WO1999067574A2

WO1999067574A2 - Airconditioning system utilizing absorption chiller cell

Info

Publication number: WO1999067574A2
Application number: PCT/KR1999/000330
Authority: WO
Inventors: Jong Hae Kim
Original assignee: Kim, Ji, Tae
Priority date: 1998-06-25
Filing date: 1999-06-24
Publication date: 1999-12-29
Also published as: AU4655299A; WO1999067574A3; GB0004141D0; GB2354063A; KR20000002974A

Abstract

This invention relates to an airconditioning system which uses a plurality of absorption chiller-cells (10-1, 10-2...), for refrigerating an antifreeze fluid for fan-coil units of an airconditioning system being circulated in each cell structure in a consecutive order for lowering the temperature of an antifreeze fluid gradually. More particularly, it relates to an absorption chiller-cell system having a plurality of evaporators (17-1, 17-2...) by employing a multi-refrigerant circulation circuits in an absorption cycle to produce sufficient refrigerant for the airconditioning system and it enables to make the physical size of the system smaller for replacing the conventional electric airconditioning unit for home applications. In further aspects, this invention provides an airconditioning system which comprising a plurality of absorption chiller-cells to produce various kinds of capacity of the system by combining more or less number of chiller-cell, and it provides also an easier and more simple solution for maintenance by replacing chiller-cell.

Description

AIRCONDITIONING SYSTEM UTILIZING ABSORPTION CHILLER CELL.

BACKGROUND OF THE INVENTION

1. Field of the invention

The present invention relates to an airconditioning system utilizing a plurality of absorption chiller-cells for refrigerating the second refrigerant medium such as an antifreeze to get sufficient low temperature for the indoor fan- coil units of an airconditioning system, by circulating and exchanging heat of the second refrigerant medium gradually from the first absorption chiller-cell and through up to N numbers of absorption chiller-cell in a consecutive order for providing an accumulative chilling effects to give more efficient and faster cooling speed.

Further the invention provides a method and apparatus to make an absorption chiller-cell utilizing an absorption refrigeration means which has a plurality of evaporator means by employing a multi-refrigerant circulation circuits in an absorption cycle, and to enable the physical size of the system smaller and the cooling capacity larger comparing the existing absorption system. This invention also provides an airconditioning system devised with absorption chiller-cell to produce various kinds of capacity of the system by combining various number of chiller cell and to make more simple solution for repairing or maintenance by replacing chiller-cell. 2. Description of the prior art

Various systems have been devised before to make an airconditioning system utilizing an absorption refrigeration means. One known arrangement is to use water as the refrigerant and lithium bromide as the absorbent.

However, this system is not suitable for home use due to its physical size and a complex construction of the system to solve the crystallization problem and also has the risk of freezing due to the freezing point of water. Another known arrangement is an airconditioning system using a solution pair of ammonia as refrigerant and water as absorbent. This system is applicable to refrigerate below 0^°C and the physical size of the system is relatively smaller comparing the system using LiBr and water, but still too big to replace the present electric airconditioning unit for home or apartment application with an absorption airconditioning system.

The main problem of the prior arts, which is not suitable for home use utilizing absorption refrigeration cycle, is the technical difficulties to produce enough refrigerant at low temperature somewhat below that of the heat load at the small physical size of the system.

The prior arts including numerous patents and studies are mainly concerned to the technology to improve the coefficient of performance (COP) of an absorption refrigeration system regardless the physical size of the system for home applications, nor convenience of maintenance for user. SUMMARY OF THE INVENTION

(1) Object of the invention

An object of this invention is to provide an airconditioning system utilizing an absorption refrigeration means having a plurality of absorption chiller-cell structures for chilling the sufficient quantity of an antifreeze to the sufficient low temperature for the fan-coil units of the air conditioning system.

Another object is to provide a method and apparatus to make an improved absorption chiller-cell which having a plurality of evaporator means by employing a multi-channel of refrigerant circuits in an absorption refrigeration cycle for improving the cooling capacity at the limited physical size of the refrigeration system.

Still another object is to provide an absorption refrigeration system which enables to reduce the physical size of the system by cell structure system particularly to replace the cooling unit of the conventional electric airconditioning system for home use.

Still another object is to provide an air conditioning system which is capable to increase or decrease of it's cooling capacity by increasing or decreasing the number of chiller-cell unit to produce various kinds of capacity of airconditioning system by combining the number of chill-cell.

Still another object is to provide an absorption airconditioning system which may be easier for maintenance of the system by replacing the chiller-cell unit. (2) Statement of the invention

The outstanding characteristic of the invention is that the refrigerating means comprises a plurality of absorption chiller-cell structures for refrigerating an antifreeze fluid to the sufficient low temperature, being circulated each absorption chiller-cell in a consecutive order, and each absorption chiller-cell comprises a multi-refrigerant circulation circuits in an absorption cycle to produce enough refrigerant in volume to improve the cooling capacity of the system.

Another outstanding characteristic of the invention is to provide the method and apparatus to make an airconditioning system based on the diffusion absorption (DA) cycle by employing a multi-refrigerant circulation circuits in an absorption cycle. The DA technology is based on the Platen-Muntecs cycle and is currently manufactured internationally for hotel room and recreational vehicle refrigerators. The unique features of this technology are (1) it can be gas-fired with no electric input required and (2) machines based on a DA cycle are essentially silent. But, until the present invention it was thought that DA cycle is consisting of one refrigerant loop circuit, one solution loop circuit and one gas loop circuit, and not suitable for airconditioning system due to its poor cooling capacity.

Another unique characteristic of the invention is the method and apparatus of heat exchange of an antifreeze of each absorption chiller-cell employing tube in tube principle to create a plurality of evaporators configuring an independent heat exchanging chamber which having a fluid inlet, a fluid outlet and the second refrigerant (an antifreeze) fluid flow path there-be tween for exchanging heat from evaporator by flowing the second refrigerant fluid in the form of fluid film along with the outside surface of evaporator tube, which accommodates to control the temperature and volume of the second refrigerant by connecting each chamber in a consecutive order for lowering temperature, and in a parallel order for increasing the amount of the second refrigerant medium to accomodate for typical airconditioning application.

Another outstanding feature of the invention is the airconditioning system utilizing a plurality of absorption chiller-cells to produce various kinds of capacity of the system by combining more or less number of chiller-cell and it provides an easier solution for maintenance by replacing chiller-cell.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG 1. is a systematic diagram of the absorption chiller-cell system of the invention

FIG 2. is a systematic diagram of double effect absorption chiller-cell system of the invention

FIG 3. is a systematic diagram of the air conditioning system of the invention

FIG 4. is a detailed schematic diagram of an embodiment of heat exchanging chamber of the invention in a parallel order.

FIG 5. is a detailed systematic diagram of an embodiment of a heat exchange chamber of the invention in a consecutive order. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

In the preferred embodiment of the invention, the ammonia is the refrigerant and the water is the absorbent. FIG 1. shows in s systematic diagram of the absorption refrigeration system in conformity with the invention. The absorption refrigeration system comprises a plurality of absorption chiller-cells 10-1, 10-2, 10-3, 10-N, and each chiller-cell comprises absorber means 11, absorber vessel 12, heating means 23, a plurality of generator means 13-1, 13-2, with rectifier 14-1, 14-2, a plurality of condenser means 16-1, 16-2, a plurality of evaporators 17-1, 17-2, 17-3, 17-4, with heat exchange chamber 18-1, 18-2, 18-3, 18-4 for exchanging heat between evaporator and antifreeze fluid, and central processing unit 20 with thermo sensors 19-1, 19-2, 19-3,19-4, and heating control means 19-5 to control the system. Referring Fig. 4, each heat exchanger chamber comprises evaporator tube 17-1, 17-2, in a tube 18-1, 18-2 of a heat exchanger chamber which having a fluid inlet 20-1, 20-2, and a fluid outlet 21-1, 21-2, and antifreeze fluid flow path there-between.

In the preferred embodiment of the invention, this system uses a three component working fluid consisting of the refrigerant (ammonia), the absorbent (water) and the auxiliary gas (hydrogen). The refrigerant serves as transporting medium to carry energy from low temperatures source to high temperature sink. The water absorbs the refrigerant at low temperature and low partial pressure and releases it at high temperature against high partial pressure, the auxiliary gas provides pressure equalization for working fluid between the condenser and evaporator.

The number of possible working fluid combination is infinite, but in practice, the combination in the wide commercial use is ammonia-water-hydrogen. Helium can also be used as the auxiliary gas with performance penalty. A thermodynamic representation of the invention is illustrated in Fig. 1. The chiller-cell uses single refrigeration cycle with multi-refrigerant circulation loop circuits by generator means 13-1, 13-2, which have at least one or more units of evaporators 17-1, 17-2, 17-3, 17-4 in each loop circuit. This arrangement results in significantly increased cooling effect by multi-evaporator which enable this circuit to produce the desired working temperature in the evaporator in a different manner than the prior absorption refrigeration concepts, resulting in a different relationship between the components in each refrigeration circuit.

The conventional diffusion absorption (DA) cycle has three fluid loop circuits, consisting of ammonia loop circuit, gas loop circuit and ammonia- water solution loop circuit. The ammonia loop circuit includes all the components since ammonia circulates through all the components. Ammonia- Water solution circuit flows through the solution loop circuit, which includes the generator (bubble rump), absorber and solution heat exchanger. The auxiliary gas circulates through the gas loop circuit, which includes the evaporator, absorber and auxiliary gas heat exchanger. The conventional DA cycle has only one ammonia loop circuit employing only one evaporating means, and it makes the performance limited and not enough to feed the cooling capacity of an airconditing system.

The present invention configures multi-ammonia loop circuits at a DA cycle and it feeds multi-evaporator means to produce enough ammonia vapor for operating a plurality of heat exchange chamber which changing heat between the evaporator tubes and antifreeze by a circulation pump.

As shown in Fig. 1, a preferred absorption solution mixture (ammonia and water) and the auxiliary gas (hydrogen gas) are filled in the absorber vessel 12. These are at sufficient pressure to condense ammonia at room temperature. When heat from the heating means 23 supplied to the generator means 13-1, 13-2, bubbles of ammonia gas are produced and rise. The vapor contains a small quantity of water vapor which can be removed by passing the mixed vapor through the rectifier tubes 14-1, 14-2, by heat rejection. The small amount of water in the ammonia, runs back and drains to the absorber vessel 12 through rectifiers leaving the dry ammonia vapor to pass to the condensers 16-1, 16-2. While the ammonia vapor passes into the finned condensers 16-1, 16-2, air circulating over the fins of the condensers removes heat from ammonia vapor and it condenses into liquid ammonia and they flow in the evaporators 17-1, 17-2, 17-3, 17-4. The evaporators are supplied with hydrogen, by tube 24. The hydrogen passes across the surface of the ammonia and return back into absorber vessel 12, it lowers the ammonia vapor pressure enough to allow the liquid ammonia to evaporate. The evaporation of the ammonia extracts heat from the evaporator. This, in turn, extracts heat from the antifreeze fluid in the heat exchange chamber 18-1, 18-2, 18-3, 18-4 lowering the temperature of an antifreeze fluid.

The ammonia-rich gas mixture leaves the bottom of the evaporators 17-1, 17-2, 17-3, 17-4 and passes down through the tube 25 to the absorber 11. In the absorber 11, the ammonia is absorbed from the gas by the liquid solution. The auxiliary gas, which is almost insoluble in the liquid, is free to rise up from the top of the absorber 11 and passes into the evaporators 17-1, 17-2, 17-3, 17-4 together with some residential ammonia vapor. The hydrogen and ^' ammonia gas circulation loop is driven by natural convection caused primarily by the large density differences associated with the ammonia fraction in the vapor.

The liquid circulation in the cycle is driven by the heat-powered bubble pump shown schematically in Fig. 1. This cycle operates continuously as long as the tubes of the generator 13-1, 13-2, means is heated. The thermostats 19-1, 19-2, 19-3, 19-4, which control the heat source 19-5 by controller 20, regulates the temperature of the antifreeze fluid. The antifreeze fluid is circulated from the first heat exchange chamber, 18-1 of the first evaporator 17-1, the second beat exchange chamber 18-2 of the second evaporator 17-2, the third heat exchange chamber 18-3 the third evaporator 17-3 and the fourth heat exchange chamber 18-4 of the fourth evaporator 17-4 by a pump and lowered it's temperature gradually by circulating each tube of a heat exchange chamber which having a fluid inlet 20-1, 20-2, a fluid outlet 21-1, 21-2, and the antifreeze fluid path there-between for exchanging heat from evaporator by 17-1, 17-2, flowing the antifreeze fluid in the form of fluid film along with outside surface of evaporator tube 17-1, 17-2, as shown schematically in Fig. 4.

Ammonia-poor hydrogen enters into the each of evaporators, and the auxiliary gas atmosphere accommodates the partial pressure of the ammonia vapor in accordance with Delton's low. As the ammonia evaporates into the hydrogen, the partial pressure of the ammonia gas rises, and the evaporation temperature also rises. Thus, the means of a plurality of evaporators 17-1, 17-2, 17-3, 17-4 by employing a multi-refrigerant circulation circuits in an absorption cycle significantly increases the cooling capacity for the airconditioning, application, comparing the prior arts which employs single evaporator means in an absorption cycle. According to the embodiment of the invention, the cooling capacity of each chiller-cell depends on the number of the evaporator and the refrigerant loop circuit in an absorbtion cycle.

Depending on cooling capacity needed for an appropriate level of the temperature, the system can adjust the number of chiller cells. If the cooling space is small, for example, 4 chiller cells are available. Meanwhile, if the cooling space is large, more chiller cells can be used for its structure to adjust the cooling capacity.

As shown schematically is Figure 2, it illustrates another useful embodiment of the invention, in which the first diffusion absorption refrigeration system is comprising a multiple generator comprising 3 tubes in the preferred embodiment, each tube having at least one evaporator and a condenser each, and second diffusion absorption refrigeration system having a generator being heated by the tubes of the 1st heat exchanger of the first diffusion absorption system after the refrigerant solution pre-heated by the 2nd heat exchanger of the first refrigeration system.

Figure 3 illustrates schematically one embodiment of the invention which can be used either for cooling or heating. If it needs to be installed for both heating and cooling the room, and interceptive valve 109 and refrigerant's (antifreeze) heating means 108 can be linked to IN/OUT pipe of chiller-cell. When heating the room, a refrigerant (antifreeze) supply pipe of each chiller-cell turns off by interceptive valve 109, while it turns on to operate a pump 109 to circulate the antifreeze, which heated by heating means 108, to pan-coil units 106-1, 106-2, 106-3.

The antifreeze is employed as a second refrigerant of the system to protect its chiller-cell and heat exchange chamber against freeze in winter, and temperature and circulation speed of an antifreeze are controled by a central processing unit 112. When an after-service is required, it provides more simple solution to the system than any prior arts and doesn't need to stop all functions of the system because the problemed chiller-cell only can be easily replaced. As aforementioned as above in the invention, a means of direct heat-transfer with chiller-cells by antifreeze which circulates in the N numbers of chiller-cell in a consecutive way to make a prompt and cumulative cooling effects.

The invention, in overcoming all of the aforesaid drawbacks of the prior art, presents a new technology to structures a chiller-cell with a small .sized improved absorption refrigeration means having multi- evaporators to produce various kinds of capacity of absorption airconditioning system by combining more or less numbers of small sized chiller-cell type cooling means, rather than a known art such as single type large sized cooling means with the fixed cooling capacity.

Further, the system provides a more efficient heat-transfer by circulating antifreeze to extract heat by the evaporation of the refrigerant, thereby, lowers gradually the temperature and makes a faster and more efficient cooling effect by circulating in each chiller-cell.

Furthermore, a cooling capacity of the invention can be adjusted by adding or subtracting number of chiller-cell. Even the system installed, when a cooling capacity needs a large size, the number of chiller-cells, depending on the required demand, is added as many as it needs. And it also provides an easier after-service by only changing the chiller-cell with no interrupting all functions of the system. The foregoing description has been set forth merely to illustrate the invention and is not intended to be limiting. It is herein understood that although the present invention has been specifically disclosed with the preferred embodiments and examples, modifications and variations of the concepts of the described embodiments herein disclosed may be resorted to by those persons skilled in the art. Such modifications and variations are considered to be within to scope of the invention and the appended claims.

Claims

WHAT IS CLAIM IS ;

1. An airconditioning system utilizing an absorption chiller-cell means, which comprising ;

(a) a plurality of absorption chiller-cell means having generator means, condenser means, evaporator means, absorber means and each of the means operatively connected together ;

(b) a plurality of heat exchange chambers configured each of the said evaporator means of the said chiller-cell means in a heat exchange chamber which having a fluid inlet, a fluid outlet and antifreeze fluid flow path therebetween for exchanging heat between evaporator and antifreeze fluid by flowing the antifreeze along with the outside surface of the evaporator's tube;

(c) a circulation pump for circulating said antifreeze fluid by connecting the inlet and the outlet of each heat exchange chamber of each chiller-cell in a consecutive order for decreasing the temperature of antifreeze fluid gradually;

(d) at least one unit of fan-coil unit for exchanging heat from antifreeze fluid which circulated by said circulation pump; and,

(e) a central processing unit for controlling temperature and the speed of antifreeze circulation by said circulation pump and the function of the said absorption refrigeration means.

2. The system according to claim 1, wherein the said absorption chiller-cell means comprising, a plurality of generator means, a plurality of condenser means, a plurality of evaporator means, and an absorber means operatively connected together to make a plurality of refrigerant circulation circuits therein, each circuit having at least one of evaporator means.

3. The system according to claim 1, wherein the said absorption chiller-cell means further comprising a diffusion absorption refrigeration means having a plurality of evaporator means by employing a multi -refrigerant circulation circuits in an absorption cycle using a three component working fluid consisting of the refrigerant means , the absorbent means and the auxiliary gas means

4. The system according to claim 1, wherein the said absorption chiller-cell means further comprising,

(a) the first refrigeration means having the first heat exchange means configured with the hottest component of the each of absorption refrigeration means after generator means and the second heat exchange means configured with the second hottest component of the each of absorption refrigeration means after said first heat exchange means.

(b) The second refrigeration means having a generator means for generating refrigerant vapor by heat of the first heat exchanges means of the first refrigeration means after the refrigerant and absorber solution pre-heated by the second heat exchange means of the first refrigeration means.

5. The system according to claim 4, wherein the said first refrigeration means having the first heat exchange means configured with tube after generator means of each absorption refrigeration means and the second heat exchange means configured with the tube after the said first heat exchanger means.

6. The system according to claim 4, wherein the said first refrigeration means having the first heat exchange means configured with tubes after generator means of each absorption refrigeration means and the second heat exchange means configured with a heat exchange means of the absorber means of each absorption refrigeration means .

7. The system according to claim 4, herein the said first refrigeration means having the first heat exchange means configured with a heat exchange means of condenser means of each absorption system.

8. The system according to claim 1, further comprising a heating means for heating said antifreeze fluid for the heating function of the system.

9. The system according to claim 1, wherein the said chiller-cell means further connected in a parallel order by group for increasing the volume of antifreeze fluid circulation and each group connected in a consecutive order for decreasing temperature of the fluid.

10. The system according to claim 1, wherein the said each chiller-cell means configured a plurality of evaporators in a heat exchange chamber by group for increasing the volume of antifreeze fluid.

11. An absorption refrigeration method by chiller-cell comprising ;

(a) providing a plurality of absorption chiller-cell means having generator means, condenser means, evaporator means and absorber means operatively connected together;

(b) configuring a plurality of heat exchange chambers each heat exchange chamber comprising the said absorption chiller- cell means by forming the tube of the evaporator means in the tube of a heat exchange chamber having a fluid inlet, a fluid outlet and the second refrigerant fluid flow path there-between for exchanging heat from evaporator by flowing the second refrigerant fluid in the form of fluid film along with outside surface of evaporator's tube ;

(c) Circulating the said second refrigerant fluid from the first chiller-cell through up to N numbers of chiller-cell repeatedly to decrease the temperature of the said second refrigerant fluid gradually by a circulation pump, and

(d) controlling the circulation speed and temperature of the second refrigerant fluid and the function of the said absorption refrigeration means by a central processor unit.

12. The method according to claim 11, wherein absorption chiller-cell means further utilizing a three- component working fluid consisting of the refrigerant, the absorbent and the auxiliary gas.

13. The method according to claim 11, wherein an absorption chiller-cell means further comprising a plurality of generator means, a plurality of condenser means, a plurality of evaporator means and an absorber means operatively connected together for making a plurality of refrigerant circuits circulation therein.

14. The method according to claim 11, wherein absorption chiller-cell means further comprising the first diffusion absorption refrigeration means having a multi-tube generator with at least one evaporator means in each tubes and the second diffusion absorption means having at least one generator which being operated by the heat of the tubes of the first diffusion absorption refrigeration means.

15. The method according to claim 11, wherein absorption chiller-cell means further comprising an absorption refrigeration means using a solution pair of ammonia and water.

16 The method according to claim 11, wherein the said heat exchange chamber further configured with tubes of evaporator means being divided into a plurality of compartments and each compartment having a fluid inlet and a fluid outlet of refrigerant fluid and a gas inlet and a gas outlet of the auxiliary gas each and being located in the tube of the said heat exchange chamber in a consecutive order.

17 The method according to claim 16, wherein the said heat exchange chamber further configured with the said compartment of tube of evaporator means in the tube of the said heat exchange chamber each, and connected the said heat exchange chamber in a parallel order.

18 A diffusion absorption refrigeration apparatus using a three component working fluid consisting of the refrigerant means, the absorbent means and the auxiliary gas means, comprising;

(a) a plurality of generator means, having bubble pump means each to make multi-refrigerant circulation circuits in a diffusion absorption cycle.

(b) a plurality of condenser means for said plurality of generation means;

(c) a plurality of evaporator means for said plurality of generator means; and

(d) an absorber means operatively connected with the said means together. 19 The heat exchanging method between an evaporator means and an antifreeze according to claim 18, comprising,

(a) providing an evaporator's tube located in the tube of heat exchange means which having a fluid inlet, a fluid outlet and a fluid flow path there between;

(b) flowing an antifreeze in a form of fluid film along with the outside surface of evaporator's tube.

20 An absorption refrigeration apparatus, comprising;

(a) a plurality of generator means having condenser means and evaporator means each;

(b) an absorber means operatively connected with the said a plurality of generator means together;

(c) a plurality of heat exchange chambers, each chamber configuring the tube of each evaporator in the tube of a heat exchange chamber having a fluid inlet, a fluid outlet and the second refrigerant fluid flow path there between for flowing the second refrigerant fluid in the form of fluid film along with outside surface of evaporator's tube; and,

(c) a pump for circulating the second refrigerant fluid from the first said heat exchange chamber and through up to N numbers of the heat exchange chamber in a consecutive order in loop for chilling the second refrigerant fluid accumulatively.