CN101441007A - Cooling system of supersonic transducer - Google Patents

Abstract

The invention relates to an ultrasonic energy converter cooling system, wherein an ultrasonic energy converter comprising a magnetic core assembly carries out direct evaporative cooling on an inner cavity and an outer cavity of the ultrasonic energy converter. The system comprises a compressor, a condenser, a throttle element, an evaporator and an electro-acoustics conversion device. The evaporator comprises a main shaft, a radial slot, an annular channel, a double-ended bolt, a magnetic core assembly, a magnetic core inner cavity, a magnetic core outer cavity, a rear cover plate, an oil return slot, an upper casing, a decoupling ring, a decoupling oil gas hole, a lower casing, and a liquid inlet, wherein the liquid inlet is connected with a central hole of the double-ended bolt, and the two outlets of the central hole of the double-ended bolt are communicated with the magnetic core inner cavity. The ultrasonic energy converter cooling system adopts steam compressing regeneration principle to form regeneration circulation, the refrigerant takes away heat quality in the inner cavity of the electro-acoustics conversion device to make the ultrasonic energy converter to work in the predetermined temperature range under the action of the temperature control system.

Description

Cooling system of supersonic transducer

Technical field

The present invention relates to a kind of Refrigeration Technique, particularly a kind of cooling system of supersonic transducer.

Background technology

Ultrasonic transducer is in electric energy and acoustic energy transfer process, and because of eddy current produces heat, system temperature raises, and might cause transducer performance decay or can't operate as normal.At present, lower-powered ultrasonic transducer, heating power are less relatively, can not establish special-purpose cooling system; And,, still do not have effective method to solve heat radiation cooling problem because of heating power is bigger for the large-power supersonic transducer system.

The fuel factor of vortex flow: around a coil, when feeding alternating current in the coil, metal cylinder just is in the alternating magnetic field on metal cylinder.Because the resistance of metallic conductor is very little, vortex flow is very big, so fuel factor is very remarkable.Theory analysis shows that vortex flow intensity is directly proportional with the frequency of alternating current, that is: i _{The whirlpool}∝ v, the Joule heat that vortex flow produces then with the Q ∝ v that square is directly proportional of alternating current ², therefore, ac frequency is high more just can to accumulate powerful eddy current in metal cylinder, discharge a large amount of Joule heats.In ultrasonic transducer because the existence of eddy current causes the magnetic core heating, to whole system normally work is caused adverse influence, must manage to solve.

Summary of the invention

The objective of the invention is provides a kind of caloric value that reduces ultrasonic transducer for the deficiency that solves above-mentioned technology, guarantees the cooling system of supersonic transducer of its operate as normal, raising ultrasonic waves energy efficiency.

In order to achieve the above object, a kind of cooling system of supersonic transducer provided by the invention, it comprises adopts the ultrasonic transducer that comprises the core assembly structure, it is characterized in that the core assembly structure that comprises according to ultrasonic transducer, the interior exocoel of ultrasonic transducer core assembly is carried out direct evaporative cooling.A kind of cooling system of supersonic transducer provided by the invention, comprise compressor, condenser, restricting element, evaporimeter and ultrasonic transducer, described evaporimeter, comprise main shaft, the upper shell flange, O shape hermetically-sealed construction, slotted eye radially, the circular passage, stud, core assembly, the magnetic core inner chamber, the magnetic core exocoel, back shroud, the oil return slotted eye, upper shell, the decoupling circle, decoupling circle oil-gas hole, lower house, feed tube, terminal plate, binding post and air returning pipe joint, feed tube is connected with the centre bore of stud, and two outlets of the centre bore of stud communicate with the magnetic core inner chamber; Form the circular passage between the upper surface of core assembly and the upper shell, the radially slotted eye that forms between main shaft and the upper shell, and be connected with the magnetic core exocoel; The magnetic core exocoel is communicated with lower house through decoupling circle oil-gas hole; Decoupling circle and back shroud form the oil return slotted eye of lubricating oil.

The present invention based on the frame for movement of ultrasonic transducer, adopts the direct transpiration-cooled method of cold-producing medium under the prerequisite that does not influence transducer performance, guarantee transducer reliability service in normal temperature range.Ultrasonic transducer uses under air ambient.Refrigeration system adopts non-corrosive cold-producing medium and lubricating oil, and lubricating oil is oil return reliably, and refrigerant inlet and outlet are installed magnetic valve.The interior exocoel of core assembly can obtain cooling simultaneously, no liquid submergence in the cooling cavity.Adopt the movable sealing structure of high-air-tightness between main shaft and the housing.Last lower house adopts high-strength aluminum alloy material, and operating pressure is 1.2～1.5MPa.Temperature sensor adopts the coiling of the using and the reserved mode in coil.Coil lead, refrigerant inlet and outlet (all adopting flexible connecting pipe) are drawn from the lower house end, guarantee sealing and easy accessibility.The key that the design and optimization mobile and heat-transfer character of cold-producing medium in the cooling cavity is the cooler exploitation.Must guarantee that cold-producing medium and lubricating oil have rational flow behavior, cold-producing medium is realized the gas-liquid two-phase evaporation and heat-exchange in cavity.Housing need be taked necessary heat preserving method, to reduce loss of refrigeration capacity.Consider that the particularity of ultrasonic transducer is to requirements such as the security of system, stability, maintainability, manufacturability, sealings.

Cooling system of supersonic transducer provided by the invention, it adopts the steam compression type refrigeration principle, compression, condensation, throttling and evaporation process by cold-producing medium, form kind of refrigeration cycle, cold-producing medium is constantly taken away the heat of ultrasonic transducer inner chamber, under the effect of temperature control system, ultrasonic transducer can be worked in the temperature range of regulation.

Description of drawings

Fig. 1 is the binding post structure of the lead-out wire of coil and sensor;

Fig. 2 is the upper shell structure;

Fig. 3 is the lower house structure;

Fig. 4 evaporation structure figure;

Fig. 5 cold-producing medium circulation process figure.

Wherein: main shaft 1, upper shell flange 2, O shape hermetically-sealed construction 3, radially slotted eye 4, circular passage 5, stud 6, core assembly 7, magnetic core inner chamber 8, magnetic core exocoel 9, back shroud 10, oil return slotted eye 11, upper shell 12, decoupling circle 13, decoupling circle oil-gas hole 14, lower house 15, feed tube 16, terminal plate 17, binding post 18, air returning pipe joint 19, compressor 20, condenser 21, restricting element 22, evaporimeter 23, ultrasonic transducer 24, sensor 25.

The specific embodiment

The invention will be further described in conjunction with the accompanying drawings below by embodiment.

Embodiment 1

A kind of cooling system of supersonic transducer that present embodiment provides, it comprises adopts the ultrasonic transducer that comprises the core assembly structure, according to the core assembly structure that ultrasonic transducer comprised, the interior exocoel of ultrasonic transducer core assembly is carried out direct evaporative cooling.As shown in Figure 5, implement a kind of cooling system of supersonic transducer of the present invention, comprise compressor 20, condenser 21, restricting element 22, evaporimeter 23 and ultrasonic transducer 24, as shown in Figure 4, described evaporimeter 23, comprise main shaft 1, upper shell flange 2, O shape hermetically-sealed construction 3, radially slotted eye 4, circular passage 5, stud 6, core assembly 7, magnetic core inner chamber 8, magnetic core exocoel 9, back shroud 10, oil return slotted eye 11, upper shell 12, decoupling circle 13, decoupling circle oil-gas hole 14, lower house 15, feed tube 16, terminal plate 17, binding post 18 and air returning pipe joint 19, feed tube 16 is connected with the centre bore of stud 6, and two outlets of the centre bore of stud 6 communicate with magnetic core inner chamber 8; Form circular passage 5 between the upper surface of core assembly 7 and the upper shell 12, the radially slotted eye 4 of formation between main shaft 1 and the upper shell 12, and be connected with magnetic core exocoel 9; The circular hole of magnetic core exocoel 9 on decoupling circle 13 is communicated with lower house 15; Decoupling circle 13 and back shroud 10 form the oil return slotted eye 11 of lubricating oil.The structure of upper shell 12 and lower house 15 such as Fig. 2, shown in Figure 3.

During work, liquid cold-producing medium, behind capillary-compensated, enter evaporimeter feed tube 16,, enter magnetic core inner chamber 8 through the centre bore of stud 6, the evaporation of part refrigerant heats, gas-liquid mixture from radially flowing out the slotted eye 4, forms liquid film through the circular passage 5 on the outer wall of core assembly 7, and continue to be subjected to thermal evaporation, refrigerant vapour and stockpile lubricating oil in lower house 15 bottoms, cooled via return air pipe joint 19 is sent into the air entry of refrigeration compressor 20 by the return-air flexible pipe, this in-line flow process, both can guarantee that the inside and outside of core assembly 7 cooled off simultaneously, in the time of also can avoiding adopting inside and outside feed liquor simultaneously, cold-producing medium is shunted unmanageable problem.After the refrigerant heats, become gas by liquid, phase-change heat transfer has taken place, the coefficient of heat transfer is very big, but difference variation is very little, has kept thermostatic characteristics.Because the inside and outside of core assembly 7 cools off simultaneously, and the thickness of core assembly 7 is less, the heat conduction temperature difference is within the range of permission controlled, thereby avoids the influence of thermal stress to core assembly.

When implementing, cold-producing medium is selected the R22 cold-producing medium for use, and it is a kind of cold-producing medium with good comprehensive thermal performance commonly used in the present refrigeration plant.In refrigeration compressor, the coil of motor also is to carry out liquid cools with the R22 cold-producing medium, so, this cold-producing medium and employed mineral lubricating oil thereof, no acid and alkali corrosion, insulating properties is good.

Because the operating temperature range of magnetic material is 5～25 ℃; Sensor 25 adopts double copies thermocouple sensor 25, these sensor 25 coilings in coil, temperature measurement accuracy is ± 3 ℃, and the lead-out wire of coil and sensor adopts binding post 18 as shown in Figure 1, can guarantee the seal request of system when drawing sensor 25 wiring.

Upper shell 12 and lower house 15 adopt the high-strength aluminum alloy (LY12CZ) of weak magnetic conductivity to make, and upper shell 12 is used for fixing core assembly 7, and decoupling circle 13 is installed, and has fixed stud 6 on the copper coin; Lower house 15 is used to install the feed tube 16 and the air returning pipe joint 19 of binding post 18 and cold-producing medium and lubricant turnover.Housing is calculated as follows:

Wall thickness of cylinder:

$S=\frac{{\mathrm{PD}}_i}{2{\left[\mathrm{\σ}\right]}^t-P}+\mathrm{C\; mm}$

The stress of cylinder barrel is checked and approved by following formula:

${\mathrm{\&sigma;}}^t=\frac{P[D_i+(S-C)]}{2(S-C)}\mathrm{kgf}/{\mathrm{<figure-callout\; id="2"\; label="cm"\; filenames="A200810163538E00091.png"\; state="\{\{state\}\}">cm</figure-callout>}}^2$

Calculating the gained stress value satisfies:

σ ^t<[σ] ^tφ

Flat cover thickness:

$S=D_c\sqrt{\frac{\mathrm{KP}}{{\left[\mathrm{\&sigma;}\right]}^t\mathrm{\&phi;}}}+\mathrm{C\; mm}$

Wherein $K=\frac{1}{4}{[1-\frac{r}{D_c}(1+\frac{2r}{D_c})]}^2$

Upper shell 12, lower house 15 calculate through checking, and meet requirement of strength design.

The transducer inner chamber is a part of refrigeration system, must satisfy the requirement of high-air-tightness.System leaks if having incoagulable gas or cold-producing medium takes place in running, will have a strong impact on refrigeration performance.Adopt following two kinds of sealing means as required:

Static seal: upper shell 12 and lower house 15, binding post 18 and lower house 15, air returning pipe joint 19 and lower house 15, feed tube 16 all adopts static seal structure with lower house 15, and seal groove adds the polytetrafluoroethylene (PTFE) pad.

Movable sealing: the hermetically-sealed construction (double-deck O RunddichtringO) that adopts high-air-tightness between upper shell 12 and the main shaft 1.

When implementing, its concrete heat exchange can be calculated as follows:

Magnetic core inner chamber 8 is the turbulent flow forced-convection heat transfer, satisfies the Dittus-Boelter formula:

${\mathrm{Nu}}_f=0.023R{e}_f^{0.8}{\mathrm{Pr}}_f^n$

Magnetic core exocoel 9 is film boiling, and flow and the heat exchange of steam film are satisfied

$h=0.62{\left[\frac{\mathrm{gr}{\mathrm{\&rho;}}_v({\mathrm{\&rho;}}_l-{\mathrm{\&rho;}}_v){\mathrm{\&lambda;}}_v^3}{{\mathrm{\&eta;}}_{v}d(t_w-t_s)}\right]}^{1/4}$

Remove ρ _jAnd the value of r is by saturation temperature t _sOutside the decision, all the other rerum naturas are all with mean temperature t _m=(t _w+ t _s)/2 are qualitative temperature, and characteristic length is external diameter of pipe d (unit is m).Be noted that because the steam film thermal resistance is bigger, and wall temperature temperature when film boiling is very high, the clean heat-transfer surface of wall also has radiation heat transfer except film boiling.Radiation heat transfer can increase the thickness of steam film, and therefore the total amount of heat of this moment is not the simple superposition of heat convection and radiation heat transfer.Radiation heat transfer obtains by following way: the surface coefficient of heat transfer of heat convection and the interactional composite heat-exchange of radiation heat transfer satisfies transcendental equation:

${\mathrm{<figure-callout\; id="3"\; label="h"\; filenames="A200810163538E00091.png"\; state="\{\{state\}\}">h</figure-callout>}}^{3/4}={\mathrm{<figure-callout\; id="3"\; label="h\; c"\; filenames="A200810163538E00091.png"\; state="\{\{state\}\}">h</figure-callout>}}_c^{}+{\mathrm{<figure-callout\; id="3"\; label="h\; r"\; filenames="A200810163538E00091.png"\; state="\{\{state\}\}">h</figure-callout>}}_r^{}$

H in the formula _r, h _cBe respectively the surface coefficient of heat transfer that calculates gained by heat convection and radiation heat transfer, wherein h _cThere is the film boiling formula to obtain, and h _rThen pressing following formula determines:

$h_r=\frac{\mathrm{\&epsiv;\&sigma;}(T_w^4-T_s^4)}{T_w-T_s}$

ε is the emissivity of boiling heat transfer face in the formula.

Claims (2)

1, a kind of cooling system of supersonic transducer, it comprises adopts the ultrasonic transducer that comprises the core assembly structure, it is characterized in that the core assembly structure that comprises according to ultrasonic transducer, the interior exocoel of ultrasonic transducer core assembly is carried out direct evaporative cooling.

2, cooling system of supersonic transducer according to claim 1, comprise compressor (20), condenser (21), restricting element (22), evaporimeter (23) and ultrasonic transducer (24), it is characterized in that described evaporimeter (23), comprise front shroud (1), upper shell flange (2), O shape hermetically-sealed construction (3), slotted eye (4) radially, circular passage (5), stud (6), core assembly (7), magnetic core inner chamber (8), magnetic core exocoel (9), back shroud (10), oil return slotted eye (11), upper shell (12), decoupling circle (13), decoupling circle oil-gas hole (14), lower house (15), feed tube (16), terminal plate (17), binding post (18) and air returning pipe joint (19), feed tube (16) is connected with the centre bore of stud (6), and two outlets of the centre bore of stud (6) communicate with magnetic core inner chamber (8); Form circular passage (5) between the upper surface of core assembly (7) and the upper shell (12), the radially slotted eye (4) that forms between front shroud (1) and the upper shell (12), and be connected with magnetic core exocoel (9); The circular hole of magnetic core exocoel (9) on decoupling circle (13) is communicated with lower house (15); Decoupling circle (13) and back shroud (10) form the oil return slotted eye (11) of lubricating oil.

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