Abstract:
An energy transmission system for exchanging thermal energy of a medium in a sealed loop, the energy transmission system comprises a compressor ( 22 ) having a first end and a second end, a control valve ( 24 ) having a first end and a second end for controlling the flow of the medium in the sealed loop of the energy transmission system, a first passageway extending from the first end of the compressor ( 22 ) to the first end of the control valve ( 24 ), at least one portion of the first passageway configured to form a first heat exchanger such that a medium flowing therein absorbs thermal energy, and a second passageway extending from the second end of the compressor ( 22 ) to the second end of the control valve ( 24 ), at least one portion of the second passageway configured to form a second heat exchanger for releasing thermal energy of the medium flowing therein, wherein the compressor ( 22 ) is configured for changing the pressure of at least one portion of the medium in the first and second passageway such that the pressure in at least one portion of the first passageway is different from the pressure in at least one portion of the second passageway, and the physical state of the medium is different between regions of the sealed loop.

Description:
TECHNICAL FIELD 
       [0001]    The present invention relates to a liquid heating apparatus, and in particular, to a liquid heating apparatus with a heat pump. 
       BACKGROUND 
       [0002]    During daily life, people always heat liquid (for example, water) to achieve various objectives. For example, during cooking, water is heated to be boiling so as to blanch food, or water is heated to generate vapor to steam food. During manufacturing of distilled water, water is heated to generate vapour, and the vapor is then condensed into distilled water. During power generation, water is heated to generate vapour, so as to push a turbine to generate electricity. 
         [0003]    In the above examples, the vapor generated during heating still contains a large amount of heat, especially latent heat absorbed during vaporation. Among common liquids, water has the highest latent heat of vaporation being up to 2250 KJ/Kg. People have been trying to recycle or utilize heat energy in vapour. For example, Chinese Patent Application No. 200810081952.5 discloses a “high-efficiency energy-saving steamer” which may recycle the heat energy of the steam generated during steaming with “high-temperature high-pressure refrigerant” through “multi-source heat pump”. However, such disclosure is subjected to the following shortcomings: 
         [0004]    1. The “high-temperature high-pressure refrigerant” compressor is limited to high pressure operation which gives a high energy consuming process with poor recycling efficiency and the compressor is fragile to wearing. 
         [0005]    2. The “high-temperature high-pressure refrigerant” is expensive and poses harmful threat to the environment. 
         [0006]    3. The multi-source heat pump” for heat absorption is bulky and not suitable for household applications. 
       SUMMARY 
       [0007]    According to a first broad form of the present invention, there is provided an energy transmission system for exchanging thermal energy of a medium in a sealed loop, the energy transmission system may comprising a compressor having a first end and a second end, a control valve having a first end and a second end for controlling the flow of the medium in the sealed loop of the energy transmission system, a first passageway extending from the first end of the compressor to the first end of the control valve, at least one portion of the first passageway configured to form a first heat exchanger such that a medium flowing therein absorbs thermal energy, and a second passageway extending from the second end of the compressor to the second end of the control valve, at least one portion of the second passageway configured to form a second heat exchanger for releasing thermal energy of the medium flowing therein, wherein the compressor is configured for changing the pressure of at least one portion of the medium in the first and second passageway such that the pressure in at least one portion of the first passageway is different from the pressure in at least one portion of the second passageway, and the physical state of the medium is different between regions of the sealed loop. 
         [0008]    Preferably, at least one portion of the medium changes from gas state to liquid state in the second heat exchanger, and at least one portion of the medium changes from liquid state to gas state in the first heat exchanger. 
         [0009]    Optionally, the medium may be water. 
         [0010]    Advantageously, the compressor and the control valve may be configured for maintaining the pressure slightly above one standard atmosphere pressure within the second passageway and the pressure slightly below one standard atmosphere pressure within the first passageway. 
         [0011]    Preferably, the energy transmission system may further comprise a first chamber comprising a further medium therein, at least one portion of the further medium in the first chamber communicating thermal energy with the medium in the second heat exchanger and changing its physical state, a second chamber receiving the further medium which has changed the physical state in the first chamber, at least one portion of the further medium in the second chamber communicating thermal energy with the medium in the first heat exchanger and changing its physical state. 
         [0012]    Advantageously, the boiling point of the further medium in the first chamber is slightly lower than the boiling point of the medium in the second heat exchanger, and the boiling point of the further medium in the second chamber is slightly higher than the boiling point of the medium in the first heat exchanger. 
         [0013]    Optionally, the energy transmission system may further comprise a third chamber receiving the further medium from the second chamber, a third heat exchanger connected to the first chamber via a passageway, wherein the further medium flowing through the third chamber communicates thermal energy with the further medium in the third heat exchanger. 
         [0014]    Optionally, the energy transmission system further comprises a fourth chamber receiving the further medium from the second chamber or the third chamber. 
         [0015]    Advantageously, the fourth chamber may be connected with the first chamber and introduces the further medium into the first chamber. 
         [0016]    Optionally, the energy transmission system may further comprise a generator located between the first chamber and the second chamber, the generator generating electricity by utilizing the flow of the further medium from the first chamber to the second chamber. 
         [0017]    Optionally, the energy transmission system may further comprise a fifth chamber removably located between the first chamber and the second chamber, the fifth chamber configured for accommodating articles which exchanges thermal energy with the further medium flowing therethrough. 
         [0018]    Advantageously, the fifth chamber may comprise a sealing cover and at least one container, the sealing cover configured for sealingly covering the at least one the container, the container comprising at least a first chamber and a second chamber, the first chamber comprising a bracket with porous structure and partition wall surrounding the bracket, the bracket having porous structure which allows the further medium flowing through, the second chamber and the first chamber separated by the partition wall, the second chamber comprising cavity which forms a passage for exporting the further medium. 
         [0019]    According to a second broad form of the present invention, there is provided a cooking vessel, comprising at least one container, the container comprising at least a first chamber and a second chamber, the first chamber comprising a bracket and partition wall surrounding the bracket, the bracket having porous structure which allows a medium flowing through, the second chamber and the first chamber separated by the partition wall, the second chamber comprising cavity which forms a passage for exporting the medium. 
         [0020]    Preferably, the cooking vessel may further comprising a sealing cover, the sealing cover configured for sealingly covering the at least one the container. 
         [0021]    Preferably, the cooking vessel may further comprising further comprising a plurality of containers which are stacked together, wherein the first chamber and the second chamber of any one of the containers are in contact with the first chamber and the second chamber of an adjacent container to form a sealed passageway for the medium. 
         [0022]    An objective of the present invention is to provide a liquid heating apparatus with a heat pump, which can recycle or utilize heat energy in exhausted vapour, thereby saving the power consumption. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0023]    The forgoing fundamental structure of the present disclosure will be more apparent from the following detailed description and drawings of illustrative embodiments of the invention. 
           [0024]      FIG. 1  is a schematic structural diagram of a first embodiment of a liquid heating apparatus according to the present invention illustrating when the liquid heating apparatus is applied to a situation such as a cooking apparatus; 
           [0025]      FIG. 2  is a schematic structural diagram of a second embodiment of a liquid heating apparatus according to the present invention illustrating when the liquid heating apparatus is applied to a situation such as a steam cooking apparatus; 
           [0026]      FIG. 3  is a schematic structural diagram of a third embodiment of a liquid heating apparatus according to the present invention illustrating when the liquid heating apparatus is applied to a situation such as a steaming apparatus; 
           [0027]      FIG. 4  is a schematic diagram of a vessel of the steaming apparatus of the third embodiment, where the vessel is used to accommodate a steamed object; 
           [0028]      FIG. 5  is a sectional diagram of multiple stacked vessels shown in  FIG. 4 ; 
           [0029]      FIG. 6  is a schematic structural diagram of the third embodiment of the liquid heating apparatus according to the present invention illustrating when the liquid heating apparatus is applied to a situation such as a distilled water generating device or a distilling apparatus; and 
           [0030]      FIG. 7  is a schematic structural diagram of a fourth embodiment of a liquid heating apparatus according to the present invention illustrating when the liquid heating apparatus is applied to a situation such as a generating apparatus. 
       
    
    
     DETAILED DESCRIPTION 
       [0031]    Various embodiments of a liquid heating apparatus according to the present invention are described merely through examples with reference to the accompanying drawings. It should be understood that, the present invention is not limited thereto. In the drawings, the same components use the same reference numerals. 
         [0032]      FIG. 1  shows a structure of a first embodiment of a liquid heating apparatus. A cooking apparatus used in a restaurant to cook hot water blanching foods such as noodles is illustrated as an example for explanation. In this type of restaurant, a pot of boiling water must be always kept in order that hot cooked food can be ready for serving quickly. During the boiling process of hot water, vapor keeps bringing heat energy away and therefore the hot water needs to be continuously heated to keep boiling. However, this practice not only causes energy waste, but also leads to extremely hot environment within the kitchen. 
         [0033]    As shown in  FIG. 1 , a cooking apparatus  1  includes a container  3 , a heater  4 , a heat pump  5 , a first heat exchanger  6 , a second heat exchanger  7 , and a fluid conveying apparatus (for example, a vapor inhalation apparatus)  18 . The container  3  is used to accommodate liquid (for example, water)  11 , and an opening  12  is disposed at an upper part of the container  3 , so as to place noodles (not shown in the figure) and the like into the liquid  11  in the container  3  or withdraw the noodles or the like from liquid  11  in the container  3 . The heater  4  is disposed at the bottom or periphery of the container  3  for heating the liquid  11  in the container  3  to boiling, so as to cook food. Vapor  13  generated by the boiling liquid  11  is inhaled by the fluid conveying apparatus (for example, an exhaust fan)  18  from an inlet  16  adjacent to the opening  12  of the container, and is conveyed to the first heat exchanger  6 , so as to perform heat exchange with working fluid  21  within an evaporator  20  of the heat pump  5 . The heat pump  5  is a compression heat pump, and includes an evaporator  20 , a compressor  22 , a control valve  24  and a condenser  26  which are connected by using a sealing pipeline  28 , and the working fluid  21  in the heat pump is water. The control valve  24  is used to limit the flow of the working fluid  21  entering the evaporator  20 . The compressor  22  takes the working fluid  21  in the evaporator  20  out, so that the pressure in the evaporator  20  is reduced, and the boiling point of the working fluid  21  is slightly lower than the temperature of the vapor  13  entering the first heat exchanger  6 . The vapor  13  is condensed in the first heat exchanger  6  to release latent heat thereof. The heat energy is absorbed by the working fluid  21  in the evaporator  20  through the first heat exchanger  6 , so that the working fluid is vaporized. The vaporized working fluid  21  is compressed within the between the compressor  22  and the control valve  24  (the second channel) by the functions of the compressor  22  and the control valve  24 , such that the pressure of the working fluid  21  is increased until its boiling point is slightly above the boiling point of the liquid  11  within the container  3 . A small portion of the working fluid within the second channel is condensed due to the pressurization and thus releases its latent heat. Such released latent heat is used for heating up the rest of the large portion of the uncondensed working fluid until its temperature reaches the temperature of increased boiling point (slightly above the boiling point of the liquid  11  within the container  3 ). The working fluid introduced into the condenser  26  is mainly vapor with a temperature slightly higher than the boiling point of the liquid  11  within the container  3 . The second heat exchanger  7  is disposed at the bottom of the container  3  and is in thermal contact with the container  3 , so that the heat energy can be conducted to the container  3  to vaporize the liquid  11  in the container through the second heat exchanger  7 , and the working fluid  21  is cooled so as to be condensed into liquid. The latent heat released by the working fluid  21  during condensation is absorbed by the liquid  11  as the latent heat of vaporation of the liquid  11 . Once the heat pump  5  is in function, the electric energy supplied to the heater  4  may be reduced properly to reduce the power consumption. The vapor  13  is condensed by the first heat exchanger  6  into liquid water  30  and flows out from an outlet  31 . The liquid water still contains high amount of heat, and can be stored in a storage  32  for other purposes such as washing. After being used for a period of time, the container  3  is inevitably contaminated by food residue. In this case, a user may take the whole container  3  out for washing to keep clean. 
         [0034]      FIG. 2  shows a structure of a second embodiment of a liquid heating apparatus according to the present invention. A steam cooking apparatus in a Chinese restaurant to steam food, such as seafood, is illustrated as an example below for explanation. 
         [0035]    As shown in  FIG. 2 , a steam cooking apparatus  41  includes a container  43 , a heater  44 , a heat pump  5 , a first heat exchanger  6 , a second heat exchanger  46 , and a vapor chamber  48 . The container  43  is used to accommodate clean water  45 , and a vapor chamber  48  is disposed above the container  43 . A support frame  49  is disposed between the vapor chamber  48  and the container  43 , and a switch door  51  or a drawer (not shown in the figure) is further disposed on a side wall of the vapor chamber  48 , so that a user can place food  52 , such as seafood, into the vapor chamber  48 , or withdraw food from the vapor chamber  48  through the switch door  51  or drawer. A heater  44  is provided at the bottom or periphery of the container  43  for heating the clean water  45  in the container  43  until boiling, so as to generate vapor  53  to steam the food  52  in the vapor chamber  48 . A pipeline  55  is disposed above the container  43 , so as to convey excessive vapor  53  to the first heat exchanger  6 , thereby performing heat exchange with working fluid  21  in an evaporator  20  of the heat pump  5 . The heat pump  5  includes an evaporator  20 , a compressor  22 , a control valve  24 , and a condenser  26 . In this embodiment, the structure and working process of the heat pump  5  are the same as those of the first embodiment shown in  FIG. 1 , and detailed descriptions thereof are omitted herein. The second heat exchanger  46  is disposed in the clean water  45  of the container  43 , and heat energy can be transmitted to the clean water  45  in the container  43  through the second heat exchanger  46 , so as to vaporize the clean water. The vapor  53  is condensed by the first heat exchanger  6  into water droplets and flows out from an outlet  31  as high-temperature clean water  57  and can be stored in a storage  59 . The storage  59  is in communication with the container  43  through a water pump  61  to reintroduce the high-temperature clean water  57  into the container  43 , thereby reducing water consumption and power consumption. 
         [0036]    The compressor in the present invention can recycle huge latent heat in vapor by minimal work done. By using the steam cooking apparatus in the second embodiment ( FIG. 2 ) as an example, the temperatures of the boiling clean water  45  and the vapor  53  are both 100° C., and in direct contact with the first heat exchanger  6  and the second heat exchanger  46  respectively, so that the working fluid (water) in the evaporator  20  and the condenser  26  passing through the first and second heat exchangers are naturally at 100° C. The compressor  22  only needs to slightly deviate the boiling point from 100° C., and the system can operate normally. For example, the boiling water of water under the pressure of 0.9 BAR is 96.71° C.; and the boiling water of water under the pressure of 1.2 BAR is 104.81° C. As such circumstance, the compressor  22  only needs to keep the pressures in the condenser  26  and the evaporator  20  respectively at 1.2 BAR and 0.9 BAR (that is, to maintain a pressure difference of 0.3 BAR). 
         [0037]    In this case, the temperature of the working fluid (mainly vapour) in the condenser  26  is 104.81° C., the working fluid passes through the second heat exchanger  46  and vaporizes the clean water  45  with a boiling point of 100° C. in the container  43 . The working fluid is thereby cooled below 104.81° C., and the working fluid is condensed into water under the pressure of 1.2 BAR so as to release latent heat thereof. The heat is absorbed by the clean water  45  to become latent heat of vaporation thereof. After passing through the second heat exchanger  46 , the working fluid is mainly liquid water at a temperature not less than 100° C., and then enters the evaporator  20  through the control valve  24 . Due to the function of the compressor  22 , the pressure in the evaporator  20  is only 0.9 BAR, and the boiling point of the water therein is 96.71° C., so that the liquid water at a temperature of not less than 100° C. is automatically boiled. A small portion of the liquid water is evaporated as vapor and absorbs latent heat from the rest of the liquid water not yet evaporated, such that the remaining liquid water is cooled to 96.71° C. The liquid water at 96.71° C. performs heat exchange with the vapor  53  at the temperature of 100° C. through the first heat exchanger  6 , so that the vapor  53  is cooled to be lower than 100° C. and is condensed into liquid water to release latent heat thereof. The heat is absorbed by the liquid water with a boiling point of 96.71° C. in the evaporator  20 , so as to vaporize the liquid water. The working fluid  21  (vapor) is then compressed by the compressor  22  to enter the next cycle after passing through the evaporator  20 . 
         [0038]    The present invention uses water as the working fluid of the heat pump. The volume of one kilogram vapor under the pressure of 0.9 BAR is 1.869 m 3 ; and the volume of one kilogram vapor under the pressure of 1.2 BAR is 1.428 m 3 . Therefore, in the above example, the work done by the compressor to recycle latent heat of vaporation (2250 KJ/KG) of one kilogram vapor during operation of the present invention is: 
         [0000]    
       
         
           
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         [0039]    That is, the energy consumption by the compressor is less than 1% of the recycled heat (2250 KJ), which is extremely high efficient. Compared with the prior art of a multi-source heat pump using a high-temperature high-pressure refrigerant, the present invention has the following advantages: 
         [0040]    (1) the compressor of the present invention operates under a low pressure, and compared with the prior art using a high-temperature high-pressure refrigerant, the present invention has obviously low requirements on the compressor, such as power, fluid tightness, and maintenance, and is relatively low-cost, energy-saving, and durable; 
         [0041]    (2) the present invention uses water as the working fluid, which is much cheaper than the high-temperature high-pressure refrigerant, and is more environmental friendly; and 
         [0042]    (3) the heat pump of the present invention uses a single heat source with highly centralized heat energy, so that the volume of the heat pump is smaller than the multi-source heat pump in the prior art. 
         [0043]      FIG. 3  to  FIG. 5  show a structure of a third embodiment of a liquid heating apparatus according to the present invention. A steaming apparatus in a Chinese restaurant to steam food, such as dim sum, is illustrated as an example for explanation. The steaming apparatus may also be used to steam other objects. 
         [0044]    As shown in  FIG. 3 , the steaming apparatus  14  includes a container  63 , a heater  44 , a heat pump  5 , a first heat exchanger  6 , a second heat exchanger  46 , one or more vessels  8  for accommodating steamed objects (such as desserts), and a top cover  89 . The container  63  is used to accommodate clean water  45 . The heater  44  is disposed at the bottom or periphery of the container for heating the clean water in the container  63  until boiling, so as to generate vapor  53 . The vessel  8  ( FIG. 4 ) is provided with a porous bottom plate  82 , a first cavity  88  with an upper opening  81  for accommodating steamed object  52 , and a second cavity  86  having an upper opening  84  and a lower opening  85 . Multiple vessels  8  may be stacked vertically as shown in  FIG. 5 , so that the first cavities  88 ( a ),  88 ( b ) and the second cavities  86 ( b ),  86 ( a ) of the vessels  8  ( 8   a  and  8   b ) in sealing communication with each other respectively. As shown in  FIG. 3 , the vapor  53  generated during boiling enters the first cavities  88 ( a ) and  88 ( b ) through the porous bottom plate  82  of the vessel  8 , so as to steam steamed objects  54  in the first cavities.  FIG. 3  merely shows two vessels  8 , but a user may stack more vessels accommodating steamed objects  54  during use to improve the efficiency of the steaming work. The vapor  53  is stopped by the top cover  89  at the topmost of the first cavity  88 ( b ), and introduced into the second cavities  86 ( b ) and  86 ( a ) to be fed into the first heat exchanger  6 , so as to perform heat exchange with a working fluid  21  in an evaporator  20  of the heat pump  5 . 
         [0045]    The heat pump  5  includes the evaporator  20 , a compressor  22 , a control valve  24 , and a condenser  26 . In this embodiment, the structure and working process of the heat pump  5  are the same as those of the first embodiment shown in  FIG. 1 , and detailed descriptions thereof are omitted herein. The second heat exchanger  46  is disposed in the clean water  45  of the container  63 , and heat energy can be transmitted to the clean water  45  in the container  63  through the second heat exchanger  46 , so as to vaporize the clean water. The vapor  53  is condensed by the first heat exchanger  6  into water droplets and flows out from an outlet  31  as high-temperature clean water  57 , and can be stored in a storage  59 . The storage  59  is in communication with the container  63  through a water pump  61  for reintroducing the high-temperature clean water  57  into the container  63 , thereby reducing water consumption and power consumption 
         [0046]    In the above example, a fluid conveyer  18  as illustrated in the first embodiment (not shown in the figure) may be disposed between the second cavity  86 ( a ) of the bottommost vessel  8  and the first heat exchanger  6  or between the first cavity  88 ( a ) of the bottommost vessel  8  and the container  63 , so as to accelerate flowing of the vapour. 
         [0047]      FIG. 6  shows a structure of a fourth embodiment of a liquid heating apparatus according to the present invention. A distilled water generating apparatus or a distilling apparatus is used as an example for description. 
         [0048]    As shown in  FIG. 6 , the distilled water generating apparatus  71  includes a container  73 , a heater  44 , a heat pump  5 , a first heat exchanger  6 , a second heat exchanger  46 , and a third heat exchanger  74 . The container  73  is used to accommodate hydrous liquid  75 . The heater  44  is disposed at the bottom or periphery of the container  73  for heating the hydrous liquid  75  in the container  73  until boiling, so as to generate vapor  77 . A pipeline  55  is disposed above the container  73  for introducing the vapor  77  in to the first heat exchanger  6 , so as to perform heat exchange with a working fluid  21  in an evaporator  20  of the heat pump  5 . The heat pump  5  includes the evaporator  20 , a compressor  22 , a control valve  24 , and a condenser  26 . In this embodiment, the structure and working process of the heat pump  5  are the same as those of the first embodiment shown in  FIG. 1 , and detailed descriptions thereof are omitted herein. The second heat exchanger  46  is disposed in the hydrous liquid  75  of the container  73 , and heat energy is transmitted to the hydrous liquid  75  in the container  73  through the second heat exchanger  46 , so as to vaporize the hydrous liquid. Hot distilled water  79  condensed at the first heat exchanger  6  still contains high heat energy, and is then introduced into the third heat exchanger  74 , so as to perform heat exchange with a liquid  83  having the same composition as the hydrous liquid  75  in the container  73 . The cooled distilled water  85  flows out from outlet  86 , and is stored in a storage  32  as back up. The liquid  83  heated up in the third heat exchanger  74  is injected into the container  73  through the pipeline  87  to serve as pre-heated distilling liquid, thereby reducing the power consumption of the heater  44 . 
         [0049]    In the above embodiment, for illustrative purpose, both the liquid and the working fluid could bewater. However, it should be understood that the present invention is not limited thereto. 
         [0050]      FIG. 7  shows a structure of a fifth embodiment of a liquid heating apparatus according to the present invention. A generating apparatus is used as an example for description. 
         [0051]    As shown in  FIG. 7 , a generating apparatus  91  includes a container  73 , a heater  72 , a heat pump  5 , a first heat exchanger  6 , a second heat exchanger  46 , and a generator  93 . The container  73  is used to accommodate liquid  95 , a pipeline  96  is disposed above the container  73 , and the generator  93  is disposed in the middle of the pipeline  96 . The heater  72  heats the liquid  95  in the container  73  until boiling to generate vapor  77 . The vapor  77  is introduced through the pipeline  96  and pushes the generator (for example, a turbine)  93  to generate electric power or drive another apparatus. The vapor  77  enters the first heat exchanger  6  through the generator  93 , so as to perform heat exchange with a working fluid  21  in an evaporator  20  of the heat pump  5 . The heat pump  5  includes the evaporator  20 , a compressor  22 , a control valve  24 , and a condenser  26 . In this embodiment, the structure and working process of the heat pump  5  are approximately identical to the first embodiment shown in  FIG. 1 , and detailed descriptions thereof are omitted herein. The second heat exchanger  46  is disposed in the liquid  95  of the container  73 , and heat energy is transmitted to the liquid  79  in the container  73  through the second heat exchanger  46 , so as to vaporize the liquid. The working fluid  21  in the heat pump  5  is water, and the liquid  95  in the container  73  may be a liquid with much less latent heat of vaporation than that of water, such as alcohol propyl. By using alcohol propyl as an example, the boiling point of the alcohol propyl is similar to that of water, that is, about 97° C.; however, the latent heat of vaporation of the alcohol propyl is only 779 KJ/Kg, which is about 35% of the latent heat of water being 2250 KJ/Kg. Therefore, vaporization of every 35-kilogram water in the evaporator  20  can absorb latent heat released by condensation of 100 kilograms alcohol propyl vapour, which greatly reduces the work load of the heat pump  5 , and increases the overall efficiency of the generating apparatus  91 . The alcohol propyl vapor  77  is condensed into liquid alcohol propyl  98  in the first heat exchanger  6  and stored in the storage  59  while the liquid alcohol propyl  98  still remains with a high temperature. The storage  59  is in communication with the container  73  through a pump  61 , so as to reintroduce the high-temperature liquid alcohol propyl  98  into the container  73 , thereby reducing the consumption of alcohol propyl as well as power consumption.