ВЕНТИЛЯЦИЯ, ОТОПЛЕНИЕ. Якобсон: Миллиарды рублей на некоторые энергосберегающие проекты потрачены впустую. - презентация

1 ВЕНТИЛЯЦИЯ, ОТОПЛЕНИЕ

2 Якобсон: Миллиарды рублей на некоторые энергосберегающие проекты потрачены впустую

3 По ряду энергосберегающих проектов не получен эффект (экономия топлива), а вложенные средства использованы крайне неэффективно. Об этом заявил председатель Комитета государственного контроля Беларуси Александр Якобсон на заседании коллегии КГК, на котором рассмотрены результаты проверки эффективности использования средств, направляемых на энергосбережение

4 "Проводя модернизацию экономики, в первую очередь необходимо обеспечить бережное и рациональное использование всех ресурсов - материальных, финансовых, трудовых, - сказал Александр Якобсон. -Вопросы бережливости касаются всех отраслей народного хозяйства. Очень важной является экономия валютных средств. Больше всего валюты тратится на приобретение энергоресурсов - в среднем $18 млрд в год, или 40% от всего объема импорта.

5 С 2011 года из всех источников, в том числе и бюджетных, на финансирование мероприятий по энергосбережению направлено около Br23 трлн. Направляя эти огромные средства на энергосбережение, страна вправе рассчитывать на адекватный результат от их использования в виде экономии топлива".

6 По результатам проверок сделан вывод, что Департамент по энергоэффективности Госстандарта не обеспечил проведение эффективной политики в области энергосбережения, а заявленная экономия топлива в ряде случаев оказалась только на бумаге. Существующая методология расчетов показателей по энергосбережению не обеспечивает их объективность и достоверность

7 DIRECTIVE 2010/31/EU OF THE EUROPEAN PARLIAMENT AND OF THE COUNCIL of 19 May 2010 on the energy performance of buildings (recast)

8 Buildings account for 40 % of total energy consumption in the Union. The sector is expanding, which is bound to increase its energy consumption. Therefore, reduction of energy consumption and the use of energy from renewable sources in the buildings sector constitute important measures needed to reduce the Unions energy dependency and greenhouse gas emissions.

9 The Commission should lay down a сomparative methodology framework for calculating cost-optimal levels of minimum energy performance requirements. Member States should use this framework to compare the results with the minimum energy performance requirements which they have adopted.

10 Should significant discrepancies, i.e. exceeding 15 %, exist between the calculated cost- optimal levels of minimum energy performance requirements and the minimum energy performance requirements in force, Member States should justify the difference or plan appropriate steps to reduce the discrepancy.

11 cost-optimal level means the energy performance level which leads to the lowest cost during the estimated economic lifecycle, where: (a) the lowest cost is determined taking into account energy-related investment costs, maintenance and operating costs (including energy costs and savings, the category of building concerned, earnings from energy produced), where applicable, and disposal costs, where applicable;

12 The cost-optimal level shall lie within the range of performance levels where the cost benefit analysis calculated over the estimated economic lifecycle is positive; Member States shall take the necessary measures to ensure that minimum energy performance requirements are set for building elements that form part of the building envelope and that have a significant impact on the energy performance of the building envelope when they are replaced or retrofitted, with a view to achieving cost-optimal levels.

13 For new buildings, Member States shall ensure that, before construction starts, the technical, environmental and economic а feasibility of high-efficiency alternative systems such as those listed below, if available, is considered and taken into account:

14 (a) decentralised energy supply systems based on energy from renewable sources; (b) cogeneration; (c) district or block heating or cooling, particularly where it is based entirely or partially on energy from renewable sources; (d) heat pumps.

15 2. Member States shall ensure that the analysis of alternative systems referred to in paragraph 1 is documented and available for verification purposes.

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18 В сообщающихся сосудах любой формы и сечения поверхности одной жидкости устанавливаются на одном уровне

19 В сообщающихся сосудах При равновесии высота столба жидкости с большей плотностью будет меньше высоты столба жидкости с меньшей плотностью ρ1ρ1

20 Условие равновесия жидкости P 1 =P 2

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23 1- комната 2- окружающее пространство 3- окно 4- вентиляционный канал 5- поверхность нулевого давления (средняя линия)

24 Закон сохранения энергии: Формула Торричелли:

25 расход воздуха, м³/ч коэффициент истечения струи площадь отверстия ускорение силы тяжести высота до нулевой линии плотность наружного воздуха плотность внутреннего воздуха /

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35 График зависимости теплопотерь Q от сопротивления теплопередачи R, при t н =-1.8˚C

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37 График зависимости теплопотерь Q от сопротивления теплопередачи R, при t н =-24˚C

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39 ASHRAE Research: Improving the Quality of Life The American Society of Heating, Refrigerating and Air-Conditioning Engineers is the worlds foremost technical society in the fields of heating, ventilation, air conditioning, and refrigeration. Its members worldwide are individuals who share ideas, identify needs, support research, and write the industrys standards for testing and practice. The result is that engineers are better able to keep indoor environments safe and productive while protecting and preserving the outdoors for generations to come. One of the ways that ASHRAE supports its members and industrys need for information is through ASHRAE Research. Thousands of individuals and companies support ASHRAE Research annually, enabling ASHRAE to report new data about material properties and building physics and to promote the application of innovative technologies. Chapters in the ASHRAE Handbook are updated through the experience of members of ASHRAE Technical Committees and through results of ASHRAE Research reported at ASHRAE meetings and published in ASHRAE special publications and in ASHRAE Transactions. For information about ASHRAE Research or to become a member, contact ASHRAE, 1791 Tullie Circle, Atlanta, GA 30329; telephone: ;

40 Temperature differences between indoors and outdoors cause stack pressure differences that drive airflows across the building envelope; the stack effect is this buoyancy phenomenon. Sherman (1991) showed that any single-zone building can be treated as an equivalent box from the point of view of stack effect, if its leaks follow the power law as described in the section on Residential Air Leakage. The building is then characterized by an effective stack height and neutral pressure level (NPL) or leakage distribution, as described in the section on Neutral Pressure Level. Once calculated, these parameters can be used in physical, single-zone models to estimate infiltration. Neglecting vertical density gradients, the stack pressure difference for a horizontal leak at any vertical location is given by where T o = outdoor temperature, K T i = indoor temperature, K ρ o = outdoor air density, kg/m3 ρ i = indoor air density, kg/m3 H NPL = height of neutral pressure level above reference plane without any other driving forces,m

41 Airflow Through Large Intentional Openings The relationship describing the airflow through a large intentional opening is based on the Bernoulli equation with steady, incompressible flow. The general form that includes stack, wind, and mechanical ventilation pressures across the opening is where Q = airflow rate, m3/s C D = discharge coefficient for opening, dimensionless A = cross-sectional area of opening, m2 ρ= air density, kg/m3 Δp = pressure difference across opening, Pa

42 Flow Caused by Thermal Forces Only If building internal resistance is not significant, flow caused by stack effect can be expressed by where Q = airflow rate, m3/s C D = discharge coefficient for opening ΔH NPL = height from midpoint of lower opening to NPL, m T i = indoor temperature, K T o = outdoor temperature, K

43 The results of a pressurization test, therefore, consist of several combinations of pressure difference and airflow rate data. An example of typical data is shown in Figure 9. These data points characterize the air leakage of a building and are generally converted to a single value that serves as a measure of the buildings airtightness. There are several different measures of airtightness, most of which involve fitting the data to a curve describing the relationship between the airflow Q through an opening in the building envelope and the pressure difference Δp across it. This relationship is called the leakage function of the opening. The form of the leakage function depends on the geometry of the opening. Openings in a building envelope are not uniform in geometry and, generally, the flow never becomes fully developed. Each opening in the building envelope can be described by Equation (40), commonly called the power law equation: where Q = airflow through opening, m³/s c = flow coefficient, m³/(s·Pa) n = pressure exponent, dimensionless

44 Typically, only 35% of infiltration from the smaller effect can be added to the larger effect. Depending on details, that percentage could go as high as 85% or as low as zero. Walker and Wilson (1993) compared several superposition techniques to measured data. Sherman, as well as Walker and Wilson, found quadrature, shown in Equation (47), to be a robust superposition technique: The following sections discuss how superposition is combined with calculation of wind and stack flows to determine total flow.

45 Local Exhaust After source elimination, the single most important source control mechanism in dwellings is local exhaust. All wet rooms and other spaces (e.g., kitchens, utility rooms, bathrooms, lavatories, toilets) designed to allow specific contaminant release should be provided with local exhaust. Workshops, recreation rooms, smoking areas, art studios, greenhouses, and hobby rooms may also require local ventilation and/or air cleaning to remove contaminants generated by the activities involved. Contaminants of concern should be evaluated to determine how much additional ventilation is required. Many of these rooms can be adequately ventilated by following the requirements for kitchens or bathrooms. If unvented combustion appliances must be used, rooms with these appliances should also meet general ventilation requirements for kitchens, because such appliances generate significant amounts of moisture and, often, ultrafine particles, even when burning properly. Mechanical exhaust is the preferred method of providing local ventilation. Normally, it is designed to operate intermittently under manual control to exhaust contaminated air outside when the contaminant is being produced and occupants recognize the need for ventilation. However, in many circumstances, a continuous, lowerflow-rate exhaust can work as well.

46 Continuous Local Mechanical Exhaust. A continuously operating mechanical exhaust is intended to operate without occupant intervention. This exhaust may be part of a balanced mechanical ventilation system. The system should be designed to operate during all hours in which the dwelling is occupied. Override control should be provided if needed. The minimum delivered ventilation should be at least that given in Table 1. Intermittent Local Mechanical Exhaust. An intermittently operating local mechanical exhaust is intended to be operated as needed by the occupant and should be designed with this intent. Shutoff timers, occupancy controls, multiple-speed fans, and switching integral with room lighting are helpful, provided they do not impede occupant control. The minimum airflow rate should be at least that given in Table 2. Alternatives. Cleaning recirculated air can sometimes be substituted for local exhaust, if it can be shown to be effective in removing contaminants of concern. Natural ventilation is not generally a suitable method for local exhaust and ventilation air needs in most climates and spaces. Using natural ventilation can cause reentrainment problems when air flows into rather than out of the space, and contaminated exhaust or exfiltrating air reenters the building. In milder climates, natural ventilation may be acceptable when the contaminant of concern is related to odor rather than health or safety. Purpose-designed passive exhaust systems have shown acceptable ventilation in some European settings, and may be considered in lieu of mechanical systems. Axley (2001b) discusses evaluation and design of passive residential ventilation systems further.

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48 Периодическая вентиляция Кухня 180 м³/ч Подсобное помещение, ванная, туалет 90 м³/ч Общая вентиляция 0,54 м³/ч на квадратный метр или 12,6 м³/ч на одного человека

49 Whole-House Ventilation Although control of significant sources of pollution in a dwelling is important, whole-house ventilation through centrally introduced, conditioned, and distributed outside air may still be needed. Each dwelling should be provided with outdoor air according to Table 3. The rate is the sum of the Area-Based and Occupancy-Based columns. Design occupancy can be based on the number of bedrooms as follows: first bedroom, two persons; each additional bedroom, one person. Additional ventilation should be considered when occupant densities exceed 1/25 m³. Natural whole-house ventilation that relies on occupant operation should not be used to make up any part of the minimum total whole-house ventilation air requirement. However, because occupancy and sources vary significantly, the capacity to ventilate above minimum rates can be provided by operable exterior openings such as doors and windows.

50 Зависимость диаметра приточного отверстия от высоты

51 Зависимость скорости воздуха в приточном отверстии от высоты

52 Зависимость диаметра вытяжного канала от высоты