单选题The general purpose of a heat exchanger is to （）.Aeliminate hot air from the condenserBmaintain steady pressure in a systemCheat, or cool one fluid by means of another fluidDreduce the engine room temperature in tropical climates
单选题
The general purpose of a heat exchanger is to （）.
A
eliminate hot air from the condenser
B
maintain steady pressure in a system
C
heat, or cool one fluid by means of another fluid
D
reduce the engine room temperature in tropical climates
参考解析
解析：
暂无解析
相关考题：
For what purpose are the diving pipes used?A. To absorb heat from the sun.B. To store heat for future use.C. To turn solar energy into heat energy.D. To carry heat down below the surface.
In a diesel engine closed freshwater cooling system, the amount of coolant flowing through the heat exchanger is controlled by the __.A.suction pressure regulatorB.thermostatic bypass valveC.sea water temperatureD.water level in the expansion tank
第二组The only attention that heat exchanger should require is to ensure that the heat transfer surfaces remain substantially clean and the flow passages generally clear of obstruction. Indication that undue fouling is occurring is given by a progressive increase in the temperature difference between the two fluids, over a period of time, usually accompanied by a noticeable rise in pressure loss at a given flow.Fouling on the sea-water side is the most usual cause of deterioration in performance. The method of cleaning the sea water-side surfaces depends on the type of heat exchanger. With shell-and-tube heat exchangers, the removal of the header covers or, m the case of the smaller heat exchangers, the headers themselves, will provide access to the tubes. Obstructions, dirt, scale etc., can then be removed, using the tools provided by the heat exchanger manufacturer. Flushing through with fresh water is recommended before a heat exchanger is returned to service. In some applications, such as piston oil cooling, progressive fouling may take place on the outside of the tubes. Most manufactures recommend a chemical flushing pr6cess to remove this in situ~ without dismantling the heat exchanger.Plate heat exchangers may be cleaned by unclamping the stack of plates and mechanically cleaning the surface of each plate as recommended by the manufacturers. The plate seals may require replacement from time to time and here the manufacturers instructions should be closely followedBy which of the following indication, can we conclude that the lube oil-sea water heat exchanger is unduly fouled?A.the heat exchanger lube oil inlet temperature loweringB.the heat exchanger sea-water outlet pressure riseC.the heat exchanger temperature difference between lube oil and sea water increasingD.the heat exchanger pressure difference between sea water inlet and outlet decreasing
According to the passage, which of the following statement is not true?A.the heat exchanging surfaces should be kept substantially cleanB.the heat exchanger flow passages should be clear of obstructionC.seals for the plate heat exchanger needs to be renewed oftenD.the cleaning process of the plate heat exchanger should be done following our experiences only
Which of the following factors tends to increase scale formation on the saltwater side of a heat exchanger used in a diesel engine cooling water system?A.Baffle plates that have been bent during prior removalB.Leaks m the cooler tube nestC.Operating the engine while maintaining a high sea water outlet temperatureD.A punctured sea water strainer supplying cooling water to the heat exchanger
The personal computer or______is the smallest general-purpose computer．A．terminalB．minicomputerC．microcomputerD．workstation
下列（）为通用橡胶。A、vulcanized rubberB、general purpose rubberC、special purpose rubberD、speciality rubber
Multi-purpose ship carries（）.A、not only general cargoB、but also bulk cargoC、A+ BD、Neither A nor B
（）carries not only general cargo but also bulk cargo.A、A bulk carrierB、A multi-purpose shipC、A general cargo shipD、A dry cargo ship
which of the following is not true about the classification of the cantainers？（）A、containers are classified as general purpose (dry cargo) container and specific purpose containerB、general purpose container (GP) is suitable for the widest varieties of cargoC、specific purpose container is suitable for the specific cargoD、bulk container， reefer container， open-top container are all general purpose containers
When comparing capacity-to-capacity， the IBM Rear Door Heat eXchanger helps provide more advantages than other available thermal environment solutions， usually at a fraction of the cost. Which of the following statements is NOT an advantage of the IBM Rear Door Heat eXchanger？ （）A、The IBM Rear Door Heat eXchanger may dramatically unburden existing AC units by cooling the air before it exhausts from the electronics into the hot aisle.B、The IBM Rear Door Heat eXchanger is a "hang， plug， and run" design so the units may be added quickly.C、The IBM Rear Door Heat eXchanger is equipped with two fans to help maintain water temperature at 18C （64.4F） and provide even air flow.D、The IBM Rear Door Heat eXchanger is designed to support a 42U rack.
Select 3 features of IBM’s CoolBlue Energy Management Innovation：（）A、IBM Active Energy Manager， Calibrated Vectored Cooling， and Water Chilled Door eXchanger B、IBM Active Energy Manager， Front Door Heat eXchanger， and Calibrated Vectored CoolingC、Power Configurator， Calibrated Vectored Cooling， and Rear Door Heat eXchangerD、Thermal Diagnostics， Front Door Heat eXchanger， and Rear Door Heat eXchanger
单选题Which of the following factors tends to increase scale formation on the saltwater side of a heat exchanger used in a diesel engine cooling water system?（）ABaffle plates that have been bent during prior removalBLeaks in the cooler tube nestCOperating the engine while maintaining a high sea water outlet temperatureDA punctured sea water strainer supplying cooling water to the heat exchanger
单选题What is the purpose of sub cooling R-12 in the condenser?（）Ato increase the system efficiency by sensible heat transferBto stop the liquid from flashingCto reduce the load on the compressorDto remove latent heat of vaporization and the suction piping transfer
单选题If the jacket water temperature of an operating diesel engine suddenly rises above normal, the cause can be attributed to （）.Aan overfilled expansion tankBexcess chromate treatment of the jacket waterCa clogged raw water sea suctionDcavitation erosion of the heat exchanger tubes
单选题The rate of heat transfer between the hot and cold fluids passing through a shell-and-tube type heat exchanger will （）.Aremain constant along the tubes lengthBbe greatest in a single pass counter flow heat exchangerCremain constant throughout the heat exchangerDvary from section to section through out the heat exchanger
单选题The purpose of designing some waste heat boilers with sinuous fire tubes, is to（）Aincrease exhaust gas velocity through the boilerBreduce accumulations of carbon deposits on the heat transfer surfacesCeliminate exhaust gas pulsations and noiseDincrease the rate of heat transfer to the waterside
单选题which of the following is not true about the classification of the cantainers？（）Acontainers are classified as general purpose (dry cargo) container and specific purpose containerBgeneral purpose container (GP) is suitable for the widest varieties of cargoCspecific purpose container is suitable for the specific cargoDbulk container， reefer container， open-top container are all general purpose containers
单选题Which of the listed effects represents the purpose of heat treating steel?（）ADevelop ductilityBImprove machining qualitiesCRelieves stressesDAll of the above
单选题Early models of the flash-type evaporators used a separate shell-and-tube heat exchanger as the air ejector condenser.More recent models use a combined air ejector condenser with the（）Adistilling condenserBsalt water feed heaterCdistillate coolerDflash chamber
单选题In a closed diesel engine freshwater cooling system, the amount of coolant flowing through the heat exchanger is controlled by the （）.Asuction pressure regulatorBthermostatic bypass valveCsea water temperatureDwater level in the expansion tank
单选题（）carries not only general cargo but also bulk cargo.AA bulk carrierBA multi-purpose shipCA general cargo shipDA dry cargo ship
单选题Sacrificial zinc anodes are used on the saltwater side of diesel engine heat exchangers to（）.Areduce electrolytic action on heat exchanger metalsBkeep heat transfer surfaces shiny and cleanCprevent rapid accumulation of marine growthDprovide a protective coating on heat exchanger surfaces
单选题Which of the problems listed would came the discharge temperature of an R-12 refrigeration compressor to increase?（）AThermal expansion valve frozen openBSuction gas heat exchanger bypassedCCondenser clogged or fouledDHigh pressure cutout switch inoperative