Sludge may be formed in the oil in the crankcase of a reciprocating air conditioning compressor as a result of ______.A.refrigerant bubbles in the lube oilB.refrigerant reducing the lube oil viscosityC.oxidation(氧化) of the lube oil from overheatingD.reduc

题目

Sludge may be formed in the oil in the crankcase of a reciprocating air conditioning compressor as a result of ______.

A.refrigerant bubbles in the lube oil

B.refrigerant reducing the lube oil viscosity

C.oxidation(氧化) of the lube oil from overheating

D.reducing the floc or cloud point of the oil

相似考题

1.Crankcase explosions in propulsion diesel engines result from ____.A.the splashing of lubrication oil by the crankshaftB.the dilution of crankcase oil with particles of combustionC.broken fuel lines spraying oil on the crankcaseD.the ignition of unburned fuel and air in the crankcase

2.What is the most usual reason for the fresh water-sea water heat exchanger fouling in the sea side?A.lube oil sludge accumulating in itB.dirt and scale etc , formed on the surfacesC.deformation of the tubes and the shell or the platesD.lube oil leakage into sea-water side

3.In a chilled(冷的) water air conditioning unit using a reciprocating compressor, the refrigerating effect of the primary refrigerant can be increased by ______.A.increasing refrigerant pressure in the coilB.increasing chilled water flow through the coolerC.sub-cooling the refrigerant in the condenserD.superheating the refrigerant in the compressor

4.第二组Under normal operation, some lubrication oil mist may be discharged from the air compressor to the air start system. This oil may be from excess compressor cylinder lubrication, from faulty oil scraper rings, or may even be suspended oil vapor contaminating the engine room atmosphere and drawn in at the compressor suction. Oil discharge is kept to a minimum by draining the after cooler, air receiver and starting system. If small quantities of lubrication oil do get passed into the starting air system, they will deposit as thin moist film over internal pipe surfaces but are not readily combustible. If a cylinder non-return valve leak while the engine is in operation, some hot gas, possibly with unburned fuel and cylinder lubrication oil, may be blown through the valve to the adjacent air manifold. With further heating from the leaky valve, this, together with the already deposited oil film, will carbonize and form. incandescent carbon. If starting air is applied to the system while still hot, the high pressure air coming into contact with the burning carbon may cause an explosion. Such an explosion will cause a flame to pass back through the air start pipe system, evaporating the deposited oil film and igniting it in the presence of air. Very high velocities and shockwaves are generated which may rupture pipes and fittings.Alternatively, if excessive oil has entered the air start system, a mixture of air and oil droplets may be discharged through the open cylinder non-return valve during starting. This spray may ignite due to high temperatures in the cylinder, causing a flame through the still open valve to the air manifold.To prevent an explosion, air start valves must be correctly maintained and lubricated to ensure correct timing and free movement with positive closing. Oil in the system must be kept to a minimum, pipe lines must be drained and cleaned internally when necessary and oil discharge from air compressors must be kept to a minimum by good maintenance.The passage is mainly aboutA.crankcase explosionB.scavenge box fireC.starting air pipeD.the danger of explosion in the starting air system

参考答案和解析
正确答案：C
更多“Sludge may be formed in the oil in the crankcase of a reciprocating air conditioning compr ”相关问题

  • 第1题：

    Sludge may form in the crankcase of an air conditioning compressor as a result of ______.

    A.bubbling refrigerant

    B.overheating and oxidation

    C.lowered operating temperatures

    D.reducing the cloud or floc point


    正确答案：B

  • 第2题：

    单选题
    A dirty intercooler on an air compressor will cause （）.
    A

    damage to the un-loader operating diaphragm

    B

    an increase in current flow to the motor

    C

    high pressure in the receiver and filter

    D

    an excessive consumption of crankcase oil


    正确答案： C
    解析： 暂无解析

  • 第3题：

    单选题
    If plastic film insulation becomes damaged in air conditioning system, （） may form within the film.
    A

    evaporation

    B

    condensation

    C

    liquefies

    D

    vaporization


    正确答案： D
    解析： 暂无解析

  • 第4题：

    单选题
    Sludge may form in the crankcase of an air conditioning compressor as a result of （）.
    A

    bubbling refrigerant

    B

    overheating and oxidation

    C

    lowered operating temperatures

    D

    reducing the cloud or flash point


    正确答案： A
    解析： 暂无解析

  • 第5题：

    单选题
    Which of the following conditions is most likely to occur when unburned fuel contaminates the crankcase of a diesel engine?（）
    A

    Lube oil is diluted and its viscosity is reduced

    B

    Sulfuric acid is formed

    C

    Bearings become pitted ad immediately fail

    D

    Valve stems develop sludge deposits


    正确答案： A
    解析： 暂无解析

  • 第6题：

    单选题
    Regarding a Diesel engine crankcase, the general arrangement and installation should preclude the possibility of （）
    A

    free entry of air to the crankcase

    B

    water entering the crankcase while engine wash-downs are being performed

    C

    excessive oil leakage during periods of increased blow-by

    D

    sub-cooling internal components


    正确答案： D
    解析： 暂无解析

  • 第7题：

    单选题
    What function is provided by the crankcase ventilation system on some diesel engines?（）
    A

    Increases the sludge forming tendency of lube oil

    B

    Prevents the accumulation of combustible gases

    C

    Improves lube oil cooling

    D

    Improves cold weather starting


    正确答案： A
    解析： 暂无解析

  • 第8题：

    单选题
    In a chilled water air conditioning unit using a reciprocating compressor, the refrigerating effect of the primary refrigerant can be increased by （）.
    A

    increasing refrigerant pressure in the coil

    B

    increasing chilled water flow through the cooler

    C

    sub-cooling the refrigerant in the condenser

    D

    superheating the refrigerant in the compressor


    正确答案： C
    解析： 暂无解析

  • 第9题：

    单选题
    The accumulation of air and other non-condensable gases in a refrigeration system will （）.
    A

    cause a loss of the liquid seal

    B

    create a vapor lock in the liquid receiver

    C

    collect in the condenser

    D

    cause foaming of the oil in the crankcase


    正确答案： B
    解析： 暂无解析

  • 第10题：

    单选题
    How dose water enter the crankcase of a diesel engine?（）
    A

    Through the crankcase exhauster

    B

    As water vapor contained in blow-by

    C

    Demulsifying lube oil passing through the main bearings

    D

    Condensation from vapor formed in the expansion tank


    正确答案： B
    解析： 暂无解析

  • 第11题：

    单选题
    When fuel enters the crankcase of a diesel engine, it （）
    A

    dilutes the lube oil and reduces its viscosity

    B

    forms sulfuric acid in the lube oil

    C

    causes pitting and failure of the bearings

    D

    causes sludge deposits on valve stems


    正确答案： C
    解析： 暂无解析

  • 第12题：

    单选题
    Which harmful consequence may be the result of lube oil sludge accumulation? （）
    A

    Clogged oil pump suction screens

    B

    Increased oil operating temperatures

    C

    Sticking piston rings

    D

    All of the above


    正确答案： C
    解析： 暂无解析

  • 第13题：

    单选题
    Excessive lube oil consumption by a reciprocating air compressor can be caused by （）.
    A

    using a slightly dirty air filter

    B

    using oil having an excessive viscosity

    C

    intercooler or after-cooler leaks

    D

    carrying the oil level higher than normal


    正确答案： B
    解析： 暂无解析

  • 第14题：

    单选题
    An increase in diesel engine crankcase pressure generally indicates excessive（）
    A

    compression pressure

    B

    lube oil header pressure

    C

    scavenge air pressure

    D

    piston ring blow-by


    正确答案： C
    解析： 暂无解析

  • 第15题：

    单选题
    In an air conditioning system, low head pressure associated with a reciprocating compressor can be the result of （）
    A

    broken valve springs

    B

    tight drive belts

    C

    high line voltage

    D

    air in the system


    正确答案： A
    解析： 暂无解析

  • 第16题：

    单选题
    In general, the oil mist defectors include a base plate with air blast pumpThe function of air blast pump is to （）crankcase.
    A

    supply clean air to the measuring compartment of the units for more accuracy

    B

    generaate the pressure required for the extraction of the oil mist from the

    C

    generate the pressure required for the extraction of the oil mist from the crankcase

    D

    supply clean air to the measuring track of the units for more accuracy


    正确答案： D
    解析： 暂无解析

  • 第17题：

    单选题
    Mist detectors used on large low-speed main propulsion diesel engines monitor and check for the presence of （）.
    A

    fuel oil vapor at the sludge tank vent

    B

    unburned fuel vapors in the scavenge air receiver

    C

    lube oil vapors in the crank case

    D

    lube oil vapors in the engine room


    正确答案： C
    解析： 暂无解析

  • 第18题：

    单选题
    In a refrigeration system, foaming of the crankcase oil may cause the （）.
    A

    expansion valve to overfeed

    B

    compressor to knock

    C

    water regulating valve to fail

    D

    crankcase drains to plug


    正确答案： B
    解析： 暂无解析

  • 第19题：

    单选题
    Under normal conditions, the main source of crankcase oil contamination is attributed to （）
    A

    metal particles loosened by wear

    B

    air when air cleaners are not used

    C

    condensation of water vapors

    D

    breakdown of the lubricating oil by dilution


    正确答案： B
    解析： 暂无解析

  • 第20题：

    单选题
    Crankcase explosions in propulsion diesel result from（）
    A

    the splashing of lubrication oil by the crankshaft

    B

    the dilution of crankcase oil with particles of combustion

    C

    broken fuel lines spraying oil on the crankcase

    D

    the ignition of unburned fuel and air in the crankcase


    正确答案： D
    解析： 暂无解析

  • 第21题：

    单选题
    Sludge may form in the lubricating oil crankcase of a reciprocating air conditioning compressor as a result of （）.
    A

    wax precipitation in the lube oil

    B

    contamination by dust, scale, or moisture

    C

    refrigerant bubbles in the lube oil

    D

    refrigerant reducing the lube oil viscosity


    正确答案： D
    解析： 暂无解析

  • 第22题：

    单选题
    In a normally operating diesel engine, the main cause of lubricating oil contamination in the crankcase is a result of the （）.
    A

    metal particles loosened by wear

    B

    air when no air cleaners are used

    C

    condensation of water vapors

    D

    breakdown of the lubricating oil by dilution


    正确答案： B
    解析： 暂无解析

  • 第23题：

    单选题
    Sludge may be formed in the oil in the crankcase of a reciprocating air conditioning compressor as a result of （）
    A

    refrigerant bubbles in the lube oil

    B

    refrigerant reducing the lube oil viscosity

    C

    oxidation of the lube oil from overheating

    D

    reducing the floc or cloud point of the oil


    正确答案： D
    解析： 暂无解析

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