Abstract:
The present invention relates to an absorptive heat pump circulation systems and heating method. According to the present invention, an absorption heat pump circulation system comprises: a generator, equipped with a heat exchanger; an evaporator, equipped with a driving heat source; an absorber, equipped with a heat exchanger; and an absorbent crystallizer. An absorption solution entrance of the crystallizer is connected to an absorption solution exit of the absorber and a crystallized absorption solution exit of the crystallizer is connected to an absorption solution entrance of the generator, and a crystal output of the crystallizer is connected to an absorption solution Entrance of the absorber; The heat exchanger of the generator and the heat exchanger of the absorber are connected to form a thermal cycling loop, which transfers the absorption heat generated by the absorber to the generator. Since the absorbent crystallizer is provided, and the heat generated by the absorber is provided to the generator directly through the thermal cycling loop, then the external driving heat source required by the generator in the traditional absorption heating circulation system is essentially saved, so that the coefficient of performance is significantly improved. The present invention extensively applies to the utilization of excess heat at a low temperature as well as energy-saving and emission-reducing in the fields such as chemical industry, food industry, sewage treatment, sea water desalination and so on.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention in general relates to absorptive heat pump circulation technology in thermal engineering field, in particular, relates to absorptive heat pump system and heating method that carry absorptive heating under the condition of only one set of external driving heat source and output heat of high grade outward, which extensively apply to the utilization of excess heat at a low temperature and also energy-saving and emission-reducing in the process of distillation fractionation, evaporation concentration, materials desiccation, adsorbent regeneration and so on, in the fields of such as chemical industry, food industry, sewage treatment, sea water desalination and so on. 
       BACKGROUND OF THE INVENTION 
       [0002]    With reference to  FIG. 1 , current absorptive heat pump circulation system is characterized in utilizing absorption solution can precipitate steam with components of low boiling points under a certain condition, and can intensively absorb steam with components of low boiling points under another condition. The absorptive heat circulation in prior art mostly adopts the absorption solution with two components, often the component of low boiling point is referred as working medium, and the component of high boiling point is referred as absorbent, and the two components form a working medium pair, which is commonly aqua-lithium bromide working medium pair. Current absorptive heat pump circulation system mainly comprises: a generator  11  equipped internally with a heat exchanger  110 , a condenser  12  equipped internally with a heat exchanger  120 , an evaporator  13  equipped internally with a heat exchanger  130  and an absorber  14  equipped internally with a heat exchanger  140 , besides, it further comprises an absorption solution self heat exchanger  150 , an absorption solution pump, a throttler (not shown in the figure) and so on as auxiliary devices. The generator  11  and condenser  12  are connected through steam pipeline  19 , and evaporator  13  and absorber  14  are connected through steam pipeline  18 . The absorption solution circulates between the generator  11  and the absorber  14  through absorption solution pipeline  16  and  15 . 
         [0003]    The operation process of the current absorptive heat pump circulation comprises: (1) utilizing driving heat source (for example, water steam, hot water, combustion gas and so on to heat the lithium bromide solution with a specific concentration transferred from the absorber  14  in the generator  11 , and evaporate the water out of the lithium bromide solution, to form the lithium bromide with thicker concentration to circulate into the absorber  14 ; (2) the water steam entering into the condenser  12  through the steam pipeline  19 , and being condensed into to condensation water by the condensing working medium in the heat exchanger  120 ; (3) the condensation water entering into the evaporator  13  through the condensation water pipeline  17 , and feeding the same one or another driving heat source with the heat exchanger  130 , so that the condensation water from the condenser can be converted into water steam; (4) the water steam entering into the generator  14  through the steam pipeline  18 , and being absorbed by the absorption solution from the generator  11  and generates absorption heat, meanwhile the concentration of the absorption solution being reduced, and the absorption solution with thicker concentration circulates into the generator  11 , the absorption heat being used to heat the working medium (generally water) in the heat exchanger  140 , increasing the temperature of the working medium and the heat as heating energy with higher grade than the driving heat source being outputted outward (when the working medium is water, it can be outputted in the form of water steam), to achieve the target that the present absorptive heat pump circulation system outputs heat energy with high grade outward. In the circulation process, the absorption solution from the absorber  14  exchanges heat with the absorption solution from the generator  11  in the absorption solution self heat exchanger  150 . 
         [0004]    Apart from the necessity of setting an external driving heat source for evaporating the condensation water in the heat exchanger  130  of the evaporator, the above mentioned current absorption heat pump circulation system, also has to adopt the same one or another external driving heat source to heat the absorption solution, so as to obtain the absorption solution with high concentration. That is to say, the current heat pump circulation system must utilize two external driving heat sources in the generator and the evaporator concurrently, which not only limits the improvement of the heat pump circulation heating coefficient, but also limits the application of the heat pump circulation system in the area in lack of high grade heat source and water source. 
       SUMMARY 
       [0005]    It is the fundamental object of the present invention to overcome the existing problem of the absorptive heat pump circulation system and the heating method, and provide an absorptive heat pump circulation system of self-energized driving heat source and a heating method, and the technical problem to be solved is to operate absorptive heating under the condition of only one external driving heat source, to output heat energy with high grade outward, in order to significantly improve heating coefficient, i.e. energy efficiency, so that it has more practicability and more industry value. 
         [0006]    The objective of the present invention and the solution of the technical problems are achieved by the following technical solution. According to the present invention, an absorptive heat pump circulation system comprises: a generator, equipped with a heat exchanger for concentrating absorption solution and outputting steam outward; an evaporator, equipped with a heat exchanger, with which feed driving heat source; an absorber, equipped with a heat exchanger; an absorbent crystallizer, receiving and cooling the absorption solution from the absorber and/or the generator, and forming the absorbent crystals and absorption solution after crystallization, wherein the absorption solution after crystallization is transferred to the generator, and the absorbent crystals is transferred to the absorber; the heat exchanger of the generator and the heat exchanger of the absorber are connected to form a thermal cycling loop, which transfers absorption heat generated by the absorber to the generator. 
         [0007]    The objectives of the present invention are further achieved by the following technical solution. 
         [0008]    Preferably, the absorptive heat pump circulation system described above further comprises: an absorption solution self heat exchanger, for exchanging heat between the absorption solution from the generator and/or the absorber, and the absorption solution after crystallization and/or the absorbent crystals or the absorption solution containing absorbent crystals. 
         [0009]    Preferably, the absorptive heat pump circulation system described above further comprises: an absorption solution self heat exchanger, for exchanging heat between the absorption solution from the absorber and the absorption solution after crystallization from the absorbent crystallizer. 
         [0010]    Preferably, the absorptive heat pump circulation system described above further comprises: an absorption solution self heat exchanger, for exchanging heat between the absorption solution from the absorber and the absorbent crystals from the absorbent crystallizer or the absorption solution containing absorbent crystals from the absorbent crystallizer. 
         [0011]    Preferably, the absorptive heat pump system described above further comprises: an absorption solution self heat exchanger, for exchanging heat between the absorption solution from the absorber as well as the absorption solution after crystallization from the absorbent crystallizer, and the absorbent crystals or the absorption solution containing absorbent crystals. 
         [0012]    Preferably, in the absorptive heat pump system described above, the absorption solution from the absorber and the absorption solution from the absorbent crystallizer are mixed and the mixture enters into the absorption solution self heat exchanger, and then exchanges heat with the absorption solution after crystallization from the absorbent crystallizer and the absorbent crystals or the absorption solution containing absorbent crystals. 
         [0013]    Preferably, in the absorptive heat pump system described above, the heat cycling loop is provided with an external heat source heating device, for compensating the insufficient part of the heating capacity of the generator caused by the heat-dissipating loss. 
         [0014]    Preferably, the absorptive heat pump circulating system further comprises water source, for providing water for the evaporator. 
         [0015]    Preferably, the absorptive heat pump system further comprises: a compression refrigeration subsystem constituted of absorbent crystallizer-evaporator, compressor, absorption solution heat exchanger-condenser, throttle valve and compression refrigeration working medium pipeline, for providing cooling capacity for the absorbent crystallizer. 
         [0016]    The objective of the present invention and the solution of the problem are achieved by the following technical solution. According to the present invention, an absorptive heating method comprises the following steps: 
         [0017]    (1) concentrating the absorption solution in a generator and meanwhile generating steam, and then outputting the steam outward, transferring the concentrated absorption solution to an absorber; 
         [0018]    (2) utilizing driving heat source to heat absorption solution in the evaporator, and the generated steam being led into the absorber; 
         [0019]    (3) the absorption solution absorbing the steam from the evaporator in the absorber and generating absorption heat, and meanwhile the concentration of the absorption solution being decreased and the absorption solution being transferred to the absorbent crystallizer; 
         [0020]    (4) performing cooling, crystallizing and liquid-solid separating for the absorption solution in the absorbent crystallizer, forming absorbent crystals and absorption solution after crystallization, the absorption solution after crystallization being transferred to the generator, and the absorbent crystal and the absorption solution containing absorbent crystals being transferred to the absorber; 
         [0021]    (5) performing heat circulation between the absorber and the generator, the absorption heat generated when the absorption solution absorbs the steam in the absorber is transferred to the generator. 
         [0022]    Preferably, the method for absorptive heating described above further comprises, before the absorption solution after crystallization being transferred to the generator and before the absorption solution outputted by the absorber being cooled, the absorption solution output by the absorber exchanges heat with the absorption solution after crystallization. 
         [0023]    Preferably, the method for absorptive heating described above further comprises, before the absorbent crystal being transferred to the absorber and before the absorption solution outputted by the absorber being cooled, the absorbent crystals or the absorption solution containing absorbent crystals exchanges heat with the absorption solution outputted by the absorber. 
         [0024]    Preferably, the method for absorptive heating described above further comprises, before the absorption solution after crystallization being transferred to the generator, the absorbent crystal being outputted to the absorber and the absorption solution outputted by the absorber being cooled, the absorption solution outputted by the absorber exchanges heat with the absorbent crystals as well as the absorption solution after crystallization. 
         [0025]    Preferably, the method for absorptive heating described above further comprises, before the absorption solution after crystallization being transferred to the generator, the absorbent crystal being transferred to the absorber and before the absorption solution outputted by the absorber being cooled, the absorption solution outputted by the generator and the absorption solution outputted by the absorber are mixed to form a mixed absorption solution, the mixed absorption solution exchanges heat with the absorbent crystals as well as the absorption solution after crystallization. 
         [0026]    Preferably, the method for absorptive heating described above further comprises, in the heat circulation process of step (5), the insufficient heating part of the heating capacity of the generator is compensated through external heat source. 
         [0027]    Preferably, for the method for absorptive heating described above, the temperature of the driving heat source after utilization is no lower than 2° C. 
         [0028]    Preferably, for the method for absorptive heating described above, the cooling capacity required for cooling and crystallizing the absorption solution in step (4) is provided by compression refrigeration circulation. 
         [0029]    Preferably, for the method for absorptive heating described above, the compression refrigeration circulation comprises: 
         [0030]    compressing the refrigeration working medium, to increase the pressure and temperature of the refrigeration working medium; 
         [0031]    the refrigeration working medium with increased temperature exchanges heat with the absorption solution after crystallization from the absorbent crystallizer and/or absorbent crystals or absorption solution containing absorbent crystals; 
         [0032]    after being dilated, the refrigeration working medium after heat exchanging absorbing heat from the absorbent crystallizer. 
         [0033]    Preferably, for the method for absorptive heating described above, the temperature of cooling and crystallizing the absorption solution in step (4) is −15˜60° C. 
         [0034]    The driving heat source in the technical solution described above can utilize the excess heat at a low temperature of great volume and difficult to utilize in the high-energy consumption industry, such as steel industry, building material industry and chemistry industry. 
         [0035]    Compared with current technology, the present invention possesses obvious advantage and beneficial effects. According to the above technical solution, because of an absorbent crystallizer and the heating energy generated by the absorber being provided to the generator directly through the heat cycling loop, the absorptive heat pump circulation systems and heating method of the present invention therefore can basically omit the external driving heat source required by the generator in the current absorptive heating circulation system to realize absorptive heating, so that the coefficient of performance (COP) is improved and the temperature of the driving heat source required, i.e. the temperature of the available excess heat at a low temperature, is significantly decreased, so as to be more practical. 
         [0036]    Besides, since the absorptive heat pump system of the present invention needs no setting of a condenser, therefore, different from the current absorption heat pump circulation, the present invention does not adopt condensation water to cool down the condenser, so that the operational load of the cooling tower can be largely reduced, meanwhile the water resource is saved. 
         [0037]    The preferred embodiments and detailed description with the accompanying drawings are set forth in this invention as below, to fully understand the technical solution of this invention and thereafter implement the solution according to the description. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0038]      FIG. 1  illustrates a flow chart of an absorptive heat pump circulation system in prior art. 
           [0039]      FIG. 2  illustrates a flow chart of an absorptive heat pump circulation system according to the first embodiment of the present invention. 
           [0040]      FIG. 3  illustrates a flow chart of an absorptive heat pump circulation system according to the second embodiment of the present invention. 
           [0041]      FIG. 4  illustrates a flow chart of an absorptive heat pump circulation system according to the third embodiment of the present invention. 
           [0042]      FIG. 5  illustrates a flow chart of an absorptive heat pump circulation system according to the fourth embodiment of the present invention. 
           [0043]      FIG. 6  illustrates a flow chart of an absorptive heat pump circulation system according to the fifth embodiment of the present invention. 
       
    
    
       [0000]    
       
         
           
               11 : generator 
               12 : condenser 
               13 : evaporator 
               14 : absorber 
               17 : condensation water pipeline 
               18  and  19 : steam passage 
               15 ,  16 ,  20  and  30 : absorption solution pipeline 
               40 : pipeline for absorption solution after crystallization 
               50 : pipeline for solution containing crystals 
               60 : working medium pipeline for heat circulation 
               110 ,  120 ,  130  and  140 : heat exchanger 
               141 : absorbent crystallizer 
               142 : mixer 
               150 : absorption self heat exchanger 
               160 : heating device for external heat source 
               200 : absorbent crystallizer-evaporator 
               210 : compressor 
               220 : absorbent heat exchanger-condenser 
               230 : throttle valve 
               240 : compression refrigeration working medium pipeline 
           
         
       
     
       DETAILED DESCRIPTION 
       [0064]    Various aspects are now described with reference to the drawings. In the following description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the absorption heat pump system and its specific embodiment, structure, feature and functions. 
         [0065]    With reference to  FIG. 2 , a flow chart of the absorption heat pump circulation system according to the first embodiment of the present invention is illustrated, the absorptive heat pump circulation system, mainly comprises: a generator  11 , an evaporator  13 , an absorber  14  and water source  200 , and absorption solution utilizing aqua-lithium bromide working medium pair. The generator  11  is configured to concentrate absorption solution, which is provided with a heat exchanger  110  therein, feed the heat circulation working medium from the heat exchanger  140  in the absorber  14  with the heat exchanger  110 , to heat the lithium bromide as the absorption solution to evaporate the water therein, so that the concentration of the absorption solution is increased, and the high temperature steam generated thereby is outputted through the steam passage  19 , as so as to be further utilized by the users. The absorption solution in the outlet of the absorber  11  enters into the generator  14  through the absorption solution pipeline  20 , and the absorption solution in the outlet of the generator  14  enters into the generator  11  through the absorption solution pipeline  30 . The absorption solution is circulated between the generator  11  and the absorber  14  through the absorption solution pipelines  20  and  30 . The heat pump evaporator  13  is provided with a heat exchanger  130 , feed the driving heat source with the heat exchanger  130  to convert the water from the water source into steam, the generated steam is led into the absorber  14  via the steam passage  18 . The absorber  14  is provided with a heat exchanger  140 , and in the absorber  14 , the absorption solution of high concentration from the generator  11  absorbs the steam from the evaporator  13  and generates the absorption heat, so that the temperature of the heat circulation working medium in the heat exchanger  140  is increased. The heat exchanger  140  and the heat exchanger  110  in the generator  11  are connected by heat circulation working medium pipeline  60  to form a heat cycling loop, so as to provide the absorption heat generated by the absorber  14  to the generator  11  as the driving heat of the generator. In the present embodiment, the heat cycling loop is a heat pipe cycling loop, at the moment, the installation position of the generator  11  is higher than that of the absorber  14 . Regarding the heat pipe cycling, the working medium in the heat pipe can form convection by the process of condensing-evaporating without external driving force, so as to circulate between the absorber and the generator and transfer heat. The heat cycling loop is provided with a heating device  160  with external heat source, for compensating the insufficient part of the heat of the generator caused by radiation loss. 
         [0066]    According to the first embodiment of the present invention, the absorptive heat pump system is further provided with an absorbent solution heat exchanger  150 , absorbent crystallizer  141  and mixer  142  between the absorber  14  and the generator  11 . The absorbent crystallizer  141  has an input for absorption solution, an output for absorption solution after crystallization and an output for absorbent crystals. The input for absorption solution of the absorbent crystallizer connects to the outlet for absorption solution of the absorber  14  through the absorption self heat exchanger  150 , the crystallization outlet for the absorption solution in the absorbent crystallizer connects to the inlet for the absorption solution of the generator  11 , and the crystallization outlet for the absorption solution connects to the inlet for the absorption solution of the generator through the mixer  142  in the case that the mixer  142  exists. The outlet for the absorption solution of the generator  11  enters into the absorber  14  through the absorption solution pipeline  20  via the mixer  142 , and outlet for the absorption solution of the absorber  14  enters into the absorbent crystallizer  141  through the absorption solution pipeline  30  via absorption solution self heat exchanger  150 . In the absorbent crystallizer  141 , the low temperature cooling capacity is utilized to cool and crystallize the absorption solution, because crystals generate if aqueous solution of lithium bromide reaches or approaches crystallization point, the lower the crystallization temperature is, the lower the equilibrium concentration of liquid-phase lithium bromide is, therefore, through cooling and crystallizing, however high the concentration of the lithium bromide the absorption solution before cooling and crystallizing, and after crystallization the concentration of the lithium bromide can reach or approach to the equilibrium concentration of liquid-phase lithium bromide at the cooling temperature. After crystallization and solid-liquid separation, the absorption solution after the crystallization in absorbent crystallizer  141 , i.e., dilute solution of lithium bromide, is transferred to the generator  11  through the absorption solution pipeline  30  via the absorption solution heat exchanger  150 . The cool source employed by the absorbent crystallizer  141  described above can be cooling water of 0-32° C. The water source  200  can be domestic water or industrial water, or the condensation water formed after the high temperature steam output by the generator  11  is utilized; if other working medium is employed as the working medium of the absorption solution, then the water source  200  can also provide corresponding liquid-phase working medium. The absorptive heating device of the present embodiment only needs driving heat source provided in the evaporator  13 , i.e., high temperature steam can be obtained in the steam pipeline  19  of the generator  11 . 
         [0067]    The absorption solution in the absorbent crystallizer  141  can form absorbent crystals and absorption solution after crystallization. The absorbent crystal mentioned in the present embodiment and the following embodiments are not only limited to adopt absorbent crystals particles, but also absorption solution containing absorbent crystals particles. There are other relationships among absorber  14 , generator  11 , absorption solution self heat exchanger  150  and absorbent crystallizer  141  as described hereinafter. 
         [0068]    With reference to  FIG. 3 , a flow chart of the second embodiment according to the present invention is illustrated. The absorption solution self heat exchanger  150  is configured to exchange heat between the absorption solution from the absorber  14  and the absorbent crystals (the absorption solution containing the absorbent crystals) outputted from the absorbent crystallizer  141 . The outlet for the absorption solution pipeline  20  of the generator  11  connects with the inlet for the absorption solution pipeline of the absorber, so that the absorption solution outputted from the generator  11  is mixed with the absorbent crystals after heat exchanging and then inputted into the absorber together. The absorption solution after crystallization from the absorbent crystallizer  141  is outputted to the generator  11  via the inlet for the absorption solution pipeline  30 . After heat exchanging, the absorption solution from the absorber  14  is delivered into the absorbent crystallizer  141  to carry on cooling, crystallizing and liquid-solid separating; after heat exchanging, the absorbent crystal from the absorbent crystallizer  141  is delivered into the absorber  14  via the inlet for the absorption solution pipeline. Because the temperature of the absorption solution from the absorber  14  is much higher than that of the absorbent crystal outputted from the absorbent crystallizer  141 , after heat exchanging, the temperature of the absorption solution entering into the absorbent crystallizer  141  significantly decreases, so as to decrease the cooling capacity for cooling the absorption solution. Meanwhile, the temperature of the absorbent crystals from the absorbent crystallizer after heat exchanging is greatly increased, and the absorbent crystals from the absorbent crystallizer is transferred to the absorber to absorb the working medium steam of the same quantity, and release absorption heat in higher operation temperature, so as to increase the temperature that the absorber outputs outward, improve the heat grade and enhance power utilization efficiency. 
         [0069]    With reference to  FIG. 4 , a flow chart of the third embodiment according to the present invention is illustrated. After crystallization, the solution outputted from the absorbent crystallizer  141  also pass through absorption solution self heat exchanger  150 , and the solution from the absorber  14  exchanges heat with the absorbent crystals outputted from the absorbent crystallizer  141  (or the absorption solution containing the absorbent crystals) as well as the absorption solution after crystallization concurrently. After heat exchanging, the absorption solution after crystallization is delivered to the generator  11  via absorption solution input pipeline  30 . The absorption solution output pipeline  20  of the generator  11  is connected with the absorption solution input pipeline of the absorber, so as to mix the absorption solution outputted from the generator  11  and the absorbent crystals after heat exchanging and deliver the mixture into the absorber together. The absorption solution after crystallization from the absorbent crystallizer  141  is delivered to the generator  11  via the absorption solution input pipeline  30 . After heat exchanging, the absorption solution from the absorber  14  is delivered into the absorbent crystallizer  141  to carry on cooling, crystallizing and liquid-solid separating; after heat exchanging, the absorbent crystals from the absorbent crystallizer  141  is delivered into the absorber  14  via absorption solution input pipeline. Because the temperature of the absorption solution from the absorber  14  is far higher than the temperature of the absorbent crystals outputted from the absorbent crystallizer  141  as well as the absorption solution after crystallization, after heat exchanging, the temperature of the absorption solution entering into the absorbent crystallizer  141  is significantly decreased, so as to decrease the cooling capacity for cooling the absorption solution. Meanwhile, after heat exchanging, the temperature of the absorbent crystals from the absorbent crystallizer is greatly increased, and the absorbent crystals from the absorbent crystallizer is transferred to the absorber to absorb the working medium steam of the same quantity, and release absorption heat in higher operation temperature, so as to increase the temperature that the absorber outputs outward and improve the heat grade. After heat exchanging, the temperature of the solution after the crystallization from the absorbent crystallizer is significantly increased, and the solution after the crystallization from the absorbent crystallizer is transferred to the generator, to evaporate the same working medium steam, and in the present embodiment the heat consumed by the generator can be reduced, so as to enhance power utilization efficiency. 
         [0070]    With reference to  FIG. 5 , a flow chart of the fourth embodiment of the present invention is illustrated. The absorption solution output pipeline  20  of the generator  11  is connected with the absorption solution output pipeline  30  of the absorber  14 , and the joint is located before the absorption solution self heat exchanger  150 . The absorption solution from the generator  11  and the absorption solution from the absorber  14  are mixed and then the mixture enters into the absorption solution self heat exchanger  150 , to concurrently exchange heat with the absorbent crystals and the absorption solution after crystallization outputted from the absorption crystallizer  141 . After heat exchanging, the absorption solution after crystallization is transferred to the generator  11  via the absorption solution input pipeline. After heat exchanging, the absorbent crystals is transferred to absorber  14  via the absorption solution input pipeline. Compared with the previous method, the method that the absorption solution from the generator  11  and the absorption solution from the absorber  14  are mixed and then carry on cooling and crystallizing increases the quantity of the absorption solution being cooled and crystallized, so as to obtain more absorption solution crystallized, so that the utilization efficiency of the absorbent crystallizer is enhanced. 
         [0071]    With reference to  FIG. 6 , a flow chart of the fifth embodiment according to the present embodiment. The absorptive heat pump circulation is essentially the same as the previous embodiment, and the difference lies in that, it further comprises a compression refrigeration circulation subsystem, for providing cooling capacity at a low temperature for the absorbent crystallizer  141 . The compression refrigeration circulation subsystem comprises: absorbent crystallizer-evaporator  200 , compressor  210 , absorption solution heat exchanger-condenser  220 , throttle valve  230  and compression refrigeration working medium pipeline  240 . After compression refrigeration working medium is condensed in the heat exchanger-condenser  220 , it is evaporated in the absorbent crystallizer-evaporator  200  through throttle valve  230 , so as to provide cooling capacity at a low temperature for the absorbent crystallizer  141 . The steam of the compression refrigeration working medium in the outlet of the absorbent crystallizer-evaporator  200  is compressed by the compressor  210  and then enters into the absorption solution heat exchanger-condenser  220 , so as to accomplish the compression refrigeration circulation. The absorbent crystallizer-evaporator  200  can be a component of the absorbent crystallizer  141 . 
         [0072]    Since part of the crystals in the absorbent (lithium bromide) extracts, the concentration of the absorbent solution crystallized after liquid-solid separation in the absorbent crystallizer  141  is decreased. After the crystallization, the absorbent solution, i.e. lithium bromide dilute solution, is inducted to the generator  11  via the absorption solution crystallization pipeline  50  and thereafter the absorption solution heat exchanger-condenser  220  and the absorption solution self heat exchanger  150 . On the other hand, the absorbent crystals and the absorption solution containing absorbent crystals after liquid-solid separation in the absorbent crystallizer  141  is inducted to the mixer  142  via pipeline  40  containing crystallization solution and thereafter the absorption solution self heat exchanger-condenser  220  and the absorption solution self heat exchanger  150 . The function of the absorption solution self heat exchanger  150  lies on heat exchanging for the absorption solution at a high temperature from the absorber  14  and the absorption solution after crystallization and the absorbent crystals or the absorption solution containing the absorbent crystals at a low temperature from the absorbent crystallizer, so as to increase the solution temperature provided to the generator  11  and the mixer  142 , and meanwhile decrease the temperature of the absorption solution provided to the absorbent crystallizer. The function of the absorption solution heat exchanger-condenser  220  lies on heat exchanging for the compression refrigeration working medium steam at a high temperature from the compressor  210  of the compression refrigeration circulation subsystem and the absorption solution after crystallization and the absorbent crystals or the absorption solution containing the absorbent crystals at a low temperature from the absorbent crystallizer  141 , so as to condense the refrigeration working medium steam, and meanwhile completely or partially melt the absorbent crystals and increase the temperature of the absorption solution. Through the condense in the generator  11 , the absorption solution in the outlet for the generator  11  with increased concentration of absorbent is inducted into the mixer  142  to mix with the absorbent crystals (or the absorption solution containing absorbent crystals) through the absorption solution pipeline  20 , and then the mixture is inducted into the absorber  14  together. The present invention can set and optimize the absorbent operation concentration of the absorption solution in the absorber  14  and generator  11  separately. That is to say, the present invention can realize an extremely advantageous technological condition for absorption refrigeration circulation, i.e., while the absorber is operating under the condition of high absorbent concentration, the generator is operating under the condition of the absorbent concentration lower than that of the absorber, which is difficult for the traditional absorptive heat pump circulation. Since the absorbent crystallizer  141  is provided, and the heat generated by the absorber  14  is provided for the generator  11  directly through thermal cycling loop, so as to basically save the external driving heat source for providing heat for the generator  11  in the current absorptive heat pump circulation, and realize the absorptive heating process with self-contained driving heat source. 
         [0073]    The sixth embodiment of the present invention provides absorptive heating method, which employs the absorptive heat pump circulation system of the embodiments described above, the refrigeration method comprises the following steps: 
         [0074]    (1) Condensing the absorption solution in the generator and meanwhile generating steam, and then delivering the steam to the users, and the concentrated absorption solution being outputted; 
         [0075]    (2) Employing driving heat source to heat the absorption solution in the evaporator, and introducing the generated steam into an absorber; 
         [0076]    (3) In the absorber, the absorption solution from the generator absorbing the steam from the evaporator and generating absorption heat, and meanwhile the concentration of the absorption solution being decreased and delivering to an absorbent crystallizer; 
         [0077]    (4) In the absorbent crystallizer, carrying on cooling, crystallizing and liquid-solid separating for the absorption solution, forming absorbent crystals and absorption solution after crystallization, the absorption solution after crystallization being transferred to the generator, and the absorbent crystals and the absorption solution containing absorbent crystals being transferred to the absorber; 
         [0078]    (5) Carrying on heat exchanging between the absorber and the generator, i.e. the absorption heat generated when the absorption solution absorbs the steam in the absorber is transferred to the generator. In particular, the heat exchanger in the absorber and the heat exchanger in the generator are connected to form a thermal cycling loop, and the working medium (commonly water) in the thermal cycling loop absorbs the absorption heat in the absorber and transfers it into the generator, releases the heat in the generator and then returns to the absorber. 
         [0079]    The water in the evaporator can be from independent water source or condensation water formed after the steam outputted by the generator is utilized. 
         [0080]    Preferably, before the absorption solution crystallized being outputted to the generator and the absorption solution outputted by the absorber being cooled, the absorption solution after crystallization and the absorption solution outputted by the absorber exchange heat. 
         [0081]    Preferably, before the absorbent crystal being output to the absorber and the absorption solution output by the absorber being cooled, the absorbent crystal and the absorption solution output by the absorber are heat exchanging. 
         [0082]    Preferably, before the absorption solution crystallized being outputted to the generator, the absorbent crystals being outputted to the absorber and the absorption solution outputted by the absorber being cooled, the absorption solution outputted by the absorber and the absorbent crystals as well as the absorption solution after crystallization are heat exchanging. 
         [0083]    Preferably, before the absorption solution crystallized being outputted to the generator, the absorbent crystals being outputted to the absorber and the absorption solution outputted by the absorber being cooled, the absorption solution outputted by the generator and the absorption solution outputted by the absorber are mixed to form a mixed absorption solution, the mixed absorption solution and the absorbent crystals as well as the absorption solution after crystallization exchange heat. 
         [0084]    Through cooling and crystallizing for the absorbent, the absorption from the generator and/or the absorber and the absorption solution after crystallization and/or the absorbent crystals outputted from the absorbent crystallize exchanges heat, one of whose effects lies in that, only minor external cooling capacity and heating capacity are utilized to maintain the absorbent operation concentration of the absorption solution in the generator relatively low, and meanwhile significantly increase the absorbent operation concentration of the absorption solution in the absorber, so that the absorption heat at a higher temperature is obtained in the absorber, and the absorption heat can be utilized as driving heat source of the generator. 
         [0085]    Since an absorbent crystallization process is involved in the method described above, in the case of maintaining the absorbent operation concentration of the absorption solution in the generator relatively low, the absorbent operation concentration of the absorption solution in the absorber is significantly increases meanwhile, so that the absorption heat at a higher temperature is obtained in the absorber, and the absorption heat can be utilized as driving heat source of the generator and raise the operation temperature of the generator, i.e., produce working medium steam with a higher temperature. 
         [0086]    Preferably, heat compensation is provided for the thermal cycling process described above, i.e. an external heat source heating device is set to compensate thermal deficiency of the generator heating capacity caused by the dissipation loss, so as to ensure the heating process to keep operating. 
         [0087]    The steps in the present embodiment are carrying concurrently without specific sequence in the operation, and all the steps constitute the absorptive heating method together. 
         [0088]    The seventh embodiment according to the present invention provides another absorptive heating method, and the absorptive heating method is essentially the same as the previous embodiment, and the difference lies in that, the low temperature cooling capacity required by the cooling and crystallizing of the absorption solution in the absorbent crystallizer comes from compression refrigeration circulation process. The steam of the compression refrigeration working medium in the outlet for the absorbent crystallizer-evaporator  200  enters into the absorption solution heat exchanger-condenser  220  to be condensed after being compressed by the compressor  210 , and the compression refrigeration working medium is evaporated in the absorbent crystallizer-evaporator  200  after passing through the throttle valve  230 , so as to accomplish the compression refrigeration circulation. Since according to the present invention, when the compression refrigeration working medium is condensed in the absorption solution heat exchanger-condenser  220 , the cooling capacity comes from the cooling capacity of the solution in the outlet for the lithium bromide crystallizer  141 , therefore the evaporation temperature and the condensation temperature of the present circulation are relatively close, so as to reach higher refrigeration performance coefficient. In another words, the power consumption of the compression refrigeration circulation according to the present invention is relatively low. 
         [0089]    The technical solution of the embodiment described above has no specific constrain over the absorption solution types utilized, and all takes working medium of aqua-lithium bromide as the absorption solution for sample explanation, in the other embodiments, the working medium can be one of or a mixture of several ones of water, methanol and ethanol; absorbent can be one of or a mixture of LiBr, LiCl, LiNO 3 , NaBr, KBr, CaCl 2 , MgBr 2  and ZnCl 2 . 
         [0090]    The applicability of the embodiments described above is demonstrated by the following embodiments with specific parameters. 
       Embodiment 1 
       [0091]    Employing the method of the sixth embodiment described, the present embodiment utilizes hot water of 100° C. as the driving heat source of the evaporator, and applies saturated steam of 195° C. as the external heat source to heat the working medium in the thermal cycling loop, so as to compensate the thermal deficiency part of the heating capacity for the driving heat source of the generator caused by dissipation loss, utilizes dimethyl silicon oil as thermal cycling working medium, and utilizes cooling water of 20° C. to cool the absorbent crystallizer  141 . In the present embodiment, the temperature outputted outward is 182° C., the pressure of the superheated vapor is 170 kPa, and coefficient of performance (COP) is 10.0. The COP of the present embodiment is calculated according to the following function: 
         [0000]      COP=—heating capacity outputted/heat capacity of external heating source employed 
       Embodiment 2 
       [0092]    Employing the method of the sixth embodiment described, the present embodiment utilizes hot water of 100° C. as the driving heat source of the evaporator, and applies saturated steam of 195° C. as the external heat source to heat the working medium in the thermal cycling loop, so as to compensate the thermal deficiency part of the heating capacity for the driving heat source of the generator caused by dissipation loss, utilizes dimethyl silicon oil as thermal cycling working medium, and utilizes cooling water of 60° C. to cool the absorbent crystallizer  141 . In the present embodiment, the temperature outputted outward is 182° C., the pressure of the superheated vapor is 170 kPa, and coefficient of performance (COP) is 10.0. The COP of the present embodiment is calculated according to the following function: 
         [0000]      COP=heating capacity outputted/heat capacity of external heating resource employed 
       Embodiment 3 
       [0093]    Employing the method of the seventh embodiment described, the present embodiment utilizes hot water of 80° C. as the driving heat source of the evaporator, and applies saturated steam of 160° C. as the external heat source to heat the working medium in the thermal cycling loop, so as to compensate the thermal deficiency part of the heating capacity for the driving heat source of the generator caused by dissipation loss, applies dimethyl silicon oil as thermal cycling working medium, and utilizes cooling water of −18° C. to cool absorbent crystallizer  141 . In the present embodiment, the temperature outputted outward is 148° C., the pressure of the superheated vapor is 95 kPa, and coefficient of performance (COP) is 5.5. The COP of the present embodiment is calculated according to the following function: 
         [0000]      COP=heating capacity outputted/(heat capacity of external heating source employed+power consumption of compressor*3.0) 
         [0094]    Wherein, the primary energy generating efficiency of the grid user end for powering the compressor is taken as 33.3%. 
       Embodiment 4 
       [0095]    Employing the method of the fourth embodiment described, the present embodiment utilizes hot water of 7° C. as the driving heat source of the evaporator, and utilizes hot water of 50° C. as the external heat source to heat the working medium in the thermal cycling loop, so as to compensate the thermal deficiency part of the heating capacity for the driving heat source of the generator caused by dissipation loss, utilizes non-freezing solution as thermal cycling working medium, and utilizes cooling water of −18° C. to cool absorbent crystallizer  141 . In the present embodiment, the temperature outputted outward is 37° C., the pressure of the superheated vapor is 0.8 kPa, and coefficient of performance (COP) is 5.0. It can be seen from the present embodiment that the heat energy at a high temperature is provided outward via the generator. Meanwhile the cool capacity at a low temperature is provided outward via the evaporator. The COP of the present embodiment is calculated according to the following function: 
         [0000]      COP=heating capacity outputted/(heat capacity of external heating source employed+power consumption of compressor*3.0) 
         [0096]    Wherein, the primary energy generating efficiency of the grid user end for powering the compressor is taken as 33.3%. 
         [0097]    The following table 1 illustrates the operation parameters and performance of the embodiments described above. 
         [0000]    
       
         
               
               
               
               
               
               
             
               
               
               
               
               
               
             
               
               
               
               
               
             
           
               
                 TABLE 1 
               
               
                   
               
               
                   
                   
                 Embodiment 1 
                 Embodiment 2 
                 Embodiment 3 
                 Embodiment 4 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 Generator 
                 Temperature of 
                 189.4 
                 189.4 
                 155.4 
                 44.4 
               
               
                   
                 Thermal 
                   
                   
                   
                   
               
               
                   
                 Cycling 
                   
                   
                   
                   
               
               
                   
                 Working 
                   
                   
                   
                   
               
               
                   
                 Medium In Inlet 
                   
                   
                   
                   
               
               
                   
                 For Heat 
                   
                   
                   
                   
               
               
                   
                 Exchanger (° C.) 
                   
                   
                   
                   
               
               
                   
                 Temperature of 
                 185.0 
                 185.0 
                 151.0 
                 40.0 
               
               
                   
                 Thermal 
                   
                   
                   
                   
               
               
                   
                 Cycling 
                   
                   
                   
                   
               
               
                   
                 Working 
                   
                   
                   
                   
               
               
                   
                 Medium In 
                   
                   
                   
                   
               
               
                   
                 Outlet For Heat 
                   
                   
                   
                   
               
               
                   
                 Exchanger (° C.) 
                   
                   
                   
                   
               
               
                   
                 Lithium 
                 60 
                 66 
                 56 
                 56 
               
               
                   
                 Bromide 
                   
                   
                   
                   
               
               
                   
                 Concentration In 
                   
                   
                   
                   
               
               
                   
                 Inlet (wt %) 
                   
                   
                   
                   
               
               
                   
                 Lithium 
                 63 
                 69 
                 59 
                 58 
               
               
                   
                 Bromide 
                   
                   
                   
                   
               
               
                   
                 Concentration In 
                   
                   
                   
                   
               
               
                   
                 Outlet (wt %) 
                   
                   
                   
                   
               
               
                   
                 Pressure of 
                 170 
                 100 
                 95 
                 0.8 
               
               
                   
                 Outputted 
                   
                   
                   
                   
               
               
                   
                 Superheated 
                   
                   
                   
                   
               
               
                   
                 Vapor (kPa) 
                   
                   
                   
                   
               
               
                   
                 Pressure of 
                 182 
                 182 
                 148 
                 37 
               
               
                   
                 Outputted 
                   
                   
                   
                   
               
               
                   
                 Superheated 
                   
                   
                   
                   
               
               
                   
                 Vapor (° C.) 
                   
                   
                   
                   
               
               
                 Evaporator 
                 Temperature 
                 100 
                 100 
                 80 
                 7 
               
               
                   
                 Before Driving 
                   
                   
                   
                   
               
               
                   
                 Heat Source 
                   
                   
                   
                   
               
               
                   
                 Being Utilized 
                   
                   
                   
                   
               
               
                   
                 (° C.) 
                   
                   
                   
                   
               
               
                   
                 Temperature 
                 95 
                 95 
                 75 
                 2 
               
               
                   
                 After Driving 
                   
                   
                   
                   
               
               
                   
                 Heat Source 
                   
                   
                   
                   
               
               
                   
                 Being Utilized 
                   
                   
                   
                   
               
               
                   
                 (° C.) 
                   
                   
                   
                   
               
               
                   
                 Pressure (kPa) 
                 81.5 
                 81.5 
                 36.1 
                 0.6 
               
               
                 Absorber 
                 Temperature of 
                 185.0 
                 185.0 
                 151.0 
                 40.0 
               
               
                   
                 Thermal 
                   
                   
                   
                   
               
               
                   
                 Cycling 
                   
                   
                   
                   
               
               
                   
                 Working 
                   
                   
                   
                   
               
               
                   
                 Medium In Inlet 
                   
                   
                   
                   
               
               
                   
                 For Heat 
                   
                   
                   
                   
               
               
                   
                 Exchanger (° C.) 
                   
                   
                   
                   
               
               
                   
                 Temperature of 
                 189.0 
                 189.0 
                 155.0 
                 44.0 
               
               
                   
                 Thermal 
                   
                   
                   
                   
               
               
                   
                 Cycling 
                   
                   
                   
                   
               
               
                   
                 Working 
                   
                   
                   
                   
               
               
                   
                 Medium In 
                   
                   
                   
                   
               
               
                   
                 Outlet For Heat 
                   
                   
                   
                   
               
               
                   
                 Exchanger (° C.) 
                   
                   
                   
                   
               
               
                   
                 Lithium 
                 75 
                 75 
                 75 
                 66 
               
               
                   
                 Bromide 
                   
                   
                   
                   
               
               
                   
                 Concentration In  
                   
                   
                   
                   
               
               
                   
                 Inlet (wt %) 
                   
                   
                   
                   
               
               
                   
                 Lithium 
                 72 
                 72 
                 72 
                 64 
               
               
                   
                 Bromide 
                   
                   
                   
                   
               
               
                   
                 Concentration In 
                   
                   
                   
                   
               
               
                   
                 Outlet (wt %) 
                   
                   
                   
                   
               
               
                   
                 Pressure (kPa) 
                 81.4 
                 81.4 
                 36.0 
                 0.5 
               
               
                 Absorbent 
                 Absorbent 
                 20 
                 60 
                 −18 
                 −18 
               
               
                 Crystallizer 
                 Crystallizer— 
                   
                   
                   
                   
               
               
                   
                 Evaporator 
                   
                   
                   
                   
               
               
                   
                 Temperature 
                   
                   
                   
                   
               
               
                   
                 (° C.) 
                   
                   
                   
                   
               
               
                 External Heat 
                 Temperature of 
                 189.0 
                 189.0 
                 155.0 
                 44.0 
               
               
                 Resource 
                 Thermal 
                   
                   
                   
                   
               
               
                 Heating 
                 Cycling 
                   
                   
                   
                   
               
               
                 Device 
                 Working 
                   
                   
                   
                   
               
               
                   
                 Medium In Inlet 
                   
                   
                   
                   
               
               
                   
                 (° C.) 
                   
                   
                   
                   
               
               
                   
                 Temperature of 
                 189.4 
                 189.4 
                 155.4 
                 44.4 
               
               
                   
                 Thermal 
                   
                   
                   
                   
               
               
                   
                 Cycling 
                   
                   
                   
                   
               
               
                   
                 Working 
                   
                   
                   
                   
               
               
                   
                 Medium In 
                   
                   
                   
                   
               
               
                   
                 Outlet 
                   
                   
                   
                   
               
               
                   
                 (° C.) 
                   
                   
                   
                   
               
             
          
           
               
                 COP 
                 10.0 
                 10.0 
                 5.5 
                 5.0 
               
               
                   
               
             
          
         
       
     
         [0098]    While the foregoing disclosure discusses illustrative aspects and/or aspects, it should be noted that various changes and modifications could be made herein without departing from the scope of the described aspects and/or aspects as defined by the appended claims. Furthermore, although elements of the described aspects and/or aspects may be described or claimed in the singular, the plural is contemplated unless limitation to the singular is explicitly stated. Additionally, all or a portion of any aspect and/or aspect may be utilized with all or a portion of any other aspect and/or aspect, unless stated otherwise. 
       INDUSTRIAL APPLICATION 
       [0099]    Because the absorption heat pump circulation systems and heating methods according to the present invention possesses an absorbent crystallizer, and the heat generated by the absorber is directly provided to the generator through thermal cycling, so as to basically save an external driving heat source required by the generator of the traditional absorptive heating circulation and realize absorption heating, to significantly increase Coefficient of Performance (COP) and significantly decrease the required temperature of the driving heat source, i.e. the temperature of the excess heat at a low temperature that can be utilized, so that it will be more applicable. Besides, since it is not necessary to provide condenser for the absorptive heat pump system according to the present invention, therefore different from the traditional absorptive heat pump circulation, in the present invention cooling water is not utilized to cool the condenser, so that the operation load of cooling tower is significantly relieved and water source is saved meanwhile.