GENERATOR

Abstract

A generator includes a liquid tank, a high temperature device and a nozzle unit. The liquid tank has a receiving room. The high temperature device is disposed on a surface of the liquid tank. The nozzle unit includes a tank, an injecting tube, a nozzle and an oscillating device. The tank is disposed in the receiving room and filled with a working fluid. The injecting tube has one end communicating with the tank. The nozzle is disposed on a surface of the tank and faces the high temperature device. The oscillating device is disposed on the tank to induce oscillation of the working fluid in the tank, wherein the oscillation changes the pressure of the working fluid so that the working fluid is pulled towards the nozzle and is sprayed on the high temperature device by the nozzle.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention generally relates to a generator and, more particularly, to a generator that is installed in an absorption refrigeration system and has an improved refrigerant vaporization efficiency.

2. Description of the Related Art

Referring to FIG. 1, a conventional absorption refrigeration system 9 generally includes a generator 91, a condenser 92, an evaporator 93 and an absorber 94. The generator 91, condenser 92, evaporator 93 and absorber 94 are connected via a plurality of circulation tubes 95 to form an enclosed loop.

The generator 91 includes a liquid tank 911 and a heat source 912. The liquid tank 911 is filled with a working fluid. The heat source 912 can provide heat to the liquid tank 911 to vaporize an absorbent flowing in the working fluid. Substantially, the heat source 912 can provide heat to the liquid tank 911 in two manners: direct and indirect manners. In the direct manner, the heat source 912 directly heats up the generator 91 using natural gas or burning oil. In the indirect manner, the heat source 912 heats up a medium first and the medium then passes the heat to the generator 91.

The commonly available working fluid is a binary solution of ammonia water or lithium bromide. Circulating cooling effect may be achieved via interaction between two substances of the binary solution. Specifically, the ammonia water is a mixture of ammonia and water, with the ammonia being a refrigerant and the water being an absorbent. The ammonia water has a cooling temperature about minus 20 degree and is often used in a large-sized refrigerator. The lithium bromide solution is a mixture of lithium bromide and water, with the water being a refrigerant and the lithium bromide being an absorbent. The lithium bromide solution has a cooling temperature about 18 degree and is thus often used in an air-conditioning system. In the following description, the lithium bromide solution is exemplarily used as the working liquid to describe the operation of the conventional absorption refrigeration system 9.

As described above, the heat source 912 provides heat to the liquid tank 911 of the generator 91 to heat up the lithium bromide solution in the liquid tank 911, producing steam with high temperature and high pressure. The high-temperature and high-pressure steam enters the condenser 92 via a first circulation tube 951 and then condenses into middle-temperature water which, in turn, enters the evaporator 93 via a second circulation tube 952 and then condenses into low-temperature water. An expansion valve 931 is provided to reduce the pressure of the low-temperature water and to spray the low-temperature water into a third circulation tube 953, so as to produce steam with low temperature and low pressure. Since the absorber 94 is in a low pressure of vacuum or nearly vacuum, the low-temperature and low-pressure steam will be automatically pulled into the absorber 94 via the third circulation tube 953. Since the vaporization of liquid requires absorption of heat, the low-temperature and low-pressure steam will absorb the heat from the ambient environment for cooling effect.

The low-temperature and low-pressure steam in the third circulation tube 953 will mix with the lithium bromide solution in the absorber 94 and thus dilute the lithium bromide solution. The diluted lithium bromide solution flows to the generator 91 via a fourth circulation tube 954 so that it can be reheated and vaporized. During vaporization of the diluted lithium bromide solution, the water contained in the diluted lithium bromide solution will be steamed out so that the concentration of the diluted lithium bromide solution is increased (high concentration). The vaporized lithium bromide solution (with higher concentration) then flows back to the absorber 94 via a fifth circulation tube 955, causing the high-concentration lithium bromide solution and low-concentration lithium bromide solution (the diluted lithium bromide solution not vaporized) to constantly circulate around the generator 91 and absorber 94. In addition, the conventional absorption refrigeration system 9 may further include a refrigerating device 96 with refrigerating water flowing therein. The refrigerating device 96 passes through the absorber 94 and condenser 92, limiting the liquid in the absorber 94 and condenser 92 at a predetermined temperature. Thus, cooling effect of the conventional absorption refrigeration system 9 is maintained.

Based on the above description, it can be known that the conventional absorption refrigeration system 9 operates on the absorbed heat of the generator 91, and the circulating cooling efficiency of the conventional absorption refrigeration system 9 is proportional to the vaporization efficiency of the lithium bromide solution in the generator 91. However, since the conventional absorption refrigeration system 9 produces steam by heating the lithium bromide solution in the generator 91, the lithium bromide solution is not vaporized in an efficient manner. To efficiently vaporize the lithium bromide solution, more energy should be given to the heat source 912 to maintain the heat source 912 at a high temperature. However, this will consume more energy.

SUMMARY OF THE INVENTION

It is therefore the primary objective of this invention to provide a generator with an improved refrigerant vaporization efficiency to achieve a better circulating cooling efficiency for an absorption refrigeration system.

The invention discloses a generator including a liquid tank, a high temperature device and a nozzle unit. The liquid tank has a receiving room. The high temperature device is disposed on a surface of the liquid tank. The nozzle unit includes a tank, an injecting tube, a nozzle and an oscillating device. The tank is disposed in the receiving room and filled with a working fluid. The injecting tube has one end communicating with the tank. The nozzle is disposed on a surface of the tank and faces the high temperature device. The oscillating device is disposed on the tank to induce oscillation of the working fluid in the tank, wherein the oscillation changes the pressure of the working fluid so that the working fluid is pulled towards the nozzle and is sprayed on the high temperature device by the nozzle.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will become more fully understood from the detailed description given hereinafter and the accompanying drawings which are given by way of illustration only, and thus are not limitative of the present invention, and wherein:

FIG. 1 shows a diagram of a conventional absorption refrigeration system.

FIG. 2 shows a diagram of a generator according to a preferred embodiment of the invention.

FIG. 3 shows an exemplary application of the generator of the invention in an absorption refrigeration system.

FIG. 4 shows a diagram of a motor cooling system of an electric vehicle.

FIG. 5 shows a coupling diagram of the generator of the invention and the motor cooling system of the electric vehicle.

In the various figures of the drawings, the same numerals designate the same or similar parts. Furthermore, when the term “first”, “second”, “third”, “fourth”, “inner”, “outer” “top”, “bottom” and similar terms are used hereinafter, it should be understood that these terms refer only to the structure shown in the drawings as it would appear to a person viewing the drawings, and are utilized only to facilitate describing the invention.

DETAILED DESCRIPTION OF THE INVENTION

Referring to FIG. 2, a generator is disclosed according to a preferred embodiment of the invention. The generator 1 includes a liquid tank 11, a high temperature device 12 and a nozzle unit 13. The high temperature device 12 and nozzle unit 13 are disposed in the liquid tank 11. The nozzle unit 13 can spray liquid on the high temperature device 12.

The liquid tank 11 has a receiving room 111 and a backflow tube 112. The backflow tube 112 may be disposed on a bottom of the liquid tank 11 or on a surface of the liquid tank 11 adjacent to the bottom of the liquid tank 11. In addition, the backflow tube 112 has one end communicating with the receiving room 111 and the other end communicating with an absorber 4 (see FIG. 3). A working fluid 5 circulates around the generator 1 and absorber 4 for circulating cooling purposes. The working fluid 5 consists of a low-concentration working fluid 5a and a high-concentration working fluid 5b. A first circulation tube 113 may be disposed on a top of the liquid tank 11 or on a surface of the liquid tank 11 adjacent to the top of the liquid tank 11. The first circulation tube 113 has one end communicating with the receiving room 111 and the other end communicating with a condenser 2.

The high temperature device 12 may be disposed on a surface of the liquid tank 11 adjacent to the top of the liquid tank 11. In this embodiment, the high temperature device 12 may be further coupled with a conduction member 121, which can absorb the heat of the high temperature device 12 and thus maintains at a high temperature. Both the conduction member 121 and high temperature device 12 are disposed in the receiving room 111.

The nozzle unit 13 includes a tank 131, an injecting tube 132, a nozzle 133 and an oscillating device 134. The tank 131 is disposed in the receiving room 111 of the liquid tank 11 and can receive the low-concentration working fluid 5a. The injecting tube 132 has one end communicating with the tank 131 and the other end communicating with the absorber 4. The nozzle 133 can be disposed on a surface of the tank 131 and faces the conduction member 121 of the high temperature device 12. The oscillating device 134 is disposed on the tank 131 and can induce oscillation of the low-concentration working fluid 5a in the tank 131 by way of high frequency oscillation, thus controlling the pressure of the low-concentration working fluid 5a. Based on this, the low-concentration working fluid 5a in the tank 131 can periodically flow to the nozzle 133 and can be sprayed on the conduction member 121.

The oscillating device 134 may be a piezoelectric film that can be electrified to cause oscillation, pushing the low-concentration working fluid 5a in the tank 131 to be sprayed out via the nozzle 133. The oscillating device 134 has a plurality of operation modes that can be switched by way of frequency control, enabling the nozzle 133 to intermittently spray the low-concentration working fluid 5a on the conduction member 121. In this way, poor heat conduction of the conduction member 121 resulting from constant spraying of the low-concentration working fluid 5a may be avoided.

FIG. 3 shows an absorption refrigeration system including a generator 1, a condenser 2, an evaporator 3 and an absorber 4. The generator 1 communicates with the condenser 2 via a first circulation tube 113. The condenser 2 communicates with the evaporator 3 via a second circulation tube 21. The evaporator 3 communicates with the absorber 4 via a third circulation tube 31 having an expansion valve 32 disposed at a position adjacent to the evaporator 3. The absorber 4 communicates with the tank 131 of the generator 1 via the injecting tube 132 and communicates with the liquid tank 11 of the generator 1 via the backflow tube 112. The backflow tube 112 may be partially disposed in the injecting tube 132 without communication therewith, so that the backflow tube 112 can have heat exchange with the liquid in the injecting tube 132.

The low-concentration working fluid 5a that enters the tank 131 via the injecting tube 132 may be sprayed into the receiving room 111 of the liquid tank 11 by the nozzle 133 based on oscillation of the oscillating device 134, allowing the low-concentration working fluid 5a to contact the conduction member 121 of the high temperature device 12. Based on this, a portion of the sprayed low-concentration working fluid 5a will be instantly steamed out and the other portion of the sprayed low-concentration working fluid 5a won't be steamed out. The refrigerant in the portion of low-concentration working fluid 5a that is steamed out will become a gaseous refrigerant with high temperature and high pressure. The high-temperature and high-pressure gaseous refrigerant then flows from the generator 1 to the condenser 2 via the first circulation tube 113 and condenses into a liquid refrigerant with middle temperature. Meanwhile, the other portion of the sprayed low-concentration working fluid 5a that is not steamed will drip down and accumulate in the receiving room 111 of the liquid tank 11 to form the high-concentration working fluid 5b. The high-concentration working fluid 5b flows back to the absorber 4 via the backflow tube 112.

The middle-temperature liquid refrigerant in the condenser 2 enters the evaporator 3 via the second circulation tube 21 and has a temperature drop in the evaporator 3, thus forming a low-temperature liquid refrigerant. The pressure of the low-temperature liquid refrigerant is reduced by the expansion valve 32 and the low-temperature liquid refrigerant is sprayed into the third circulation tube 31 to produce a gaseous refrigerant with low temperature and low pressure. Note the absorber 4 is in a low pressure of vacuum or nearly vacuum. Therefore, the low-temperature and low-pressure gaseous refrigerant will be automatically pulled into the absorber 4 via the third circulation tube 31, absorbing the heat from the ambient environment for cooling effect.

The low-temperature and low-pressure gaseous refrigerant in the third circulation tube 31 will mix with the working fluid 5 in the absorber 4 that is at a room temperature, diluting the high-concentration working fluid 5b that flows back to the absorber 4. As a result, the working fluid 5 will have lower concentration after dilution. The diluted working fluid 5 will reenter the tank 131 via the injecting tube 132 for reuse, allowing the low-concentration working fluid 5a and high-concentration working fluid 5b to constantly circulate around the generator 1 and absorber 4.

Based on the design that the backflow tube 112 is partially disposed in the injecting tube 132 without communication therewith, the high-concentration working fluid 5b that is at a high temperature is allowed to pass its heat to the injecting tube 132 while flowing back to the absorber 4. Therefore, the low-concentration working fluid 5a that enters the tank 131 via the injecting tube 132 can be preheated to facilitate vaporizing the low-concentration working fluid 5a sprayed on the high temperature device 12.

The generator of the invention improves the vaporization efficiency of the refrigerant of the working fluid 5 by directly spraying the working fluid 5 on the high temperature device 12 in an impingement cooling manner, so as to improve the circulation efficiency of the absorption refrigeration system. Since the vaporization efficiency of the refrigerant of the working fluid 5 is improved, lesser energy can be provided to the high temperature device 12 for energy saving.

The generator of the invention can be applied to various equipments using an absorption refrigeration system for cooling purposes. In such an application, the high temperature device 12 can be heated up by the exhausted heat generated by other components of the equipments to achieve full utilization of energy. Following, an example showing the use of the generator in an electric vehicle (in which the generator is coupled with a refrigeration system of the electric vehicle, as well as a motor cooling system of the electric vehicle) is described.

FIG. 4 shows an exemplary use of the generator of the invention. To efficiently collect the exhausted heat generated by a motor cooling system 6 of the electric vehicle, the motor cooling system 6 includes a housing 61, a fan 62, a heat-storing medium 63 and a heat-conducting device 64. The housing 61 includes essential components of a motor such as a stator or rotor. The fan 62 is coaxially mounted with the rotor and includes a plurality of vanes protruding out of one end of the housing 61. The heat-storing medium 63 is disposed on the other end of the housing 61. The heat-storing medium 63 may be a porous material that can provide a ventilation function while storing heat, such as aluminum material or ceramic. The heat-conducting device 64 is disposed on a face of the heat-storing medium 63 that faces away from the housing 61. The heat-conducting device 64 may be a metal material with excellent heat conductivity such as a copper.

When the fan 62 operates, external cool air is drawn into the housing 61 and the heat generated by internal components of the housing 61 is guided to the heat-storing medium 63 for storing. Since the heat-storing medium 63 is porous, a small portion of the heat can be expelled from the housing 61 therethrough, whereas most heat goes to the heat-conducting device 64, heating up the heat-conducting device 64. In this embodiment, the face of the heat-conducting device 64 that abuts against the heat-storing medium 63 may be a saw-toothed face to increase the contact area between the heat-conducting device 64 and heat-storing medium 63. Thus, heat absorption of the heat-conducting device 64 is facilitated.

Referring to FIG. 5, the motor cooling system 6 may be connected to the generator 1 of the absorption refrigeration system, serving as a heat source providing required heat for cyclic vaporization operation of the generator 1. In the embodiment, the heat-conducting device 64 of the motor cooling system 6 may be connected to the high temperature device 12 of the generator 1, allowing the exhausted heat generated during operation of a motor using the motor cooling system 6 to be concentrated on the high temperature device 12. In this way, heat required for operation of the generator 1 can be provided. Advantageously, no additional energy of the electric vehicle is consumed, preserving more energy for other systems of the electric vehicle. Thus, overall performance of the electric vehicle is improved. By coupling the refrigeration system and the motor cooling system 6 together, not only the overall volume of a power plant of the electric vehicle can be reduced to improve the space availability of the electric vehicle, but also more energy can be saved to improve the motive power of the electric vehicle. Moreover, when the refrigeration system operates, no extra burden is caused for a power source of the electric vehicle, thus not affecting operation of other systems of the electric vehicle.

Furthermore, the refrigeration system may also be coupled to other systems that generate/exhaust heat, such as a battery unit, power generator or current transformer. Thus, the exhausted heat of the systems can be reused in an efficient manner. As can be readily appreciated by one skilled in the art, the refrigeration system can also be coupled with other systems rather than just the motor cooling system.

Although the invention has been described in detail with reference to its presently preferable embodiment, it will be understood by one of ordinary skill in the art that various modifications can be made without departing from the spirit and the scope of the invention, as set forth in the appended claims.

Claims

1. A generator, comprising:

a liquid tank having a receiving room;

a high temperature device disposed on a surface of the liquid tank; and

a nozzle unit having a tank, an injecting tube, a nozzle and an oscillating device, wherein the tank is disposed in the receiving room and is filled with a working fluid, the injecting tube has one end communicating with the tank, the nozzle is disposed on a surface of the tank and faces the high temperature device, the oscillating device is disposed on the tank to induce oscillation of the working fluid in the tank, and the oscillation changes the pressure of the working fluid so that the working fluid is pulled towards the nozzle and is sprayed on the high temperature device by the nozzle.

2. The generator as claimed in claim 1, wherein the high temperature device is coupled with a conduction member disposed in the receiving room of the liquid tank.

3. The generator as claimed in claim 1, wherein the oscillating device is a piezoelectric film.

4. The generator as claimed in claim 1, wherein the high temperature device is coupled with a cooling system.

5. The generator as claimed in claim 4, wherein the cooling system includes a heat-conducting device coupled with the high temperature device.

6. The generator as claimed in claim 5, wherein the heat-conducting device has one face abutting against a heat-storing medium made of a porous material.

7. The generator as claimed in claim 6, wherein the face of the heat-conducting device that abuts against the heat-storing medium is a saw-toothed face to increase the contact area between the heat-conducting device and the heat-storing medium.