QC/T 324-2000Automotive fuel-fired air heaters (English PDF)

3.1 Heater

A device which uses fuel oil as fuel and air as heat exchange medium for automobile occupant heating, windscreen defrosting, and heating of engine cooling water and oil. It includes atomizer, combustor, heat exchanger, oil pump, motor, and other components.

3.2 Stable working condition

When the heater is working under the rated heat release, the thermal condition is in a stable state. Within 5 min, the temperature change of air outlet is not more than 1 °C; the discharge temperature change is not more than 5 °C; and the motor voltage changes by no more than 2 %.

4.2 Appearance

4.2.1 The outer surface of heater shall be smooth and free from scratches, rust, and other harmful defects.

4.2.2 The fasteners and exposed parts of heater shall be treated for corrosion protection or made of materials with corrosion resistance.

4.2.3 The plating and chemical treatment layer of metal parts shall comply with the provisions of QC/T 625. The paint coating shall comply with the requirements of QC/T 484.

4.3 Structure

4.3.1 The connection part of heater shall be fastened and reliable, easy to assemble and disassemble, and during use, shall not be loose or deformed.

4.3.2 The moving parts of heater shall be flexible; and there shall be no collision or clamping stagnation.

4.3.3 The heater oil circuit shall be unblocked, and no blockage is allowed. The fuel used shall comply with the provisions of GB 252.

4.3.4 The joints of the sealing surfaces of heater and the combustor, air pipe, and oil pipe shall be well sealed. When the heater is started or is working, there shall be no air or oil leakage. After it is ignited for a period of time, the drip pipe

5.1 Test conditions

Unless otherwise specified, heaters are generally tested under the following conditions.

5.1.3 The heater is mounted on the bench. Its axis must be horizontal and shall not be disturbed by natural wind. After installing the air duct, there shall be no obstacles in the surrounding space with a distance of 3 D (D is the diameter of the air duct) away from the center of air inlet, outlet, and exhaust port end faces.

The axis shall be no less than 1 m from the ground.

5.1.4 The measurement of each parameter must be carried out under stable working condition of heater.

5.1.1 Test voltage

When the nominal voltage is 12 V, the test voltage is (13.5±0.3) V. When the nominal voltage is 24 V, the test voltage is (27.0±0.6) V.

5.1.2 Atmospheric pressure. 86 kPa~106 kPa

5.2 Heat release test

5.2.2 The air duct shall meet the following requirements.

a) The diameter of air duct shall remain constant throughout the length and be equal to the diameter of the inlet and outlet of heater as much as possible. If not equal, the taper joint shall be used for connection. The taper joint shall meet the requirements of Chapter 5 of GB 1236;

b) The air duct for air-out and discharge must be insulated. The insulation

5.2.1 Test equipment

a) Special test bench;

b) Pitot tube;

c) Micromanometer. minimum division value 1.0 Pa;

d) Thermometer. minimum scale value 0.1 °C;

e) Air duct. SEE 5.2.2 for the requirements.

The arrangement of heat release test is shown in Figure 1.

5.4 Noise test

The heater is arranged according to the normal working position. The noise measurement is carried out in accordance with the relevant provisions of GB 1859. The measurement results shall comply with the provisions of 4.6.3.

5.5 Low temperature starting test

5.5.1 Test conditions

a) The test shall be carried out separately in the following temperature ranges. (-15±2) °C (-30±2) °C (-40±2) °C

b) If there is no low temperature chamber, it is allowed to be carried out in cold regions, but the temperature deviation is extended to ±5 °C.

5.5.2 Test procedures

a) PLACE the heater and fuel oil in a low temperature chamber or cold region, LEAVE it for 10 h in a non-working condition; and then at the same temperature, PERFORM a low temperature starting test;

b) The test results shall be in accordance with the provisions of 4.6.4.

5.6 Test of resistance to vibration

5.6.1 Test equipment

Vibration test bench.

5.6.2 Test procedures

a) The heater, according to the use requirements during working, is installed on the vibration test bench. The test is conducted according to the requirements of Table 4. During the vibration, PAY attention to the abnormality of the oil circuit, circuit, mechanical parts, and working conditions of heater; and FILL in the record. In the event of a fault, it is allowed to stop the vibration. After troubleshooting, the test is continued;

b) During the vibration in the front-back and up-down directions, ignition test is performed once respectively;

A.1 Calculation equation for the distance from the air-out dynamic

pressure measuring point to the center of air duct Where. Ri - The distance from the center of air duct to the measuring point on the ith ring, mm;

R - Radius of air duct, mm; i - The ring sequence number calculated from the center of air duct; m - Number of rings divided on the cross section of air duct.

A.2 Calculation equation for average air-out dynamic pressure

Where. Pd - Average air-out dynamic pressure, kPa; n - Number of measuring points on the measuring section of air duct;

Pd,1, Pd,2..., Pd, n - Dynamic pressure measured at the measuring point 1, 2..., n, kPa.

A.3 Calculation equation for inlet (outlet) air density

Where. gamma - Inlet (outlet) air density, kg/m3;

P - Atmospheric pressure, kPa; t - Inlet (outlet) air temperature, °C. […]