Patent Publication Number: US-2018031272-A1

Title: Ptc heater for liquid heating

Description:
CROSS REFERENCE 
     This application claims the benefit and priority of Chinese Application No. 201620804786.7, filed Jul. 28, 2016. The entire disclosures of each of the above applications are incorporated herein by reference. 
     FIELD OF THE INVENTION 
     The present disclosure relates to a heater, particularly to a PTC heater for liquid heating. 
     BACKGROUND 
     Currently, PTC (Positive Temperature Coefficient) heaters have been widely applied in household appliances, such as SPA pools, entertainment pools, water dispensers, foot baths, and other industrial products. 
     One type of common PTC heaters in the prior art may include a heat conductor and a PTC heating element. A plurality of ducts is provided within the heat conductor. Some of the ducts are used for placing PTC heating elements while some of the ducts are used for liquid passage. 
     The heat conductors for some of the PTC heaters employ metal materials without an anti-corrosion treatment, which are prone to corrosion after long-term use. When the water is with chemical substances such as oxidizing disinfectants, the oxidation and corrosion of the heat conductor will be accelerated to cause the leakage of liquid easily from the ducts inside the heat conductor. It is an increase in the risk of safety. 
     SUMMARY 
     A technical problem to be solved by the present disclosure is to provide a PTC heater for liquid heating in order to overcome the defect that the PTC heaters in the prior art are prone to corrosion during long-term use. 
     The above-mentioned technical problems are solved in the present disclosure by the following technical solution: 
     a PTC (Positive Temperature Coefficient) heater for liquid heating may include: 
     a heat conductor including at least one first accommodating duct and at least one second accommodating duct; 
     a PTC heating assembly at least partially disposed in the first accommodating duct; and 
     at least one water pipe assembly at least partially disposed in the second accommodating duct, with an outer surface of the water pipe assembly at least partially abutting against an inner surface of the second accommodating duct. 
     Preferably, the first and second accommodating ducts are disposed in parallel. 
     Preferably, the first accommodating duct is disposed between at least two second accommodating ducts. 
     Preferably, the heat conductor is a material of an aluminum alloy. 
     Preferably, the water pipe assembly is a material of a corrosion-resistant heat-conducting material. 
     Preferably, the water pipe assembly is a material of one of stainless steel, stainless iron and copper. 
     Preferably, the water pipe assembly may include at least one water inlet pipe and at least one water outlet pipe, at least one of ends of the water inlet pipe extends out of the second accommodating duct, and at least one of ends of the water outlet pipe extends out of the second accommodating duct. 
     Preferably, the PTC heater may further include a water inlet portion, the water inlet portion includes a water inlet duct, the water inlet portion is connected to a first end of the water inlet pipe, and the water inlet duct is in communication with the water inlet pipe. 
     Preferably, the first end of the water inlet pipe is disposed inside the water inlet duct of the water inlet portion. 
     Preferably, the water inlet portion is connected to a first end of the heat conductor. 
     Preferably, a seal is disposed between an outer surface of the first end of the water inlet pipe and an inner surface of the water inlet duct of the water inlet portion. 
     Preferably, a seal is disposed between an end face of the water inlet portion and an end face of the first end of the heat conductor. 
     Preferably, the PTC heater for liquid heating may further include a water outlet portion, the water outlet portion includes a water outlet duct, the water outlet portion is connected to a first end of the water outlet pipe, and the water outlet duct of the water outlet portion is in fluid communication with the water outlet pipe. 
     Preferably, the first end of the water outlet pipe is disposed inside the water outlet duct of the water outlet portion. 
     Preferably, the water outlet portion is connected to a first end of the heat conductor. 
     Preferably, a seal is disposed between an outer surface of the first end of the water outlet pipe and an inner surface of the water outlet duct of the water outlet portion. 
     Preferably, a seal is disposed between an end face of the water outlet portion and an end face of the first end of the heat conductor. 
     Preferably, the PTC heater for liquid heating may further include a connecting portion, the connecting portion includes a water flow duct, the connecting portion is connected to a second end of the water inlet pipe and a second end of the water outlet pipe respectively, and the water flow duct is in fluid communication with the water inlet pipe and the water outlet duct. 
     Preferably, the connecting portion is connected to a second end of the heat conductor, the second end of the water inlet pipe and the second end of the water outlet pipe being disposed inside the water flow duct of the connecting portion. 
     Preferably, the connecting portion is connected to the second end of the heat conductor. 
     Preferably, a seal is disposed between an outer surface of the second end of the water inlet pipe and an inner surface of the water flow duct of the connecting portion, and a seal is disposed between an outer surface of the second end of the water outlet pipe and an inner surface of the water flow duct of the connecting portion. 
     Preferably, a seal is disposed between an end face of the connecting portion and an end face of the heat conductor. 
     Preferably, the water pipe assembly may include at least one U-shaped water pipe at least partially disposed in the second accommodating duct. 
     Preferably, the PTC heater for liquid heating may further include a water inlet portion, the water inlet portion includes a water inlet duct, the water inlet portion is connected to a first end of the U-shaped water pipe, and the water inlet portion is in fluid communication with the U-shaped water pipe. 
     Preferably, the first end of the U-shaped water pipe is disposed inside the water inlet duct of the water inlet portion. 
     Preferably, the water inlet portion is connected to a first end of the heat conductor. 
     Preferably, a seal is disposed between an outer surface of the first end of the U-shaped water pipe and an inner surface of the water inlet duct of the water inlet portion. 
     Preferably, a seal is disposed between an end face of the water inlet portion and an end face of the first end of the heat conductor. 
     Preferably, the PTC heater for liquid heating may further include a water outlet portion, the water outlet portion includes a water outlet duct, the water outlet portion is connected to a second end of the U-shaped water pipe, and the water outlet duct of the water outlet portion is in fluid communication with the U-shaped water pipe. 
     Preferably, the second end of the U-shaped water pipe is disposed inside the water outlet duct of the water outlet portion. 
     Preferably, the water outlet portion is connected to a first end of the heat conductor. 
     Preferably, a seal is disposed between an outer surface of the second end of the U-shaped water pipe and an inner surface of the water outlet duct of the water outlet portion. 
     Preferably, a seal is provided between an end face of the water outlet portion and an end face of the first end of the heat conductor. 
     Preferably, the heat conductor is an integrally formed component, and the integrally formed component is a one-piece metal alloy shell. 
     Preferably, the heat conductor may include: 
     a first component, the first component including the first accommodating duct and a first groove disposed on an outer surface of the first component, and 
     a second component detachably connected to the first component, the second component including a second groove, the second groove corresponding to the first groove; 
     wherein the first component is connected to the second component, the second groove is in combination with the first grooves to be configured to the second accommodating duct, and the water pipe assembly is disposed in the second accommodating ducts. 
     Preferably, the first and second grooves are profiled grooves. 
     Preferably, the water pipe assembly may include a profiled water pipe fastened to the second accommodating duct. 
     The positive progressive effects of the present disclosure lie in: 
     the PTC liquid heating tube of the present disclosure can achieve a better corrosion resistance, greatly extend the service life of the PTC heater and prevent electric leakage accidents. Furthermore, the PTC heater for liquid heating of the present disclosure has a simple structure and low costs, and is convenient to assemble, especially in the replacement of the water pipes for maintaining the PTC heater in future. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above-mentioned and other features, characteristics and advantages of the present disclosure will be more apparent from the following description taken in conjunction with the accompanying drawings and embodiments, and in the accompanying drawings, like reference numbers indicate like features, in which: 
         FIG. 1  is a first structural schematic view of a first embodiment of a PTC heater for liquid heating of the present disclosure. 
         FIG. 2  is a second structural schematic view of the first embodiment of the PTC heater for liquid heating of the present disclosure. 
         FIG. 3  is a third structural schematic view of the first embodiment of the PTC heater for liquid heating of the present disclosure. 
         FIG. 4  is a longitudinal sectional view of the first embodiment of the PTC heater for liquid heating of the present disclosure. 
         FIG. 5  is an exploded view of the first embodiment of the PTC heater for liquid heating of the present disclosure. 
         FIG. 6  is a first structural schematic view of a second embodiment of the PTC heater for liquid heating of the present disclosure. 
         FIG. 7  is a second structural schematic view of the second embodiment of the PTC heater for liquid heating of the present disclosure. 
         FIG. 8  is a third structural schematic view of the second embodiment of the PTC heater for liquid heating of the present disclosure. 
         FIG. 9  is a longitudinal sectional view of the second embodiment of the PTC heater for liquid heating of the present disclosure. 
         FIG. 10  is an exploded view of the second embodiment of the PTC heater for liquid heating of the present disclosure. 
         FIG. 11  is a first structural schematic view of a third embodiment of the PTC liquid heater of the present disclosure. 
         FIG. 12  is a second structural schematic view of a third embodiment of the PTC heater for liquid heating of the present disclosure. 
         FIG. 13  is a third structural schematic view of the third embodiment of the PTC heater for liquid heating of the present disclosure. 
         FIG. 14  is a longitudinal sectional view of the third embodiment of the PTC heater for liquid heating of the present disclosure. 
         FIG. 15  is an exploded view of the third embodiment of the PTC heater for liquid heating of the present disclosure. 
         FIG. 16  is a first structural schematic view of a fourth embodiment of the PTC heater for liquid heating of the present disclosure. 
         FIG. 17  is a second structural schematic view of the fourth embodiment of the PTC heater for liquid heating of the present disclosure. 
         FIG. 18  is a third structural schematic view of the fourth embodiment of the PTC heater for liquid heating of the present disclosure. 
         FIG. 19  is a longitudinal sectional view of the fourth embodiment of the PTC heater for liquid heating of the present disclosure. 
         FIG. 20  is an exploded view of the fourth embodiment of the PTC heater for liquid heating of the present disclosure. 
         FIG. 21  is a first structural schematic view of a fifth embodiment of the PTC heater for liquid heating of the present disclosure. 
         FIG. 22  is a second structural schematic view of the fifth embodiment of the PTC heater for liquid heating of the present disclosure. 
         FIG. 23  is a third structural schematic view of the fifth embodiment of the PTC heater for liquid heating of the present disclosure. 
         FIG. 24  is a longitudinal sectional view of the fifth embodiment of the PTC heater for liquid heating of the present disclosure. 
         FIG. 25  is an exploded view of the fifth embodiment of the PTC heater for liquid heating of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     To make the above-mentioned object, features and advantages of the present disclosure apparent and easily understood, a detailed description of particular embodiments of the present disclosure is made in conjunction with the drawings. 
     Embodiments of the present disclosure will now be described in detail with reference to the accompanying drawings. Reference now will be made in detail to preferred embodiments of the present disclosure, examples of which are illustrated in the accompanying drawings. The same reference numerals in all the figures denote the same or similar parts wherever possible. Furthermore, although the terms used in the present disclosure are selected from well-known common terms, some of the terms mentioned in the description of the present disclosure may be selected by the applicant according to his or her judgement, and the detailed meaning thereof is described in the relevant section described herein. Furthermore, the present disclosure must be understood, not simply by the actual terms used but also by the meanings encompassed by each term. 
     First Embodiment 
       FIG. 1  is a first structural schematic view of a first embodiment of a PTC heater for liquid heating of the present disclosure.  FIG. 2  is a second structural schematic view of the first embodiment of the PTC heater for liquid heating of the present disclosure.  FIG. 3  is a third structural schematic view of the first embodiment of the PTC heater for liquid heating of the present disclosure.  FIG. 4  is a longitudinal sectional view of the first embodiment of the PTC heater for liquid heating of the present disclosure.  FIG. 5  is an exploded view of the first embodiment of the PTC heater for liquid heating of the present disclosure. 
     As shown in  FIGS. 1-5 , the present disclosure discloses a PTC heater for liquid heating  10 , which may include a heat conductor  11 , a PTC heating assembly  12  and at least one water pipe assembly  13 . The heat conductor  11  is provided with at least one first accommodating duct and at least one second accommodating duct, the PTC heating assembly  12  is at least partially provided in the first accommodating duct, the water pipe assembly  13  is at least partially provided in the second accommodating duct, and an outer surface of the water pipe assembly  13  at least partially abuts against an inner surface of the second accommodating duct. The first and second accommodating ducts are disposed in parallel. Particularly, the first accommodating duct is disposed between the second accommodating ducts. 
     The PTC heating assembly  12  can include a PTC heating element, a first electrode, a second electrode, a first protection layer, a second protection layer, a first interlayer, and a second interlayer. The PTC heating element has a first side and a second side. The first electrode and the second electrode can be positioned on the first side of the PTC heating element and the second side of the PTC heating element respectively. The first insulating interlayer can be located between the first protection layer and the first electrode. The second insulating interlayer can be located between the second protection layer and the second electrode. The first protection layer and the second protection layer can have a greater hardness in comparison with the first and second insulating interlayer. 
     Moreover, the PTC heating assembly  12  can further include a heat conductive housing. The first interlayer and second insulating interlayer are placed into the heat conductive housing. A first side wall and a second side wall of the heat conductive housing are inwardly curved. 
     Preferably, the heat conductor  11  may include a component  111  and a second component  112 . The first component  111  is disposed with the first accommodating duct  113  and a first groove  114  which is disposed at an outer surface of the first component  111 , the second component  112  is detachably connected to the first component  111 , and the second component  112  is disposed with a second groove  115  corresponding to the first groove  114 . When the first component  111  is connected to the second component  112 , the second groove  115  and the first groove  114  are combined to form the second accommodating duct, and the water pipe assembly  13  may be disposed in the second accommodating duct. 
     Of course, the first groove  114  and the second groove  115  herein may also be profiled grooves, and the water pipe assembly  13  can include a profiled water pipe fastened to the second accommodating duct accordingly. Because of the combination of the first groove  114  and the second groove  115  to configure to the second accommodating duct, the type of the second accommodating duct can be particular corresponding with the type of the profiled groove in accordance with the configuration of first groove  114  and second groove  115 . The type of the profiled groove can be the S-shaped groove, U-shaped groove, or other specific shape of the groove. Moreover, the shape of the profiled water pipe can be matched with the type of profiled groove to achieve the assembling of pipe being disposed inside the heat conductor  11 . 
     Further, the water pipe assembly  13  in this embodiment may include at least one U-shaped water pipe  131 , and the U-shaped water pipe  131  is at least partially disposed in the second accommodating ducts. 
     Preferably, the PTC heater for liquid heating  10  may further include a water inlet portion  14 , and the water inlet portion  14  is provided with a water inlet duct  141 . The water inlet portion  14  is connected to a first end of the U-shaped water pipe  131 , and the water inlet portion  141  is in communication with the U-shaped water pipe  131 . For example, the first end of the U-shaped water pipe  131  is disposed in the water inlet duct  141  of the water inlet portion  14 , such that the water inlet portion is connected to the first end of the heat conductor  11 . Seals  142  are disposed both between an outer surface of the first end of the U-shaped water pipe  131  and an inner surface of the water inlet duct  141  of the water inlet portion  14 , and between an end face of the water inlet portion  14  and an end face of the first end of the heat conductor  11 . 
     Further, the ITC heater for liquid heating  10  may further include a water outlet portion  15 , and the water outlet portion  15  is provided with a water outlet duct  151 , wherein the water outlet portion  15  is connected to a second end of the U-shaped water pipe  131 , and the water outlet duct  151  of the water outlet portion  15  is in communication with the U-shaped water pipe  131 . For example, the second end of the U-shaped water pipe  131  is disposed in the water outlet duct  151  of the water outlet portion  15 , such that the water outlet portion  15  is connected to the first end of the heat conductor  11 . Seals  152  are disposed both between an outer surface of the second end of the U-shaped water pipe  131  and an inner surface of the water outlet duct  151  of the water outlet portion  15 , and between an end face of the water outlet portion  15  and the end face of the first end of the heat conductor  11 . 
     Of course, the material of the heat conductor  11  in this embodiment may preferably be an aluminum alloy. The material of the water pipe assembly  13  may preferably be a corrosion-resistant heat-conducting material, such as one of stainless steel, stainless iron or copper. 
     Second Embodiment 
       FIG. 6  is a first structural schematic view of a second embodiment of the PTC heater for liquid heating of the present disclosure.  FIG. 7  is a second structural schematic view of the second embodiment of the PTC heater for liquid heating of the present disclosure.  FIG. 8  is a third structural schematic view of the second embodiment of the PTC heater for liquid heating of the present disclosure.  FIG. 9  is a longitudinal sectional view of the second embodiment of the PTC heater for liquid heating of the present disclosure.  FIG. 10  is an exploded view of the second embodiment of the PTC heater for liquid heating of the present disclosure. 
     As shown in  FIGS. 6-10 , the present disclosure discloses another PTC heater for liquid heating  20 , which may include a heat conductor  21 , a PTC heating assembly  22  and at least one water pipe assembly  23 . The heat conductor  21  in this embodiment is made of an integrally formed component. Particularly, the heat conductor  21  is provided with a first accommodating duct  211  and second accommodating ducts  212 , the PTC heating assembly  22  is at least partially disposed in the first accommodating duct  211 , the water pipe assembly  23  is at least partially disposed in the second accommodating duct  212 , and an outer surface of the water pipe assembly  23  at least partially abuts against an inner surface of the second accommodating duct  212 . The first accommodating duct  211  and the second accommodating ducts  212  are disposed in parallel. Particularly, the first accommodating duct  211  is disposed between the second accommodating ducts  212 . 
     Further, the water pipe assembly  23  in this embodiment may include at least one U-shaped water pipe which is at least partially disposed in the second accommodating ducts  212 . 
     Preferably, the PTC heater for liquid heating  20  may further include a water inlet portion  24 , and the water inlet portion  24  is provided with a water inlet duct  241 . The water inlet portion  24  is connected to a first end of the U-shaped water pipe  231 , and the water inlet portion  241  is in communication with the U-shaped water pipe  231 . For example, the first end of the U-shaped water pipe  231  is disposed in the water inlet duct  241  of the water inlet portion  24 , such that the water inlet portion is connected to the first end of the heat conductor  21 . Seals  242  are disposed both between an outer surface of the first end of the U-shaped water pipe  231  and an inner surface of the water inlet duct  241  of the water inlet portion  24 , and between an end face of the water inlet portion  24  and an end face of the first end of the heat conductor  21 . 
     Further, the PTC heater for liquid heating  20  may further include a water outlet portion  25 , and the water outlet portion  25  is provided with a water outlet duct  251 , wherein the water outlet portion  25  is connected to a second end of the U-shaped water pipe  231 , and the water outlet duct  251  of the water outlet portion  25  is in communication with the U-shaped water pipe  231 . For example, the second end of the U-shaped water pipe  231  is disposed in the water outlet duct  251  of the water outlet portion  25 , such that the water outlet portion  25  is connected to the first end of the heat conductor  21 . Seals  252  are disposed both between an outer surface of the second end of the U-shaped water pipe  231  and an inner surface of the water outlet duct  251  of the water outlet portion  25 , and between an end face of the water outlet portion  25  and the end face of the first end of the heat conductor  21 . 
     Of course, the material of the heat conductor  21  in this embodiment may preferably be an aluminum alloy. The material of the water pipe assembly  23  may preferably be a corrosion-resistant heat-conducting material, such as one of stainless steel, stainless iron or copper. 
     Third Embodiment 
       FIG. 11  is a first structural schematic view of a third embodiment of the PTC heater for liquid heating of the present disclosure.  FIG. 12  is a second structural schematic view of a third embodiment of the PTC beater for liquid heating of the present disclosure.  FIG. 13  is a third structural schematic view of the third embodiment of the PTC heater for liquid heating of the present disclosure.  FIG. 14  is a longitudinal sectional view of the third embodiment of the PTC heater for liquid heating of the present disclosure.  FIG. 15  is an exploded view of the third embodiment of the PTC heater for liquid heating of the present disclosure. 
     As shown in  FIGS. 11-15 , the present disclosure still discloses a PTC heater for liquid heating  30 , which may include a heat conductor  31 , a PTC heating assembly  32  and at least one water pipe assembly  33 . The heat conductor  31  is provided with first and second accommodating ducts, the PTC heating assembly  32  is at least partially disposed in the first accommodating duct, the water pipe assembly  33  is at least partially disposed in the second accommodating duct, and an outer surface of the water pipe assembly  33  at least partially abuts against an inner surface of the second accommodating duct. The first and second accommodating ducts are disposed in parallel. Particularly, the first accommodating duct is disposed between the second accommodating ducts. 
     Preferably, the heat conductor  31  may include a first component  311  and a second component  312 . The first component  311  is provided with the first accommodating duct  313  and a first groove  314  which is disposed at an outer surface of the first component  311 , the second component  312  is detachably connected to the first component  311 , and the second component  312  is provided with a second groove  315  corresponding to the first groove  314 . When the first component  311  is connected to the second component  312 , the second groove  315  and the first groove  314  are combined to form the second accommodating duct, and the water pipe assembly  33  may be disposed in the second accommodating duct. 
     Of course, the first groove  314  and the second groove  315  herein may also be profiled grooves, and the water pipe assembly  33  can include a profiled water pipe fastened to the second accommodating duct accordingly. Because of the combination of the first groove  314  and the second groove  315  to configure to the second accommodating duct, the type of the second accommodating duct can be particular corresponding with the type of the profiled groove in accordance with the configuration of first groove  314  and second groove  315 . The type of the profiled groove can be the S-shaped groove, U-shaped groove, or other specific shape of the groove. Moreover, the shape of the profiled water pipe can be matched with the type of profiled groove to achieve the assembling of pipe being disposed inside the heat conductor  31 . 
     Further, the water pipe assembly  33  in this embodiment may include at least one water inlet pipe  331  and at least one water outlet pipe  332 . At least one end of the water inlet pipe  331  and at least one end of the water outlet pipe  332  extend out of the second accommodating duct. 
     Moreover, the water pipe assembly  33  in the PTC heater for liquid heating  30  may further include a connecting portion  333 , the connecting portion  333  is provided with a water flow duct, the connecting portion  333  is connected to a second end of the water inlet pipe  331  and a second end of the water outlet pipe  332  respectively, and the water flow duct is in communication with the water inlet pipe  331  and the water outlet duct  332 . Seals  334  are disposed between an outer surface of the second end of the water inlet pipe  331  and an inner surface of the water flow duct of the connecting portion  333 , and between an outer surface of the second end of the water outlet pipe  332  and an inner surface of the water flow duct of the connecting portion  333 . A seal  334  may also be disposed between an end face of the connecting portion  333  and an end face of the heat conductor  31 . 
     Preferably, the PTC heater for liquid heating  30  may further include a water inlet portion  34 , and the water inlet portion  34  is provided with a water inlet duct  341 . The water inlet portion  34  is connected to a first end of the water inlet pipe  331 , and the water inlet duct  341  is in communication with the water inlet pipe  331 . For example, the first end of the water inlet pipe  331  is disposed in the water inlet duct  341  of the water inlet portion  34 , such that the water inlet portion  34  is connected to the first end of the heat conductor  11 . Seals  342  are disposed both between an outer surface of the first end of the water inlet pipe  331  and an inner surface of the water inlet duct  341  of the water inlet portion  34 , and between an end face of the water inlet portion  34  and an end face of the first end of the heat conductor  31 . 
     Further, the PTC heater for liquid heating  30  may further include a water outlet portion  35 , and the water outlet portion  35  is provided with a water outlet duct  351 , wherein the water outlet portion  35  is connected to the first end of the water inlet pipe  332 , and the water outlet duct  351  of the water outlet portion  35  is in communication with the water outlet pipe  332 . For example, the first end of the water outlet pipe  332  is disposed in the water outlet duct  351  of the water outlet portion  35 , such that the water outlet portion  35  is connected to the first end of the heat conductor  31 . Seals  352  are disposed both between an outer surface of the first end of the water outlet pipe  332  and an inner surface of the water outlet duct  351  of the water outlet portion  35 , and between an end face of the water outlet portion  35  and the end face of the first end of the heat conductor  31 . 
     Of course, the material of the heat conductor  31  in this embodiment may preferably be an aluminum alloy. The material of the water pipe assembly  33  may preferably be a corrosion-resistant heat-conducting material, such as one of stainless steel, stainless iron or copper. 
     Fourth Embodiment 
       FIG. 16  is a first structural schematic view of a fourth embodiment of the PTC heater for liquid heating of the present disclosure.  FIG. 17  is a second structural schematic view of the fourth embodiment of the PTC heater for liquid heating of the present disclosure.  FIG. 18  is a third structural schematic view of the fourth embodiment of the PTC heater for liquid heating of the present disclosure.  FIG. 19  is a longitudinal sectional view of the fourth embodiment of the PTC heater for liquid heating of the present disclosure.  FIG. 20  is an exploded view of the fourth embodiment of the PTC heater for liquid heating of the present disclosure. 
     As shown in  FIGS. 16-20 , the present disclosure discloses yet another PTC heater for liquid heating  40 , which may include a heat conductor  41 , a PTC heating assembly  42  and at least one water pipe assembly  43 . The heat conductor  41  in this embodiment is made of an integrally formed component. Particularly, the heat conductor  41  is provided with a first accommodating duct  411  and second accommodating ducts  412 , the PTC heating assembly  42  is at least partially disposed in the first accommodating duct  411 , the water pipe assembly  43  is at least partially disposed in the second accommodating duct  412 , and an outer surface of the water pipe assembly  43  at least partially abuts against an inner surface of the second accommodating duct  412 . The first accommodating duct  411  and the second accommodating ducts  412  are disposed in parallel. Particularly, the first accommodating duct  411  is disposed between the second accommodating ducts  412 . 
     Further, the water pipe assembly  43  in this embodiment may include at least one water inlet pipe  431  and at least one water outlet pipe  432 . At least one end of the water inlet pipe  431  and at least one end of the water outlet pipe  432  extend out of the second accommodating duct  412 . 
     Moreover, the water pipe assembly  43  in the PTC heater for liquid heating  40  may further include a connecting portion  433 , the connecting portion  433  is provided with a water flow duct, the connecting portion  433  is connected to a second end of the water inlet pipe  431  and a second end of the water outlet pipe  432  respectively, and the water flow duct is in communication with the water inlet pipe  431  and the water outlet duct  432 . Seals  434  are disposed both between a surface of the second end of the water inlet pipe  431  and an inner surface of the water flow duct of the connecting portion  433 , and between the second end of the water outlet pipe  432  and an inner surface of the water flow duct of the connecting portion  433 , and may be also disposed between an end face of the connecting portion  433  and an end face of the heat conductor  41 . 
     Preferably, the PTC heater for liquid heating  40  may further include a water inlet portion  44 , and the water inlet portion  44  is provided with a water inlet duct  441 . The water inlet portion  44  is connected to a first end of the water inlet pipe  431 , and the water inlet duct  441  is in communication with the water inlet pipe  431 . For example, the first end of the water inlet pipe  431  is disposed in the water inlet duct  441  of the water inlet portion  44 , such that the water inlet portion  44  is connected to the first end of the heat conductor  41 . Seals  442  are disposed both between an outer surface of the first end of the water inlet pipe  431  and an inner surface of the water inlet duct  441  of the water inlet portion  44 , and between an end face of the water inlet portion  44  and an end face of the first end of the heat conductor  41 . 
     Further, the PTC heater for liquid heating  40  may further include a water outlet portion  45 , and the water outlet portion  45  is provided with a water outlet duct  451 , wherein the water outlet portion  45  is connected to the first end of the water inlet pipe  432 , and the water outlet duct  451  of the water outlet portion  45  is in communication with the water outlet pipe  432 . For example, the first end of the water outlet pipe  432  is disposed in the water outlet duct  451  of the water outlet portion  45 , such that the water outlet portion  45  is connected to the first end of the heat conductor  41 . Seals  452  are disposed both between an outer surface of the first end of the water outlet pipe  432  and an inner surface of the water outlet duct  451  of the water outlet portion  45 , and between an end face of the water outlet portion  45  and the end face of the first end of the heat conductor  41 . 
     Of course, the material of the heat conductor  41  in this embodiment may preferably be an aluminum alloy. The material of the water pipe assembly  43  may preferably be a corrosion-resistant heat-conducting material, such as one of stainless steel, stainless iron or copper. 
     Fifth Embodiment 
       FIG. 21  is a first structural schematic view of a fifth embodiment of the PTC heater for liquid heating of the present disclosure.  FIG. 22  is a second structural schematic view of the fifth embodiment of the PTC heater for liquid heating of the present disclosure.  FIG. 23  is a third structural schematic view of the fifth embodiment of the PTC heater for liquid heating of the present disclosure.  FIG. 24  is a longitudinal sectional view of the fifth embodiment of the PTC heater for liquid heating of the present disclosure.  FIG. 25  is an exploded view of the fifth embodiment of the PTC heater for liquid heating of the present disclosure. 
     As shown in  FIGS. 21-25 , the present disclosure discloses another PTC heater for liquid heating  50 , which may include a heat conductor  51 , a PTC heating assembly  52  and at least one water pipe assembly  53 . The heat conductor  51  in this embodiment is made of an integrally formed component. Particularly, the heat conductor  51  is provided with a first accommodating duct  511  and second accommodating ducts  512 , the PTC heating assembly  52  is at least partially disposed in the first accommodating duct  511 , the water pipe assembly  53  is at least partially disposed in the second accommodating duct  512 , and an outer surface of the water pipe assembly  53  at least partially abuts against an inner surface of the second accommodating duct  512 . The first accommodating duct  511  and the second accommodating ducts  512  are disposed in parallel. Particularly, the first accommodating duct  511  is disposed between the second accommodating ducts  512 . 
     Further, the water pipe assembly  53  in this embodiment may include at least one water inlet pipe  531  and a plurality of water outlet pipes  532 . At least one end of the water inlet pipe  531  and at least one end of the water outlet pipes  532  extend out of the second accommodating duct  512 . 
     Moreover, the water pipe assembly  53  in the PTC heater for liquid heating  50  may further include a connecting portion  533 , the connecting portion  533  is provided with a water flow duct, the connecting portion  533  is connected to a second end of the water inlet pipe  531  and a second end of each water outlet pipe  532  respectively, and the water flow duct is in communication with the water inlet pipe  531  and the water outlet duct  532 . Seals  534  are disposed both between an outer surface of the second end of the water inlet pipe  531  and an inner surface of the water flow duct of the connecting portion  533 , and between an end face of the connecting portion  533  and an end face of the heat conductor  51 . 
     Preferably, the PTC heater for liquid heating  50  may further include a water inlet portion  54 , and the water inlet portion  54  is provided with a water inlet duct  541 . The water inlet portion  54  is connected to a first end of the water inlet pipe  531 , and the water inlet duct  541  is in communication with the water inlet pipe  531 . For example, the first end of the water inlet pipe  531  is disposed in the water inlet duct  541  of the water inlet portion  54 , such that the water inlet portion  54  is connected to the first end of the heat conductor  51 . Seals  56  are disposed both between an outer surface of the first end of the water inlet pipe  531  and an inner surface of the water inlet duct  541  of the water inlet portion  54 , and between an end face of the water inlet portion  54  and an end face of the first end of the heat conductor  51 . 
     Further, the PTC heater for liquid heating  50  may further include a water outlet portion  55 , and the water outlet portion  55  is provided with a water outlet duct  551 , wherein the water outlet portion  55  is connected to the first end of the water inlet pipe  532 , and the water outlet duct  551  of the water outlet portion  55  is in communication with the water outlet pipe  532 . For example, the first end of the water outlet pipe  532  is disposed in the water outlet duct  551  of the water outlet portion  55 , such that the water outlet portion  55  is connected to the first end of the heat conductor  51 . Seals  56  are disposed both between an outer surface of the first end of the water outlet pipe  532  and an inner surface of the water outlet duct  551  of the water outlet portion  55 , and between an end face of the water outlet portion  55  and the end face of the first end of the heat conductor  51 . 
     Preferably, in this embodiment, for convenience of production, both the water inlet portion  54  and the water outlet portion  55  may be integrally formed. 
     Of course, the material of the heat conductor  51  in this embodiment may preferably be an aluminum alloy. The material of the water pipe assembly  53  may preferably be a corrosion-resistant heat-conducting material, such as one of stainless steel, stainless iron or copper. 
     As mentioned previously, the PTC heater for liquid heating can include the heat conductor having one first accommodating duct arranged in one side, and one second accommodating duct arrange in another side for holding the PTC heating assembly and water pipe assembly, respectively. Additionally, the heat conductor may be a type of configuration having a plurality of first accommodating ducts and second accommodating ducts forming a plurality of holding chambers the PTC heating assemblies and water pipe assemblies are arranged inside the holding chambers. 
     In summary, the PTC liquid heating tube of the present disclosure can achieve a better corrosion resistance, greatly extend the service life of the PTC heater and prevent electric leakage accidents. Furthermore, the PTC heater for liquid heating of the present disclosure has a simple structure and low costs, and is convenient to assemble, especially in the replacement of the water pipes for maintaining the PTC heater in future. 
     While the particular embodiments of the present disclosure have been described, a person skilled in the art should understand that these are merely illustrative, and that the scope of protection of the present disclosure is defined by the appended claims. Various alterations or modifications can be made by a person skilled in the art to these embodiments without departing from the principle and substance of the present disclosure; however, these alterations and modifications all fall within the scope of protection of the present disclosure.