Solar-powered LiBr-water absorption air conditioning system using hybrid storage

Patent metadata

Field	Value
Publication number	US-9835361-B2
Application number	US-201514936483-A
Country	US
Kind code	B2
Filing date	Nov 9, 2015
Priority date	Nov 9, 2015
Publication date	Dec 5, 2017
Grant date	Dec 5, 2017

Abstract

The solar-powered LiBr-water absorption air conditioning system using hybrid storage includes one or more solar collectors generating heat energy to drive the system. The solar collector communicates with a generator to heat an aqueous LiBr solution and release refrigerant through vaporization. The refrigerant feeds into a condenser to form a refrigerant condensate. The condensate feeds into an evaporator, which throttles the refrigerant and causes flash vaporization, resulting in cooling discharged into a load. The refrigerant from the evaporator feeds into an absorber containing a weak LiBr-water mixture from the generator to facilitate absorption of the refrigerant. A pump feeds the resultant aqueous LiBr solution back to the generator for another cycle. The hybrid storage includes a combination of heat storage tank, refrigerant storage tank, and/or a cold water tank coupled to the generator, condenser, and the evaporator to supplement driving or additional cooling during nighttime for continuous daily operation.

First claim

We claim:

1. A solar-powered LiBr-water absorption air conditioning system using hybrid storage, comprising:
at least one solar collector adapted to heat a heat transfer medium and generate heat energy to drive a cooling process;
a single generator coupled to the at least one solar collector, the generator having a LiBr-water solution contained therein, the at least one solar collector being configured for circulating the heat transfer medium through the generator to heat the LiBr-water solution and generate water vapor, leaving the LiBr-water solution weak in refrigerant, the single generator being configured in a single-effect absorption system;
a condenser communicating with the generator downstream thereof for forming a refrigerant condensate from the water vapor;
an evaporator communicating with the condenser downstream thereof for throttling the refrigerant condensate to cause flash vaporization of the refrigerant condensate, resulting in a cooling effect;
a load coupled to the evaporator, the load receiving the cooling effect from the evaporator;
an absorber communicating with the evaporator downstream thereof, the absorber having an input path in communication with the generator to receive the weak-in-refrigerant LiBr-water solution from the generator, the absorber being in communication with the evaporator to receive vaporized refrigerant from the evaporator, whereby the vaporized refrigerant is absorbed by the weak-in-refrigerant LiBr-water solution in order to reconstitute the LiBr-water solution as strong in refrigerant, the absorber having an output path in communication with the generator for feeding the reconstituted LiBr-water solution to the generator; and
a hybrid storage assembly coupled to components of the solar-powered LiBr-water absorption air conditioning system, the hybrid storage assembly having a plurality of hybrid storage tanks and thermal media disposed in each of the tanks to provide additional cooling assistance during nighttime and uninterrupted operation.

2. The solar-powered LiBr-water absorption air conditioning system according to claim 1 , further comprising:
a first expansion valve disposed in the input path of said absorber, the first expansion valve regulating flow of absorbent from said generator to said absorber; and
a pump disposed in the output path of said absorber for feeding the reconstituted LiBr-water solution from said absorber to said generator.

3. The solar-powered LiBr-water absorption air conditioning system according to claim 2 , further comprising a heat exchanger disposed between said generator and said absorber, the absorbent from said generator and the reconstituted LiBr-water solution from said absorber passing through the heat exchanger in substantially opposite flow paths, the heat exchanger pre-cooling the absorbent prior to discharge into said absorber and pre-heating the reconstituted LiBr-water solution prior to discharge into said generator.

4. The solar-powered LiBr-water absorption air conditioning system according to claim 1 , further comprising a second expansion valve coupled to said condenser and to said evaporator for regulating flow of refrigerant from said condenser to said evaporator.

5. The solar-powered LiBr-water absorption air conditioning system according to claim 1 , wherein said at least one solar collector comprises a pair of solar collectors.

6. The solar-powered LiBr-water absorption air conditioning system according to claim 5 , wherein said pair of solar collectors comprises:
a first solar collector coupled to said generator, the first solar collector having a first collector outflow valve and a first collector inflow valve coupled to the first solar collector, the first collector outflow valve and the first collector inflow valve selectively regulating flow of the heat transfer medium between the first solar collector and said generator to circulate the heat transfer medium, the first collector outflow valve and the first collector inflow valve being normally open during daytime operation and normally closed during nighttime operation; and
a second solar collector coupled to said hybrid storage assembly, the second solar collector having a second collector outflow valve and a second collector inflow valve coupled to the second solar collector, the second collector outflow valve and the second collector inflow valve selectively regulating flow of the heat transfer medium between the second solar collector and said hybrid storage assembly to circulate the heat transfer medium, the second collector outflow valve and the second collector inflow valve being normally open during daytime operation and normally closed during nighttime operation.

7. The solar-powered LiBr-water absorption air conditioning system according to claim 6 , wherein said plurality of hybrid storage tanks includes a heat storage tank coupled to said second solar collector, the heat storage tank storing heat transfer medium therein, the heat transfer medium being heated by circulating the heat transfer medium from said second solar collector through said second collector outflow valve and said second collector inflow valve, the heat storage tank having a generator supply valve and a generator outlet valve coupled to said generator, the generator supply valve and the generator outlet valve selectively regulating flow of the heat transfer medium between the heat storage tank and said generator to circulate the heat transfer medium, the generator supply valve and the generator outlet valve being normally closed during daytime operation and normally open during nighttime operation to drive the cooling process during nighttime operation.

8. The solar-powered LiBr-water absorption air conditioning system according to claim 7 , wherein said plurality of hybrid storage tanks further includes a refrigerant storage tank communicating with said condenser and said evaporator, the refrigerant storage tank having a refrigerant supply valve coupled to said condenser and a refrigerant outflow valve coupled to said evaporator, the refrigerant supply valve being normally open during daytime to accumulate and store refrigerant from said condenser and normally closed during nighttime, the refrigerant outflow valve being normally open during nighttime to feed additional refrigerant to said evaporator during nighttime operation and normally closed during daytime.

9. The solar-powered LiBr-water absorption air conditioning system according to claim 8 , wherein said thermal media comprises said heat transfer medium stored in said heat storage tank and said refrigerant stored in said refrigerant storage tank.

10. The solar-powered LiBr-water absorption air conditioning system according to claim 8 , wherein said plurality of hybrid storage tanks further includes a cold water storage tank coupled to said evaporator and said load, the cold water storage tank having cold water stored therein, said evaporator having an auxiliary refrigerant outflow valve and an auxiliary refrigerant inflow valve coupled to the cold water storage tank, the auxiliary refrigerant outflow valve and the auxiliary refrigerant inflow valve being normally open during daytime to circulate refrigerant through the cold water storage tank to cool and maintain the cold water at a predetermined temperature and closed during nighttime, the cold water storage tank having a cold water outflow valve and a cold water inflow valve coupled to said load, the cold water outflow valve and the cold water inflow valve being normally open during nighttime to facilitate circulation of the cold water and provide additional cooling during nighttime operation, the cold water outflow valve and the cold water inflow valve being normally closed duri

Assignees

• Univ King Fahd Pet & Minerals

Inventors

• El-Shaarawi Maged A I
• Al-Ugla Ali Abdulaziz

Classifications

• F25B27/007

  in sorption type systems · CPC title

• F25B15/06 Primary

  the refrigerant being water vapour evaporated from a salt solution, e.g. lithium bromide {(F25B15/025 takes precedence)} · CPC title

• F25B2400/0415

  for receivers · CPC title

• F25B2400/24

  Thermal storage element · CPC title

• F25B41/04

  Mechanical Engineering · mapped topic