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Standard Data Collector www.17bzw.cn – YiQi Standard Network offers free downloads of 100,000 standard books. If you know how to type, you can create a website quickly in just 5 minutes at www.17jzw.com – YiQi Website Building Network, which provides a free website-building platform; the cost for a commercial website is only 60 yuan per year. www.17jzw.com www.17bzw.cn www.17jzw.net www.3x888.com J 73 JB/T 7658.5－1995 Evaporative condensers for ammonia refrigeration units. Published on June 16, 1995; implemented on July 1, 1996. Issued by the Ministry of Machinery Industry of the People’s Republic of China. Standard Data Collector www.17bzw.cn – YiQi Standard Network offers free downloads of 100,000 standard books. If you know how to type, you can create a website quickly in just 5 minutes at www.17jzw.com – YiQi Website Building Network, which provides a free website-building platform; the cost for a commercial website is only 60 yuan per year. www.17jzw.com www.17bzw.cn www.17jzw.net www.3x888.com 1 1 Subject matter and scope of application: This standard specifies the terms, product classification, technical requirements, testing methods, inspection rules, labeling, packaging, and transportation for evaporative condensers used in ammonia refrigeration units (hereinafter referred to as condensers). This standard applies to evaporative condensers for ammonia refrigeration units. 2 Referenced standards: GB 699 – Technical requirements for high-quality carbon structural steel; GB 700 – Carbon structural steel; GB 912 – Hot-rolled thin sheets and strips of carbon structural steel and low-alloy structural steel; GB 1300 – Welding wires; GB 1591 – Low-alloy structural steel; GB/T 3091 – Galvanized welded steel pipes for low-pressure fluid transport; GB/T 3092 – Welded steel pipes for low-pressure fluid transport; GB 5117 – Carbon steel electrodes; GB 5118 – Low-alloy steel electrodes; GB 8162 – Seamless steel pipes for structural use; GB 8163 – Seamless steel pipes for fluid transport; GB/T 13306 – Placards; ZB J73 029 – Method for determining the cleanliness of tubular heat exchangers used in ammonia refrigeration systems. 3 Terms: 3.1 Evaporative condenser – A condenser that uses forced air circulation and the evaporation of moisture to remove the condensed heat from the refrigerant. 4 Product Classification 4.1 Type: Condensers are divided into two types based on their air supply method: air-supply type and air-suction type. 4. 2 Models 4.2.1 Method of indicating models The model of a condenser is composed of uppercase Chinese Pinyin letters and Arabic numerals (hereinafter referred to as numbers). The method for indicating its model is specified as follows: Approved by the Ministry of Machinery Industry on June 16, 1995; it is a mechanical industry standard of the People’s Republic of China. It replaces JB 3337—91 and JB 4339—91. It came into effect on July 1, 1996. www.17jzw.com www.17bzw.cn www.17jzw.net www.3x888.com. Standard data collectors: www.17bzw.cn offers free downloads of hundreds of thousands of standard books. If you know how to type, you can create a website quickly in 5 minutes at www.17jzw.com. YiQi Website Building provides a free website-building platform; commercial websites can be created for only 60 yuan per year at www.17jzw.com www.17bzw.cn www.17jzw.net www.3x888.com. JB/T 7658.5－1995. 2. Modification number: Indicated by numbers; this field is omitted for products in their first design stage. Nominal condensing area: Based on the external surface area of the condensing tubes, indicated by numbers in square meters. Air supply type: S denotes air supply type, while X denotes air suction type. Code for the condenser. 4.2.2 Example of model designation: ZNS200–1: Indicates a nominal condensing area of 200 m2, and it is a condenser with air supply type, belonging to the first modification stage. ZNX120: Refers to an exhaust-type condenser with a nominal condensation area of 120 m2. 4.3 Basic parameters 4.3.1 The nominal condensing area and basic parameters of the condenser shall comply with the provisions in Table 1. Table 1: Nominal condensing area, in m2: 40, 60, 80, 120, 160, 200, 250. Nominal heat rejection capacity, in kW: 70, 105, 140, 210, 280, 350, 430. Air flow rate: ≤15400, ≤23100, ≤30800, ≤46200, ≤61600, ≤77000, ≤96250. Water circulation volume, in m3/h: ≤8.10, ≤12.15, ≤16.20, ≤24.30, ≤32.40, ≤40.50, ≤50.63. Make-up water volume, in m3/h: 0.24–0.41, 0.38–0.63, 0.51–0.86, 0.73–1.22, 0.93–1.56, 1.13–1.89, 1.54–2.57. 4. 3. 2 Thermal parameters: 4. 3. 2.1 Heat transfer coefficient on the outer surface of the condenser: q ≥ 1.74 kW/m2. 4. 3. 2. 2 The operating conditions for measuring the heat transfer coefficient of the condenser shall comply with the provisions in Table 2. Table 2: Project parameters Unit Parameter Condensation temperature t1: 35 Inlet wet-bulb temperature t2: 24 Inlet dry-bulb temperature: 35 Wet-bulb temperature under maximum load condition: 27 °C Fouling coefficient: 0.00034 m2·°C/W 4.4 Design conditions: a. Design pressure: 2 MPa ； b. Design temperature: 75℃. 5 Technical Requirements 5.1 General Requirements The condenser shall comply with the provisions of this standard and be manufactured in accordance with the drawings and technical documents approved through prescribed procedures; it may also be manufactured based on an agreement between the user and the manufacturer. 5.2 Materials 5.2.1 The materials of the main pressure-bearing components of the condenser shall be accompanied by material certification. 5.2.2 The standard for the main materials used in the condenser shall comply with the provisions in Table 3. Standard material collector: www.17bzw.cn – YiQi Standard Network offers free downloads of 100,000 standard books. If you know how to type, you can create a website quickly in just 5 minutes at www.17jzw.com – YiQi Website Building Network, which provides a free website-building platform; the cost for a commercial website is only 60 yuan per year. www.17jzw.com, www.17bzw.cn, www.17jzw.net, www.3x888.com. JB/T 7658.5–1995, Table 3: Material names – steel pipes, steel plates, welding rods, welding wires. Standard numbers: GB/T 3091, GB/T 3092, GB 8162, GB 8163; GB 699, GB 700, GB 912, GB 1591; GB 5117, GB 5118; GB 1300. 5.3 Condenser coils: 5.3.1 Before installation, the condenser coils should be straightened, and any surface oxide or dirt should be removed to ensure that the inside of the coils is clean and dry. 5.3.2 The roundness tolerance of the bent pipe shall not exceed 15% of the outer diameter of the pipe. 5.3.3 The wall thickness reduction at the bend of the pipe shall not exceed 17% of the original wall thickness, and the bend shall be free from defects such as wrinkles and indentations. 5. 3. 4 The condensing coils and supports shall be hot-dip galvanized. 5.4 Water tank 5.4.1 The tank body shall be made of metal sheets with anti-corrosion coating, stainless steel sheets, or corrosion-resistant non-metallic sheets. The pallet boards should be flat and smooth. When the box is made of ordinary steel plates, the oxide scale and dirt on its inner and outer surfaces must be removed, and anti-corrosion treatment must be applied. The surface should be smooth, without any defects such as spots or protrusions. 5. 4. 2 The water tank shall be equipped with a drain outlet. 5. 4. 3 The water tank shall be leak-free. 5. 4. 4 The float valve and other automatic control components must ensure a leak-free seal, as well as smooth operation without any jamming. 5.5 Fans and Pumps Fans and pumps shall comply with the requirements of relevant standards. 5. 6 Water barriers 5. 6.1 The material should be galvanized steel sheet, plastic sheet, or fiberglass. 5. 6.2 It shall have sufficient stiffness to ensure that the water baffle is flat and aesthetically pleasing. 5. 6. 3 There should be no deformation, warping, or mechanical damage, and the surface should be smooth. 5. 7 Nozzles 5. 7.1 The material should be copper or plastic. 5. 7. 2 The water spray should be even. 5. 7. 3 Threaded connections shall not leak. 5.8 Sealing 5.8.1 Rubber gaskets, foam plastic, or sealant should be used to seal the joints of the side panels as well as other joints. 5. 8. 2 The surface of the gasket should be flat. 5.9 Insulation Resistance: The terminal boxes of the motors in fans and pumps should be tested for insulation resistance, and the insulation resistance between the insulated circuits and the ground should be no less than 2 MΩ (measured using a 500 V megohmmeter). 5.10 Welding: The welding of the condenser shall be carried out in accordance with the specifications in the drawings and the relevant process requirements. 5.11 Airtightness requirements: The condensing coil of the condenser shall undergo an airtightness test before assembly, with a test pressure of 2 MPa. 5.12 Cleanliness: The interior of the condenser must be clean, and the impurity content in the areas where it comes into contact with the refrigerant should not exceed 800 mg/m2. 5. 13 Appearance Quality: www.17jzw.com, www.17bzw.cn, www.17jzw.net, www.3x888.com. Standard Data Collector: www.17bzw.cn – Yiqi Standard Network offers free downloads of 100,000 standard books. If you know how to type, you can create a website quickly in just 5 minutes: www.17jzw.com – Yiqi Website Building Network provides a free website building platform; commercial websites can be created for only 60 yuan per year. www.17jzw.com, www.17bzw.cn, www.17jzw.net, www.3x888.com. JB/T 7658.5–1995: 4. The design of the condenser should be aesthetically pleasing; the weld surfaces must be free of cracks, pores, slag inclusions, and other defects. The outer surface should be painted, with a uniform, smooth finish and consistent color, without any defects that could affect its appearance. 5. 14 Completeness The condenser supplied as a complete set should also include: a. Ammonia inlet fitting ； b. Ammonia outlet connector ； c. Drain fitting ； d. Balanced pipe joint ； e. Drain fitting, vent fitting ； f. Inlet, outlet, and drain fittings ； g. Safety valve connector. 5. 15 Appendix 5. 15.1 The accessories of the condenser are: a. Condensing coil ； b. box ； c. Water system (including float valves, water pumps, water spray pipes, nozzles) ； d. Intake manifold (which includes a pressure gauge, safety valve, intake valve, and air release valve) ； e. Liquid outlet header (including liquid outlet valve and balance valve) ； f. Upper frame (includes the fan when the structural type is suction-type) ； g. Lower frame (includes the fan when the structural type is air supply type). 5. 15. 2 The accessories of the condenser shall comply with the provisions of the relevant standards or drawings. 5. 16 Warranty Period: Under the condition that the user complies with all the provisions in the product instructions, within 18 months from the date of shipment by the manufacturer, if the condenser is damaged or fails to function properly due to manufacturing defects, the manufacturer shall replace it or repair it at no cost. 6 Test Methods 6.1 Performance Tests The performance testing method for condensers can involve industrial operation tests. 6.2 Tank leak test: After welding the tank, it should be filled with water or kerosene to check for leaks, ensuring that there are no leaks at any of the welds. 6.3 Insulation resistance test: At normal temperature or under conditions of relative humidity of 80% or less, a 500 V megohmmeter is used to measure the insulation resistance between the wiring terminals of the motor drives for fans and pumps and the ground; this value should be no less than 2 MΩ. 6.4 Airtightness test 6.4.1 The gas used for the airtightness test shall be dry and clean air, nitrogen, or an inert gas. 6.4.2 Safety measures shall be in place for the air pressure withstand test, and these measures shall be supervised and inspected by the safety department of the testing unit. 6. 4. 3 The test pressure is 2 MPa. 6.4.4 The steps for the airtightness test are as follows: a. During the test, pressure should be increased slowly to the test pressure; after maintaining this pressure for 10 minutes, the subject should be placed in water at a temperature of at least 5°C (or foam solution should be applied to its surface). No bubbles forming indicates that the test is successful. Standard material collector: www.17bzw.cn – YiQi Standard Network offers free downloads of 100,000 standard books. If you know how to type, you can create a website quickly in just 5 minutes at www.17jzw.com – YiQi Website Building Network, which provides a free website-building platform; the cost for a commercial website is only 60 yuan per year. www.17jzw.com, www.17bzw.cn, www.17jzw.net, www.3x888.com. JB/T 7658.5－1995 5 b. In case of leakage, perform pressure relief and repairs, then conduct another airtightness test. c. The pressure should remain constant during the inspection; continuous pressurization to maintain the test pressure is not allowed, nor should screws be tightened while under pressure. 6.5 Cleanliness measurement: The cleanliness measurement of condensers can be carried out in accordance with the provisions of ZB J73 029. 7 Inspection Rules 7.1 General Requirements The condenser shall be inspected by the manufacturer’s technical inspection department in accordance with this standard and relevant technical documents, and may only leave the factory upon passing the inspection. 7.2 Inspection Items 7.2.1 Inspection Classification The inspection of condensers is divided into factory inspection and type inspection. 7.2.2 Inspection items: The inspection items for the condenser shall be in accordance with the provisions of Table 4. Table 4 Inspection Items: Factory inspection, shoe type inspection, performance tests, cleanliness – processing quality, water tank leak test, insulation resistance test, appearance quality, airtightness test, verification of all contents on the label, verification of the completeness of the product according to the factory documents. √ √ 7.3 Factory Inspection: Each condenser shall undergo factory inspection after it is manufactured. 7.4 Type inspection 7.4.1 Type inspection shall be carried out on new products of at least one specification for condensers, or on old products that have undergone significant modifications. 7.4.2 The performance testing method for condensers can employ industrial operation tests. 8 Marking, Packaging, and Transportation 8.1 Marking 8.1.1 Labels Labels shall be fixed to the condenser at visible and flat locations; such labels shall comply with the requirements of GB/T 13306. The labels shall indicate the following information: a. Manufacturer and trademark ； b. Product model ； c. Product name ； www.17jzw.com www.17bzw.cn www.17jzw.net www.3x888.com Standard Data Collector; www.17bzw.cn Yiqi Standard Network offers free downloads of 100,000 standard books. If you know how to type, you can create a website quickly in just 5 minutes at www.17jzw.com – Yiqi Website Building Network provides a free website-building platform; the cost for a commercial website is only 60 yuan per year. www.17jzw.com www.17bzw.cn www.17jzw.net www.3x888.com JB/T 7658.5－1995 6 d. Design pressure ； e. Design temperature ； f. Condensation area ； g. Refrigerant ； h. Fan power, pump power ； i. Manufacturing number ； j. Manufacturing date. 8.1.2 Factory documents: The condenser shall be accompanied by the following factory documents at the time of delivery. 8. 1. 2. 1 Product certificate, whose contents are: a. Manufacturing unit and trademark ； b. Product model ； c. Product name ； d. Serial number ； e. Inspection conclusion ； f. Signature of inspector and responsible person ； g. Inspection date. 8. 1. 2. 2 Product instruction manual, whose contents are: a. Product model and name ； b. Uses and scope of application ； c. Specifications and technical parameters ； d. Structure and working principle ； e. Installation and Usage Instructions ； f. Maintenance, upkeep & repair ； g. Outline diagram. 8. 1. 2. 3 Packing list. 8.2 Packaging and Transportation 8.2.1 The exposed machined surfaces of the condenser as well as the connection fittings should be coated with an anti-rust agent and sealed. The assembly flanges should be secured with bolts, their sealing surfaces coated with anti-rust grease, and then sealed. 8.2.2 The condenser can be supplied bare or in a box. During transportation, care should be taken to use brackets for fixation to prevent rolling and shifting. At the time of shipment, there should be shipping marks and packaging marks. Additional note: This standard was proposed and is under the responsibility of Hefei General Machinery Research Institute of the Ministry of Machinery Industry. This standard was drafted by Dalian Refrigerator Co., Ltd. and Wuhan New World Refrigeration Industry Co., Ltd. The main drafters of this standard are Ha Hongbo, Li Muzhen, Sun Zhengguo, and Hu Zengwu. This standard was first published in January 1964, and was first revised in December 1986. Standard material collector: www.17bzw.cn – YiQi Standard Network offers free downloads of 100,000 standard books. If you know how to type, you can create a website quickly in just 5 minutes at www.17jzw.com – YiQi Website Building Network, which provides a free website-building platform; the cost for a commercial website is only 60 yuan per year. www.17jzw.com, www.17bzw.cn, www.17jzw.net, www.3x888.com. JB/T 7658.5－1995: Standards of the Machinery Industry of the People’s Republic of China – Evaporative condensers for ammonia refrigeration units. JB/T 7658.5－1995. Published by the Institute of Mechanical Science; printed by the same institute (No. 2 South Shouti Road, Beijing, postal code 100044). Format: 880×1230, 1/16; number of pages: 5/8; word count: 12,000. First edition published in January 1996; first printing also in January 1996. Print run: 1–500 copies. Price: 8.00 yuan. Catalog number: 95－072. Machinery Industry Standards Service Network: http://www.JB.ac.cn. www.17jzw.com, www.17bzw.cn, www.17jzw.net, www.3x888.com