JB/T 7658.3-1995 Vertical evaporator for ammonia refrigeration equipment
Some standard content:
Mechanical Industry Standard of the People's Republic of China
Vertical Evaporator for Ammonia Refrigeration Device
1 Subject Content and Scope of Application
JB/T 7658. 3-- 95
JB 468-86
Replaces JB4341--86
JB4352-86
This standard specifies the terminology, product classification, technical requirements, test methods, inspection rules, marking, packaging and transportation of vertical evaporators for ammonia refrigeration devices (hereinafter referred to as evaporators). This standard applies to evaporators with an evaporation temperature of -40 to +5°C (gauge pressure of 0.027 to +0.426MPa). 2 Reference standards
Technical conditions
High-quality carbon structural steel
Carbon structural steel
GB1300
GB 1591
Welding steel wire
Low alloy structural steel
GB/T1804
GB 5117
GB5118
GB6654
GB 8162
GB 8163
General tolerances
Unspecified tolerances for linear dimensions
Carbon steel welding rods
Low alloy steel welding rods
Seamless steel pipes for carbon steel and low alloy steel thick plate structures for pressure vessels
Seamless steel pipes for conveying fluids
GB/T13306 label
ZB J73029
3 Terminology
3.1 Vertical evaporator
Method for determining the cleanliness of tubular heat exchangers for ammonia refrigeration units Evaporators consisting of a group of vertically arranged parallel straight or spiral tubes for cooling water, brine or other liquids. 4 Product classification
4.1 Type
According to their structural type, evaporators are divided into two types: straight tube type with open water tank type and spiral tube type with open water tank type. 4.2 Model
4.2.1 Model Indication Method
The model of the evaporator consists of capital Chinese phonetic letters and Arabic numerals (hereinafter referred to as numbers). The model indication method is as follows:
Approved by the Ministry of Machinery Industry of the People's Republic of China on June 16, 1995 and implemented on July 1, 1996
4.2.2 Model Example
JB/T7658.3-95
Retrofit number: Indicated by numbers, omitted for the first design product Nominal evaporation area: Based on the surface area of the evaporating tube, indicated by numbers, m Type: B indicates straight tube type, L indicates spiral tube type Code for evaporators
LZZ60 indicates a straight tube evaporator with a nominal evaporation area of 60m2. LZI.90-1: indicates a spiral tube evaporator with a nominal evaporation area of 90m2, the first retrofit. 4.3 Basic parameters
4.3.1 The nominal evaporation area of the evaporator shall comply with the provisions of Table 1. Table 1
4.3.2 Thermal parameters
4.3.2.1 Heat transfer coefficient of the outer surface of the evaporator 40
When the coolant is salt water: K ≥ 395W/(m·C); a.
When the coolant is water: K ≥ 520W/(m·℃). b.
4.3.2.2 The operating conditions for measuring the heat transfer coefficient of the outer surface of the evaporator shall comply with the provisions of Table 2. Table 2
Evaporation temperature t
Heat transfer temperature difference △tm
Fouling coefficient r
4.4 Design conditions
Design pressure: 1.4MPa;
Design temperature: 38C.
5 Technical requirements
5.1 General requirements
Water side (steel pipe)
The evaporator shall comply with the provisions of this standard and be manufactured according to the drawings and technical documents approved by the prescribed procedures. It can also be manufactured according to the agreement between the user and the manufacturer.
5.2 Materials
5.2.1 The materials of the main pressure-bearing components of the evaporator shall have material certificates. 5.2.2 The main material standards used for the evaporator shall comply with the provisions of Table 3. 1384
Material name
Standard number
5.3 Unindicated tolerance
GB 8162,
GB8163
JB/T 7658. 3--95
GB 699,GB 700,
GB 1591,GB 6654
GB 5117,
GB 5118
GB1300
The unindicated tolerance dimensions of machined surfaces shall comply with the tolerance grade m (medium grade) in GB/T1804. The unindicated tolerance dimensions of non-machined surfaces shall comply with the tolerance grade c (rough grade). 5.4 Cold and hot processing
5.4.1 The roundness tolerance of bent pipes shall not exceed 15% of the outer diameter of the pipe. 5.4.2 The wall thickness reduction at the bend of the pipe should not exceed 17% of the original pipe wall thickness, and there should be no defects such as wrinkles and indentations at the bend. 5.4.3 The center distance tolerance of the two adjacent holes on the upper and lower horizontal main pipes is ±2mm, and the center distance tolerance of any two holes is ±3mm. The pipe hole offset should not exceed ±2mm.
5.5 Water tank
5.5.1 The water tank plate should be flat.
5.5.2 The scale and dirt on the inner and outer surfaces of the water tank should be removed. 5.5.3 The water tank should be tested for water leakage, and there should be no leakage at its welds. 5.6 Automatic control components
The float valve and its automatic control components should ensure that the seal is leak-free, and the operation is flexible and without obstruction. 5.7 Insulation resistance
The motor terminal of the mixer should be tested for insulation resistance, and the insulation resistance between the insulation line and the ground should be not less than 2M (measured by a 500V megohmmeter).
5.8 Welding
The welding of the evaporator shall comply with the requirements of the drawings and processes. 5.9 Technical requirements for assembly
5.9.1 During assembly, the flange surface of the take-over pipe shall be perpendicular to the main axis of the take-over pipe. The installation of the take-over flange shall ensure that the flange surface is horizontal or vertical, and the deviation shall not exceed 1% of the outer diameter of the flange and shall not exceed 3mm. 5.9.2 The bolt holes of the take-over flange shall be symmetrically distributed on both sides of the main axis. 5.9.3 After the horizontal main pipe is welded to the spiral pipe or straight pipe, its straightness shall not exceed 5mm per meter. 5.9.4 When assembling the mixer, the gap between the impeller and the guide tube shall be kept uniform and shall not collide. 5.10 Pressure resistance and airtightness requirements
All parts of the evaporator in contact with the refrigerant shall be subjected to pressure resistance test and airtightness test, and an airtightness test shall also be carried out after assembly. 5.11 Cleanliness
The inside of the evaporator should be clean, and the impurity content in the part in contact with the refrigerant should not exceed 800mg/m2.5.12 Appearance quality
The evaporator should be beautiful and elegant, and the weld surface should be free of cracks, pores, arc pits and slag inclusions. The outer surface should be painted, and the paint should be smooth and uniform in color, and there should be no defects that affect the appearance. 5.13 Completeness
The evaporator supplied as a set should also include:
Nitrogen inlet joint;
Nitrogen outlet joint;
Oil drain joint;
Water tank;
e. Water inlet, water outlet, overflow and drain joints; f. Assembly flanges.
5.14 Accessories
5.14.1 The accessories of the evaporator are:
Ammonia valve, oil drain valve;
Agitator together with driving motor;
JB/T 7658.3-95
Float valve or other automatic liquid level control device; c.
Ammonia liquid filter.
5.14.2 The accessories of the evaporator shall comply with the provisions of the relevant standards. 5.15 Warranty period
If the user complies with the provisions of the product manual, within 18 months from the date of shipment from the manufacturer, if the evaporator is damaged or fails to work normally due to poor manufacturing, the manufacturer shall replace or repair it free of charge. 6 Test method
6.1 Performance test
The performance test method of the evaporator can adopt industrial operation test. 6.2 Pressure and airtightness test
6.2.1 Gas pressure test
6.2.1.1 The gas used in the gas pressure test should be dry, clean air, nitrogen or inert gas. 6.2.1.2 The gas pressure test should have safety measures, which shall be supervised and inspected by the safety department of the test unit. 6.2.1.3 The test pressure is 1.15 times the design pressure. 6.2.1.4 Evaporator gas pressure test method: a. Before the test, the fastening bolts of each connection part of the evaporator should be fully assembled and properly tightened. The dial diameter of the test pressure gauge should be above 100mm. The pressure test should use two pressure gauges with the same range, which have been calibrated and are within the validity period. The range of the pressure gauge should be about 2 times the test pressure, and should not be lower than 1.5 times and higher than 3 times the test pressure. b.During the test, the pressure should be increased slowly to the test pressure, and the pressure should be maintained for 10 minutes before being reduced to the design pressure. Under the design pressure, the evaporator is qualified if there is no leakage or abnormal deformation at all places after being checked with soap solution or other leak detection liquid. If there is leakage, the pressure should be relieved and repaired, and then the test should be repeated according to the above provisions.
The pressure should remain unchanged during the inspection. The practice of continuous pressure increase to maintain the test pressure unchanged should not be adopted, and the screws should not be tightened under pressure. 6.2.2 Airtightness test
6.2.2.1 If the parts of the evaporator that are in contact with the refrigerant have been subjected to the pressure resistance test, the airtightness test can be exempted. However, the airtightness test should be carried out after assembly.
6.2.2.2 The test pressure is equal to the design pressure. 6.2.2.3 The gas used for the airtightness test should be dry, clean air, nitrogen, or inert gas. 6.2.2.4 Evaporator airtightness test method:
The preparation work before the test is the same as that specified in 6.2.1.4a. During the test, the pressure should be slowly increased to the test pressure, and after maintaining the pressure for 10 minutes, it should be placed in water at not less than 5°C (or coated with foaming bi
liquid on the outside). If there is no bubble, it is qualified.
c. If there is leakage, the pressure test and air tightness test should be repeated after pressure relief and repair. ·6.2.3 Water tank leak test
Before placing the evaporation tube group, fill the evaporator water tank with water, and then check that there should be no leakage at the welds of the water tank. 6.3 Insulation resistance test
JB/T7658.3—95
Under normal temperature or relative humidity less than or equal to 80%, use a 500V megohmmeter to measure the insulation resistance between the insulation line of the motor terminal of the mixer and the ground, and the value should be not less than 2M26.4 Cleanliness determination
The cleanliness determination of the evaporator can refer to the provisions of ZBJ73029. 7 Inspection rules
7.1 General requirements
The evaporator shall be inspected by the technical inspection department of the manufacturer in accordance with this standard and technical documents, and can only be shipped after passing the inspection. 7.2 Inspection items
7.2.1 Inspection classification
The inspection of the evaporator is divided into factory inspection and type inspection. 7.2.2 Inspection items
The inspection items of the evaporator shall be in accordance with the provisions of Table 4. Table 4
Inspection items
Performance test
Cleanliness
Processing quality
Water tank leak test
Insulation resistance test Check appearance quality
Pressure and airtightness test
Check the contents of the label
Check the completeness of the product according to the factory documents
7.3 Factory inspection
Each evaporator shall be inspected after it is manufactured. 7.4 Type inspection
Factory inspection
Type inspection
7.4.1 For at least one specification of evaporator, new products or old products that have undergone major reforms should be subject to type inspection. 7.4.2 The performance test method of evaporator can adopt industrial operation test. 8 Marking, packaging and transportation
8.1 Marking
8.1.1 Label
The evaporator should be fixed with a label in a conspicuous and flat position. The label should comply with the provisions of GB/T13306. The following contents should be marked on the label:
Manufacturing unit and trademark;
Product model;
Product name;
Design pressure;
Design temperature;
Evaporation area;
Refrigerant:
h. Water tank capacity;
Total motor power;
j. Net weight;
k．Manufacturing number;
1．Manufacturing date.
8.1.2 Factory documents
The following factory documents shall be brought along with the evaporator when it leaves the factory. 8.1.2.1 Product certificate, the contents of which are: a.
Manufacturing unit and trademark;
Product model;
Product name;
Factory number;
Inspection conclusion;
Signature and seal of the inspector and person in charge;
Inspection date.
Product manual, the contents of which are:
Product model and name;
Purpose and applicable scope;
Specifications and technical parameters;
Structure and working principle;
Installation and use instructions;
Maintenance, care and repair:
Appearance drawing.
8.1.2.3 Packing list.
8.2 Packing and transportation
JB/T7658.3—95
8.2.1 The exposed machined surfaces and pipe connections of the evaporator shall be coated with anti-rust agent and properly sealed. The assembly flange shall be fastened with bolts, and its sealing surface shall be coated with anti-rust grease and sealed with a blind plate.
8.2.2 The evaporator can be installed naked, but a bracket shall be provided to prevent rolling and movement during transportation, and the accessories shall be packed. During shipment, there shall be a shipping mark and a transport packaging mark.
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 Dalian Refrigeration Co., Ltd. and Wuhan New World Refrigeration Industry Co., Ltd. The main drafters of this standard are: Li Muzhen, Ha Hongbo, Sun Zhengguo, and Hu Zengwu. This standard was first issued in January 1964 and revised for the first time in December 1986.1 Product certificate, the contents of which are: a.
Manufacturing unit and trademark;
Product model;
Product name;
Factory number;wwW.bzxz.Net
Inspection conclusion;
Signature and seal of the inspector and person in charge;
Inspection date.
Product manual, the contents of which are:
Product model and name;
Purpose and applicable scope;
Specifications and technical parameters;
Structure and working principle;
Installation and use instructions;
Maintenance, care and repair:
Appearance drawing.
8.1.2.3 Packing list.
8.2 Packaging and transportation
JB/T7658.3—95
8.2.1 The exposed machined surfaces and connecting pipes of the evaporator should be coated with anti-rust agent and properly sealed. The assembly flange should be fastened with bolts, and its sealing surface should be coated with anti-rust grease and sealed with a blind plate.
8.2.2 The evaporator can be installed naked. During transportation, a bracket should be provided to prevent rolling and movement. The accessories should be packed. During shipment, there should be a shipping mark and a transport packaging mark.
Additional notes:
This standard was proposed and coordinated by the Hefei General Machinery Research Institute of the Ministry of Machinery Industry. This standard was drafted by Dalian Refrigeration Co., Ltd. and Wuhan New World Refrigeration Industry Co., Ltd. The main drafters of this standard are: Li Muzhen, Ha Hongbo, Sun Zhengguo, and Hu Zengwu. This standard was first issued in January 1964 and revised for the first time in December 1986. 13881 Product certificate, the contents of which are: a.
Manufacturing unit and trademark;
Product model;
Product name;
Factory number;
Inspection conclusion;
Signature and seal of the inspector and person in charge;
Inspection date.
Product manual, the contents of which are:
Product model and name;
Purpose and applicable scope;
Specifications and technical parameters;
Structure and working principle;
Installation and use instructions;
Maintenance, care and repair:
Appearance drawing.
8.1.2.3 Packing list.
8.2 Packaging and transportation
JB/T7658.3—95
8.2.1 The exposed machined surfaces and connecting pipes of the evaporator should be coated with anti-rust agent and properly sealed. The assembly flange should be fastened with bolts, and its sealing surface should be coated with anti-rust grease and sealed with a blind plate.
8.2.2 The evaporator can be installed naked. During transportation, a bracket should be provided to prevent rolling and movement. The accessories should be packed. During shipment, there should be a shipping mark and a transport packaging mark.
Additional notes:
This standard was proposed and coordinated by the Hefei General Machinery Research Institute of the Ministry of Machinery Industry. This standard was drafted by Dalian Refrigeration Co., Ltd. and Wuhan New World Refrigeration Industry Co., Ltd. The main drafters of this standard are: Li Muzhen, Ha Hongbo, Sun Zhengguo, and Hu Zengwu. This standard was first issued in January 1964 and revised for the first time in December 1986. 1388
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