发布时间 : 星期六 文章日立压缩机SD074CV-H3BU更新完毕开始阅读
THE GENERAL SPECIFICATIONS FOR SD SERIES ROTARY COMPRESSOR
If a compressor is not operated properly, not only will it be impossible to display its performance to the full, but it may lead to a shortened service life and even malfunctions and breakdowns. These operating instructions have been prepared so that the rotary compressor will be used properly and efficiently without malfunctions and breakdowns, and here lists the operation standards and handling precautions. It is recommended that you acquire a full understanding of the special properties of the compressor and that you operate it properly.
1. Operation standards and operational limits
When the compressor is being used, check with the final test data of the application product to see whether or not the following standards are being maintained. ITEM (1) Refrigerant used. OPERATIONAL LIMIT The R-22 (CHClF2) refrigerant must be used. The quality of the refrigerant used must comply with JIS standard K1519. -10℃( 14F ) to 15℃( 59F ) [ 0.35~0.79MPa(2.61~7.05kg/cm2G )]. 。。。(2) Evaporating The lower limit of this temperature may drop to -20℃( -4F ) during the temperature range. start of a heating operation (2~3min.) or during the transitional period between cooling/heating selection with the heatpump. 228℃(82.4F ) to 65℃( 149F ) [ 1.13~2.70MPa(10.5~26.5 kg/cmG )]. (3) Condensing 2temperature range. The maximum limit is 2.84MPa(28kg/cmG) for short-term loads such as overloads. 。。(4) Compression ratio. This should be 6 or less. But this does mot apply to short-term loads of a transitional nature. Not exceed 120℃( 248F ), except for heat pump unit or dehumidifiers 。(5) Discharge gas temperature. (which are operated throughout a year) of which limit is 115℃( 239F ) at discharge gas temperature. This temperature should be measured at the surface of the heat-insulated discharge pipe at 150mm distance from the shell surface.(This limit should be considered under the expected life unit, such as clodge heat exchangers, etc.) The suction gas’s overheat must be over 0℃(32F) and the gas must be used on condition that discharge gas temperature is satisfied. Not exceed 120℃(248F). The compressor must be operated on within the range of rated voltage ±10%. But if the model which voltage range at 208～230V,then the compressor must be operated on within the range at 208V-5%～23.V+10%. The operating voltage shall be the terminal voltage of the compressor during operation. 。。。(6) Suction gas temperature. (7) Motor wiring temperature. (8) Supply voltage. (during operation)
SHEC-EG011 (1/6)
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ITEM OPERATIONAL LIMIT A voltage of 80% or more of the rated voltage shall be supplied at start-up. But if the model which voltage range at 208～230V,then a voltage of 85% or more of the rated voltage shall be supplied at start-up. (9) Starting voltage. The starting voltage shall be the terminal voltage of the compressor when the voltage drops due to starting. The starting voltage is provided for start-up on the high/low pressure balanced 1.1MPa(10.3kg/cm2G ). The ON/OFF cycle shall be a maximum of 10 times an hour. The OFF (10) ON/OFF cycle. period shall extend from start until the high/low pressure are balanced, and balanced start-up. The maximum amount shall be 0.9kg (displacement ≥10.4cm3 ) or (11) Amount of refrigerant charged. 0.55kg(displacement ≤9.1cm3 ) The equipment shall be designed with less than 170,000 cycles in the (12) ON/OFF frequency. cooling and / or heating types. (13) Abnormal rise in The abnormal pressure rise limit caused by locking of the condenser or pressure. cooling fan, etc. shall be 4.02MPa( 40kg/cm2G ). The piping must have such a shape and length that the pipe deviation does not exceed 0.8mm when the frequency ranges from 40Hz to 70Hz (14) Pipe vibration. and the compressor is operated within the range of voltage +10%. There is no need to adhere to the above conditions if other method can be used to check the pipe resonance. The piping must be designed so that no damage will result from transporting of the product and the ON/OFF of the compressor. (15) Pipe stress. At starting and stopping : 34.3N/mm2(3.5kgf/mm2) or less During operation : 17.7N/mm2(1.8kgf/mm2) or less A clearance of at least 13mm must be left between the piping and active parts (compressor, fan, anti-resonance rubber, piping, etc.). (16) Pipe clearance A clearance of at least 10mm must be left between the piping and inactive parts. 1. Temperature of the compressor shell-bottom = ”To” ; 2. Temperature of the discharge pipe at 120mm from shell-surface = “Tdis”; (17) Prevention against 3. Condensing temperature at that time = “Tc”; To ≥Tc + 20（℃） flood-back Tdis ≥Tc + 20（℃） ★Flood-back is never guaranteed. In case of three phase motor, there are possibility for compressors to rotate in reverse cycle and damage the compressor when the supplied (18) Protecting reverse phase is in wrong order. operation Carefully design the unit and wiring to keep the right order for three phase.
2. Precautions for system design
2-1. Basic structure of rotary compressor
The rotary compressor is fundamentally different from the reciprocating type in the following ways. Care must be taken in this respect when designing the system. BASIC ITEM Compressor vessel pressure Suction gas intake system
DETAILS Reciprocating : Low Pressure Rotary : High pressure EXAMPLE OF PRECAUTION Material of leads (heat-resistant wires.) Volume inside accumulator, and Reciprocating : Indirect intake accumulator, amount of into cylinder from inside of shell Refrigerant charged. SHEC-EG011 (2/6)
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Compressor inside support structure Reciprocating : Inside support or inside suspension. External support structure, shape and stress of piping, Pipe clearance.
2-2. Compressor’s design pressure (high pressure side)
The applicable value for the compressor’s design pressure is 2.84MPa(28kg/cm2G) and so an equipment design must be selected where the high pressure side design pressure is not more than 2.84MPa(28kg/cm2G) .
2-3. Heat exchanger capacity
(1) The capacity and air flow of the heat exchanger must be determined so that they are compatible with the high and low pressure side pressure of the operational standards.
(2) Compared with the reciprocating type, the rotary compressor is characterized by the fact that its input current does not affect the evaporation temperature much. It is therefore a god idea to design the equipment with the evaporation temperature on the high side.
(3) Since using the compressor with a reduced condensation temperature is effective in that the input current is reduced, the break-down voltage is reduced and the cooling capacity is increased, every effort should be made to reduce the condensation temperature in the equipment design.
(4) Therefore, when aiming for a equipment design with a high E.E.R., it is recommended that the most be made of above features (2) and (3), and the evaporation temperature be set on the high side while the condensation temperature be set on the low side for compressors with a small output.
2-4. Amount of refrigerant charged
Reduce the amount of refrigerant charged as possible in order to prevent the liquid refrigerant from damaging the sliding parts. Reducing the amount not only increases the reliability of the compressor but also engances the start-up and shut-down characteristics of the compressor.
2-5. Capacity setting
Because of its characteristics, the rotary compressor tends to have a lower capacity ratio than the conventional reciprocating type when operated on a 50 / 60 Hz power line frequency. As a result, consideration in the determination of the amount of refrigerant in the equipment and in the performance test should be given to the compressor’s performance not only on a 60Hz line frequency but also 50Hz frequency.
2-6. Piping
Unlike the reciprocating type of compressor, the rotary compressor has a construction where the compression sections and motor sections are fixed to the compressor container, and so the compressor’s mounting parts employ anti-vibration rubbers and springs to reduce the shock sustained at ON/OFF.
Therefore, the following points must be borne in mind when designing the pipes which are to be connected to the compressor and when determining those pipes. (a) Clearance between piping and compressor, and other parts. (b) Piping vibration with compressor operation. (C) Pipe stress with compressor ON/OFF. (D) Pipe stress during product transportation.
It is sometimes a good idea to anchor the equipment with rubber packing when vibration may be violent and when contact may arise. Refer to point (14), (15), and (16) in section 1 when it comes to the piping clearance, piping vibration and stress since a design must be implemented where there is no chance of abnormal pipe vibration or damage.
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SHEC-EG011 (3/6)
2-7. Electrical parts
Use the designated electrical parts properly. The following electrical parts are used in a rotary compressor and the specifications of each are given in the individual specification sheet of the compressor. ELECTRICL PART PRECAUTIONS Dome mount type: Connect the wires properly and mount inside the terminal box on the top of the compressor. Remote type: Connect the wires properly and mount inside the equipment [60℃（140°F）max. ambient temperature]. Mount properly inside the terminal box on the top of the compressor. (These are not used in types where the motor protector serves as the thermal protector.) Use capacitors with the required capacitance and withstanding voltage. Use capacitors under the heat-withstanding temperature. Mount these in the prescribed mounting direction. The relays must not tilt more than 5°. 3-phase power compressor are protected from reverse operation and so these units should be used in the proper circuit. Motor protector (Over current relay) Thermal protectors Running capacitor Voltage relays Phase protectors
Use heat-resistant cable for the leads which are connected to the compressor terminal, motor protectors (attached to compressor).
(Example) Ethylene tetrafluoride or polypropylene heaxafluoride resin cable. 2-8. Refrigeration oil
In order to maintain a high reliability , one specially developed refrigeration oil for rotary compressors is used. This oil has excellent load-withstanding and heat stability properties. No other type of oil must therefore be used.
2-9. Amount of refrigeration oil
It is important for the piping to be designed with sufficient consideration given to oil return during the refrigeration cycle since the refrigeration oil in the compressor is sometimes discharged in volume inside the equipment as a transitional phenomenon (due to the storing of the refrigerant ) during start-up, etc.
Oil is liable to collect when an auxiliary accumulator is attached within the refrigerating cycle, which necessitates an oil-return structure. Care is required with short ON/OFF cycles. In the event of exceeding the restricted amount and / or liquid flood back, it is mandatory that a properly sized accumulator and / or crankcase heater be used.
2-10. Immunity from vibration during transportation
Sufficient consideration in design must be given so that mounting parts and connected parts are not damaged as a result of vibration or shock sustained while transporting the fully assembled equipment.
SHEC-EG011 (4/6)
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