Some standard content:
Mechanical Industry Standard of the People's Republic of China
Four-way electromagnetic reversing valve for heat pump
1 Subject content and scope of application
JB/T 7230-94
This standard specifies the terminology, model and basic parameters, technical requirements, test methods, inspection rules, marking, packaging and storage of four-way electromagnetic reversing valves for heat pumps.
This standard applies to four-way electromagnetic reversing valves (hereinafter referred to as reversing valves) used to change the flow direction of gas refrigerant in refrigeration devices with a nominal capacity of no more than 90kW and refrigerant R22 to achieve cooling or heating purposes. Reference standards
GB2423.1 Basic environmental test procedures for electric and electronic products Test A: Low temperature test method GB2423.2 Basic environmental test procedures for electric and electronic products Test B: High temperature test method GB2423.3 Basic environmental test procedures for electric and electronic products Test Ca: Constant damp heat test method GB2423.4 Basic environmental test procedures for electric and electronic products Test Db: Alternating damp heat test method GB2624 Flow measurement throttling device
3 Terms
3.1 Four-way solenoid reversing valve
It is a valve composed of a pilot solenoid valve (pilot valve) and a four-way reversing valve (main valve). It is driven by the pilot solenoid valve to generate a pressure difference on both sides of the main valve body, so that the slider moves horizontally to the left and right to change the flow direction of the gas refrigerant (see Figure 1). Figure 1
1 Pilot solenoid valve; 2--Reversing valve;
D air pipe, connected to the exhaust pipe of the refrigeration compressor, C air pipe, connected to the intake pipe of the condenser, S air pipe, connected to the suction pipe of the refrigeration compressor, E air pipe, connected to the return pipe of the evaporator 3.2 Pilot solenoid valve
The electromagnetic force generated by the coil being energized and magnetized drives the valve block (core) in the pilot valve and moves it left and right, and generates a pressure difference on both sides of the valve block (core) to drive the valve of the main valve. Approved by the Ministry of Machinery Industry of the People's Republic of China on July 18, 1994 1358
Implementation on July 1, 1995
3.3 Nominal capacity of reversing valve
JB/T 7230-94
The nominal capacity of reversing valve is the product of the mass flow of refrigerant flowing through the suction channel of reversing valve under nominal working condition and the difference between the liquid flame ratio at the inlet of expansion valve under nominal working condition of refrigeration system and the value of the suction superheated vapor ratio of compressor at evaporation temperature. Model and basic parameters
4.1 Model
The model representation method of reversing valve is stipulated as follows: DHF
Nominal capacity: Expressed in Arabic numerals, kw basic code of reversing valve
4.2 Basic parameters
The basic parameters of reversing valve shall be in accordance with the provisions of Table 1. Table 1
Nominal working conditions
The nominal working conditions of the reversing valve are as follows:
Condensing temperature: 40℃,
Outer diameter of the pipe, mm
Inlet electricity
Temperature of liquid refrigerant entering the expansion valve: 38℃; Evaporation temperature: 5℃;
Suction temperature of the compressor: 15℃;
Pressure drop through the valve suction channel (E→S): △=0.015MPa. 5 Technical requirements
5.1 The reversing valve shall comply with the provisions of this standard and be manufactured according to the drawings and technical documents approved by the prescribed procedures. 5.2 The design pressure of the reversing valve is 3.0MPa. 5.3 The fluid temperature applicable to the reversing valve is -20～120℃. 5.4 The ambient temperature applicable to the reversing valve is -10～43℃, and the relative humidity shall not exceed 95%. Nominal capacity
5.5 The reversing valve should be smooth, and the metal surface should not have inclusions, burrs, cracks, and the weld should not have pores and visible slag inclusions and other defects and splashes.
5.6 The reversing valve should be installed in a horizontal position, and its electromagnetic coil should be on the upper part of the valve. 5.7 The reversing valve should be able to withstand the hydraulic strength test of 1.5 times the design pressure, and there should be no leakage and deformation on the outside. 5.8 The reversing valve should be able to withstand the airtightness test of the design pressure, and there should be no bubbles on the outside and at each welding point. 1359
5.9 Electrical performance requirements of reversing valve
5.9.1 Power supply
AC 50 Hz, 220 V, 380 V;
JB/T7230-94
The voltage change is 85% to 110% of the rated voltage. Insulation resistance
The insulation resistance between the live and non-live parts of the reversing valve at room temperature should be greater than 100MQ; after the heat resistance test, the insulation resistance of the electromagnetic coil should be no less than 1.5MQ. 5.9.3 Withstand voltage
The withstand voltage test between the live and non-live parts of the reversing valve at room temperature should be able to withstand the specified test voltage, and should a.
no breakdown and flashover;
After the moisture and heat resistance test, the retest test voltage should be 80% of the original specified test voltage 5.9.4 Coil temperature
The temperature of the electromagnetic coil of the reversing valve should be as specified in Table 2. Table 2
5.9.5 Moisture and heat resistance
The reversing valve should be subjected to the moisture and heat resistance test, and the insulation resistance and withstand voltage performance should be retested after the test. 5.10 Requirements for the reversing action of the reversing valve
5.10.1 Maximum reversing pressure difference
Circuit temperature, ℃
When the maximum reversing pressure difference is 2.5MPa and the voltage is 85% of the rated voltage, the reversing valve should be able to operate and reversing normally. 5.10.2 Minimum reversing pressure difference
The valve should be able to operate and reversing normally under the following pressure difference and rated voltage: 0.25MPa when the nominal capacity of the reversing valve is not more than 9kW, a.
0.3MPa when the nominal capacity of the reversing valve is greater than 9kW. b.
5.11 The total internal leakage of the reversing valve should not exceed the provisions of Table 3. Table 3
Total internal leakage, mL/min
5.12 The measured capacity of the reversing valve under nominal working conditions should not be less than 90% of the rated nominal capacity. 1360
JB/T7230—94
5.13 The reversing valve shall be subjected to a low temperature resistance test of -10±3°C, and shall be able to operate and reversing normally after the test. 5.14 The reversing valve shall be subjected to a high temperature resistance test of 55±2'C, and shall be able to operate and reversing normally after the test. 5.15 The reversing valve shall be subjected to a vibration resistance test, and during the test, the electromagnetic coil shall not loosen, the weld shall not fall off, or break. 5.16 The reversing valve shall be able to withstand a life test of 10,000 continuous reversing times, and the reversing action requirements of Article 5.10 shall be retested after the test. 5.17 Under the condition that the user complies with the provisions of the product manual, if the reversing valve cannot work normally due to quality problems within 18 months from the date of shipment, the manufacturer shall be responsible for free repair or replacement. 6 Test methods
6.1 Measuring instruments and meters
Measuring instruments and meters shall comply with the following provisions and shall be within the valid period of use and accompanied by a calibration certificate. 6.1.1 The accuracy of the temperature measuring instrument shall be ±0.3℃, and the minimum scale division shall not exceed twice the specified accuracy. 6.1.2 The accuracy of the pressure measuring instrument shall be 1% of the absolute pressure reading, and the minimum scale division shall not exceed 2.5 times the specified accuracy. 6.1.3 Flow measuring instruments shall comply with the following requirements. 6.1.3.1 The accuracy of the flow measuring instrument shall be ±2% of the reading value within the entire flow measurement range, and the minimum scale division shall not exceed 2.5 times the specified accuracy.
6.1.3.2 The design, manufacture, installation and use of the flow measurement throttling device shall comply with the provisions of GB2624. 6.1.4 Electrical measuring instruments shall comply with the following requirements: Voltmeter: Determined by the voltage being measured. When the measured voltage is greater than 150~300V, the accuracy tolerance is ±1.50V; when it is greater than 300a.
~750V, the accuracy tolerance is ±3.75V; b. Ammeter: The accuracy should be ±1% of the indicated value of the ammeter; resistance meter: The accuracy should be ±1% of the indicated value of the bridge resistance meter; c.
d. The minimum scale of the electrical measuring instrument should not exceed twice the specified accuracy. 6.2 Hydraulic strength test
Before installing the electromagnetic coil, install the reversing valve on the device shown in Figure 2, block all the air pipes E and SC, and slowly input a liquid (water) with a pressure of 4.5MPa from the air pipe D, and maintain the pressure for 3min, which should meet the requirements of Article 5.7. Water source
1, 5, 7, 8.9, 12—manual valve; 2, 11-check valve; 3—pressure regulating valve; 4—pressure gauge: 6—reversing valve; 10Container connected to high-pressure gas source
6.3 Air tightness test
JB/T 7230-94
Before installing the electromagnetic coil, install the reversing valve on the device shown in Figure 2, block the air pipes E and C respectively, connect the air pipes D and S respectively, and immerse the entire valve in a water tank with a temperature not lower than 30℃, then slowly input gas with a pressure of 3.0MPa and maintain the pressure for 1min. It should meet the requirements of 5.8 requirements.
6.4 Insulation resistance test
Use a 500V insulation resistance meter to measure the insulation resistance between the electromagnetic coil terminal and the valve body shell. It should meet the requirements of 5.9.2a. 6.5 Withstand voltage test
On a high-voltage test bench with a capacity of not less than 0.25kVA and a power supply frequency of 50Hz, slowly apply the test voltage specified in Table 4 between the electromagnetic coil terminal and the valve body shell for 1 minute. It should meet the requirements of 5.9.3a. Table 4
Power supply voltage
Test voltage
6.6 Coil temperature test
Put the reversing valve in a 40±3°C constant temperature box. After the coil temperature is balanced, measure and record the initial resistance value of the coil. Then turn on the power and adjust the voltage to 110% of the rated voltage for 4 hours. When the coil reaches thermal stability, measure and record the coil resistance value again. Calculate the coil temperature rise by the resistance method. The temperature should not exceed the requirements of 5.9.4. 6.7 Humidity and heat resistance test
Any of the following methods can be used. 6.7.1 Constant humidity and heat test method
According to the test method specified in GB2423.3. Place the reversing valve in the test box and preheat it at 30~35°C for not less than 1 hour. When the temperature is stable, increase the relative humidity to 90%~~95%, and then heat it to 40±2°C according to the severity level. The test lasts for two days. After the test, place the reversing valve in normal atmospheric conditions for 1 hour, and immediately conduct insulation resistance and withstand voltage retests, which should meet the requirements of 5.9.2b and 5.9.3b. 6.7.2 Alternating damp heat test method
Perform a 24h cycle and two cycles test according to the method specified in GB2423.4. Place the reversing valve in a test chamber at a temperature of 25±3C and a relative humidity of 45% to 75% to stabilize the temperature for no less than 1 hour. Then keep the temperature in the chamber constant, increase the relative humidity to 90% to 96%, and then continuously increase the temperature to the severe level of 40±2℃ within 3±0.5h, keep warm for about 8h, and the cycle is 12±0.5h from the start of the temperature increase. Then the temperature drops to 25±3℃ within 3~6h, during which the relative humidity should still be no less than 95%, until the end of a 24h cycle, and do two cycles in total. After the test, place the reversing valve under normal atmospheric conditions for 1 to 2 hours and immediately retest the insulation resistance and withstand voltage performance. The test shall meet the requirements of 5.9.2b and 5.9.3b. 6.8 Reversing action test of reversing valve
6.8.1 Maximum reversing pressure difference test
Install the reversing valve on the device shown in Figure 3, adjust the voltage of the electromagnetic coil terminal to 85% of the rated voltage, slowly input gas from the gas pipe D, so that the pressure of the DC tube gas is the maximum reversing pressure difference, and the gas pipe S is connected to the atmosphere. At this time, the pressure gauge value on the gas pipe C is the maximum reversing pressure difference, and the pressure gauge value on the gas pipe E is 0. Turn on the power supply to make the slider reversing. At this time, the pressure of the DE tube gas is the maximum reversing pressure difference, the pressure gauge value on the gas pipe E is the maximum reversing pressure difference, and the pressure gauge value on the gas pipe C is 0. Reversing is performed three times in a row, with an interval of 1 minute each time. The test results shall meet the requirements of 5.10.1. 6.8.2 Minimum reversing pressure difference test
Install the reversing valve on the device shown in Figure 3, the voltage is the rated voltage, the input gas pressure is the minimum reversing pressure difference, the test method is the same as 6.8.1, and the test result should meet the requirements of 5.10.2. 1362
6.9 Leakage test
JB/T 7230--94
1-pressure gauge; 2-manual valve; 3-rotameter; 4-reversing valve; 5-check valve; 6-pressure regulating valve After the reversing action test of the reversing valve is completed, connect the rotameter to the top of the gas pipe S with a hose, and perform the leakage test of the reversing valve as shown in Figure 3. The gas pressure is 1.0MPa from the gas pipe D. When the pressure gauge value of the gas pipe C is 1.0MPa and the pressure gauge value of the gas pipe E is 0, the leakage measured from the top of the gas pipe S is the leakage of the ES system (refrigeration). Turn on the power to make the slider reverse. Conversely, the leakage measured from the top of the air pipe S is the leakage of the CS system (heating). The leakage of any system should not exceed the specified value in Table 3. 6.10 Nominal capacity test
The nominal capacity test and calculation method of the reversing valve shall be in accordance with the provisions of Appendix A (Supplement). 6.11 Low temperature test
According to the method of "Test Ad: Low temperature test with gradual temperature change of heat dissipation test sample" specified in GB2423.1. Place the reversing valve in a 10±3°C test box for 16 hours, then place it in atmospheric conditions for 2 hours and immediately conduct an appearance inspection and reversing action and insulation resistance and withstand voltage performance tests. It should comply with the requirements of 5.9.2a, 5.9.3a and 5.10. 6.12 High temperature test
According to the method of "Test Bd: High temperature test with gradual temperature change of heat dissipation test sample" specified in GB2423.2. Place the reversing valve in a 55±2°C test box for 16 hours, then place it in atmospheric conditions for 2 hours and immediately conduct an appearance inspection and retest of reversing action and insulation resistance and withstand voltage performance. It should comply with the requirements of 5.9.2a, 5.9.3a and 5.10. Meet the requirements of 5.9.2a, 5.9.3a and 5.10. 6.13 Vibration resistance test
Fix the reversing valve on the vibration test bench. Under the conditions of a frequency of 10Hz and a single-sided amplitude of 1.5mm, perform vibration tests for 1 hour each in up and down, left and right, and front and back. After the test, the performance meets the requirements of 5.9.2, 5.9.3 and 5.10. 6.14 Life test
6.14.1 Requirements
a. The reversing valve to be tested should be a product that has passed the factory inspection; b. During the test, keep the valve body (except the electromagnetic coil and the pilot valve) at a temperature of 70±2°C. 6.14.2 Method
Install the reversing valve on the device shown in Figure 3 and remove the rotor flowmeter. Connect a pressure gauge to the top of each of the E and C pipes, and pass the S pipe through a large Gas, connect the electromagnetic coil, automatic counter and timer to the power supply, input 1.5MPa high-pressure gas from the D pipe, and make the slider switch back and forth at a frequency of 6 times/min (oil lubrication), the method is the same as Article 6.8.1. After the test, it should meet the requirements of Article 5.16. 7 Inspection rules
7.1 The reversing valve shall be inspected and qualified by the quality inspection department of the manufacturer before leaving the factory. 7.2 The items, technical requirements and test methods of factory inspection, sampling inspection and type inspection of the reversing valve shall be in accordance with the provisions of Table 5. 1363
Hydraulic strength
Air tightness
Insulation resistance
Withstand voltage
Coil temperature rise
Moisture and heat resistance
Maximum reversing pressure difference
Minimum reversing pressure difference
Leakage Quantity
Nominal capacity
High temperature resistance
Vibration resistance
7.3 Factory inspection
JB/T7230-94
Inspection type
Each reversing valve shall be inspected before delivery and can be delivered only after passing the inspection. 7.4 Sampling inspection
Technical requirements
Article 5.10.1
Article 5.10.2
Test method
Sampling inspection shall be conducted from the products that have passed the factory inspection, and sampling inspection can also be conducted from the products produced in batches to check the process stability of 7.4.1 in the production process.
7.4.2-The number of products of the same model within one year shall be regarded as an inspection batch, and the sampling time shall be evenly distributed throughout the year. 7.4.3 Sampling plan shall be a single sampling plan as specified in Table 6. Table 6
Batch size
>50~100
>100～500
7.5 Type inspection
Sample size n
Type inspection should be carried out in any of the following cases: a.
New trial-produced directional valve:
Qualified judgment number A
When the product has major changes in structure, material, and process, which may affect product performance; When the factory inspection results are significantly different from the last type inspection. 8 Marking. Packaging and storage
8.1 A label should be attached to one end of the directional valve body. The label should be legible and have the following basic content: 1361
Unqualified judgment number R.
Model and marking of reversing valve;
Rated voltage;
Maximum working pressure;
Code of each air pipe:
Date of manufacture or batch number.
JB/T723094
When the reversing valve leaves the factory, the top of each air pipe should be sealed with a plastic cover to prevent dust and other impurities from entering. 8.2
8.3The finished reversing valve should be covered with a plastic bag, and the capillary should be prevented from being damaged or broken when packed in boxes or cartons. The following technical documents should be carried with the reversing valve when it leaves the factory: 8.4
a. Product certificate;
b. Product manual, which should include the main technical parameters, working principle, installation requirements, and usage methods; c.
Packing list.
5 Directional valves should be stored in a clean, dry, and ventilated room. 8.5
Measurement device
JB/T 7230—94
Appendix A
Method for measuring nominal capacity of directional valve
(Supplement)
The device for measuring nominal capacity of directional valve is shown in Figure A1. Refrigeration compressor exhaust
To compressor
From evaporator
To cooler or condenser
1—pressure difference measuring instrument; 2—pressure gauge 3—manual valve: 4—thermometer: 5—reversing valve; 6—glass sight glass; 7—flow measuring device; 8—temperature regulating device A2 Measurement point location and requirements
A2.1 Pressure hole measurement location
A2.1.1 The intake pipe pressure hole should be set on the main pipe at a distance of two times the inner diameter of the main pipe from the upstream side of the D pipe inlet pipe end face. A2.1.2 The exhaust pipe pressure hole should be set on the main pipe at a distance of 10 times the inner diameter of the main pipe from the downstream side of the E and S pipe outlet pipe end faces.
A2.2 Fluid temperature measurement location
The fluid temperature measurement point should be set at a position where the downstream distance from the outlet pipe end face does not exceed 12 times the inner diameter of the main pipe. A2.3 Main pipeline sizebZxz.net
The main pipeline size should be consistent with the size of the reversing valve inlet and exhaust pipes. A3 Measurement procedure
A3.1 Start the refrigeration system test bench to gradually reach the nominal valve operating conditions specified in Article 4.3. A3.2 Adjust the gas parameters on the exhaust side of the refrigeration system to keep the gas refrigerant pressure through the reversing valve high-pressure inlet pipe (D pipe) at the saturated vapor pressure corresponding to the condensing temperature of 40±0.5°C. 1366
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