection measures must be implemented concurrently with the construction of water treatment plants. 2. Water supply system. Urban water supply systems are generally integrated systems for domestic use, industrial use, and fire fighting purposes. They can be classified as follows: a unified system, in which water is supplied at the quality standard suitable for drinking, and this type is used in small and medium-sized towns; a differentiated quality system, where, due to varying requirements regarding water quality, a separate water supply system is established for applications with lower quality requirements, while other uses are combined into another unified system; if there is a reclaimed water system, non-potable water used for cleaning, landscaping, etc., can be routed through that system; a pressure-differentiated system, in which different pressure levels are utilized depending on the requirements of the pipeline network; a zoned system, in which different water supply areas are created based on geographical locations; and a regional system, in which, due to factors such as water sources, a large-scale water supply system is needed to supply water to several towns simultaneously. For water supply systems in larger towns and large industrial complexes, several types of water supply systems may exist simultaneously. For example, systems that have both quality classification and zoning, etc. The water supply system consists of a series of interconnected structures. Its task is to draw water from natural sources, treat it according to the quality requirements of users, then deliver the water to the supply areas and distribute it to the users. A water supply system usually consists of the following components: (1) Water intake structures, which are used to draw water from the selected source and transport it to the water treatment plant. (2) Water treatment facilities that treat water from natural sources to meet users’ requirements for water quality. (3) Pump stations, used to lift the required amount of water to a specified height. (4) Water conveyance pipes and pipelines, which deliver raw water to the water plant. Pipes that deliver clean water to the water supply areas and consumption points. (5) Regulation structures, which are various types of tanks (high-level tanks, water towers, clear water tanks, etc.), used to store and regulate water volume; high-level tanks and water towers also serve to maintain water pressure. Based on the topographical characteristics of the town, water towers can be located at the starting point, in the middle, or at the end of the pipeline network, thereby forming supply systems consisting of a pre-network water tower, an in-network water tower, and a counterposed water tower. " The water supply aspect of a project feasibility study aims to determine the water consumption and quality, as well as to examine sources of water, water transmission methods, water purification processes, and the water supply systems within the facility. Determine the type of water supply system in the location where the research project is carried out, and identify the water usage parameters for the project. Calculate the daily water consumption and quality requirements for production water, domestic water, recycled water, chemical processes, and fire-fighting purposes. When calculating the water demand, due attention should be paid to water recycling and reuse; determine the rate of water reuse and prepare a schedule of daily water usage. To determine the water supply plan, it is first necessary to rely on existing societal solutions; when those are insufficient, a self-built water supply plan should be proposed, including the type and scale of the water source, the location for water extraction, as well as the plans for water extraction, transmission, and purification. The main facilities and equipment required for water supply should be listed, along with the construction or acquisition of various components of the water supply system, as well as any existing components that can be utilized. 3·Drainage system. In the feasibility study, the main tasks are to determine the discharge volume, examine drainage schemes, calculate the annual average and daily maximum discharge volumes of process wastewater, domestic wastewater, and natural precipitation, and analyze water quality and pollutant composition. Propose the disposal route for the wastewater based on its volume and degree of pollution. For areas with severe pollution, wastewater treatment solutions should be considered, listing the main facilities and equipment for drainage. The design principles and main requirements for drainage systems are as follows: The design of drainage systems must first comply with relevant guidelines, policies, and laws; secondly, there should be a separation of clean water and wastewater – that is, domestic and industrial wastewater should be discharged through separate systems from wastewater containing toxic substances, flammable materials, corrosive substances, or organic pollutants. This approach helps to reduce the load on wastewater treatment facilities dealing with harmful substances, thereby minimizing investment costs, preventing water pollution, and contributing to the improvement and protection of the environment as well as the enhancement of public health. GBJ14-7 «Code for Design of Outdoor Drainage» serves as the basis for the design of permanent outdoor drainage systems in towns, enterprises, and residential areas. The design of auxiliary buildings and equipment at wastewater treatment plants must comply with the provisions of standard GB31?9. The design of drainage systems should be based on regulatory requirements, taking an overall perspective to properly handle the relationships among urban areas, industry, and agriculture, as well as between centralized and decentralized approaches, treatment and utilization, and short-term and long-term considerations. The design of the drainage system should be detailed; it is required to be coordinated with sewage and sludge treatment in adjacent areas. Sewage and sludge should be utilized comprehensively or disposed of properly, with systems for recycled water and reuse employed. Waste water, waste gas, or waste residues from within the plant or from other plants should be used to treat other types of waste. The drainage system must also be coordinated with the water supply systems in adjacent areas and within the same area, as well as with the systems for managing floods and rainwater. It should adapt to changes in production processes in order to reduce the amount of waste water discharged or improve its quality. Useful substances in the sewage or sludge should be recovered based on the different qualities of those wastes. Existing drainage facilities should be appropriately modified to maximize their effectiveness. The choice between a separate sewerage system and a combined sewerage system should be determined through comprehensive consideration of factors such as the town’s and enterprises’ development plans, local rainfall patterns and discharge standards, existing sewerage facilities, wastewater treatment and reuse practices, as well as topography and water bodies. The water quality of industrial wastewater discharged into the urban drainage system must not cause pollution to the urban drainage pipes or disrupt the normal operation of sewage treatment plants and similar facilities; it must not pose any risks to maintenance personnel, nor should it affect the discharge and utilization of the treated water and sludge. The requirements for the quality of wastewater include the following: when discharging sewage into urban sewers, it is strictly prohibited to release sewage that can corrode sewer facilities; it is forbidden to pour garbage, snow, feces, industrial waste, and substances prone to aggregation that can block sewers into urban sewers; the discharge of highly toxic substances (such as sodium cyanide and potassium cyanide), flammable and explosive substances (such as gasoline, kerosene, heavy oil, lubricants, coal tar, benzene derivatives, ethers, and other organic solvents), and harmful gases into urban sewers is also prohibited. Sewage containing pathogens from medical and health services, biopharmaceutical production, scientific research, meat processing, etc., must undergo strict disinfection. Finally, draw a water balance diagram and prepare a list of the main equipment in the water supply, drainage, and wastewater treatment plants, including their names, specifications, materials, quantities, and consumption rates. II. Power Supply and Communication Facilities 1. Power supply. The main tasks related to power supply during the project feasibility study phase are: (1) Understanding and collecting detailed information on the power supply sources located near the construction site. Such as the distance to the ** or local power grid, the capacity and number of transformers installed at the nearest regional or local substation to the construction project, the wiring methods on the primary and secondary sides, the power supply conditions and reliability at that substation, its future development plans, the current load situation, and an overview of the future electricity demand in that area. If the substation is equipped with a three-winding transformer, it is necessary to collect detailed information on the capacity of the high-voltage and low-voltage windings as well as the existing load conditions. For external power supply, it is necessary to first consider obtaining power from the ** national grid or local power grids; only when there is no available power grid in the vicinity and it is not possible to obtain stable and reliable power supply in the near future should the option of building one’s own power plant be considered. The construction of a self-provided power station should be approached with great caution, and a decision should be made after comparing multiple options. (2) Collect and determine the power voltage levels of the grid substations located near the construction project, in order to identify the voltage level that can be used as a power supply for the project. (3) The distance between the construction site and the nearest power grid substation, the topography and presence of obstacles in the surrounding area, as well as the conditions for laying cables and making connections. (4) Collect information on local electricity prices (including the basic price of X yuan/kV·A and the usage-based price of X yuan/kW·h), capacity expansion costs, and electricity subsidies (XXX yuan/kV·A), etc. (5) If a construction project has a Class 1 critical power load, it is necessary to determine whether the power grid substation has two independent power supply sources and the reliability of their power supply. (6) Based on the electrical equipment used in the project and its installed capacity, the maximum calculated load of the project (active, reactive, and apparent) as well as the annual electricity consumption in k*kW·h are calculated. These values are submitted to the project owner so that a power supply agreement can be established with the electricity supply company, and they serve as a basis for cost analysis of the project. (7) The compensation method for the project’s power factor shall be determined in accordance with the provisions of the electricity sector’s ‘National Power Supply Rules’ and the calculated natural power factor of the project; the power factor must meet the requirements set out in those rules (above 0.9). (8) The internal power supply scheme for this project shall be determined based on the project’s power supply conditions, load characteristics, and overall layout. Prepare the plant-wide power supply system diagram, the plant-wide calculated load table including the scheme with artificial power factor correction), and the selection of major equipment (including the main equipment for substations). (9) Calculate the requirements for major equipment, the volume of major works (including equipment, construction, installation, and other works), and external power supply connections. (10) Lighting design plan for the plant area and buildings. The basis and primary sources for preparing reports on the aforementioned tasks include: the aforementioned basic information regarding the current status and development plans of power grids, substations, and power supply systems; high-scale topographic data (1:t5000 to 1:10000, etc.) showing the area between regional or local substations and the construction sites, as well as information on obstacles; the basic requirements set by power authorities for the construction of external power supply lines; local meteorological data (wind speed, temperature, wind direction, rainfall, days of icing, days of lightning strikes, etc.); detailed information on various electrical equipment used in the construction project, such as process equipment (motors, electric heaters, electric furnaces, electroplating systems, electrolysis units, electrochemical devices, etc.), including their installed capacity, operating capacity, number of units, shift patterns, voltage levels, and motor models; as well as information on materials used for various electrical equipment in utility and auxiliary facilities (such as water supply systems, circulating water systems, sewage treatment systems, environmental protection facilities, mechanical and electrical maintenance facilities, storage areas, etc.); prices of various electrical equipment, standards for electrical installation, as well as technical and economic indicators related to electrical equipment installation and energy consumption in different industries. For technical renovation projects, power supply enhancement plans should be proposed based on the enterprise’s existing power source, scale, and electricity consumption load. After the power supply scheme for the project is determined through comparison, a power supply system diagram should be drawn up, along with a list of the main power supply facilities and equipment. 2. Communication facilities. The research project addresses various communication facilities required for production and operations; based on the production process flow or functional requirements of the project to be constructed, it determines the number of communication users throughout the plant, as well as the networking structure of the communication systems, the methods and lines for signal transmission, and other low-voltage facilities such as those for automatic fire alarm detection. Compare and select communication (low-voltage) setup solutions. List a catalog of the main equipment, including the equipment name, model, specifications, quantity, and source. For facilities such as wired communication, wireless communication, optical fiber communication, and satellite communication, it is necessary to rely as much as possible on existing societal infrastructure, reduce unnecessary large-scale constructions, and move away from the past practice of pursuing \"complete solutions in all aspects\" for project development. Fully explain the reasons for relying on social collaboration and the scope of such reliance. 3·Calculate the building area, land area, and designated capacity. III. Heating facilities: Heating refers to the general term for supplying steam, or hot water and warm air converted from steam, to industrial processes, production activities, heating needs, and service facilities. Different projects, processes, and scales have different heating requirements. Industries such as textiles, dyeing and printing, and traditional Chinese medicine extraction require large amounts of steam; meanwhile, heating in various buildings is usually achieved using hot water or hot air. In the feasibility study of the project, the steam pressure level is determined based on the main process steps. The steam consumption and pressure levels for production units, auxiliary facilities, and service facilities are listed separately. Based on the project’s thermal load, the heat source and heating scheme are selected. The selection of heat sources should prioritize making use of social heating systems and the waste heat from auxiliary facilities. For cases where it is truly necessary to construct heating facilities independently, it is essential to study the construction plan for the heat source, as well as compare and select appropriate heating schemes—including coal feeding facilities, water softening systems, the size of the boiler room, equipment selection, and the number of units required. Additionally, it is necessary to compare fuel sources, specifications, consumption rates, transportation and storage methods, as well as the quantity of ash and slag, and measures for their storage and comprehensive utilization. If a combined heat and power scheme is adopted, it shall comply with **relevant regulations. Industrial boilers with a capacity of 100 tons per hour or more, and operating for 4,000 hours per year or more, should utilize cogeneration. Cogeneration involves using high-temperature, high-pressure power station boilers to generate superheated (high-calorific value) steam; electricity is produced first and then steam is supplied, thereby improving the efficiency of heat utilization. After comparing various heating options, the preferred scheme is selected; a steam balance diagram for the entire plant should be prepared, along with a list of the main heating equipment, as well as information regarding the building area, land area, staff capacity, and consumption of utility services. IV. Air separation, air compression, and refrigeration facilities: Determine the demand for oxygen, nitrogen, compressed air, and cooling energy required for the production processes involved in the research and calculation projects, and specify the relevant supply parameters such as quality requirements, usage methods, and consumption rates. It also proposes options based on social supply schemes or the construction of own air separation, air compression, and refrigeration facilities. After determining the scale of the aforementioned auxiliary facilities. Prepare a list of the main equipment for various functional facilities (name, model, specifications, key control parameters, source); consumption indicators, building area, land area, staffing capacity, and usage amounts for utility services. For technical renovation and expansion projects, make use of existing facilities as much as possible. V. Maintenance facilities: Maintenance facilities mainly refer to the maintenance and repair of mechanical equipment, electrical equipment, instruments and meters, industrial furnaces, transportation facilities, etc. The repair of corporate equipment is generally divided into routine maintenance, minor repairs, medium-scale repairs, and major repairs. Tasks of the research project regarding maintenance facilities (the workload undertaken by the maintenance department), the system and principles for their establishment as well as working procedures (explaining the coordination relationships and the capabilities of the collaborating units), principles for supplying maintenance materials and spare parts, and maintenance systems; the scale of composition of various maintenance facilities and the installation of key equipment. For the maintenance facilities of the proposed project, reliance on society and extensive professional collaboration should be the foundation. General projects are equipped only with the capability for routine maintenance and minor repairs; if it is necessary to establish one’s own repair facilities, a construction plan should be submitted. Prepare a list of major equipment, building area, land area, staffing capacity, and consumption of utility services. For technical renovation and expansion projects, make use of the existing facilities as much as possible, with only minor changes. VI. Storage Facilities: The storage volume and area required for major raw materials, intermediate products, and finished products are determined based on production needs and reasonable turnover rates, including the area of indoor and outdoor storage sites as well as the land area occupied. When studying storage facility plans, try to make use of existing social facilities wherever possible. VII. Central Laboratory: The central laboratory is a laboratory that serves the entire factory. Its main tasks include providing the standard solutions and reagents needed by all the laboratories in the factory, such as distilled water and reagent solutions used for calibration; analyzing the specifications, composition, and quality of raw materials, auxiliary materials, and fuel that enter the factory; assessing the quality of products produced by the factory; and monitoring the discharge of waste materials. The setup of an enterprise laboratory varies depending on the process of the project to be constructed; generally, there are three levels of laboratories: plant-level, workshop-level, and section-level. For special processes, on-site analysis is also required. The content of the project feasibility study includes outlining the principles for setting up the laboratory in the entire plant, the tasks it undertakes, its working procedures and responsibilities, as well as the division of labor with laboratories in other workshops; the structure of the work units; the selection of equipment and instruments, the required floor area, and the staffing requirements. For some of the tests requested by the laboratory, services can be obtained from external sources; therefore, there is no need to include facilities for distilling water in the setup to supply distilled water.