This section discusses a solution for the external lightning protection system for a gas holder located at a gas transfer station.
Background data for the lightning protection design:
- facility: gas holder (gas transfer station);
- architectural drawings of the facility;
- facility height: 40 m;
- facility diameter: 38 m;
- the facility is classified as Class B1 zone (according to the EIC);
- soil resistivity: 100 Ohm*m.
General
The technical solutions adopted in design documents comply with the requirements of environmental protection, sanitary and hygienic, fire safety as well as other standards effective in the territory of the Russian Federation and provide operation of the facility in a way safe for lives and health of the people, while complying with the events provided for by design drawings. Design documentation complies with the requirements of the effective regulatory documents.
Lightning protection of the facility
This section discusses a solution for the external lightning protection system for a gas holder located at a gas transfer station.
The gas holder is classified as "special facilities dangerous for the immediate environment" in accordance with INSTRUCTIONS FOR ARRANGEMENT OF LIGHTNING PROTECTION FOR BUILDINGS, STRUCTURES, AND INDUSTRIAL UTILITIES SO 153-34.21.122-2003 and to Category I in accordance with INSTRUCTIONS FOR ARRANGEMENT OF LIGHTNING PROTECTION OF BUILDINGS AND STRUCTURES RD 34.21.122-87. The necessary reliability of the lightning protection system should not be less than 0.995.
The lightning protection of the facility is made using four standalone lightning arresters, which are 54 m high. The distance to the facility should not be less than 5 m according to RD 34.21.122-87, item 2.3.
According to SO 153-34.21.122-87, item 3.3.1. In general, the lightning arresters should be chosen using the respective software capable of calculating the protection zones or the probability of the lightning strike into the facility (or a group of facilities) of any configuration, with the random position of almost any lightning arrester.
In addition to SO 153-34.21.122-2003, RECOMMENDATIONS FOR OPERATIONAL TECHNICAL DOCUMENTS, PROCEDURE FOR ACCEPTANCE INTO OPERATION, AND OPERATION OF THE LIGHTNING PROTECTION ARRANGEMENTS state:
"When testing reliability of the protection using the software, data of computer calculations are provided as a summary of design options, and a conclusion on their efficiencies is generated.
The calculation of reliability of the lightning protection system is made in accordance with Technical Bulletin of the ROSELECTROMONTAZH Association No. 25/2009 ON USING SPECIAL SOFTWARE TO CALCULATE EFFICIENCY OF THE PROTECTIVE EFFECT OF LIGHTNING ARRESTERS, stating:
"When designing the external lightning protection system for the facilities, apply the following:
For optimal generation of protection zones for complex buildings and structures having roofs of different heights, protruding needles, towers, variable geometry, buildings higher than 150 m, building complexes and other complex facilities, use the respective software, e.g. "Software for calculation of efficiency of rod and wire lightning arresters using the statistical method" developed by OAO ENIN.
The grounding arrangement of the lightning protection system is made according to RD 34.21.122-87, item 2.2.d and GOST R 59789-2021, item 5.4.1, Appendix D. The resistance of the grounding device should not exceed 10 Ohm.
The space measuring H = 2.5 m, R = 5 m above the breather, located at the gas holder's top, is protected according to RD 34.21.122-87, item 2.6.
Materials of the grounding arrangement conform to GOST 50571.5.54-2024.
The results of calculations using the software are provided in Appendix 1. Protection zone of the "Zone A" type according to RD 34.21.122-87, Appendix 1, is shown in Sheet 7 in the design's PDF file.
Calculation of a ground terminal resistance
Resistance of the vertical electrode:
Верт - Vert/
Экв Eq
whereρeq is soil resistivity, Ohm*m;
L is vertical electrode length, m;
d is vertical electrode diameter, m;
T is depth, i.e. the distance from the ground surface to the ground terminal, m;
Resistance of a horizontal electrode:
Гор - Hor
where ρ is soil resistivity, Ohm*m;
b is horizontal electrode width, m;
h is horizontal electrode depth, m;
Lhor is horizontal electrode length, m.
where t is the depth of the electrode top, m.
Full resistance of a ground terminal::
ЗУ - GA
where n is the number of sets;
kutil is the utilization ratio
Ом - Ohm
The estimated resistance of the grounding arrangement is 9,29 Ohm, conforming to GOST R 59789-2021, item 5.4.1.
Layout of elements of the lightning protection and grounding for the gas holder
Specifications
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Appendix: design in DWG and PDF formats
Условные обозначения - Legend
Зона защиты - Protection zone
Вертикальный заземлитель - Vertical arrangement
К молниеприемнику - To lightning arrester
Двойной стержневой молниеотвод - Double rod lightning arrester
Высота молниеприемника от земли до вершины - Lightning arrester height from the ground to the top
Расстояние между молниеприемниками - Distance between lightning arresters
Высота защищаемого объекта - Height of the protected facility
Высота конуса зоны защиты - Height of the protection zone cone
Радиус конуса зоны защиты - Radius of the protection zone cone
Радиус горизонтального сечения вокруг молниеприемника - Radius of horizontal cross-section around the lightning arrester
м - m
Радиус зоны посередине между молниеприемниками - Radius of the zone in the middle between lightning arresters
Защищенность объекта от молний обеспечивается только при использовании молниеприемников ZANDZ определенной расчетом высоты, наименования и артикулы которых указаны в спецификации - The protection of the facility against lightning is ensured only when using ZANDZ lightning arresters with the height determined by calculations, names and product numbers as stated in the specifications
Объекты относятся к I категории молниезащиты (Таблица 1). - The facilities are classified as Category I of the lightning protection (Table 1).
Соответствующая зона защиты – Зона А. Требуемая надежность системы молниезащиты – не менее 0,995. - The respective protection zone is Zone A. The required reliability of the lightning protection system is at least 0.995.
Молниезащита выполнена при помощи отдельно стоящих молниеприемников высотой 54 м (ZZ-201-054), которые устанавливаются по периметру объекта на расстоянии не менее 5 м, согласно РД 34.21.127-87, п. 2.3 - The lightning protection is made using standalone lightning arresters 54 m high (ZZ-201-054) installed along the facility’s perimeter at the distance of at least 5 m according to RD 34.21.127-87, item 2.3.
Конструкция заземляющего устройства соответствует требованиям РД 34.21.122-07, п. 22 и ГОСТ Р 59709-2021, п. 5.4.1 и Приложение D. - The structure of the grounding arrangement conforms to RD 34.21.122-07, item 22, and GOST R 59709-2021, item 5.4.1, and Appendix D.
В качестве вертикального заземлителя используется омедненные стальные электроды длиной 3 м. - Steel copper-plated electrodes 3 m long are used as a vertical grounding electrode
В качестве горизонтального заземлителя используется омедненная стальная полоса сечением 30х4 мм, объединяющая все вертикальные электроды. Заглубление полосы 0,5-0,7 м. - A steel copper-plated plate with the cross-section of 30 x 4 mm combining all vertical electrodes is used as a horizontal grounding electrode. The plate depth is 0.5 to 0.7 m.
Расчетное значение сопротивления заземляющего устройства (одно) – 9,29 Ом. - Estimated resistance of the grounding arrangement (single) is 9.29 Ohm.
Подключение к заземляющему устройству выполняется при помощи зажимов ZZ-005-064. - The connection to the grounding arrangement is made using clamps ZZ-005-064.
Итоги расчетов при помощи программного обеспечения, разработанного ЭНИН им. Кржижановского: надежность составляет 0,99906; среднее время между ударами молний в систему 2 года; среднее время между прорывами, минуя защиту: 2326 лет. - The results of calculations using the software developed by Krzhizhanovsky ENIN: the reliability is 0.9996; the average time between the lightning strikes to the system is 2 years; the average time between the breakthroughs is 2326 years.
Изм. - Rev.
Кол. Уч. - Q-ty of areas
Лист - Sheet
Подп. - Signature
Дата - Date
ГАП - CPA
ГИП - CPE
Разработал - Developed by
Руководит. - Manager
Н. контроль - Quality control
Молниезащита и заземление - Lightning protection and grounding
Газгольдер - Gas holder
Стадия - Stage
Лист - Sheet
Листов - Sheets
П - D
Формат А2 - Size A2
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