This standard specifies the technical requirements, test methods, inspection rules, marking, packaging and storage of air-inlet heating units. This standard applies to various units specified in JB/T 6413 that use steam with a maximum working pressure not exceeding 1.3MPa or hot water at 60-150℃ as heat medium. JB/T 7224-1994 Technical conditions for air-inlet heating units JB/T7224-1994 standard download decompression password: www.bzxz.net

Mechanical Industry Standard of the People's Republic of China
Air Inlet Heating Unit
1 Subject Content and Scope of Application
Technical Conditions
JB/T 7224-94
This standard specifies the technical requirements, test methods, inspection rules, marking, packaging and storage of air inlet heating units (hereinafter referred to as units). This standard applies to various units specified in JB/T6413 that use steam with a maximum operating pressure not exceeding 1.3MPa or hot water at 60~~150C as heat medium.
Referenced standards
Safety requirements for air handling units
GB 10891
GB/T13306 Label
Technical conditions for coils
JB/T4292
JB/T5149
JB/T 6413
Test methods for modular air handling units
Types and basic parameters of air inlet heating units
ZBJ72026
General technical conditions for packaging of heating and cooling ventilation equipment ZB J72 029
ZB J72 044
Appearance quality and cleanliness of heating and cooling ventilation equipment Combined air handling unit type and basic parameters Combined air handling unit technical conditions
ZBJ72045
3 Technical requirements
3.1 The unit shall comply with the requirements of this standard and be manufactured according to the drawings and technical documents approved by the prescribed procedures. 3.2 The insulation material of the unit box and the wall panel shall be firmly and densely attached. The thermal resistance of the wall panel insulation layer shall not be less than 0.68m2·K/W, and the insulation material shall be odorless and self-extinguishing (oxygen index shall not be less than 30) and non-absorbent. 3.3 The parts and components of the unit shall be rust-free and anti-corrosive. 3.4 The appearance quality and cleanliness of the unit shall comply with the provisions of ZBJ72029. 3.5 The main parts and components of the unit shall comply with the following provisions. 3.5.1 Standard parts, purchased parts and outsourced parts shall all comply with the relevant standards and be accompanied by a certificate of conformity. 3.5.2 The flange size of the assembled coil pipe shall be consistent with the flange size of the matching pipe, and the tolerance shall comply with the provisions of JB/T4292. 3.6 When the static pressure inside the unit is maintained at 500Pa, the air leakage rate shall not exceed 3%. 3.7 The performance of the unit shall comply with the following provisions. 3.7.1 The actual heating capacity shall not be less than 93% of the rated heating capacity under rated conditions. 3.7.2 The air flow rate shall not be less than 95% of the rated value. 3.7.3 The vibration speed shall not be greater than 4mm/s. 3.7.4 The noise sound pressure level limit shall comply with the provisions of Table 1. 3.7.5 The unit shall be able to start and operate normally at 90%~~110% of the rated voltage. The coil shall not leak when undergoing the pressure resistance performance test in accordance with Article 4.4. 3.7.6
3.7.7Safety performance requirements shall comply with the provisions of GB10891Approved by the Ministry of Machinery Industry of the People's Republic of China on July 18, 1994738
Implementation on July 1, 1995
Air volume range
≥5 000~10 000
>10 000 ~~50 000
>50 000~-100 000
JB/T 7224—94
Axial flow fan
Noise sound pressure level dB(A)
Centrifugal fan
3.8If the user complies with the provisions of the product manual, the manufacturer shall replace or provide warranty for the unit if it is damaged or cannot work properly due to poor manufacturing quality within 18 months from the date of shipment from the manufacturer. 4 Test methods
4.1 Test conditions
4.1.1 Test conditions shall comply with the provisions of Table 1 in JB/T6413. 4.1.2 The stability of test conditions shall comply with the provisions of Table 2. Table 2
Item nameWww.bzxZ.net
Air inlet and outlet dry bulb temperature
Hot water inlet and outlet temperature
Air inlet and outlet wet bulb temperature
Steam supply pressure
Water flow
Rated air volume
4.2 Measuring instruments
The instruments shall be within the effective period of use and be accompanied by a calibration certificate. 4.3 Performance measurement
The measurement shall be carried out according to the method specified in JB/T5149. Main measurement and calculation items:
Measure the air flow and resistance through the unit coil; b.
Single maximum value
Measure the dry bulb temperature of the air before and after passing through the unit coil; measure the water or steam flow through the unit coil; measure the inlet and outlet water or steam temperatures through the unit coil: calculate the heat exchange when water or steam passes through the unit coil; calculate the heat exchange when air passes through the unit coil; operating condition fluctuation value
Arithmetic mean
Use the calculated results of items e and f to calculate the balance error of the unit coil. The thermal balance deviation calculated by the two methods is ±10%. Take the arithmetic mean of the two as the unit heat exchange rate; h.
Vibration, noise, static pressure, outlet residual pressure, and air leakage rate. 4.4 Unit coil pressure test
4.4.1 The water pressure test pressure should be 1.5 times the design pressure, with a deviation of ±0.02MPa, and the pressure should be maintained for at least 3min4.4.2 The pressure test pressure should be 1.2 times the design pressure, with a deviation of ±0.02MPa, and the pressure should be maintained for at least 1min, and reliable safety 739
protective measures should be taken.
JB/T 7224---94
4.5 Unit insulation resistance test
Under normal temperature conditions, the insulation resistance between the live parts and the non-live metal parts of the unit measured with a 500V insulation resistance meter should be no less than 2MQ.
4.6 Operation test
Start the motor and check that the fan should operate normally. Inspection rules
5.1 Inspection categories and inspection items
5.1.1 Unit inspection is divided into factory inspection, type inspection and insertion inspection. 5.1.2 The inspection items of each type of inspection shall be in accordance with the provisions of Table 3. Table 3
Inspection items
Appearance,
Safety requirements
Start-up and operation
Air volume, residual pressure
Power input
Heating supply
Water resistance
Air leakage rate
5.2 Factory inspection
Inspection category
Each unit shall be inspected and qualified by the quality inspection department of the manufacturer and be accompanied by a quality inspection certificate before it can be shipped out of the factory. 5.3 Type inspection
Type inspection shall be carried out for the unit when any of the following situations occur: when a new trial-produced product is finalized;
When there are major changes in the structure, manufacturing process, and materials of the product, which may affect the product performance; when production is resumed after being stopped for more than one year.
5.4 Sampling inspection
Batch production units should be subject to routine sampling inspection to check the stability of the production process. The number of products of the same model within a year is regarded as an inspection batch, and the sampling time should be evenly distributed within a year. The sampling plan adopts the one-time sampling plan specified in Table 4. Table 4
Batch N
51～100
Sample size n
Qualified judgment number A.
Unqualified judgment number R.
6 Marking, packaging and storage
6.1 Marking
JB/T 7224—94
6.1.1Each unit shall have a product label fixed in a conspicuous position on the front. Its type, size and technical requirements shall comply with the provisions of GB/T13306 and shall include the following contents:
Unit model and name:
Main technical parameters of the unit (rated air volume, residual pressure, heating supply, rated voltage, frequency, input power); unit weight;
Unit overall dimensions;
Factory number;
Factory date:
Manufacturer name.
The unit shall have a label indicating the working conditions, such as an arrow indicating the direction of rotation of the fan, a label indicating the direction of movement of the control switch knob, etc., and an electrical circuit diagram shall be provided in an appropriate position.6.1.2

6.2 The packaging should comply with the provisions of ZBJ72026. 6.3 Storage
The unit should be stored in a moisture-proof, rain-proof and fire-proof place, with no corrosive gas around. Additional remarks:
This standard was proposed and managed by the Hefei General Machinery Research Institute of the Ministry of Machinery Industry. This standard was drafted by Harbin Air Conditioning Machine Factory and Tianjin University. The main drafters of this standard are Ren Shouyu, Zhu Yutian and Tu Guangbei. 741
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