Skip to product information
1 of 12

PayPal, credit cards. Download editable-PDF & invoice In 1 second!

GB 20800.3-2008 English PDF (GB20800.3-2008)

GB 20800.3-2008 English PDF (GB20800.3-2008)

Regular price $205.00 USD
Regular price Sale price $205.00 USD
Sale Sold out
Shipping calculated at checkout.
Quotation: In 1-minute, 24-hr self-service. Click here GB 20800.3-2008 to get it for Purchase Approval, Bank TT...

GB 20800.3-2008: General rules of explosion-protect techniques of reciprocating internal combustion engines for explosive atmospheres -- Part 3: Group I engines for use in underground workings susceptible to firedamp and/or combustible dust

This part of GB 20800 specifies the safety requirements and (or) safety measures for Group I category M2 reciprocating compression ignition engines for use in underground workings with methane and/or combustible dust (hereinafter referred to as internal combustion engines), which are used to eliminate or limit various dangers and hazards that may occur on internal combustion engines.
GB 20800.3-2008
GB
NATIONAL STANDARD OF THE
PEOPLE REPUBLIC OF CHINA
ICS 29.060.20
K 35
General rules of explosion-protect techniques of
reciprocating internal combustion engines for
explosive atmospheres - Part 3: Group I engines for
use in underground workings susceptible to firedamp
and/or combustible dust
ISSUED ON: MAY 20, 2008
IMPLEMENTED ON: APRIL 01, 2009
Issued by: General Administration of Quality Supervision, Inspection and Quarantine;
Standardization Administration of PRC.
Table of Contents
Foreword ... 3
1 Scope ... 5
2 Normative references ... 5
3 Terms and definitions ... 7
4 Safety requirements and safety measures ... 9
5 Inspection of safety requirements and safety measures ... 19
6 Data provided by the manufacturer to the user ... 29
7 Marking and nameplate ... 30
Appendix A (Informative) List of various hazards ... 32
Appendix B (Normative) Operating conditions and ignition sources of internal combustion engines ... 33
Appendix C (Informative) Comparison of clause numbers between this part and EN 1834-2:2000 ... 36
Appendix D (Informative) Technical differences between this part and EN 1834- 2:2000 and their reasons ... 39
General rules of explosion-protect techniques of
reciprocating internal combustion engines for
explosive atmospheres - Part 3: Group I engines for
use in underground workings susceptible to firedamp
and/or combustible dust
1 Scope
This part of GB 20800 specifies the safety requirements and (or) safety measures for Group I category M2 reciprocating compression ignition engines for use in underground workings with methane and/or combustible dust
(hereinafter referred to as internal combustion engines), which are used to eliminate or limit various dangers and hazards that may occur on internal combustion engines.
This part applies to the explosion-proof structure design, manufacture and inspection of internal combustion engines 1).
This part does not apply to Group I category M1 internal combustion engines that require special conditions.
This part does not apply to internal combustion engines used in places where explosives are processed, manufactured, stored.
This part does not apply to ignition type internal combustion engines.
2 Normative references
The provisions in following documents become the provisions of this Standard through reference in this Standard. For the dated references, the subsequent amendments (excluding corrections) or revisions do not apply to this Standard; however, parties who reach an agreement based on this Standard are
encouraged to study if the latest versions of these documents are applicable. For undated references, the latest edition of the referenced document applies. 1 EN 1834-2:2000 has no specific requirements for inspection procedure. For the specific requirements of the inspection procedure, see Appendix A of GB 38336.1-2000.
GB/T 15706.2-1995 Safety of machinery - Basic concepts, general principles for design - Part 2: Technical principles and specifications (eqv ISO/TR 12100-2:1992, eqv EN 292-2:1991)
GB/T 16856-1997 Safety of machinery - Principles for risk assessment
GB 20800.1-2008 General rules of explosion-protect techniques of
reciprocating internal combustion engines for explosive atmospheres - Part 1: Group II engines for use in flammable gas and vapor atmospheres (MOD EN 1834-1:2000)
JB 8890-1999 Reciprocating internal combustion engines - Safety
requirement
3 Terms and definitions
This part adopts the terms and definitions as proposed in GB/T 1883.1-2005, GB 6809.1-1986, GB 6809.2-1988, GB 6809.3-1989, GB 6809.4-1989 as well
as the following terms and definitions.
3.1
Explosive atmosphere
Under atmospheric conditions, the atmosphere wherein the mixture of
combustible substances in the form of methane and/or combustible dust with air whose, after being ignited, combustion can spread to the entire unburned mixture.
3.2
Potentially explosive atmospheres
An explosive atmosphere that cause explosion due to the influence of site conditions and operating conditions.
3.3 Category
3.3.1
Engines of category M1 of group 1
The internal combustion engines for use in underground workings and mine above-ground operation areas where methane and/or combustible dust
exist.
The explosion-proof measures of this kind of internal combustion engine can When the internal combustion engine needs to install an intake air booster device, it shall select a booster device whose internal temperature and pressure cannot produce ignition conditions (see 4.4 and 4.9), meanwhile be equipped with air filter, to prevent foreign objects from entering the booster device. Alternatively, the intake air booster device shall be part of the flameproof enclosure and be tested in accordance with the requirements of 5.3.
4.7.5 Reverse
Except for the internal combustion engine that can be reversed, the internal combustion engine shall be designed so that it cannot be reversed.
4.7.6 Fuel system
4.7.6.1 For the installation requirements of the fuel system, see 6.5.
4.7.6.2 The fuel tank shall be of metal structure, protected from corrosion, installed in a place free from mechanical damage.
The fuel tank shall pass a seal test with a pressure of at least 20 kPa. 4.7.6.3 The fuel filling port of the fuel tank shall be easily accessible; the structure and configuration shall be able to prevent fuel spillage or leakage. The metal cap of the fuel filler opening shall not be loose when it is covered and shall not be lost when it is opened.
4.7.6.4 The fuel tank shall be provided with vents, to keep the fuel tank under atmospheric pressure and not allow foreign objects to enter it.
4.7.6.5 The fuel tank shall be provided with an easy-to-control shut-off valve. 4.7.6.6 The fuel system shall be designed so that fuel will not flow out of the fuel tank in the event of failure of any fuel pipeline on the pumping side of the fuel pump.
4.7.6.7 The fuel pipeline shall:
a) Designed as a metal pipe or hose with a metal mesh braid;
b) Prevent internal and external chemical, thermal and mechanical damages; c) Lay in a place that can prevent mechanical damage;
d) Be accessible.
4.7.6.8 The connection of the fuel pipeline shall be as short as possible; it shall minimize leakage during operation.
starting auxiliary devices uses the cylinder block of the internal combustion engine as the ground circuit during the operation of the starting auxiliary circuit, this is an exception; when starting auxiliary devices are not used, both the positive and negative connections shall be insulated from the cylinder block of the internal combustion engine.
For mobile internal combustion engines, if the power source is not together with the internal combustion engine and is installed in a place where the starter is only used in non-hazardous areas, the electric starter can also be of ordinary type.
4.12 Static electricity
4.12.1 Plastic materials
If there is no possibility of electrostatic discharge ignition, plastic materials can only be applied to external parts.
If any of the following measures are taken, it can prevent electrostatic discharge from ignition:
- The surface resistance shall not exceed 109 ?? when measured in
accordance with the provisions of 23.4.7.8 in GB 3836.1-2000;
- The electrostatic discharge surface area is limited to 100 cm2;
- The thickness of the non-conductive material on the conductive layer or the metal mesh shall not exceed 2 mm; when the metal mesh is used as the
conductive layer, the mesh width shall not exceed 100 mm.
4.12.2 Potential balance
All externally accessible components shall be connected to the cylinder block of the internal combustion engine using conductors, to achieve potential balance. If these components are firmly installed and maintain metallic contact with the cylinder block, separate conductors are not necessary for connection. 4.13 Drive belt
The drive belt shall meet the requirements for resistance in GB 10715-1989. 4.14 Compressed air system
It is recommended not to install a compressor on the internal combustion engine. If the internal combustion engine is equipped with a compressor under special circumstances, the following safety precautions shall be considered.
If air enters from a hazardous area, the internal temperature and pressure of It shall not be possible to restart the internal combustion engine before the shutdown device is manually reset.
4.15.3 Internal combustion engine's shutdown system
The normal shutdown device and emergency automatic shutdown device of the internal combustion engine shall be located next to the fuel shutoff device of the fuel injection pump or directly close to the fuel injection pump.
All internal combustion engines shall be equipped with intake shutoff valves. When the overspeed protection device is activated, it shall automatically cut off the fuel supply and close the intake shutoff valve.
The intake shut-off valve shall be capable of manual operation. For an
unattended internal combustion engine, control shall be performed at the operator's position. For an unattended internal combustion engine, control shall be performed at an obvious and accessible location outside the engine
enclosure.
For large internal combustion engines, manual control shall be possible in several positions.
In the case of emergency shutdown, the inert gas can be injected into the intake pipe while operating the air shut-off valve. No other types of fire extinguishing liquids are allowed in the intake pipe.
5 Inspection of safety requirements and safety
measures
5.1 Documentation
The manufacturer shall prepare some technical documents to stipulate all the technical requirements for explosionproof of internal combustion engines (including accessories and auxiliary devices), so as to show that the internal combustion engine has implemented the requirements of this part when
designing.
5.2 Test requirements
The internal combustion engine and its accessories and auxiliary devices (including flame arresters, spark extinguishers and pipelines) shall be type tested in accordance with the requirements of 5.3, 5.4, 5.5.
5.3 Type test of flameproof enclosure
The following devices are required for the test:
1) Simulate the cylinder block. It replaces the cylinder block and is used to install accessories. The simulated cylinder block shall be equipped
with a simulated combustion chamber with a volume not greater than
the cylinder volume.
If it is confirmed that the cylinder head has no effect on the test results, the corresponding volume can be used instead.
Note: The test has shown that the cylinder volume has no effect on the
test results.
2) Low-energy ignition source. They are installed on the floor in the
simulated combustion chamber. The design of the floor shall enable the
ignition source to be installed at each entrance and exit of the simulated combustion chamber.
3) Inlet valve. It is installed on the floor in the simulated combustion chamber.
4) Pressure sensor and pressure recording system. There are at least
three pressure sensors, installed on the floor close to the ignition source or far from the ignition source, inside or near the flame arrestor. The measurement system shall use a frequency limit of 5 kHz ?? 10%, in
order to obtain a smooth measurement pressure.
5) A device that supplies the corresponding test gas mixture.
6) Test container. It consists of the following units:
(1) The airtight test cover used to contain the flameproof enclosure
[intake system and/or exhaust system], such as a transparent
plastic bag or a steel container, or a combination of the two; or,
(2) A separate transparent plastic bag, which is used to close the end
of the system away from the pipe and each joint surface.
No part of the test container shall be within 300 mm from any vent or joint surface on the flameproof enclosure.
b) Two-stroke internal combustion engine - Exhaust system
The test device shall meet the requirements of 5.3.3.2a).
c) Two-stroke internal combustion engine - Intake system
The following devices are required for the test:
component next to the flame arrestor. The relevant valve shall be in the open position.
b) Install and seal an airtight test cover or a transparent plastic bag as a test container containing the flameproof enclosure and gas under test.
c) Flush the test system with a test gas mixture of at least 6 times the volume of the test system and determine the state of the test gas mixture:
- Ambient temperature (0 ~ 40 ??C);
- Atmospheric pressure.
d) After flushing, use a low-energy ignition source to ignite and detonate; record the resulting explosion pressure.
e) Refill the test gas mixture that meets the requirements, to confirm that the system is connected correctly and detonate again.
Use each ignition source located at the inlet and outlet positions to carry out multiple tests on the inlet and outlet, respectively. Perform at least 5 tests at the inlet and outlet where the maximum pressure is formed.
Record the maximum pressure displayed during each test as the maximum
explosion pressure.
When testing water-based flame arresters, the liquid level before the test shall be the maximum level as specified by the manufacturer, meanwhile the
explosion shall be carried out under static conditions (no air flow).
Note: There is danger of explosion, so it shall take preventive and protective measures. 5.3.4 Overpressure test
5.3.4.1 Overview
The purpose of this test is to apply a control pressure to the flameproof enclosure that is greater than the maximum explosion pressure that has ever occurred under the most severe explosion conditions, to show that the
flameproof enclosure can maintain its integrity under such conditions.
5.3.4.2 Static pressure test device
The following devices are required for the test:
a) Simulate the cylinder block. It replaces the cylinder block and seals the opening to the surrounding environment.
- The liquid level of the flame arrestor before the test shall be the minimum value specified by the manufacturer;
- The lateral and longitudinal inclination angles of the flame arrestor shall be the maximum value as specified by the manufacturer;
- During the test, the test gas mixture shall be filled into the system with a flow rate equal to the maximum flow rate of the exhaust gas. Maximum flow shall be specified by the manufacturer.
5.3.5.5 Qualification judgement criteria
If the test gas mixture outside the flameproof enclosure is not ignited during each test, the system test is considered qualified.
5.3.6 Type test of the complete set of internal combustion engine and
accessories
5.3.6.1 Overview
The purpose of these tests is to verify that the safety requirements listed in this part are correct. The test can be carried out either on the test bench or on-site. 5.3.6.2 Operation of internal combustion engine
The internal combustion engine shall be operated at its maximum surface temperature, or according to the specific working cycle of the internal combustion engine and its use. If the installation of the enclosure and the ventilation device can accurately represent the actual state of use, the load can be applied by connecting ordinary driving equipment, dynamometer or taking other appropriate measures.
5.3.6.3 Measuring instrument
The test equipment and instruments shall meet the accuracy requirements specified in GB/T 6072.1-2000. The test shall be carried out in accordance with the manufacturer's instructions; the internal combustion engine runs at the specified speed and working conditions for a long enough time until the temperature stabilizes before reading the data.
5.3.6.4 Test data
When the internal combustion engine is running and inhaling ambient gas, measure and record the following data:
a) Ambient air temperature.
b) Maximum surface temperature. Measure the temperature at the possible - A filter that captures particles passing through the spark extinguisher; - A measuring device for measuring the gas flow through the spark
extinguisher.
When the spark extinguisher is tested on an internal combustion engine, the exhaust gas from the internal combustion engine shall be used instead of the blower. At this time, there is no need to measure the exhaust gas flow rate. In order to determine the capture efficiency, the test particles shall be sprayed into the air blown by the blower or the air flow from the internal combustion engine. The trapping efficiency is the ratio of the mass of particles trapped in the filter to the mass of particles injected.
The test particles shall be non-flammable; the apparent density shall be less than 0.9 g/cm3. The specification grades of the test particles are 0.1 mm, 0.2 mm, 0.5 mm. The test shall be performed with the middle value representing the range of the exhaust gas flow rate designed for the spark extinguisher. When the spark extinguisher is tested on an internal combustion engine, it shall be tested at least at no load and idle speed, 50% of the rated power and rated speed, 100% of the rated power and rated speed.
At each flow rate and each particle specification grade, at least one
measurement is made to determine the capture efficiency of the spark arrestor. The mass ratio of particles to air or particles to exhaust gas shall be about 1/100. The test particles shall be sprayed into the air blown by the blower or the air flow from the internal combustion engine at a uniform rate; the spray time is about 1 min (the error is ??5%).
Note: When performing this test on an internal combustion engine, care shall be taken to adjust the water, burned and unburned particles.
5.4.3 Visual inspection
The spark extinguisher can be installed on the tested internal combustion engine for type testing; or installed on an internal combustion engine with similar exhaust flow for type testing. During the type test, the spark extinguisher shall be installed as close as possible to the exhaust pipe of the internal combustion engine.
The test shall use freshly ground carbon which has a particle size between 0.5 mm and 1 mm.
The internal combustion engine shall reach a stable operating temperature with the air filter and air intake flame arrestor removed.
6 Data provided by the manufacturer to the user
6.1 General rules
The data provided by the manufacturer to the user shall meet the following requirements in addition to the technical requirements specified in Chapter 5 of GB/T 15706.2-1995.
6.2 Accompanying files
The manufacturer shall provide some accompanying documents, detailing all the maintenance requirements of the internal combustion engine included in this part, specifying the conditions for the restricted use of the internal combustion engine.
Due to different conditions of use, subsequent hazards may occur, which may require some additional safety measures. The internal combustion engine's installation designer shall consider these conditions.
In particular, the accompanying documents shall point out that the temperature of the hot surface and hot gas as specified in 4.2 shall not exceed the ignition temperature of the explosive environment, meanwhile the externally accessible parts that have the risk of collision or friction shall comply with the requirements of 8.1 in GB 3836.1-2000.
6.3 Inspection items
The accompanying documents shall stipulate the inspection period of the following items according to the usage and working system of the internal combustion engine:
a) General maintenance and external cleaning of internal combustion
engines;
b) The cleanliness, size and working condition of the flame arrester, as well as the corrosion damage degree of the air inlet flame arrester;
c) Exhaust system with spark extinguisher: carbon deposit, corrosion
damage degree;
d) Rotating mechanical parts: Robustness, no contact with stationary parts; e) Fan belt: Working condition and tightness;
f) Electrical equipment: Degree of damage and aging;
g) Shutdown system sensor: Functional status of the set limit;
Appendix A
(Informative)
List of various hazards
This part lists the various hazards of internal combustion engines for use in potentially explosive environments according to the provisions of GB/T 16856- 1997 as follows.
- The hazards arising from the materials processed, used, discharged or ejected by machinery, including fire and explosion (see 4.4, 4.10, 4.11); - Various hazards caused by failure or malfunction of the control system (see 4.15);
- Various hazards caused by incorrect positions or missing of protective devices or safety devices (including starting devices and shutdown devices, as well as safety signals and safety signs, warning devices or information) (see 4.5, 4.6, 4.7, 4.8, 4.9).
The main sources of ignition are:
- Hot surface;
- Flame (sparks) and hot gas;
- Mechanical sparks;
- Electrical equipment and systems;
- Static electricity.
The potential sources of ignition that may ignite the surrounding explosive environment are listed in Appendix B.2.
The design and technical conditions of internal combustion engines shall reduce the possibility of ignition as much as possible according to the operating environment of the internal combustion engine, and stipulate:
- Temperature group;
- Existence of combustible dust;
- Existence of other combustible gases besides methane.

View full details