GB 25034-2020 Gas-fired heating and hot water combi-boiler English
Gas-fired heating and hot water combi-boiler
1 Scope
This standard specifies the terms and definitions, classification and models, materials, structure and safety requirements, performance requirements, test methods, inspection rules, marking and instructions, and packaging, transportation and storage of the gas-fired heating and hot water combi-boiler (hereinafter referred to as the "combi-boiler").
This standard is applicable to the combi-boilers with rated heat input less than 100 kW, maximum working water pressure of heating not greater than 0.6 MPa, working water temperature not greater than 95°C, and atmospheric or fully premixed burning mode, including:
a) Type 1P and 1G forced gas supply/exhaust combi-boilers specified in Annex A;
b) Types 9P and 9G forced exhaust fully premixed condensing boilers with a heat input greater than 70 kW specified in Annex A;
c) Types 10Z, 10P and 10G outdoor combi-boilers specified in Annex A.
The gas in this standard refers to artificial gas, natural gas and liquefied petroleum gas specified in GB/T 13611.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GB/T 191 Packaging - Pictorial marking for handling of goods
GB/T 2828.1 Sampling procedures for inspection by attributes - Part 1: Sampling schemes indexed by acceptance quality limit (AQL) for lot-by-lot inspection
GB/T 3768-2017 Acoustics - Determination of sound power levels and sound energy levels of noise sources using sound pressure - Survey method using an enveloping measurement surface over a reflecting plane
GB 4706.1-2005 Household and similar electrical appliances - Safety - Part 1: General requirements
GB/T 5013.1 Rubber insulated cables of rated voltages up to and including 450/750 V - Part 1: General requirements
GB/T 5023.1 Polyvinyl chloride insulated cables of rated voltages up to and including 450/750 V - Part 1: General requirements
GB/T 6663.1 Directly heated negative temperature coefficient thermistors - Part 1: Generic specification
GB/T 7306.1 Pipe threads with 55 degree thread angle where pressure-tight joints are made on the threads - Part 1: Parallel internal and taper external threads
GB/T 7306.2 Pipe threads with 55 degree thread angle where pressure-tight joints are made on the threads - Part 2: Taper internal and external threads
GB/T 7307 Pipe threads with 55 degree thread angle where pressure-tight joints are not made on the threads
GB/T 9124.1 Steel pipe flanges - Part 1: PN designated
GB/T 12113-2003 Methods of measurement of touch current and protective conductor current
GB/T 14536.1-2008 Automatic electrical controls for household and similar use - Part 1: General requirements
GB/T 16411 Universal test methods of gas burning appliances for domestic use
GB/T 17626.2-2018 Electromagnetic compatibility - Testing and measurement techniques - Electrostatic discharge immunity test
GB/T 17626.4-2018 Electromagnetic compatibility - Testing and measurement techniques - Electrical fast transient/burst immunity test
GB/T 17626.5 Electromagnetic compatibility - Testing and measurement techniques - Surge immunity test
GB/T 17626.6 Electromagnetic compatibility - Testing and measurement techniques - Immunity to conducted disturbances, induced by radio-frequency fields
GB/T 17626.11 Electromagnetic compatibility - Testing and measurement techniques - Voltage dips, short interruptions and voltage variations immunity tests
GB/T 17627 High-voltage test techniques for low-voltage equipment - Definitions, test and procedure requirements, test equipment
GB/T 19212.1-2016 Safety of transformers, reactors, power supply units and combinations thereof - Part 1: General requirements and tests
GB/T 22688 Pressure-type temperature controls for household and similar use
GB/T 37499 Safety and control devices for gas burners and gas-burning appliances - Particular requirements - Automatic and semi-automatic valves
GB/T 38603-2020 Safety and control devices for gas burners and gas-burning appliances - Particular requirements - Electronic controller
GB/T 38693 Safety and control devices for gas burners and gas-burning appliances - Particular requirements - Thermoelectric flame supervision controls
GB 50057 Code for design protection of structures against lightning
CJ/T 157-2017 Hotplate of lacquered toughened glass for gas appliance
CJ/T 198 Stainless steel exhaust pipe for burning equipment
CJ/T 199 Supply-exhaust pipe for combustion appliance
CJ/T 356 General specifications of home and building electronic systems (HBES)
CJ/T 398 Electronic gas/air ratio adjustment devices for household gas appliances
CJ/T 450 Pneumatic gas/air ratio adjustment devices for gas-burning appliances
HG/T 20592 Steel pipe flanges (PN designated)
JB/T 81 Slip-on-welding plate steel pipe flanges
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
gas rate adjuster
device for adjusting the gas flow rate of the burner to a predetermined value based on the gas supply conditions
3.2
range-rating device
device used by the installer for setting the rated heat input of the combi-boiler within the maximum and minimum rated heat inputs given by the manufacturer according to the actual heat demand of the user
3.3
control thermostat
control device for automatically maintaining the water temperature within a predetermined range
3.4
temperature limiter
device for closing the gas path to the main burner when the temperature reaches a limit temperature value and automatically re-opening the gas path to the main burner when the temperature drops below the limit value
3.5
overheat cut-out device
protective device that triggers a safety shutdown and a non-volatile lockout before the combi-boiler overheat causes damage to the combi-boiler or a safety accident
3.6
ignition rate
ФIGN
average heat input during ignition safety time
3.7
ignition delay opening time
TIA
time of thermoelectric flame monitoring device from the ignition of the monitored flame to the flame signal causing the gas valve to be in a close-in state
3.8
extinction delay closing time
TIE
time of thermoelectric flame monitoring device from extinction of the monitored flame to cutting off the gas supply
3.9
ignition safety time
TSA
time from the command to turn on the main burner gas supply to the command to turn off the gas supply in the case of non-ignition
3.10
extinction safety time
TSE
time from the extinction of the monitored flame to the issuance of the command to cut off the gas supply
3.11
spark restoration
control function of turning on the ignition device again without completely cutting off the gas supply in the case of unexpected flame failure
3.12
recycling
control function of cutting off the gas supply immediately and restarting automatically according to the starting program in the case of unexpected flame failure of the combi-boiler during operation
3.13
safety shutdown
safe de-energization of the main gas flow means as the result of the action of a controller, a safety device or the detection of an internal fault of the system
3.14
volatile lockout
safety shutdown state in which, in addition to manual reset, the system can also be restarted by resuming power supply after power failure
3.15
non-volatile lockout
safe shutdown state in which the system can only be restarted by manual reset
3.16
air proving device
device for safely turning off the combi-boiler when there is an abnormal condition in air supply or burning fume emission
3.17
pneumatic gas/air ratio control system
control system that adjusts the gas/air ratio of the output gas pressure by comparing the response of the air pressure (or differential pressure)
3.18
electronic gas/air ratio control system
closed-loop control system composed of an electronic control module, an actuator (including at least a gas adjusting unit and an air flow adjusting unit) and a specified feedback signal, which is used for adjusting the gas/air ratio
3.19
nominal condensing output
heat output of the reference gas used in the condensing boiler at the supply/return water temperature of 50°C/30°C, under the reference conditions specified in this standard
3.20
modular boiler
combi-boiler consisting of two or more identical modules that may be operated independently under the same enclosure
3.21
common chamber of combustion products
common flue for collecting fume in the modular boiler
3.22
fault tolerating time
maximum tolerating time from the occurrence of fault in the combi-boiler to the safety action without causing any hazard
3.23
remote controller
device for controlling the combi-boiler through wired or wireless connection in addition to a wired control device of the combi-boiler body
3.24
remote reset function
function of resetting the combi-boiler from locked state to restart by remote control
3.25
intermittent/interrupted ignition burner
cross-lighting burner
ignition burner that has flame failure immediately after a main burner is ignited burner re-ignited by the flame of the main burner before the flame failure of the main burner
3.26
storage type combination boiler
combination boiler in which flames and combustion products do not directly heat domestic hot water in storage tanks
4 Classification and models
4.1 Classification
4.1.1 Classification by utilization of water vapor in fume
See Table 1 for classification by utilization of water vapor in fume.
Table 1 Classification by utilization of water vapor in fume
Foreword i
1 Scope
2 Normative references
3 Terms and definitions
4 Classification and models
4.1 Classification
4.2 Model
5 Material, structure and safety requirements
5.1 Materials
5.2 Structure
5.3 Adjustment, control and safety devices
5.4 Remote controller
5.5 Additional requirements for modular boiler
6 Performance requirements
6.1 Tightness
6.2 Heat input and heat output
6.3 Operational safety
6.4 Adjustment, control and safety devices
6.5 Burning
6.6 Thermal efficiency
6.7 Domestic hot water performance
6.8 Antifreeze performance of outdoor combi-boiler
6.9 Durability of heat exchanger of condensing boiler
6.10 Noise
6.11 Electrical safety
6.12 Safety of electromagnetic compatibility
6.13 Risk assessment
7 Test methods
7.1 Test conditions and combi-boiler installation
7.2 Airtightness test
7.3 Heat input and heat output test
7.4 Operational safety test
7.5 Testing of adjusting, controlling and safety devices
7.6 Burning test
7.7 Thermal efficiency test
7.8 Domestic hot water performance test
7.9 Antifreeze performance test of outdoor combi-boiler
7.10 Durability test of condensing heat exchanger
7.11 Noise test
7.12 Test for electrical safety
7.13 Test for safety of electromagnetic compatibility
7.14 Risk assessment test
8 Inspection rules
8.1 End-of-manufacturing inspection
8.2 Type inspection
8.3 Inspection items and rejection classification
9 Marking and Instructions
9.1 Marking
9.2 Instructions
10 Packaging, transportation and storage
10.1 Packaging
10.2 Transportation
10.3 Storage
Annex A (Informative) Classification by gas supply/exhaust installation method
Annex B (Normative) Performance of carbon steel and stainless steel
Annex C (Normative) Chemical composition of aluminium materials for casting
Annex D (Normative) Properties of copper or copper alloy components
Annex E (Normative) Minimum wall thickness of rolled components
Annex F (Normative) Minimum wall thickness of (water) pressure casting components
Annex G (Informative) Composition of automatic valve gas path
Annex H (Normative) NOx test
Annex I (Normative) Electrical safety of combi-boilers using AC power supply
Annex J (Normative) Safety of electromagnetic compatibility
Annex K (Normative) Risk assessment
Annex L (Normative) Correction of thermal efficiency of condensing boiler with the return water temperature of 30°C
Annex M (Normative) Test method for ignition time under rated heat input
Annex N (Informative) Basic risk level
Annex O (Informative) Safety protection measures
Annex P (Informative) Examples of risk assessment
Bibliography
