CN101298946A

CN101298946A - Refrigerating device

Info

Publication number: CN101298946A
Application number: CNA2008100710823A
Authority: CN
Inventors: 洪国伟
Original assignee: Individual
Current assignee: Individual
Priority date: 2008-05-20
Filing date: 2008-05-20
Publication date: 2008-11-05
Anticipated expiration: 2028-05-20
Also published as: CN100590371C

Abstract

A refrigerator belongs to the refrigeration technology, belonging to the mechanical engineering field refrigerator technology, which comprises four chief components of a compressor, an expander, a regenerator, a working medium. The cycle working medium uses the expander machine body to adsorb the coolant heat, and uses the compressor machine body for warming the heat carrying agent. The refrigerator adopts the natural gas working medium such as air and the like, executes the H-thermodynamic cycle. The invention provides an air refrigerator with higher refrigeration efficiency, and changes the lagging status of the air refrigeration technology.

Description

A kind of refrigeration machine

Technical field

The present invention relates to Refrigeration Technique, belong to mechanical engineering field refrigeration machine technology.

Background technology

Kind of refrigeration cycle is refrigeration machine development theory basis, and the development and application of new each time kind of refrigeration cycle can both drive the leap of Refrigeration Technique, has promoted the social progress development effectively.

The current refrigeration epoch are the freezing by change of state epoch based on the freezing by change of state circulation, and cold-producing medium--after-Fu Li Ang were proved the depletion of the ozone layer behavior, the idea that limits the use of and forbid of Fu Li Ang was day by day struck fire into the people's hearts since one of the leading role in these epoch of freezing.The whole world many refrigeration expert has also produced multiple novel alternative chlorofluoro carbon in the substitute of making great efforts exploitation Fu Li Ang.Whether novel alternative chlorofluoro carbon also has other to destroy the problem of natural environment, unknown at present, thought thousands of tons chemical industry material to be arranged to airborne release the every year coming years but the synthetic refrigeration working medium of the chemical industry of annual thousands of tons manufactures out just can be similar to by chemical plant all over the world, its hidden danger is sorrow very.The knowledgeable people thinks the kind of refrigeration cycle of development and use natural refrigerant, is that the kind of refrigeration cycle of cold-producing medium is the way that the most basic prevention refrigeration working medium destroys natural environment with air or water particularly.Because the general efficient of refrigeration machine of existing available natural refrigerant is lower, make with the refrigeration machine development process of natural refrigerant slow.Target of the present invention wishes to propose a kind ofly can use natural refrigerant, the higher Gas Refrigerator of refrigerating efficiency just.

Contrary Carnot cycle is best kind of refrigeration cycle, and the method for utilizing that refrigeration educational circles rarely has the people to pay attention to two constant temperature process in the contrary Carnot cycle since the birth is the method for utilizing of isotherm compression process and isothermal expansion process.The inventor notices that isotherm compression process and isothermal expansion process have good thermal power transfer and be worth, and the thermodynamic cycle that the present invention relates to has then utilized this value.

A kind of kind of refrigeration cycle that the present invention relates to is formed (as shown in Figure 1) by two level pressure heat recovery processes and two polytropic processes, is referred to as the H kind of refrigeration cycle here.The difference that need to prove the A Jinsen circulation in the contrary Carnot cycle of H kind of refrigeration cycle and generality is the difference of two polytropic processes and two constant temperature process.Compare with the A Jinsen circulation, but the H circulation has more function definition, the A Jinsen circulation is a special case of H thermodynamic cycle.

Two level pressure heat recovery processes are realized by a cover regenerator (gas---gas heat exchanger).

Two polytropic processes are respectively a changeable compression process and a polytropic expansion process, are an intensification compression process and a cooling expansion process strictly speaking.Obviously, H circulated in the regenerator heat transfer temperature difference enough hour, can approach the contrary Carnot cycle of generality.The inventor thinks with the air to be that the H circulation of cold-producing medium is better than known all kinds of air refrigeration cycle (as: Brayton cycle) at present, can be used as a developing direction of air cooling technology.

Summary of the invention

For realizing two polytropic processes in the H circulation, the present invention has designed a kind of polytropic expansion unit and a kind of changeable Compressor Group that realizes changeable compression process that realizes the polytropic expansion process, has also designed the cold method and the method for heat-obtaining of getting simultaneously.Polytropic expansion unit and changeable compressor bank are combined as a Gas Refrigerator of carrying out the H circulation.

Target of the present invention is to propose a kind ofly can to use natural refrigerant, the higher Gas Refrigerator of refrigerating efficiency.

Description of drawings

Fig. 1 is contrary circulation (H kind of refrigeration cycle) tephigram of H thermodynamic cycle, and arrow points is the cyclic process direction, and 1 → 2 is the level pressure temperature-rise period among the figure, and 2 → 3 is changeable compression process, and 3 → 4 is the level pressure temperature-fall period, 4 → 1 polytropic expansion processes.

Fig. 2 is the decompressor schematic diagram, gases at high pressure are entered in the decompressor by the below arrow points, and decompressor is left by the below arrow points, the drives impeller turning cylinder in the back of expanding, externally work done absorbs the heat Q (heating) that the top flows into the refrigerating medium in the decompressor body simultaneously.The inflow and outflow direction and the expanding gas of refrigerating medium move towards identical, and expanding gas is by the refrigerating medium indirect, and refrigerating medium self also obtains cooling.

Fig. 3 is the interlocking matrix of Fig. 2 and Fig. 6, forms unit, is polytropic expansion unit schematic diagram.

Fig. 4 is the compressor schematic diagram, low-pressure gas is entered in the compressor by the below arrow points, be compressed the back and leave compressor by the below arrow points, external force drives impeller turning cylinder, gas is compressed, gas is by the indirect cooling of the cooling medium (catalyst carrier) of top inflow compressor block, heat extraction Q (heat release) simultaneously.The inflow and outflow direction and the gas of cooling medium move towards identical, and gas is cooled off by the compressor body.

Fig. 5 is the interlocking matrix of Fig. 4 and Fig. 6, forms unit, is changeable compressor bank schematic diagram.

Fig. 6 is the regenerator schematic diagram, and cold and hot gas points to the inflow and outflow regenerator by opposite arrows respectively and carries out heat exchange, and regenerator is the adverse current type heat exchanger.

Fig. 7 is the assembly of Fig. 3 and Fig. 5 for the refrigeration machine schematic diagram of H circulation.Decompressor and external force are by turning cylinder drive compression machine, and refrigeration machine is implemented refrigeration to refrigerating medium.

The specific embodiment:

One decompressor is got cooling method and polytropic expansion unit:

As shown in Figure 2, refrigerating medium (thermal source) is to the heating of decompressor body, and body can be designed to the hollow lumen formula, and refrigerating medium flows in the body hollow lumen, and refrigerating medium is by decompressor body and expanded gas flow heat exchange.Inner chamber runner trend moves towards identical with expanded gas flow, forms following current heat exchange effect.It is enough big that cabinet size is wanted, so that expanded gas flow and body contact area are enough big, guarantees that refrigerating medium is swimmingly with the heat transferred expanded gas flow.The decompressor impeller can be designed to the leaflet multi-stag, perhaps directly with reference to screw-rod structure, guarantees that runner is good along length, heat transfer condition, constantly absorbs the heat of refrigerating medium when making flow expansion.Decompressor is imported and exported air-flow and is inserted two import and export of regenerator respectively, as shown in Figure 3.It is enough big so that heat transfer temperature difference is less that the regenerator size is wanted, and is equal to and utilizes regenerator to force expansion process to approach isothermal.Working medium not only can be sent maximum mechanical power in the isothermal expansion process, can also absorb the heat of maximum; Expansion process is approached isothermal more, and the amount of work of expansion process and caloric receptivity are just big more.Only can find out, enter decompressor again after the low pressure cold air-flow cooling that the high-pressure side air-flow is come out from decompressor from the angle of regenerator.Because regenerator has heat transfer temperature difference, the temperature when the high-pressure side air-flow enters decompressor must be higher than the temperature of the low pressure cold air-flow that decompressor comes out.Decompressor and regenerator merging is as a whole, and this integral body is called the polytropic expansion unit, and expanded gas flow is carried out polytropic process in the machine.Be not difficult to find out that this polytropic expansion unit is exactly a refrigeration source to refrigerating medium refrigeration, when enough hour of the heat transfer temperature difference of regenerator high and low pressure air-flow, this polytropic expansion unit was with regard to the visual isothermal expansion unit that is all.

Get cold main points: refrigerating medium must not be got cold in the unexpansive procedure segment of air-flow!

Two compressor heat taking methods and changeable compressor bank:

As shown in Figure 4, catalyst carrier (cooling source) is cooled off compressor block by the outside, and body can be designed to the hollow lumen formula, and catalyst carrier flows in the body hollow lumen, with the compressed air stream heat exchange.Inner chamber runner trend must move towards identical with compressed air stream, forms following current heat exchange effect.It is enough big that cabinet size is wanted, so that compressed air stream and body contact area are enough big, guarantees the smooth and easy absorption compressed air stream of catalyst carrier heat, and large scale can lower heat transfer temperature difference simultaneously.Compression impeller can be designed to the leaflet multi-stag, perhaps directly with reference to the long bolt structure, guarantees that runner is good along length, heat transfer condition, continuous heat release and cooling when making the air-flow compression.Compressor is imported and exported air-flow and is inserted regenerator, as shown in Figure 5.It is enough big so that heat transfer temperature difference is less that the regenerator size is wanted, and is equal to and utilizes regenerator to force compression process to approach isothermal.Working medium not only can be consumed minimum mechanical power in the isotherm compression process, can also discharge maximum heat; Compression process is approached isothermal more, and the wasted work amount of compression process is just more little, thermal discharge is just big more.Only can find out that self obtaining heating up behind the hot high pressure air-flow that low-pressure end cold airflow cooling is come out from compressor enters compressor again from the angle of regenerator.Because regenerator has heat transfer temperature difference, the temperature when the low-pressure end air-flow enters compressor must be lower than the temperature of the high pressure draught that compressor comes out.Compressor and regenerator merging is as a whole, be not difficult to find out that this integral body is exactly a changeable compressor bank, compressed air stream is carried out polytropic process in the machine, is not difficult to find out that also this integral body is exactly a supplying heat source to the catalyst carrier heat supply.When enough hour of the heat transfer temperature difference of regenerator high and low pressure air-flow, changeable compressor bank was with regard to the visual isothermal compressor that is all.

The heat-obtaining main points: catalyst carrier must not be at the non-compression process section of air-flow heat-obtaining!

The structural design main points (Fig. 6) of three regenerators (gas---gas heat exchanger, contra-flow heat exchanger):

It is contra-flow heat exchanger that thermal structure requires regenerator, can make board-like, shell-and-tube or bushing type etc.Flow passage resistance force of waterproof will do little as far as possible.The heat transfer temperature difference that it is emphasized that regenerator is more little, and the refrigerating capacity of refrigeration machine is big more.The heat transfer temperature difference of regenerator has determined the import and export temperature difference of compressor and decompressor, also be the compression and one of the material impact factor of two polytropic process polytropic exponents that expands, so the structural design of regenerator is extremely important.

Four desirable H circulation heating power process analysis procedure analyses (as shown in Figure 1):

(reference [Engineering Thermodynamics] Pang Lu ring etc., Higher Education Publishing House 1986)

Suppose that working medium is perfect gas:

Changeable thermal procession PV ⁿ=C (constant)

Expansion process polytropic exponent n ₁

Compression process polytropic exponent n ₂

High-low pressure is than π=high pressure P ₂/ low pressure P ₁

Gas constant R

Adiabatic exponent k

Regenerator heat transfer temperature difference T ₃-T ₂=T ₄-T ₁=Δ T

Expansion work

W = \frac{n_{1} R}{n_{1} - 1} (T_{4} - T_{1})

Caloric receptivity

Q_{L} = R (T_{4} - T_{1}) (\frac{n_{1}}{n_{1} - 1} - \frac{k}{k - 1})

Work done during compression

W_{t} = \frac{n_{2} R}{n_{2} - 1} (T_{3} - T_{2})

The clean input work of system

W_{Nt} = W_{t} - W = R (T_{4} - T_{1}) (\frac{n_{2}}{n_{2} - 1} - \frac{n_{1}}{n_{1} - 1})

Coefficient of refrigerating performance

ϵ = \frac{Q_{L}}{W_{Nt}} = \frac{\frac{n_{1}}{n_{1} - 1} - \frac{k}{k - 1}}{\frac{n_{2}}{n_{2} - 1} - \frac{n_{1}}{n_{1} - 1}} = \frac{1 - \frac{n_{1} - 1}{k - 1}}{\frac{n_{1} - 1}{n_{2} - 1} - 1} = \frac{1 - \frac{l_{n} (T_{4} / T_{1})}{(1 - 1 / k) l_{n} π}}{\frac{l_{n} (T_{4} / T_{1})}{l_{n} (T_{3} / T_{2})} - 1}

Conclusion:

1) pressure ratio is high more, and coefficient of refrigerating performance is high more.

2) the regenerator heat transfer temperature difference is more little, and coefficient of refrigerating performance is high more.

When 3) the regenerator heat transfer temperature difference approaches zero, coefficient of refrigerating performance

ϵ = \frac{T_{1}}{T_{2} - T_{1}},

Equal contrary Carnot cycle coefficient of refrigerating performance.

Five H recyclegas refrigeration machines:

As shown in Figure 7: polytropic expansion unit and changeable compressor combination can be become the Gas Refrigerator of carrying out the H circulation.

Refrigeration machine adopts enclosed heating power H circulation, and working medium is approximate ideal gas, and alternative working medium has: natural mediums such as air, oxygen, carbon dioxide, nitrogen, krypton, argon.The low-pressure end of refrigeration machine is the reference pressure of cycle fluid, and reference pressure has determined the cycle fluid mass flow, has also determined the refrigeration total capacity of refrigeration machine.Reference pressure is high more, helps to improve the heat transfer property of refrigeration working medium more, helps to dwindle the volume of refrigeration machine.The high-pressure side of refrigeration machine is the restriction pressure of cycle fluid, and it is by the voltage endurance capability decision of refrigeration machine material.The inventor thinks that in isotherm compression and isothermal expansion process after configuring high pressure, the high-low pressure ratio has a theoretic optimum value, makes " refrigerating capacity/volume " the best of H circularly cooling machine.After configuring high pressure,, when moving, actual H circularly cooling machine requires high-low pressure than being 2.72-3.5 for making " refrigerating capacity/volume " the best.

61 kinds of refrigeration machines:

The Gas Refrigerator of carrying out the H circulation is called for short a kind of refrigeration machine, and the efficient of this refrigeration machine is mainly by following factor decision:

1. regenerator heat transfer temperature difference.

2. working medium and the heat transfer temperature difference of planting thermit powder (cooling source) in the compressor.

3. working medium and the heat transfer temperature difference of planting cryogen in the decompressor.

4. high-low pressure force rate.

5. the effective efficiency of compressor and decompressor.

Claims

1 one kinds of refrigeration machines, its principal character is: it comprises: 1. decompressor, 2. compressor, 3. regenerator, 4. four big critical pieces such as cycle fluid, decompressor is the hot type decompressor, compressor is the cooling type compressor, refrigeration machine is by the external cooling of refrigerating medium, refrigeration machine is by cooling source (catalyst carrier) heat radiation, and this refrigeration machine is carried out the H thermodynamic cycle.

2 according to the described a kind of refrigeration machine of claim 1, and its principal character is: described regenerator is a gas--and circulation of vital energy in the wrong direction stream heat exchanger, material requires to have higher voltage endurance capability.

3 according to the described a kind of refrigeration machine of claim 1, and its principal character is: described decompressor be combined into the polytropic expansion unit according to the described regenerator of claim 2, the polytropic expansion unit realize to absorb refrigerating medium heat and expansion working two big functions.

The described polytropic expansion unit of 4 claims 3, its principal character is: refrigerating medium heating decompressor body, refrigerating medium heat energy sees through the decompressor body and passes to the cycle fluid that is expanding, and refrigerating medium is lowered the temperature simultaneously.Cycle fluid absorbs the heat of refrigerating medium in expansion process, cycle fluid is externally work done simultaneously, and decompressor is imported and exported air-flow and inserted the regenerator exit port, is a kind of hot type expansion unit.

Described compressor of 5 claims 1 and the described regenerator of claim 1 are combined into changeable compressor bank, and its principal character is: the two big functions that changeable compressor bank realizes mediating the heat of compression of cycle fluid and makes gases at high pressure.

The described changeable compressor bank of 6 claims 5, its principal character is: cooling source (catalyst carrier) sees through compressor block, and compressed air stream is cooled off indirectly.It is enough big that cabinet size is wanted, and guarantees the smooth and easy absorption compressed air stream of cooling source heat.Compressor is imported and exported air-flow and is inserted the regenerator import and export, and compressor and regenerator merge as a whole, and this integral body constitutes changeable compressor bank, also is a kind of cooling type compressor bank.

7 according to the described a kind of refrigeration machine of claim 1, and its principal character is: described cycle fluid is gases such as air, oxygen, carbon dioxide, nitrogen, krypton, argon.

8 according to the described a kind of refrigeration machine of claim 1, and its principal character is: described refrigerating medium is got cold at described decompressor body.

9 according to the described a kind of refrigeration machine of claim 1,, its principal character is: described cooling source (catalyst carrier) is at the compressor block heat-obtaining.

10 according to the described refrigeration machine of claim 1, and its principal character is: during described refrigerator operation, high-low pressure is than being 2.72-3.5.