난류관 냉방기 Vortex-Tube Cooling

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난류관 냉방기 Vortex-Tube Cooling

Brief Description

Vortex tubes separate compressed air into hot and cold airstreams for process cooling applications

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Background

Technology Description

Vortex tube cooling cycle utilizes compressed air and several geometric features to generate separate hot and cold air streams that can provide usable heating and cooling. Originally characterized in the early 20th century, compressed air enters the vortex tube through a tangential nozzle and rotates down the tube at high RPM to produce a hot air stream at the tube walls and a cold air stream in the center. A nozzle at one end of the tube directs the hot outer airstream out of one side of the tube and directs the cool gas to the other end of the tube. The temperature difference between the incoming air and existing air streams can be +/-60°F or greater at 100 psig, and adjustable with inlet pressure and nozzle position. Figure A-2 provides a diagram of a vortex-tube cooler.

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Figure A-2: Schematic of a vortex-tube cooler

Source: Gao (2005)

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(1) 압축공기(compressed air supply), (2) 소용돌이를 만드는 공간(vortex spin chamber) (3) 조절밸브(control valve) (4) 더운 공기(hot air) (5) 찬 공기(cold air)

 

 

압축공기[위 그림 (1)]를 소용돌이 튜브에 주입하면 나선상의 공기흐름이 만들어지면서 더운 공기[위 그림(4)]와 찬공기[위 그림(5)]가 만들어진다. 그 과정을 대략 설명하면 아래와 같다.

 

1. 압축공기를 소용돌이를 유발하는 공간으로 주입하면

2. 소용돌이의 흐름이 만들어지면서

- 소용돌이의 중앙은 기압이 낮고,

- 소용돌이의 주변은 기압이 높아짐

3. 소용돌이 공기 흐름의 중앙에서 주변으로 열의 이동이 일어남

4. 차가운 공기의 흐름과 더운 공기의 흐름이 분리되어 서로 다른 공기흐름의 길로 나누어짐

Due to their low efficiency, vortex tubes have limited application for space conditioning, except for specialized instances. Vortex tube COPs are typically below 0.1, which limit their application only for instances where conventional vapor-compression systems are impractical (Nellis and Klein 2002). For many industrial settings where compressed air is available, vortex tubes supply cold air on demand for spot cooling of machinery or electronics and personal cooling suits for workers in hazardous conditions, shown in Figure A-3. Additionally, vortex tube diameters must remain relatively small to function, so cooling capacity is restricted to fractional ton sizes.

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Technical Maturity and Current Developmental Status

Vortex tubes are available for process applications from Vortec, Nex Flow, Exair and others. No products are available for building heating or cooling other than personal cooling vests that require a compressed air source.

Barriers to Market Adoption

Low efficiency and the need for a compressed air source limit the applicability for space-conditioning applications. Most buildings lack the infrastructure of a compressed air system, and a personal air compressor is too energy intensive to be portable for long periods.

Energy Efficiency Advantages

No advantages expected.

Energy Savings Potential

Potential Market and Replacement Applications

As mentioned previously, vortex-tube cooling is only relevant for building conditioning as a personal cooling mechanism where other methods are unavailable or impractical.

Energy Savings

As a primary cooling system, vortex tubes would provide no energy savings with COPs on the order of 0.1 and less (Gao 2005).

Some research has investigated the benefit of vortex tubes to recover a portion of throttling losses in R-744 vapor-compression cycles, similar to ejectors (Li et al. 2000). Findings in this area have been inconclusive thus far (Nellis and Klein 2002).

Cost and Complexity

Containing no moving parts (other than the compressed air source), vortex tubes are inherently simple, lightweight, and compact. The price for the vortex tubes and personal cooling vests range from one to several hundred dollars depending on capacity and air pressure.

Peak-Demand Reduction and Other Non-Energy Benefits

Convenient and simple way to provide personal cooling where compressed air is available.

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2014. 06. 13 작성

2014. 06. 16 추가

1. Non-vapor compression HVAC report, DOE [본문으로]
2. Non-vapor compression HVAC report, DOE [본문으로]
3. http://blog.naver.com/bjgim21/130151256745 [본문으로]
4. Non-vapor compression HVAC report, DOE [본문으로]
5. Non-vapor compression HVAC report, DOE [본문으로]