Title of Invention | IMPROVED ABSORPTION REFRIGERATOR |
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Abstract | The purpose of the present invention is to improve the thermal efficiency of an absorption refrigerator. The absorption refrigerator is provided with the refrigerant heat recovery equipment 11 for performing heat exchange between the refrigerant which radiated heat and is condensed by heating the intermediate absorption solution in the low temperature regenerator 3 and is introduced into the condenser 4 through the refrigerant pipe 20, and a part of the dilute absorption solution discharged from the absorber 7 and sent to the high temperature regenerator 1 bypassing the low temperature heat exchanger 9, and the rotation speed of the absorption solution pump 18 is controlled by the controller 33 so that the temperature of the dense absorption solution detected by the temperature sensor 32 is higher than a predetermined temperature, for example 40°C. |
Full Text | SPECIFICATION BACKGROWND OF THE INVENTION 1. Field of the Invention The present invention relates to an absorbing refrigerator excellent in thermal efficiency. 2. Detailed Description of the Prior Art As shown in Fig.4, such an absorption refrigerator is known, as is devised to reduce a necessary heating amount by a gas burner 2 and reduce fuel consumption by sequentially sending the exhaust gas exhausted from the gas burner 2 for heating and boiling the dilute absorption solution of the high temperature regenerator 1 to a first exhaust gas heat recovery equipment 27 arranged between a high temperature heat exchanger 10 of an absorption solution pipe 12 and a high temperature regenerator 1, and to a second exhaust gas heat recovery equipment 28 arranged between a low temperature heat exchanger 9 and a high temperature heat exchanger 10, and thereby the dilute absorption solution transported to the high temperature regenerator 1 from an absorber 7 is increased in temperature. Namely, in the absorption refrigerator of the above construction, the dilute absorption solution at about 40°C (at rated operation, thereafter the same) exhausted from the absorber 7 is heated by the low temperature heat exchanger 9, the second exhaust gas heat recovery equipment 28, the high temperature heat exchanger 10, and the first exhaust gas heat exchanger 27, respectively, to be raised up to around 140 °C, and flows into the high temperature regenerator 1, therefore, fuel consumption of the gas burner 2 can be saved. Moreover, the absorption refrigerator is so constructed that when both the exhaust gas discharged from the gas burner 2 and the dilute absorption solution supplied from the absorber 7 are at low temperatures, the water vapor contained in the exhaust gas is prevented from being condensed and dewed, by increasing a flow rate of the dilute absorption solution flowing through the absorption solution pipe 14 by increasing the opening of the a flow control valve 29, and preventing the exhaust gas from remarkably lowering in temperature by decreasing heat recovering from the exhaust gas in the second exhaust gas heat recovery equipment 28. However, in the above-mentioned conventional absorption refrigerator, the flow control valve has been arranged in the absorption solution pipe bypassing the second exhaust gas heat recovery equipment, therefore, not a little of the dilute absorption solution has flown into the exhaust gas heat recovery equipment through the absorption solution pipe even if the flow control valve is fully opened. Therefore, when both the absorption solution and the exhaust gas are at a low temperature at the time of being started or the like, the exhaust gas temperature is excessively lowered even if the flow control valve is fully opened, and the water vapor contained in the exhaust gas has been condensed and dewed, and this has sometimes caused to corrode the heat exchanger and the exhaust pipe Moreover, most of the heat held by the exhaust gas discharged from the gas burner is recovered enough, therefore, when heat recovery of the exhaust gas is aimed at more than now, the exhaust gas temperature has become lower than the dew point of the water vapor contained in the exhaust gas even not at the time of starting operation, the water vapor has been dewed and sometimes corroded the heat recovery equipment and the piping part, therefore, the thermal efficiency needs to be improved by the other methods, and this has been a problem to be solved. SUMMARY OF THE INVENTION To solve the problem of the prior art described above, the present invention provides, as a first construction an absorption refrigerator, comprising : a high temperature regenerator for obtaining a vapor of a refrigerant and an intermediate absorbing solution from a dilute absorption solution by which evaporates and separates a refrigerant by heating and boiling a dilute absorption solution, to obtain a vapor of the refrigerant and an intermediate absorbing solution from the dilute absorption solution ; a low temperature regenerator which further vaporizes and separates the refrigerant by heating the intermediate absorption solution generated and supplied by said high temperature regenerator with the refrigerant vapor regenerated by said high temperature regenerator, to obtain the refrigerant vapor and a dense absorption solution ; a condenser which is supplied with the refrigerant solution obtained by heating and condensing the intermediate absorption solution by said low temperature regenerator, and which also obtains the refrigerant solution by cooling the refrigerant vapor regenerated and supplied by said low temperature regenerator; an evaporator in which the refrigerant solution supplied from said condenser is sprayed on heat conductive pipes and the refrigerant evaporates by absorbing the heat from the fluid flowing in the heat conductive pipes ; an absorber for making the refrigerant vapor generated and supplied by said evaporator absorb the dense absorption solution which is separated and supplied from said low temperature regenerator with the refrigerant vapor into a dilute absorption solution, and supplying it to said high temperature regenerator; a low temperature heat exchanger for performing heat exchange between the dilute absorption solution and the dense absorption solution going in and out of said absorber; and a high temperature heat exchanger for performing heat exchange between the intermediate absorption solution and the dilute absorption solution going in and out of the high temperature regenerator; characterized in that the absorption refrigerator is provided with a refrigerant heat recovery equipment for heat exchanging a part of the dilute absorption solution discharged from the absorber with the refrigerant heat-radiated and discharged from the low temperature regenerator bypassing the low temperature heat exchanger, and a proportion control means for controlling the proportion of the branched absorption solutions flowing through said refrigerant heat recovery equipment and the low temperature heat exchanger. In a second construction of the absorption refrigerator the proportion control means is one of a rotation speed controllable pump arranged in the absorption solution pipe from the absorber up to the refrigerant heat recovery equipment, an opening adjustable flow control valve, and a regulation valve for proportion of flow quantity arranged at the branch point of the absorption solution pipe to the refrigerant heat recovery equipment and the absorption solution pipe to the low temperature heat exchanger, In a third construction of the absorption refrigerator, the flow rate of the dilute absorption solution discharged from the absorber and supplied to the refrigerant heat recovery equipment is controlled on the basis of the temperature of the dense absorption solution discharged from the low temperature heat exchanger after heat exchange with the dilute absorption solution, in the first or second construction of the absorption refrigerator, a fourth construction of an absorption refrigerator is arranged so as to control the flow rate of the dilute absorption solution discharged from the absorber and supplied to the refrigerant heat recovery equipment on the basis of the temperature of the refrigerant discharged from the refrigerant heat recovery equipment after heat exchange with the dilute absorption solution, in the first or second construction of the absorption refrigerator, a fifth construction of an absorption refrigerator arranged so as to limit the dilute absorption solution discharged from the absorber and supplied to the refrigerant heat recovery equipment to 10 to 30% of the whole dilute absorption solution which is discharged from the absorber and is led to the high temperature regenerator, in the first or second construction of the absorption refrigerator, a sixth construction of an absorption refrigerator wherein a fitter 'is installed at each inlet side of the low temperature heat exchanger, the high temperature heat exchanger, and the refrigerant heat recovery equipment also a pressure detecting means for detecting a pressure difference is provided across each filter; and a checking indication means for indicating to check the filter based on the differential pressure detected by the pressure detecting means, in one of the first through fifth constructions of the absorption refrigerators, and a seventh construction of an absorption refrigerator wherein the respective filters installed at the inlet sides of the Sow temperature heat exchanger and the refrigerant heat recovery equipment are replaced with a single common filter arranged in the absorption solution pipe before the branch point of the absorption solution pipe going to the low temperature heat exchanger and the absorption solution pipe going to the refrigerant heat recovery equipment, in one of the first through 5th constructions of the absorption refrigerators BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS These and other objects and advantages of the present invention will become clear from the following description with reference to the accompanying drawings, wherein : Fig. 1 is an explanation view showing an embodiment of the present invention ; Fig. 2 is an explanation view showing another embodiment of the present invention ; Fig. 3 is an explanation view showing yet another embodiment of the present Invention ; and Fig. 4 is an explanation view showing the prior art. [Description of Reference Numerals] 1: high temperature regenerator 2: gas burner 3: low temperature regenerator 4:condenser 5: hot drum 6: evaporator 7: absorber 8: cold drum 9: low temperature heat exchanger 10: high temperature heat exchanger 11: refrigerant heat recovery equipment 12-16: absorption solution pipe(s) 17,18: absorption solution pump(s) 18A: flow control valve 18B: regulation valve for proportion of flow quantity 20-22: refrigerant pipe(s) 23: refrigerant pump 24: cold water pipe 25: cooling water pipe 26: exhaust gas pipe 27: first exhaust gas heat recovery equipment 28: second exhaust gas heat recovery equipment 29: flow control valve 30-32, 32A temperature sensor(s) 33: controller 34: checking indication means Fi-F6:filter(s) PF1-PF6 differential pressure gauge(s) DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described below, mentioning an example of an absorption refrigerator using water as a refrigerant and an aqueous solution of lithium bromide (LiBr) as an absorption solution. An embodiment of the present invention will be explained referring to Fig 1. In the figure, the reference numeral 1 is a high temperature regenerator constructed so as to evaporate and separate the refrigerant by heating the absorption solution with the heating power of the gas burner 2 using, for example, town gas as. fuel; the reference numeral 3 is a low temperature regenerator; 4 is a condenser; 5 is a hot drum in which the low temperature regenerator 3 and the condenser 4 are housed; 6 is an evaporator, 7 is an absorber; 8 is a cold drum in which the evaporator 6 and the absorber 7 are housed; 9 is a low temperature Heat exchanger; 10 is a high temperature heat exchanger; 11 is a refrigerant heat recovery equipment; 12 to 16 are absorption pipes; 17 to 19 are absorption solution pumps; 20 to 22 are refrigerant pipes; 23 is a refrigerant pump; 24 is a cold water pipe; 25 is a cooling water pipe; 26 is an exhaust gas pipe through which the exhaust gas discharged from the gas burner 2 passes; 27 is the first exhaust gas heat recovery equipment; 28 is the second exhaust gas heat recovery equipment; 29 is a flow control valve placed in the absorption solution pipe 12 downstream side from the branch part of the absorption solution pipe 14 and upstream side from the exhaust gas heat recovery equipment 28, 30 is a temperature sensor which is installed in a downstream part of the exhaust gas pipe 26 and detects the exhaust gas temperature; 31 is a temperature sensor which is installed in the upstream part of the absorption solution pipe 12 and detects the temperature of the dilute absorption solution before heat-exchanged, 32 is a temperature sensor which is installed in the downstream part of the absorption solution pipe 16 and detects the temperature of the dense absorption solution which has heat-exchanged with the dilute absorption solution >n the low temperature heat exchanger 9 and has radiated heat; and 33 is a controller for controlling the opening of the flow control valve 29 so that the temperature sensor 30 continuously deters a predetermined temperature, for example, 100°C, and also controlling a quantity of the dilute absorption solution made to flow into the refrigerant heat recovery equipment 11 bypassing the low temperature heat exchanger 9 by controlling the rotation speed of the absorption solution pump 18 so that the temperature detected by the temperature sensor 32 is not lower than a predetermined temperature, for example 40°c. Moreover, F1-F5 are filters installed at the respective inlet sides of the low temperature heat exchanger 9, the high temperature heat exchanger 10, and the refrigerant heat recovery equipment 11, and PF1-PF5 are differential pressure gauges for detecting pressure differences across the respective filters installed across them and are configured to output the detected pressure differences to the controller 33. In the absorption refrigerator of the construction described above, when the dilute absorption solution is heated and boiled in the high temperature regenerator 1 by burning town gas by the gas burner 2, refrigerant vapor evaporated and separated from the dilute absorption solution, and an intermediate absorption solution increased in the density of the absorption solution due to the separation of the refrigerant vapor are obtained. The high temperature refrigerant vapor generated by the high temperature regenerator 1 goes into the low temperature regenerator 3 through the upstream part of the refrigerant pipe 20, heats the intermediate absorption solution, which is generated in the high temperature regenerator 1 and goes into the low temperature regenerator 3 through the absorption solution pipe 15 via the high temperature heat exchanger 10, radiates heat to be condensed, and enters the condenser 4 through the downstream part of the refrigerant pipe 20 in which the refrigerant heat recovery equipment 11 intervenes. Moreover, the refrigerant evaporated and separated from the intermediate absorption solution by being heated in the low temperature regenerator 3 enters the condenser 4, being heat-exchanged with the water flowing through the cooling water pipe 25, to be condensed and liquefied, and entering the evaporator 6 through the refrigerant pipe 21 together with the condensed refrigerant supplied from the refrigerant pipe 20. The refrigerant solution collected in the bottom of the evaporator 6 is sprayed on the heat conductive pipe 24A connected with the cold water pipe 24 by the refrigerant pump 23 lying in the refrigerant pipe 22, and is evaporated by being heat-exchanged with the water supplied through the cold water pipe 24, and cools down the water flowing inside the heat conductive pipe 24A. The refrigerant evaporated by the evaporator 6 enters the absorber 7, and is absorbed into the absorption solution which is heated by the low temperature regenerator 3 to evaporate and separate the refrigerant and is more increased in density, namely, the refrigerant is absorbed into the dense absorption solution which is supplied from the absorption solution pipe 16 by the absorption solution pump 19 via the low temperature heat exchanger 9 and is sprayed from above. Then, the absorption solution which has absorbed the refrigerant in the absorber 7 and has become thinner in density, namely, the dilute absorption solution is fed back to the high temperature regenerator 1 by operation of the absorption solution pump 17, 18. When the absorption refrigerator is operated as described above the cold water cooled by the vaporization heat of the refrigerant in the heat conductive pipe 24A piped inside of the evaporator 6 can circularly be supplied to an air conditioning load, not shown, via the cold water pipe 24, therefore, cooling operation such as air conditioning can be carried out. in the absorption refrigerator of the construction described above, a part of the dilute absorption solution to be fed back to the high temperature regenerator 1 from the absorber 7 by the operation of the absorption solution pumps 17, 18 passes through the low temperature heat exchanger 9 lying in the absorption solution pipe 12, and the remaining part passes through the refrigerant heat recovery equipment 11 lying in the absorption solution pipe 13, and they are heated by the respective heat exchangers Moreover, a quantity of the dilute absorption solution heated by the exhaust gas discharged from the gas burner 2 via the second exhaust gas heat recovery equipment 28 is controlled by the flow control valve 29 intervened in the absorption solution pipe 12, and the whole quantity of the dilute absorption solution to be fed back to the high temperature regenerator 1 from the absorber 7 is made to flow through the high temperature heat exchanger 10 and the first exhaust gas heat recovery equipment 27, and is heated by each of them Namely, a part of the dilute absorption solution of about 40°C discharged from the absorber 7 to the absorption solution pipe 12 is heat-exchanged in the low temperature heat exchanger 9 with the dense absorption solution of about 90 oC which is discharged from the low temperature regenerator 3 into the absorption solution pipe 15 and is flowing into the absorber 7, and the remaining part thereof exchanges heat with the refrigerant solution of about 95°C in the refrigerant pipe 20 which is condensed by the low temperature regenerator 3 and is flowing into the condenser 4, and is raised in temperature. And, the respective dilute absorption solutions heat-exchanged and heated in the low temperature heat exchanger 9 and the refrigerant heat recovery equipment 11 join together to be a dilute absorption solution of, for sample, about 80oc, and flow into the second exhaust gas heat recovery equipment 28. The flow rate of the dilute absorption solution flowing into the second exhaust gas heat recovery equipment 28 is controlled by the controller 33 for adjusting the opening of the flow control valve 29 placed in the absorption solution pipe 12. For example, when the temperature sensor 30 is detecting a temperature higher than the predetermined 100°C, the controller 33 increases the opening of the flow control valve 29, and supplies more dilute absorption solution being returned to the high temperature regenerator 1 from the absorber 7 to the second heat recovery equipment 28 to promote recovery of the heat held by the exhaust gas, therefore, the thermal efficiency is improved and the fuel consumption of the gas burner 2 is reduced. Moreover, the dilute absorption solution heated by passing through the second exhaust gas heat recovery equipment 28, and the dilute absorption solution, which does not pass through the second exhaust gas. heat recovery equipment 28, therefore, which is not heated thereby, are joined and pass through the heat exchanger 10 and the first exhaust gas heat recovery equipment 27, and exchange heat with the intermediate absorption solution flowing from the high temperature regenerator 1 to the low temperature regenerator 3 through the absorption solution pipe 15, and with the exhaust gas of about 200 °C exhausted from the gas burner 2, and flow into the high temperature regenerator 1 as a dilute absorption solution at about 140 °C, therefore, the gas burner 2 can save its fuel consumption. Further, the refrigerant solution which is condensed by the low temperature regenerator 3 and flows into the condenser 4 passing through the downstream part of the refrigerant pipe 20, exchanges heat with the dilute absorption solution of about 40oC in the refrigerant heat recovery equipment 11 and heats it as described above, and the refrigerant itself is cooled down to about 45°C and is decreased in calorie to be radiated to the cooling water flowing through the cooling water pipe 25, therefore, necessary heat gain in the high temperature regenerator 1 can be decreased, and the absorption refrigerator is remarkably improved in thermal efficiency also at this point. Moreover, the rotation speed of the absorption solution pump 18 is controlled by the controller 33 so that the temperature of the dense absorption solution detected by the temperature sensor 32 after the heat exchange in the low temperature heat exchanger 9 is higher than the predetermined 40 °C, therefore, the dense absorption solution flowing through the downstream part of the absorption solution pipe 16 is not crystallized and clogging of the absprption solution pipe 16 due to the crystallization does not occur. Moreover, when the temperature sensor 30 is detecting a temperature lower than 100°C, it is possible to reduce the calorie to be recovered from the exhaust gas to the minimum of zero by fully closing the flow control valve 29 to the minimum, until the whole quantity of the dilute absorption solution is made to flow through the absorption solution pipe 14 by bypassing the second exhaust gas heat recovery equipment 28, therefore, the temperature of the exhaust gas exhausted via the exhaust gas pipe 26 is maintained at 100°C higher than the dew-point temperature (the dew-point temperature of the exhaust gas is 60-70°C when town gas, namely, natural gas is used as fuel), and so even at the time of starling or partial load operation of the absorption refrigerator when the exhaust gas temperature is low, water vapor contained in the exhaust gas cannot be condensed to produce drain water, and the drain water does not cause a corrosion problem either. Further, since the filters F1-F6 are installed on the inlet sides of the low temperature heat exchanger 9, the high temperature heat exchanger 10, and the refrigerant heat recovery equipment 11, scales are filtered out by the filters F1-F6 even if the scales enter the passages of the absorption solution and the refrigerant. Moreover, the filters F1 and F2 can be replaced with a single filter (shown by imaginary lines in Fig. 1) to be provided on the discharge side of the absorption solution pump 17 and on the upstream side of the branch part of the piping. Therefore, inconvenience of clogging the flow passages is not caused even when the low temperature heat exchanger 9, the high temperature heat exchanger 10, the refrigerant heat recovery equipment 11, etc. are constructed of plate-type heat exchangers improved in heat exchange efficiency by narrowing the flow passages as proposed in, for example, the Japanese Patent Laid-Open 1987-131196 the Japanese Patent Laid-Open 1991-271697, the Japanese Patent Laid-Open 1992-73595, the Japanese Patent Laid-Open 1995-190649, the Japanese Patent LaW-Open 1995-229637, etc. Moreover, the differential pressure gauges PF1-PF6 are installed across the filters F1-F6, and since the differential pressure gauges are configured so that the controller 33 issues an alarm by the checking indication means 34 when a predetermined pressure difference of, for example, 30kPa or higher is not detected across each filter, normal circulation of the solutions can be secured by cleaning the filters, and so on by observing the operation status of the checking indication means 34. Moreover, the temperature of the refrigerant which radiates heat by heating the intermediate absorption solution in the low temperature regenerates 3 and further radiates heat by heating the dilute absorption solution also in the refrigerant heat recovery equipment 11 is lowered to around 45°C as mentioned above, the refrigerant does not need to be sent to the condenser 4 for being cooled down by the cooling water flowing through the cooling water pipe 25. Therefore, it is also possible to shorten the pipe length and simplify the piping structure by connecting the downstream side of the refrigerant pipe 20 not to the condenser 4 but to the evaporator 6 so that the condensed refrigerant can be made to flow into it, as shown by an imaginary line (In Fig.1, the shortest parts of the refrigerant pipes 20, 21 are connected via the imaginary lines, but in a practical machine, the hot drum 5 is located on an upper side, and the cold drum 8 and the refrigerant heat recovery equipment 11 are located on a lower side, therefore, it is possible to place the evaporator 6 of the cold drum 8 and the refrigerant heat recovery equipment 11 adjacent to each other and connect between them via a short refrigerant pipe). Moreover, as shown in Fig.2, the flow control valve 18A is installed in the absorption solution pipe 13 instead of the absorption solution pump 18. Or, as shown in Fig.3, the rate of flow proportion control valve 18B is installed at the branch part of the absorption solution pipes 12, 13, and the flow control valve 18A or the rate of flow proportion control valve 18B can be configured so as to control a quantity of the dilute absorption solution flowing through the low temperature heat exchanger 9 by the controller 33 so that the temperature of the dense absorption solution having radiates heat in the low temperature heat exchanger 9 is not detected at the predetermined 40 oC or lower by the temperature sensor 32. Moreover, it is also possible to determine and construct the internal resistance (the diameters and lengths of the pipes) of the refrigerant heat recovery equipment 11 and the absorption solution pipe 13 so that 10-30% of the absorption solution is made to bypass the low temperature heat exchanger 9 and flow through the refrigerant heat recovery equipment 11, without installing the absorption solution pump 18, the flow control valve 18A, and the rate of flow proportion control valve 18B in the absorption solution pipe 13 (including the branch part/joint part of the absorption solution pipe 12). Moreover, instead of the temperature sensor 32, the temperature sensor 32A is installed on the downstream side of the refrigerant pipe 20 so as to be able to detect the temperature of the refrigerant having radiates heat by heat exchange with the dilute absorption solution in the refrigerant heat recovery equipment 11, and thereby it is also possible to arrange the rotation speed of the absorption solution pump 15, the flow control valve 18A, the opening of the rate of flow proportion control valve 18B, etc. to be controlled by the controller 33 so that the temperature of the refrigerant detected by the temperature sensor 32A after heat exchange in the refrigerant heat recovery equipment 11 is, for example, the temperature of the dilute absorption solution detected by the temperature sensor 31 before heat exchange in the refrigerant heat recovery equipment 11 plus a predetermined temperature, for example, plus 5°C, and it is aiso possible to arrange them to surety lower the temperature of the condensed refrigerant directly supplied to the condenser 4 or the evaporator 6 down to a predetermined temperature. Further, the configuration may be made up to control the valve to open/close or to be switched by the controller 33 so that an exhaust gas temperature detected by the temperature sensor 30 is not lower than, for example, 100°C, by arranging an inexpensive on-off valve in the absorption solution pipe 12 on the upstream side of the second heat recovery equipment 28 or arranging an inexpensive switching valve at the branch part (or joining part) of the absorption solution pipes 12, 14, instead ot the expensive flow control valve 29. Moreover, instead of the absorption solution pipe 14 hypassing the second heat recovery equipment 28, not only an exhaust gas pipe bypassing the second heat recovery equipment 28 is arranged, but also a passage switching valve is arranged at the branch part (or joining part) of the exhaust pipe. Or, a on-off valve is arranged in the exhaust gas pipe passing through the second heat recovery equipment 28, and thereby open/close or passage switching of the valve may be controlled by the controller 33 so that the temperature of the exhaust gas. which has flown through the second heat recovery equipment 28 and exchanged heat with the dilute absorption solution, is not lower than the predetermined 100°c Moreover, the absorption refrigerator may exclusively be used for cooling operation of air conditioning as described above, and may also be arranged so as to able to perform heating operation of air conditioning by arranging piping connection permitting to directly supply the cold drum 8 with the refrigerant vapor heat-generated by the high temperature regenerator 1 and the absorption solution from which the refrigerant vapor has been separated by vaporization, heating the dilute absorption solution by the gas burner 2 without making the cooling water flow through the cooling water pipe 25, and circularly supplying a load with water heated, for example, at 55oC by the heat conductive pipe 24 A of the evaporator 6 through the cold water pipe 24 (preferred to be called a hot water pipe when hot water circulates). Further, as a fluid to be supplied to an air-conditioning load by cooling it by the evaporator 6, not only water or the like may be supplied without phase change as described in the above embodiment, but also fluorocarbon or the like may be supplied with phase change so as to be able to transfer heat utilizing latent heat. Moreover, by installing the pressure gauges across the respective filters F1-F6 to detect the pressure differences across the filter, such a warning means can also be arranged as indicates cleaning the filters when a predetermined pressure difference is not detected across the filters. While the presently preferred embodiment of the present invention has been shown and described, it will be understood that the present invention is not limited thereto, and that various, changes and modifications may be made by those skilled in the art without departing from the scope of the invention as set forth in the appended claims. According to the present invention as described above, since the refrigerant heat recovery equipment in which a pgrt of the dilute absorption solution discharged from the absorber exchanges heat with the refrigerant discharged from the low temperature regenerator after heat radiation, bypassing the low temperature heat exchanger, and the rate of flow proportion control means for controlling the proportion of the dilute absorption solution branching to flow through the refrigerant heat recovery equipment and the fow temperature heat exchanger, are installed, the remaining heat held by the refrigerant condensed by heat radiation to the intermediate absorption solution in the tow temperature regenerator and discharged to the refrigerant pipe can be heat- recovered by the dilute absorption solution in the refrigerant heat recovery equipment, and the fuel consumption of the combustion equipment attached to the high temperature regenerator can be reduced. Moreover, the proportion of the dilute absorption solutions branching to flow through the refrigerant heat recovery equipment and the low temperature heat exchanger can be controlled, and for example, in the absorption refrigerator in which the proportion is adjusted by controlling the flow rate of the dilute absorption solution discharged from the absorber and supplied to the refrigerant heat recovery equipment based on the temperature of the dense absorption solution discharged from the low temperature heat exchanger after having exchanged heat with the dilute absorption solution, the dense absorption solution flowing into the absorber after having radiated heat to the dilute absorption solution in the low temperature heat exchanger can be prevented from being crystallized by setting the temperature of the dense absorption solution to an appropriate temperature. Moreover, in the absorption refrigerator arranged so as to control the aforementioned proportion by controlling the flow rate of the dilute absorption solution discharged from the absorber and supplied to the refrigerant heat recovery equipment based on the temperature of the refrigerant discharged from the refrigerant heat recovery equipment after having exchanged heat with the dilute absorption solution, the temperature of the condensed refrigerant can surely be lowered to a predetermined temperature by setting the temperature of the refrigerant to a suitable temperature, and thus a necessary amount of heat radiation by the condenser is reduced, and a piping arrangement directly supplying the condensed refrigerant to the evaporator is also possible. Further, in the absorption refrigerator arranged so as to limit the dilute absorption solution discharged from the absorber and supplied to the refrigerant heat recovery equipment to 10-30% of the whole dilute absorption solution discharged from the absorber and reaching the high temperature regenerator, the temperature of the dense absorption solution releasing heat through heat exchange with the dilute absorption solution in the low temperature heat exchanger is surely lowered. Therefore, the refrigerant is promptly absorbed into the absorption solution in the absorber into which the dense absorption solution flows. Further, in the absorption refrigerator wherein the fitters are installed on respective inlet sides of the low temperature heat exchanger, the high temperature heat exchanger, and the refrigerant heat recovery equipment, and wherein the differential pressure detecting means are also installed for detecting the differential pressures across the respective filters, and wherein the checking indication means is arranged for indication of checking the filters based on the differential pressures detected by the differential pressure detecting means, scales are filtered even if they enter the flow passages of the absorption solution and the refrigerant. Therefore, inconvenience of clogging the flow passages is r\ot caused even when the low temperature heat exchanger, the high temperature heat exchanger, the refrigerant heat recovery equipment, etc. are constructed of plate-type heat exchangers improved in heat exchange efficiency by narrowing the flow passages as proposed in, for example, the Japanese Patent Laid-Open 1987-131195. the Japanese Patent Laid-Open 1991-271697, the Japanese Patent Laid-Open 1992-73595, the Japanese Patent Laid-Open 1995-190649, the Japanese Patent laid-Open 1995-229687, etc. Further, normal circulation of the solutions can be secured by cleaning the filters by observing the operation status of the checking indication means. WE CLAIM : 1. An absorption refrigerator, comprising : a high temperature regenerator for obtaining a vapor of a refrigerant and an intermediate absorbing solution from a dilute absorption solution by which evaporates and separates a refrigerant by heating and boiling a dilute absorption solution, to obtain a vapor of the refrigerant and an intermediate absorbing solution from the dilute absorption solution ; a low temperature regenerator which further vaporizes and separates the refrigerant by heating the intermediate absorption solution generated and supplied by said high temperature regenerator with the refrigerant vapor regenerated by said high temperature regenerator, to obtain the refrigerant vapor and a dense absorption solution ; a condenser which is supplied with the refrigerant solution obtained by heating and condensing the intermediate absorption solution by said low temperature regenerator, and which also obtains the refrigerant solution by cooling the refrigerant vapor regenerated and supplied by said low temperature regenerator; an evaporator in which the refrigerant solution supplied from said condenser is sprayed on heat conductive pipes and the refrigerant evaporates by absorbing the heat from the fluid flowing in the heat conductive pipes ; an absorber for making the refrigerant vapor generated and supplied by said evaporator absorb the dense absorption solution which is separated and supplied from said low temperature regenerator with the refrigerant vapor into a dilute absorption solution, and supplying it to said high temperature regenerator; a low temperature heat exchanger for performing heat exchange between the dilute absorption solution and the dense absorption solution going in and out of said absorber; and a high temperature heat exchanger for performing heat exchange between the intermediate absorption solution and the dilute absorption solution going in and out of the high temperature regenerator; characterized in that the absorption refrigerator is provided with a refrigerant heat recovery equipment for heat exchanging a part of the dilute absorption solution discharged from the absorber with the refrigerant heat-radiated and discharged from the low temperature regenerator bypassing the low temperature heat exchanger, and a proportion control means for controlling the proportion of the branched absorption solutions flowing through said refrigerant heat recovery equipment and the low temperature heat exchanger. 2. An absorption refrigerator as claimed in claim 1, wherein the proportion control means is anyone of a rotation speed controllable pump(s) arranged in the absorption solution pipe from the absorber up to the refrigerant heat recovery equipment, an opening adjustable flow control valve, and a regulation valve for proportion of flow quantity arranged at a branch point of the absorption solution pipe to the refrigerant heat recovery equipment and the absorption solution pipe to the low temperature heat exchanger. 3. An absorption refrigerator as claimed in claim 1 or 2, wherein the flow rate of the dilute absorption solution discharged from the absorber and supplied to the refrigerant heat recovery equipment is controlled on the basis of the temperature of the dense absorption solution discharged from the low temperature heat exchanger after heat-exchanging with the dilute absorption solution. 4. An absorption refrigerator as claimed in claim 1 or 2, wherein the flow rate of the dilute absorption solution discharged from the absorber and then supplied to the refrigerant heat recovery equipment is controlled on the basis of the temperature of the refrigerant discharged from the low temperature heat exchanger after heat-exchanging with the dilute absorption solution. 5. An absorption refrigerator as claimed in claim 1 or 2, wherein the dilute absorption solution discharged from the absorber and supplied to the refrigerant heat recovery equipment is limited to 10 to 30% of the whole dilute absorption solution which is discharged from the absorber and is led to the high temperature regenerator. 6. An absorption refrigerator as claimed in any one of the claims 1 to 5, wherein a filter is installed at each inlet side of the low temperature heat exchanger, the high temperature heat exchanger, and the refrigerant heat recovery equipment ; also a pressure detecting means for detecting a pressure difference is provided across each filter, and a checking indication means is provided for indicating to check the filter based on the differential pressure detected by the pressure detecting means. 7. An absorption refrigerator as claimed in claim 6, wherein the filters installed at the inlet sides of the low temperature heat exchanger and the refrigerant heat recovery equipment are replaced with a single common filter arranged in the absorption solution pipe before branching the absorption solution pipe going to the low temperature heat exchanger and the absorption solution pipe going to the refrigerant heat recovery equipment. 8. An absorption refrigerator substantially as herein described, particularly with reference to the accompanying drawings. The purpose of the present invention is to improve the thermal efficiency of an absorption refrigerator. The absorption refrigerator is provided with the refrigerant heat recovery equipment 11 for performing heat exchange between the refrigerant which radiated heat and is condensed by heating the intermediate absorption solution in the low temperature regenerator 3 and is introduced into the condenser 4 through the refrigerant pipe 20, and a part of the dilute absorption solution discharged from the absorber 7 and sent to the high temperature regenerator 1 bypassing the low temperature heat exchanger 9, and the rotation speed of the absorption solution pump 18 is controlled by the controller 33 so that the temperature of the dense absorption solution detected by the temperature sensor 32 is higher than a predetermined temperature, for example 40°C. |
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95-kol-2003-granted-abstract.pdf
95-kol-2003-granted-claims.pdf
95-kol-2003-granted-correspondence.pdf
95-kol-2003-granted-description (complete).pdf
95-kol-2003-granted-drawings.pdf
95-kol-2003-granted-form 1.pdf
95-kol-2003-granted-form 18.pdf
95-kol-2003-granted-form 2.pdf
95-kol-2003-granted-form 3.pdf
95-kol-2003-granted-form 5.pdf
95-kol-2003-granted-letter patent.pdf
95-kol-2003-granted-priority document.pdf
95-kol-2003-granted-reply to examination report.pdf
95-kol-2003-granted-specification.pdf
95-kol-2003-granted-translated copy of priority document.pdf
Patent Number | 219081 | |||||||||||||||
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Indian Patent Application Number | 95/KOL/2003 | |||||||||||||||
PG Journal Number | 17/2008 | |||||||||||||||
Publication Date | 25-Apr-2008 | |||||||||||||||
Grant Date | 23-Apr-2008 | |||||||||||||||
Date of Filing | 19-Feb-2003 | |||||||||||||||
Name of Patentee | SANYO ELECTRIC CO. LTD. | |||||||||||||||
Applicant Address | 5-5,KEIHANHONDORI 2-CHOME, MORIGUCHI-SHI, OSAKA-FU | |||||||||||||||
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PCT International Classification Number | F25 B 15/00 | |||||||||||||||
PCT International Application Number | N/A | |||||||||||||||
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