JB/T 5145.3-1991 Test methods for oil-injected screw single-stage refrigeration compression condensing units
Some standard content:
Mechanical Industry Standard of the People's Republic of China
Test Methods for Oil-Injected Screw Single-Stage Refrigeration Compression Condensing Units
1 Subject Content and Scope of Application
JB 5145.3--91
This standard specifies the test items, test requirements and test methods for oil-injected screw single-stage refrigeration compression condensing units. This standard applies to oil-injected screw single-stage refrigeration compression condensing units (hereinafter referred to as "units") specified in JB5145.1. Oil-injected screw single-stage refrigeration compression condensing liquid storage units can be used as a reference. 2 Reference standards
Design, installation and use of flow throttling devicesGB 2624
Performance test methods for volumetric refrigeration compressorsGB5773
GB7786Noise sound power level limits for power air compressors and diaphragm compressorsJB4330
Engineering method for determination of noise sound power level for refrigeration and air-conditioning equipmentZBJ73002Technical conditions for oil-injected screw single-stage refrigeration compressorsJB 5145.1
Types and basic parameters of oil-injected screw single-stage refrigeration compression condensing unitsTechnical conditions for oil-injected screw single-stage refrigeration compression condensing unitsJB 5145.2
3 Test itemswwW.bzxz.Net
3.1 Airtightness test
After the unit is assembled, its refrigeration system should be filled with dry air or nitrogen for an airtightness test. The test pressure shall be as specified in Table 1 and the duration shall be 5 to 10 minutes. There should be no leakage. Table 1
Refrigerant category
3.2 Electrical performance test of semi-hermetic unit 3.2.1 Insulation resistance test
Test pressure
The insulation resistance of the compressor terminal to the shell of the semi-hermetic unit should be measured with a 500V insulation resistance meter under normal temperature and relative humidity less than or equal to 80%. The value should be not less than 5M2. 3.2.2 Electrical strength test
The application capacity of the semi-hermetic unit is not less than 0.5kVA. After the high-voltage test, a 50Hz, sinusoidal AC voltage of 1000V plus twice the working voltage is applied between the compressor terminal and the shell for 1 minute. There should be no breakdown or flashover. 3.3 Electrical and control element action test
The electrical and control elements in the unit should be tested for action, and they should be sensitive and reliable. Approved by the Ministry of Machinery and Electronics Industry of the People's Republic of China on July 22, 1991 and implemented on July 1, 1992
3.4 Nominal operating condition cooling capacity test
JB 5145.3--91
Under rated voltage and frequency, the nominal operating conditions specified in Article 3.1 of JB5145.1 shall be followed to determine the nominal operating condition cooling capacity, total input power, unit input power cooling capacity, water volume and water resistance. 3.5 Partial load operation test
For units with energy regulation devices, three-level partial load operation tests of 25%, 50% and 75% shall be carried out to measure the cooling capacity and input power under the nominal operating conditions.
3.6 Maximum load operation test
3.6.1 Carry out in accordance with the requirements of 3.2 of JB5145.2. 3.6.2 When the power supply voltage deviation is -10% to +5% of the rated voltage, the unit should be able to start normally and run for at least 1 hour each. 3.7 Full performance test
The unit should provide a full performance curve chart after the test, that is, the cooling capacity, total input power and other values under different condenser inlet water (inlet air) temperatures (no less than 3 points) and different evaporation temperatures (no less than 5 points each). The water volume during the test of the water-cooled unit is the same as the water volume under nominal conditions.
3.8 Noise test
The unit shall measure the sound power level under nominal conditions in accordance with JB4330 and convert it into sound pressure level in accordance with JB7786. The result shall meet the noise value specified in 3.11 of JB5145.2. 3.9 Determination of cleanliness of the unit
After the type inspection or sampling inspection of the unit, the dedicated refrigerant liquid pipeline drying filter (100um filter screen) is disassembled and cleaned, and the mass of the impurity content is weighed to be the cleanliness of the unit. 3.10 Determination of vibration value of the unit
The test method of vibration value of the unit shall comply with the provisions of Appendix A (Supplement) of ZBJ73002. 4 Test requirements
4.1 General requirements for test equipment
4.1.1 The test equipment shall be set in a test room where the ambient temperature can be controlled. 4.1.2 The refrigeration system of the test equipment shall ensure that there is no refrigerant leakage and escape. 4.1.3 The liquid pipeline and suction pipeline of the test equipment shall be insulated. 4.1.4 When a liquid receiver is used, the refrigerant in the liquid receiver shall maintain a normal liquid level during operation. 4.1.5 The test equipment shall be equipped with a joint that can extract the refrigerant-oil mixture. 4.1.6 There should be no abnormal air flow around the test equipment. 4.2 Adjustment requirements during the test
4.2.1 During the test, the reading deviations of each test parameter shall comply with the provisions of Table 2. Table 2
Test parameters
Suction pressure
Suction temperature
Condenser inlet air temperature
Condenser inlet water temperature
Maximum deviation between measured values and specified values
1.0℃
Maximum deviation of each measured value reading relative to the average value
4.2.2 The ambient temperature of the water-cooled unit shall comply with the temperature specified in the corresponding compressor standard. The temperature value is the average reading of four temperature measuring instruments placed on a horizontal plane at a height of half the unit height and 450mm away from each side. 4.2.3 The condenser inlet air temperature of air-cooled units shall be the average reading of at least four temperature measuring instruments placed in a position that can indicate the average air temperature. It can also be measured using a sampling device. 4.2.4 Each temperature measuring instrument for the condenser inlet air of an air-cooled unit shall avoid heat radiation. 4.2.5 The unit shall take readings after the temperature of each test condition and each measuring point has stabilized. 4.3 Measuring instruments and accuracy requirements
The measuring instruments used for the test shall be within the effective use period and be accompanied by a certificate of compliance with the recent calibration by the relevant departments. 4.3.1 Temperature measuring instruments and accuracy
4.3.1.1 Instruments
Glass mercury thermometer, resistance thermometer, thermocouple. 4.3.1.2 Accuracy
The inlet and outlet temperatures of brine or water in the calorimeter and refrigerant shall be accurate to ±0.1°C; the cooling water temperature in the condenser shall be accurate to ±0.1°C; b.
The dry and wet bulb temperatures shall be accurate to ±0.1°C; c.
Other temperatures shall be accurate to ±0.3°C.
4.3.2 Pressure measuring instruments and accuracy
4.3.2.1 Instruments
Mercury column barometer, U-type differential pressure gauge, Bourdon tube pressure gauge, pressure sensor, etc. 4.3.2.2 Accuracy
Pressure measuring instruments, the accuracy of which shall be ±1% of the measured value; b.
Differential pressure gauges with a reading less than 250mm liquid column height shall not be used: the range of the pressure gauge shall be selected so that the indicated pressure value is between 1/3 and 2/3 of the full scale; c.
The refrigerant vapor saturation temperature shall be determined by the vapor pressure of the refrigerant measured on a straight pipe section at least 150mm and not less than 4 times the pipe diameter in front of the compressor suction port. d.
The pressure of the refrigerant vapor shall be used to determine the refrigerant vapor saturation temperature. 4.3.3 Electrical measuring instruments and accuracy
4.3.3.1 Instruments
Voltmeter, ammeter, power meter (indicating or integrating), frequency meter, etc. 4.3.3.2 Accuracy
Indicating instruments, the accuracy is ±0.5% of the full scale reading; a.
Integrating instruments, the accuracy is ±1% of the measured value, frequency meters, the accuracy is ±0.5%.
4.3.4 Flow measurement instruments and accuracy
4.3.4.1 Instruments
Liquid flow meters, liquid dosing meters, flow throttling devices. 4.3.4.2 Accuracy
a. The accuracy is ±2% of the measured value;
b. The design, manufacture, installation and calculation of flow throttling devices shall comply with the provisions of JB 2624. 4.3.5 Speed measurement instruments and accuracy
4.3.5.1 Instruments
Tachometers, tachometers, flash frequency meters, etc. 4.3.5.2 Requirements
The accuracy is ±1% of the measured speed.
4.3.6 Time measurement
JB 5145.391
Use a stopwatch to measure, with an accuracy of ±0.1% of the measured time. 4.3.7 Weight measurement
Use a platform scale or a pound scale to measure, with an accuracy of ±0.2% of the measured weight. 5 Test method
The performance test of the unit can be carried out by one of the following methods: the second refrigerant calorimeter method, the secondary fluid calorimeter method, the dry refrigerant calorimeter method, the refrigerant vapor flowmeter method, the water-cooled condenser method, and the refrigerant liquid flowmeter method. 5.1 Second refrigerant calorimeter method (Figure 1) Calorimeter
5.1.1 Construction of the device
he2 hg
5.1.1.1 The second refrigerant calorimeter consists of a group of direct evaporation coils as the main evaporator. The evaporator is suspended on the top of an insulated pressure vessel. The bottom of the vessel contains the volatile second refrigerant (R11 or R1.2) and a heater device for heating the second refrigerant liquid. 5.1.1.2 The flow of the first refrigerant is controlled by the expansion valve installed close to the calorimeter. The refrigerant pipeline between the expansion valve and the calorimeter should be insulated.
5.1.1.3 The heat leakage of the calorimeter should not exceed 5% of the nominal cooling capacity of the unit. 5.1.1.4 The calorimeter should have a measuring device for the pressure of the second refrigerant. 5.7.1.5 The calorimeter should be equipped with a safety switch to stop heating the second refrigerant when the rated pressure is exceeded. 5.1.2 Calibration of the device
5.1.2.1 Adjust the heat input to the second refrigerant so that the saturation temperature corresponding to the pressure of the second refrigerant is 15°C higher than the ambient temperature. The ambient temperature should be kept below 32°C at any temperature, and the temperature fluctuation should be within ±1°C. 5.1.2.2 The heat input to the second refrigerant should remain constant, and the pressure should be measured every 1 hour until the corresponding saturation temperature fluctuation does not exceed ±0.5°C for four consecutive times.
5.1.2.3 The heat leakage coefficient is calculated by formula (1): 520
JB 5145.3-91
5.1.2.4 The heat leakage during the unit test is calculated by formula (2): t
QK,(ta - ts)
Where: K, calorimeter heat leakage coefficient, W/C; Q—the amount of heat input to the calorimeter during calibration, W; t—the saturation temperature of the second refrigerant, °C; t. —the average ambient temperature around the calorimeter, °C; Q,
—the amount of heat leakage of the calorimeter, W.
5.1.3 Adjustment method and requirements for test conditions 5.1.3.1 The unit suction pressure corresponding to the refrigerant saturation temperature is adjusted by the expansion valve. 5.1.3.2 The suction temperature of the refrigerant vapor is adjusted by the amount of heat input to the second refrigerant. 5.1.3.3 During the test period, the fluctuation of the heat input to the calorimeter shall be within ±1% of the unit's cooling capacity. 5.1.3.4 After the test conditions are established, the following data shall be recorded: a.
The refrigerant vapor pressure and temperature at the evaporator outlet; the liquid refrigerant pressure and temperature at the expansion valve inlet; the ambient temperature of the calorimeter;
The pressure of the second refrigerant;
The heat input to the calorimeter.
5.1.4 Measurement method and requirements
Measurement shall be made every 15 minutes, and the test shall continue until four consecutive readings are within the range specified in Article 4.2.1. 5.1.5 Calculation of cooling capacity
Where: Q.
-cooling capacity of the unit, W;
Q:-heat input to the calorimeter, W;
hghn(Q: +Q) V)
hg2 — ht2
h.Specific melting point of refrigerant vapor entering the unit under specified operating conditions, kJ/kg, hg2
Specific melting point of refrigerant vapor leaving the calorimeter, kJ/kg: ht—Specific melting point of refrigerant liquid leaving the unit, kJ/kg; ht2
Specific melting point of refrigerant liquid at the inlet of the expansion valve, kJ/kg: Actual specific volume of refrigerant vapor entering the unit, m/kg; Specific volume of refrigerant vapor entering the unit under specified operating conditions, m/kg. 5.2 Secondary Fluid Calorimeter Method (Fig. 2)
5.2.1 Apparatus Construction
·(3)
5.2.1.1 The calorimeter consists of two independent fluid circuits that exchange heat with each other. The liquid refrigerant flows through the inner circuit to evaporate and superheat. The heating medium flows through the outer circuit to provide the heat required for evaporation and superheating. a. When steam, water or brine is used as the heating medium, the calorimeter can be made into a concentric tube type. When water or brine is used as the heating medium, the calorimeter can be made into a liquid cooler with a set of direct evaporation refrigerant coils, b.
and the coils are immersed in a second fluid in a container. 521
Calorie
Heating device
JB 5145. 3--91
Flowmeter
Compressor
5.2.1.2 The flow of refrigerant is controlled by the expansion valve installed close to the calorimeter. The refrigerant pipeline between the expansion valve and the calorimeter should be insulated. 5.2.1.3 The heat leakage of the calorimeter should not be greater than 5% of the nominal cooling capacity of the unit. 5.2.2 Calibration of the device
5.2.2.1 The heat leakage of the calorimeter is determined by the circulation flow of the heating medium in the outer loop of the calorimeter. a.
When water or brine is used as the heating medium, the temperature difference between the inlet and outlet of the water or brine should not be less than 6°C. At this time, the ambient temperature should be at any temperature below 32°C, and its fluctuation value should be within ±1°C. The inlet temperature of the water or brine should be 17°C higher than the ambient temperature. The test should be continued and the flow rate should remain unchanged. Measure once every 1 hour until the fluctuation value of the water or brine inlet and outlet temperature of the calorimeter measured for four consecutive times should be within ±1.
When steam is used as the heating medium, the condensate collected from the heating medium circuit is used to determine the heat leakage of the calorimeter, and the water vapor pressure fluctuation value should be within ±4kPa. At this time, the ambient temperature should be any temperature below 32℃, and its fluctuation value should be within ±1℃. Keep the superheat of the water vapor entering the calorimeter not less than 5℃, and at the same time use the method of supercooling the condensate to prevent the loss of the collected condensate due to evaporation. The average temperature of the outer surface of the concentric tube is measured by at least 10 equidistantly distributed temperature measuring instruments. The test should be continued, measured once every 1 hour until the difference between the condensate water weight readings for four consecutive times should be within ±10%. 5.2.2.2 The heat leakage coefficient is calculated by formula (4) and formula (5): a.
When water or salt water is used:
When steam is used:
miC(ti - t2)
0. 5(t2 + t) - t
(hsl - hsa)m.
te ta
The heat leakage during the unit test is calculated by formula (6) and formula (7): 5.2.2.3
When water or salt water is used:
Qa = K,[t - 0. 5(2 + t)]
When steam is used:
Q. - Ki(t, - te)
In formulas (4) to (7): m-
Flow rate of circulating water or brine, kg/s$
C——Specific heat of water or brine at 20°C, kJ/(kg·℃); t.-Temperature of water or brine at the inlet of the calorimeter, Ct2
-Temperature of water or brine at the outlet of the calorimeter, C; Average temperature of the outer surface of the concentric tube, C:
hl—Specific heat of water vapor entering the calorimeter, kJ/kg; 522
（5）
（6）
.（7)
JB 5145.3--91
Specific heat of condensate at the outlet temperature, kJ/kg, condensate flow rate, kg/s.
5.2.3 Adjustment method and requirements for test conditions 5.2.3.1 The unit suction pressure corresponding to the refrigerant saturation temperature is adjusted by the expansion valve. 5.2.3.2 The suction temperature of the refrigerant vapor is adjusted by the electric heating input to the secondary fluid. 5.2.3.3 When water or brine is used as the heating medium, the temperature fluctuation of the water or brine entering and leaving the calorimeter should be within ±0.1℃, and the flow fluctuation of the circulating water or brine through the calorimeter should be within ±0.5%. 5.2.3.4 When water vapor is used as the heating medium, the superheat of the steam entering the calorimeter should not be less than 5℃. At the same time, the loss of condensed water due to evaporation should be prevented.
5.2.3.5 After the test conditions are established, the following data should be recorded: a.
Refrigerant vapor pressure and temperature at the evaporator outlet: liquid refrigerant pressure and temperature at the expansion valve inlet; ambient temperature of the calorimeter;
When water or brine is used, the temperature of the water or brine inlet and outlet of the calorimeter, the flow rate of circulating water or brine; when steam is used, the water vapor temperature at the inlet of the calorimeter, the water vapor pressure in the calorimeter, the condensate temperature and flow rate at the outlet of the calorimeter, and the surface temperature of the steam pipe.
5.2.3.6 Measurements should be taken every 15 minutes, and the test should continue until four consecutive readings are within the range specified in Article 4.2.1. 5.2.3.7 The fluctuations in the pressure and temperature of the heating medium during the test should not be large enough to cause the change in the unit's cooling capacity to exceed 1%. 5.2.4 Calculation of cooling capacity
5.2.4.1 When water or salt water is used:
When water vapor is used:
hn=hmiC(t, - t) + QV
hg2 ht2
hal_hnm.(h - he) + Q.) V
5.3 Dry refrigerant calorimeter method (Figure 3) Heater
5.3.1 Construction of the device
Compressor
(8)
(9)
5.3.1.1 The calorimeter is composed of a group of tubular sealed pressure vessels of appropriate length and diameter to meet the evaporation of the refrigerant circulating in the unit under test. The tubular vessels should be electrically insulated and equipped with electric heating devices. A tubular electric heater is installed in the tubular vessel, and a linear heater is wrapped around the outside.
5.3.1.2 The refrigerant flow is controlled by an expansion valve installed close to the calorimeter. The refrigerant pipeline between the expansion valve and the calorimeter should be insulated. 5.3.1.3 The heat leakage of the calorimeter should not be greater than 5% of the nominal cooling capacity of the unit. 5.3.1.4 When a heater is installed on the outer surface of a tubular pressure vessel, the electrically insulated outer surface of the heater and the outer surface of the bonding material when bonding material is used should be equipped with at least 10 equidistantly distributed temperature measurement points to determine the average surface temperature of the vessel. 523
5.3.2 Calibration of the device
JB 5145.3—91
5.3.2.1 The heater of the tubular pressure vessel should provide sufficient heat to make the surface temperature of the evaporator 15°C higher than the ambient temperature. 5.3.2.2 When an electric heater is installed in a tubular pressure vessel, the evaporator should be filled with refrigeration oil for calibration, after which the oil should be drained and thoroughly cleaned.
5.3.2.3 The test environment temperature shall be maintained at any temperature below 32℃, and its fluctuation value shall be within ±1℃. The temperature shall be measured every 1h until the average difference of four consecutive times is within ±0.5℃. 5.3.2.4 The heat leakage coefficient is calculated by formula (10): Qh
K,= t.-- t.
5.3.2.5 The heat leakage during the unit test is calculated by formula (11): Q - K,(t, - t'.)
Where: t-
The average temperature of the pipe surface. When the heater is installed outside, it is the average surface temperature of the heater, ℃. 5.3.3 Adjustment method and requirements for test conditions 5.3.3.1 The unit suction pressure corresponding to the refrigerant saturation temperature is adjusted by the expansion valve. 5.3.3.2 The suction temperature of the refrigerant vapor is adjusted by the heat of the electric heater. 5.3.3.3 During the test, the fluctuation of heat input to the calorimeter shall be within ±1% of the cooling capacity of the unit. 5.3.3.4 After the test conditions are established, the following data shall be recorded: a.
Refrigerant vapor pressure and temperature at the outlet of the evaporator; liquid refrigerant pressure and temperature at the inlet of the expansion valve; ambient temperature of the calorimeter:
Heat input to the calorimeter:
Average surface temperature of the pipe (when the heater is installed outside, it is the average surface temperature of the heater). (10)
(11)
5.3.3.5 Measurements shall be taken every 15 minutes. The test shall continue until four consecutive readings are within the range specified in Article 4.2.1. 5.3.4 Calculation of Refrigeration Capacity
5.4 Refrigerant Vapor Flow Meter Method (Figure 4) Throttling Device
Yan Fajun
5.4.1 Construction of the Device
(Q. + Q.)V
Pulsation Buffer Cover
Compressor
Condenser
? (12)
5.4.1.1 The refrigerant vapor flow meter is composed of a nozzle or orifice type flow measurement throttling device, which is used to measure the volume flow of the refrigerant vapor flowing through.
5.4.1.2 The throttling device should be installed on the suction side pipeline of the unit and in a closed system composed of a compressor, condenser, etc.
JB 5145.3—91
5.4.1.3 When flowing through the throttling device, the refrigerant vapor should be superheated evenly and completely free of droplets. 5.4.1.4 In order to reduce or eliminate the pulsation of the refrigerant vapor flow rate, a pulsation buffer should be installed on the suction side pipeline. 5.4.2 Adjustment method and requirements for test conditions 5.4.2.1 The unit suction pressure corresponding to the refrigerant saturation temperature is adjusted by the expansion valve. The unit suction temperature is adjusted by changing the evaporator load. 5.4.2.2
After the test conditions are established, the data to be recorded are: the refrigerant vapor temperature and pressure before the throttling device; the pressure drop before and after the throttling device.
5.4.2.4 The measurement should be carried out every 15 minutes, and the test should be continued until four consecutive readings are within the range specified in Article 4.2.1. 5.4.3 Calculation of cooling capacity
Q. (hg h)m
Where: m
Refrigerant flow measured by the throttling device, kg/s. 5.5 Water-cooled condenser method (Figure 5)
Compressor
Condenser
5.5.1 Requirements for use
5.5.1.1 The water-cooled condenser method is only applicable to water-cooled units. Evaporator
hg3hgl
5.5.1.2 The heat leakage of the condenser should be less than 2% of the cooling capacity of the unit. · (13))V
Pulsation buffer cover
Compressor
Condenser
?(12)
5.4.1.1 The suction refrigerant vapor flow meter consists of a nozzle or orifice type flow measurement throttling device, which is used to measure the volume flow rate of the refrigerant vapor flowing through.
5.4.1.2 The throttling device should be installed on the suction side pipeline of the unit and in a closed system composed of the compressor, condenser, etc.
JB 5145.3—91
5.4.1.3 When flowing through the throttling device, it should be ensured that the refrigerant vapor is evenly superheated and completely free of droplets. 5.4.1.4 In order to reduce or eliminate the pulsation of the suction refrigerant vapor flow, a pulsation buffer should be installed on the suction side pipeline. 5.4.2 Adjustment method and requirements of test conditions 5.4.2.1 The unit suction pressure corresponding to the refrigerant saturation temperature is adjusted by the expansion valve. The unit suction temperature is adjusted by changing the evaporator load. 5.4.2.2
After the test conditions are established, the data to be recorded are: the refrigerant vapor temperature and pressure before the throttling device; the pressure drop before and after the throttling device.
5.4.2.4 The test should be continued every 15 minutes until four consecutive readings are within the range specified in Article 4.2.1. 5.4.3 Calculation of cooling capacity
Q. (hg h)m
Where: m
Refrigerant flow measured by the throttling device, kg/s. 5.5 Water-cooled condenser method (Figure 5)
Compressor
Condenser
5.5.1 Requirements for use
5.5.1.1 The water-cooled condenser method is only applicable to water-cooled units. Evaporator
hg3hgl
5.5.1.2 The heat leakage of the condenser should be less than 2% of the cooling capacity of the unit. · (13))V
Pulsation buffer cover
Compressor
Condenser
?(12)
5.4.1.1 The suction refrigerant vapor flow meter consists of a nozzle or orifice type flow measurement throttling device, which is used to measure the volume flow rate of the refrigerant vapor flowing through.
5.4.1.2 The throttling device should be installed on the suction side pipeline of the unit and in a closed system composed of the compressor, condenser, etc.
JB 5145.3—91
5.4.1.3 When flowing through the throttling device, it should be ensured that the refrigerant vapor is evenly superheated and completely free of droplets. 5.4.1.4 In order to reduce or eliminate the pulsation of the suction refrigerant vapor flow, a pulsation buffer should be installed on the suction side pipeline. 5.4.2 Adjustment method and requirements of test conditions 5.4.2.1 The unit suction pressure corresponding to the refrigerant saturation temperature is adjusted by the expansion valve. The unit suction temperature is adjusted by changing the evaporator load. 5.4.2.2
After the test conditions are established, the data to be recorded are: the refrigerant vapor temperature and pressure before the throttling device; the pressure drop before and after the throttling device.
5.4.2.4 The test should be continued every 15 minutes until four consecutive readings are within the range specified in Article 4.2.1. 5.4.3 Calculation of cooling capacity
Q. (hg h)m
Where: m
Refrigerant flow measured by the throttling device, kg/s. 5.5 Water-cooled condenser method (Figure 5)
Compressor
Condenser
5.5.1 Requirements for use
5.5.1.1 The water-cooled condenser method is only applicable to water-cooled units. Evaporator
hg3hgl
5.5.1.2 The heat leakage of the condenser should be less than 2% of the cooling capacity of the unit. · (13)
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