GB/T 32224-2015 English PDF (GBT32224-2015)

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GB/T 32224-2015: Heat meters
GB/T 32224-2015
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
ICS 91.140.60
P 40
Heat meters
ISSUED ON: DECEMBER 10, 2015
IMPLEMENTED ON: NOVEMBER 01, 2016
Issued by: General Administration of Quality Supervision, Inspection and
Quarantine of PRC;
Standardization Administration of PRC.
Table of Contents
Foreword ... 3 
1 Scope ... 4 
2 Normative references ... 4 
3 Terms and definitions ... 5 
4 Technical characteristics ... 9 
5 Requirements ... 13 
6 Test methods ... 19 
7 Inspection rules ... 27 
8 Marking, packaging, transportation, storage ... 29 
Appendix A (Normative) Density and enthalpy of water ... 31 
Appendix B (Normative) Structure and installation of platinum-resistance
temperature sensor ... 35 
Appendix C (Normative) Optical interface and data communication ... 51 
Appendix D (Normative) Test and calculation of measurement accuracy of heat
meter ... 53 
Appendix E (Normative) Test and calculation of calculator’s accuracy ... 54 
Appendix F (Normative) Test and calculation of accuracy of temperature sensor
... 56 
Appendix G (Normative) Test and calculation of accuracy of flow sensor ... 60 
Heat meters
1 Scope
This standard specifies the terms and definitions, technical characteristics,
requirements, test methods, inspection rules, marking, packaging,
transportation, storage of heat meters.
This standard applies to the production and inspection of heat meters which
use water as medium.
2 Normative references
The following documents are essential to the application of this document. For
the dated documents, only the versions with the dates indicated are applicable
to this document; for the undated documents, only the latest version (including
all the amendments) are applicable to this standard.
GB/T 191 Packaging - Pictorial marking for handling of goods
GB/T 2423.1 Environmental testing for electric and electronic and electronic
products - Part 2: Test methods - Tests A: Cold
GB/T 2423.2 Environmental testing for electric and electronic products - Part
2: Test methods - Tests B: Dry heat
GB/T 2423.4 Environmental testing for electric and electronic products - Part
2: Test method - Test Db: Damp heat, cyclic (12h + 12h cycle)
GB/T 26831.1 Society energy metering for reading system specification -
Part 1: Data exchange
GB/T 26831.2 Society energy metering for reading system specification -
Part 2: Physical and link layer
GB/T 26831.3 Society energy metering for reading system specification -
Part 3: Dedicated application layer
GB 4208-2008 Degrees of protection provided by enclosure (IP code)
GB 4706.1-2005 Household and similar electrical appliances - Safety - Part
1: General requirements
GB/T 9113 Integral steel pipe flange
GB/T 17241.6 Integral cast iron flanges
GB/T 17626.2 Electromagnetic compatibility - Testing and measurement
techniques - Electrostatic discharge immunity test
GB/T 17626.3 Electromagnetic compatibility - Testing and measurement
techniques - Radiated, radio-frequency, electromagnetic field immunity test
GB/T 17626.4 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 17626.8 Electromagnetic compatibility (EMC) - Part 4-8: Testing and
measurement techniques - Power frequency magnetic field immunity test
GB/T 17626.9 Electromagnetic compatibility - Testing and measurement
techniques - Pulse magnetic field immunity test
GB/T 17626.11 Electromagnetic compatibility - Testing and measurement
techniques - Voltage dips, short interruptions and voltage variations
immunity tests
GB/T 17626.29 Electromagnetic compatibility (EMC) - Testing and
measurement techniques - Voltage dips short interruptions and voltage
variations on D.C. input power port immunity tests
CJJ 34 Design code for city heating network
JB/T 8622-1997 Technical specification and reference table for industrial
platinum thermal resistance
JB/T 9329 Basic environmental conditions and testing methods for
instruments transportation and storage in the transportation
3 Terms and definitions
The following terms and definitions apply to this document.
3.1
Heat meter
A meter which is used to measure and display the released or absorbed
temperature of water supply and water return of the heat exchange system.
3.9
Calculator
A component that receives signals from the flow sensor and the temperature
sensor pair for heat calculation, storage, display of heat values as
exchanged by the system.
3.10
Temperature difference
The difference between the temperature of water supply and water return of
the heat exchange system.
3.11
Minimum temperature difference
The lower limit of the temperature difference, under which the accuracy of
the heat meter shall not exceed the error limit.
3.12
Maximum temperature difference
The upper limit of the temperature difference, under which the accuracy of
the heat meter shall not exceed the error limit.
3.13
Minimum flowrate
Under the condition that the accuracy of the heat meter does not exceed the
error limit, the lower limit of flowrate of the water when it flows through the
heat meter.
3.14
The permanent flowrate
Under the condition that the accuracy of the heat meter does not exceed the
error limit, the upper limit of flowrate when the heat meter is continuously
operated for a long time.
3.15
4 Technical characteristics
4.1 Heat measurement
4.1.1 Method of heat measurement
The heat may be measured by the enthalpy difference method or the thermal
coefficient method.
4.1.2 Enthalpy difference method
When water flows through an complete heat meter or a combined heat meter
which is installed in a heat exchange system, according to the flowrate as given
by the flow sensor and the temperature signal of water supply and return as
given by the temperature sensor pair as well as the time the water flows, the
calculator is used to calculate and display the released or absorbed heat of this
system. The released or absorbed heat of this system is calculated according
to formula (1):
Where:
Q - The heat released or absorbed by the system, in Joule (J);
qm - The mass flowrate of water which flows through the heat meter, in
kilograms per hour (kg/h);
qv - The volume flowrate of water which flows through the heat meter, in
cubic meters per hour (m3/h);
ρ - The density of water which flows through the heat meter, in kilograms per
cubic meter (kg/m3);
Δh - The difference in enthalpy of water at the temperature of water supply
and water return in the heat exchange system, in Joule per kilogram (J/kg);
τ - Time, in hours (h).
4.1.3 Thermal coefficient method
When water flows through an complete heat meter or a combined heat meter
which is installed in a heat exchange system, according to the signal of
temperature difference of water supply and water return as given by the
temperature sensor pair as well as the total volume (the volume) of water as
given by the flow sensor, the calculator is used to calculate and display the
5.2.1.3 The visible height of the displayed number shall not be less than 4 mm.
The fractional part of the displayed value shall be clearly distinguishable from
the rest of the value. When using display by multiple pages, the v...