Abstract:
A fluid control device includes a housing and a fluid temperature control assembly. The housing includes a first inlet, a second inlet for receiving a fluid, and a first outlet through which a fluid of a third temperature flows. The fluid temperature control assembly is in the housing, with apertures for regulating fluid communication between a mixing cavity and the first inlet of the housing, apertures communicating with the first outlet. The fluid temperature control assembly modifies properties of the apertures for regulating the amount of fluid having a first temperature relative to the amount of fluid having a second temperature with the mixing cavity, thereby maintaining the fluid discharged from the first outlet at a predetermined temperature.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    Field of Invention 
         [0002]    The present invention relates to a fluid control device, and in particular to a fluid control device with a temperature control function and energy recovery system. Specifically, the present invention relates to a valve assembly with a thermostatic function and a heat energy recovery device including the valve assembly. 
         [0003]    Related Art 
         [0004]    In everyday life, people may use different washing facilities for cleaning and washing. 
         [0005]    These washing facilities include, for example, bathrooms, washing sinks, hair washing sinks, and the like. However, if the washing facilities use hot water as a washing medium, wastewater discharged by the facilities still contains a huge amount of heat energy, resulting in a waste of energy. Therefore, people try to recover and utilize heat energy from the discharged wastewater. 
         [0006]    An invention patent CN201010224654.4 filed on Jul. 7, 2010 and entitled “valve assembly and heat energy recovery device with the valve assembly” discloses a valve assembly. As shown in  FIG. 1 , the valve assembly  2  includes a housing  30 , a spool  31  disposed in the housing  30  and a handle  32  for controlling the spool. The housing  30  is provided with a cold water input pipe  24 , a cold water output pipe  25 , a tepid water input pipe  26 , a hot water output pipe  27 , and a hot water input pipe  29 , so as to be in communication with the spool  31 . The heat energy recovery device disclosed in the patent can be directly installed without transforming or changing a building structure, thereby simplifying the installation procedure and reducing the installation cost. Moreover, as shown in  FIG. 2 , in the heat energy recovery device, a cold water source is not directly communicated with a heat exchange device, but is communicated with the valve assembly and provides cold water for the heat exchange device by means of the valve assembly. The cold water is heated into tepid water by the heat exchange device, and the tepid water is returned to the valve assembly to be mixed with hot water supplied by a hot water source, to generate tepid water at a suitable temperature, and the tepid water is input, by means of the valve assembly, into a washing facility to be utilized. Therefore, water pressure borne by the heat exchange device can be effectively reduced, to prevent seepage of clean water caused by damage to the heat exchange device. However, in the heat energy recovery device, because the cold water enters the valve assembly after heat exchange is performed in a heat exchanger, and the temperature of the cold water rises slowly to achieve stability, in the meantime, a user needs to regulate a handle of the valve assembly constantly to stabilize the water temperature, which is inconvenient. 
       SUMMARY OF THE INVENTION 
       [0007]    In view of the foregoing problems in the prior art, one objective of the present invention is to provide a fluid control device for stabilizing the temperature of fluid output, such that to output a fluid with desirable temperature. In one of the embodiments, the fluid control device may implement as a valve assembly with a thermostatic function. 
         [0008]    According to a first aspect of the present invention, there is provided a fluid control device, comprising: a housing including a first inlet for receiving a fluid having a first temperature, a second inlet for receiving a fluid having a second temperature, and first outlet through which a fluid of a third temperature flows; a fluid temperature control assembly disposed in the housing, and including a mixing cavity defined therein, wherein the fluid temperature control assembly comprises: a first group of one or more apertures of the mixing cavity configured for regulating fluid communication between the mixing cavity and the first inlet of the housing; a second group of one or more apertures of the mixing cavity for regulating fluid communication between the second inlet of the housing and the mixing cavity; a third group of one or more apertures of the mixing cavity in fluid communication with the first outlet; wherein the fluid temperature control assembly modifies properties of at least one or more of the first group of apertures or the second group of apertures for regulating the amount of fluid having a first temperature relative to the amount of fluid having a second temperature received within the mixing cavity, thereby maintaining the fluid discharged from the first outlet at a predetermined temperature. 
         [0009]    The fluid temperature control assembly may further comprises: a sensor for detecting the temperature of the mixed fluid within the mixing cavity and modifying the at least one or more of the first group of apertures or one or more of the second group of apertures of the fluid temperature control assembly according to the detected temperature of the mixed fluid within the mixing cavity. 
         [0010]    The fluid control device may further includes a third inlet and a third outlet for receiving and discharging fluid of a fourth temperature, wherein the fluid of a fourth temperature may be thermally isolated from the fluid within the fluid control device other than the fluid of a third temperature. 
         [0011]    The fluid control device may further includes a flow regulating valve disposed within the housing, the flow regulating valve comprising: a first plate having a first hole and a second hole therethrough, the first and second holes being spaced apart from each other, a second plate moveable relative to the first plate and including a first slot formed therein, wherein changing the alignment of the first slot of the second plate relative to the holes of the first plate may regulates the amount of fluid flow through a passageway from the third inlet to the third outlet. 
         [0012]    The first plate may further includes at least a further hole in fluid communication with the first inlet and a fourth hole in fluid communication with first group of one or more apertures of the fluid temperature control assembly; the second plate may further includes a second slot, wherein by changing the alignment of the first and second slots of the second plate relative to the holes of the first plate may control the fluid communication between the third inlet and the third outlet and the fluid communication between the first inlet and the first group of one or more apertures of the fluid temperature control assembly. 
         [0013]    The flow regulating valve may further includes a third plate, arranged such that the second plate may be disposed between the first plate and the third plate, wherein each of the first plate, second plate and third plate further includes at least a further hole therein, and said at least one further hole of the third plate and the fluid temperature control assembly being in fluid communication; and the second plate may be configured such that movement of the second plate relative to the first and third plates and the first slot and at least one further hole therein simultaneously regulates flow between the third inlet and the third outlet and flow between the first inlet and fluid temperature control assembly. 
         [0014]    The fluid control device may further includes: a flow regulating knob disposed on the housing for adjusting via a connecting rod the flow regulating valve so as to modify the alignment of the second plate relative to the holes of the other plates; a temperature regulating knob disposed on the housing, for regulating the predetermined temperature of the mixed fluid within the mixing cavity by adjusting the regulating knob or connecting rod thereof; wherein the flow regulating knob or the connecting rod thereof may be axially coincident. 
         [0015]    The fluid control device may further includes: a flow regulating knob disposed on the housing for adjusting via a connecting rod a flow regulating valve so as to modify the alignment of the second plate relative to the holes of the other plates; wherein the connector of the second plate and the flow regulating knob may extend through the interior of the fluid temperature control assembly. 
         [0016]    The third group of one of more apertures of the mixing cavity of the fluid temperature control assembly may be connected to the first outlet of the housing via one of the first plate or the second plate or the third plate. 
         [0017]    The second inlet of the housing may be connected to the second group of one or more apertures of the fluid temperature control assembly through at least one of the first plate, second plate or third plate. 
         [0018]    The fluid control device may further includes: a heat exchanger thermally isolated from the housing; a fluid passageway for conveying fluid with a fourth temperature from the third outlet of the housing to the heat exchanger; wherein the fluid of fourth temperature may undergoes heat exchange with the mixed fluid with third temperature from the first outlet within the heat exchanger, such that the temperature of the fluid with fourth temperature may approach the second temperature, wherein at least a portion of the fluid with a second temperature after heat exchange may be conveyed via the second inlet. 
         [0019]    The fluid control device may further includes a heater, wherein at least a portion of the fluid having a second temperature following heat exchange may be conveyed to the heater for heating to a first temperature and re-introduction into the first inlet. 
         [0020]    Another objective of the present invention is to provide a heat energy recovery device including the aforementioned valve assembly with thermostatic function, where the heat energy recovery device can simplify the installation procedure and reduce the installation cost, effectively reduce water pressure borne by a heat exchange device, to prevent leakage of clean water, and can stably provide the temperature of hot water output. 
         [0021]    According to the present invention, a valve assembly with a thermostatic function is provided, including: a housing with a cavity formed therein, the housing being provided with a cold water inlet, a cold water outlet, a hot water inlet, a tepid water inlet, and a tepid water outlet that are in communication with the cavity, where the cold water inlet is used for communicating with a cold water source, and the hot water inlet is used for communicating with a hot water source; a flow regulating knob; a flow regulating valve disposed in the cavity and connected with the flow regulating knob, used for communicating with the cold water inlet and the cold water outlet of the housing in different degrees; a water-temperature regulating knob; and a thermostat disposed in the cavity and connected with the water-temperature regulating knob, the thermostat having a tepid water inlet, a hot water inlet and a mixing chamber, where the tepid water inlet is in communication with the tepid water inlet of the housing to receive tepid water input externally, the hot water inlet is directly or indirectly in communication with the hot water inlet of the housing, the mixing chamber is in communication with the tepid water outlet of the housing to provide tepid water to the mixing chamber, and the thermostat can automatically regulate the amount of tepid water and hot water that enter the mixing chamber so as to stabilize the water temperature in the mixing chamber to be a temperature preset by the water-temperature regulating knob. 
         [0022]    In the valve assembly, the flow regulating valve includes a first fixed plate and a moveable plate, where a cold water inlet aperture and a cold water outlet aperture are disposed as spaced apart on the fixed plate, and are in communication with the cold water inlet and the cold water outlet of the housing respectively, the moveable plate is relatively rotatably disposed on the fixed plate, and a surface of the fixed plate to which the moveable plate faces is provided with a first groove, where the groove is disposed to be capable of communicating with the cold water inlet and the cold water outlet in different degrees with rotation of the moveable plate so as to control cold water flow. 
         [0023]    In the valve assembly, a contact surface between the fixed plate and the moveable plate is a plane. 
         [0024]    In the valve assembly, the flow regulating knob and the water-temperature regulating knob are located on two ends of the housing separately. 
         [0025]    In the valve assembly, a hot water inlet aperture and a hot water outlet aperture are further disposed as spaced apart on the first fixed plate, and are in communication with the hot water inlet of the housing and the hot water inlet of the thermostat respectively; and the surface of the fixed plate to which the moveable plate faces is further disposed with a second groove, where the first groove and the second groove are disposed to be capable of synchronously communicating the cold water inlet of the housing with the cold water outlet of the housing and communicating the hot water inlet of the housing with the hot water inlet of the thermostat simultaneously in different degrees with rotation of the moveable plate. 
         [0026]    In the valve assembly, the flow regulating knob and the water-temperature regulating knob are located on two ends of the housing separately. 
         [0027]    In the valve assembly, the flow regulating valve further includes a second fixed plate, where the first fixed plate is further provided with a hot water inlet aperture, and the second fixed plate is also provided with a hot water inlet aperture; the moveable plate is disposed between the first fixed plate and the second fixed plate, and is further provided with a hot water aperture; the hot water inlet aperture of the first fixed plate is in communication with the hot water inlet of the housing, and the hot water inlet aperture of the second fixed plate is in communication with the hot water inlet of the thermostat; and the groove and the hot water aperture of the moveable plate are disposed to be capable of synchronously communicating the cold water inlet of the housing with the cold water outlet of the housing and communicating the hot water inlet of the housing with the hot water inlet of the thermostat with different degrees depending on the rotation of the moveable plate. 
         [0028]    In the valve assembly, a contact surface between the moveable plate and the first fixed plate or the second fixed plate is a plane. 
         [0029]    In the valve assembly, the flow regulating knob and the water-temperature regulating knob are located on the same end of the housing. 
         [0030]    In the valve assembly, the flow regulating knob or a connecting rod thereof and the water-temperature regulating knob or a connecting rod thereof are disposed to be capable of rotating coaxially. 
         [0031]    In the valve assembly, the valve assembly further includes a connector connecting the moveable plate and the flow regulating knob, and passing through the interior of the thermostat. 
         [0032]    In the valve assembly, the mixing chamber of the thermostat is communicated with the tepid water inlet of the housing through the first fixed plate, the second fixed plate, or the moveable plate. 
         [0033]    In the valve assembly, the tepid water inlet of the housing is communicated with the tepid water outlet of the thermostat through the first fixed plate, the second fixed plate, or the moveable plate. 
         [0034]    In the valve assembly, the fixed plate and the moveable plate are made of metal or ceramics. 
         [0035]    According to another aspect, the present invention further provides a heat energy recovery device including the aforementioned valve assembly, which further includes a heat exchanger, the heat exchanger receiving hot wastewater from an application device and cold water output by the cold water outlet of the housing, to enable the hot wastewater to exchange heat with the cold water to heat the cold water into tepid water, where at least part of the tepid water is input into the valve assembly through the tepid water inlet of the housing so as to be mixed with external hot water inputted through the hot water inlet of the housing into lukewarm water and provided to the application device through the tepid water outlet. 
         [0036]    The valve assembly with a thermostatic function and the heat energy recovery device including the aforementioned valve assembly with thermostatic function according to the present invention can be directly installed without transforming or changing a building structure, so as to simplify the installation procedure and reduce the installation cost, can effectively reduce water pressure borne by the heat exchange device, so as to effectively prevent leakage of clean water caused by damage to the heat exchange device, and can stably provide the temperature of hot water output. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0037]    The basic structure of the device of the present invention is illustrated below with reference to the accompanying drawings, where: 
           [0038]      FIG. 1  is a schematic structural view of a valve assembly in the prior art; 
           [0039]      FIG. 2  is a structural block diagram of a heat energy recovery device in the prior art; 
           [0040]      FIG. 3  is an exploded perspective view of a first embodiment of a fluid control device with a temperature control function according to the present invention; 
           [0041]      FIG. 4  is an assembling perspective view of the fluid control device shown in  FIG. 3 ; 
           [0042]      FIG. 5  is an assembling sectional view of a temperature control device in the fluid control device shown in  FIG. 4 ; 
           [0043]      FIG. 6  is an exploded perspective view of the temperature control device shown in  FIG. 5 ; 
           [0044]      FIG. 7  is an exploded perspective view of a flow regulating valve in the fluid control device with a temperature control function shown in  FIG. 4 ; 
           [0045]      FIG. 8  is a schematic view of a state change of rotation of a moveable plate in the flow regulating valve shown in  FIG. 7  relative to a fixed plate, illustrating that the flow regulating valve is in an off state; 
           [0046]      FIG. 9  is a schematic view of a state change of rotation of the moveable plate in the flow regulating valve shown in  FIG. 7  relative to a fixed plate, illustrating that the flow regulating valve is in an on state; 
           [0047]      FIG. 10  is a structural block diagram of a heat energy recovery device including the said fluid control device with a temperature control function shown in  FIG. 3 ; 
           [0048]      FIG. 11  is an exploded perspective view of a second embodiment of a fluid control device with a temperature control function according to the present invention; 
           [0049]      FIG. 12  is an assembling perspective view of the fluid control device shown in FIG.  11 ; 
           [0050]      FIG. 13  is an exploded perspective view of a flow regulating valve in the fluid control device shown in  FIG. 12 ; 
           [0051]      FIG. 14  is a schematic view of a state change of rotation of a moveable plate in the flow regulating valve shown in  FIG. 13  relative to a fixed plate, illustrating that the flow regulating valve is in an off state; 
           [0052]      FIG. 15  is a schematic view of a state change of rotation of the moveable plate in the flow regulating valve shown in  FIG. 13  relative to a fixed plate illustrating that the flow regulating valve is in an on state; 
           [0053]      FIG. 16  is a structural block diagram of a heat energy recovery device including the fluid control device with a temperature control function shown in  FIG. 11 ; 
           [0054]      FIG. 17  is a perspective view of a third embodiment of a fluid control device with a temperature control function according to the present invention; 
           [0055]      FIG. 18  is an exploded perspective view of the fluid control device with a temperature control function shown in  FIG. 17 ; 
           [0056]      FIG. 19  is an exploded perspective view of a flow regulating valve in the fluid control device with a temperature control function shown in  FIG. 18 ; 
           [0057]      FIG. 20  is an exploded perspective view of a thermostat in the fluid control device with a temperature control function shown in  FIG. 18 ; 
           [0058]      FIG. 21  is an assembling sectional view of the temperature control device shown in  FIG. 20 ; 
           [0059]      FIG. 22  is a schematic view of a state change of rotation of a moveable plate in the flow regulating valve shown in  FIG. 18  relative to a fixed plate, illustrating that the flow regulating valve is in an off state; 
           [0060]      FIG. 23  is a schematic view of a state change of rotation of the moveable plate in the flow regulating valve shown in  FIG. 18  relative to a fixed plate, illustrating that the flow regulating valve is in an on state; 
           [0061]      FIG. 24  is a sectional perspective view of the fluid control device with a temperature control function shown in  FIG. 17 ; and 
           [0062]      FIG. 25  is a structural block diagram of a heat energy recovery device including the fluid control device with a temperature control function shown in  FIG. 17 . 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0063]    Various embodiments in which the valve assembly with a thermostatic function and the heat energy recovery device including the valve assembly according to the present invention are described below only by way of examples with reference to the accompanying drawings. It should be understood that the present invention is not limited thereto. Throughout accompanying drawings, same accompanying drawing reference signs are used for same components. 
         [0064]    In the embodiments as mentioned below, the fluid control device with temperature control function are implemented as valve assembly with thermostat function. One would be appreciated that the fluid control device with temperature control function is not only limited to valve assembly, while temperature control function and temperature control device are not only limited to thermostat functions and thermostat devices. Any devices comprising fluid control functions and devices with temperature control function fall within the scope of the present invention. 
         [0065]    Meanwhile, in the embodiments as mentioned below, the movable plate within the fluid control device are implemented as a rotatable plate for regulating the fluid communication flowing therein. It should be understood that such movable plate is not limited to rotatable plate where any devices comprising fluid flow regulating functions such as linear movable plate fall within the scope of the present invention. 
         [0066]      FIG. 3  to  FIG. 9  illustrate a structure of a first embodiment of a valve assembly with a thermostatic function according to the present invention, and  FIG. 10  is a structural block diagram of a heat energy recovery device including the aforementioned valve assembly with thermostatic function according to the present invention. 
         [0067]    As shown in  FIG. 3  and  FIG. 4 , the valve assembly  4  includes a housing  41 , a flow regulating knob  45 , a water-temperature regulating knob  46 , a thermostat  42  disposed in the housing  41 , a flow regulating valve  43 , and a connector  44  that is in communication with the flow regulating valve  43  and the housing  41 . The housing  41  is internally formed with a cavity  418 , and is externally formed with a cold water inlet  414 , a cold water outlet  415 , a hot water inlet  419 , a tepid water inlet  416 , and a tepid water outlet  417  that are in communication with the cavity  418 . In particular, the distance between the center of the cold water inlet  414  and hot water inlet  419  is approximately 150 mm, which is the same distance between the centers of the cold and water inlet of the cold hot water mixing valve utilized in the general bathroom in the market. Users only need to remove the existing mixing valve of the bathroom and replace with the valve assembly of the present invention without replacing the existing conduit of the building. 
         [0068]    As shown in  FIG. 5  and  FIG. 6 , the thermostat  42  has a hot water inlet  429  in communication with the hot water inlet  419  of the housing  41 , a tepid water inlet  426  in communication with the tepid water inlet  416  of the housing  41 , a mixing chamber  428  in communication with the tepid water outlet  417  of the housing  41 , and a control rod  424  connected with the water-temperature regulating knob  46 . The mixing chamber  428  of the thermostat  42  is provided with a thermostatic element  423  and a slider  425  therein. Substance in the thermostatic element  423  can automatically change the length of a tail  422  of the thermostatic element  423  based on the water temperature in the mixing chamber  428  through the principle of thermal expansion and contraction. When the water temperature in the mixing chamber  428  is higher than a temperature preset by the water-temperature regulating knob  46  by means of the control rod  424 , the tail  422  of the thermostatic element  423  may lengthen to press the slider  425  downwards so as to reduce the degree of communication between the hot water inlet  429  and the mixing chamber  428  and increase the degree of communication between the tepid water inlet  426  and the mixing chamber  428 , to increase the amount of tepid water in the mixing chamber  428  and decrease the amount of hot water, thereby lowering the water temperature in the mixing chamber  428 . However, when the water temperature in the mixing chamber  428  is lower than the temperature preset by the water-temperature regulating knob  46  by means of the control rod  424 , the tail  422  of the thermostatic element  423  may shorten, a spring  427  pushes the slider  425  upwards so as to increase the degree of communication between the hot water inlet  429  and the mixing chamber  428  and reduce the degree of communication between the tepid water inlet  426  and the mixing chamber  428 , to increase the amount of hot water in the mixing chamber  428  and decrease the amount of tepid water, thereby raising the water temperature in the mixing chamber  428 . 
         [0069]    As shown in  FIG. 3  and  FIG. 4 , the flow regulating valve  43  is disposed in the cavity  418  of the housing  41 , and by means of a control rod  431  through which the flow regulating valve  43  is connected with the flow regulating knob  45 , the flow regulating valve  43  can communicate with the cold water inlet  414  and the cold water outlet  415  of the housing  41  in different degrees to regulate water output of the cold water outlet  415 . 
         [0070]      FIG. 7  is an exploded perspective view of the flow regulating valve  43 . The flow regulating valve  43  includes a housing  53  with a cavity formed therein, a bottom cover  54  snapped to the housing  53  in a sealing manner, a fixed plate  55  fixedly disposed on the bottom cover  54  in the cavity of the housing  53 , a rotatable plate  56  relatively rotatably disposed on the fixed plate  55 , and a control rod  431  passing through the housing  53  and connecting to the rotatable plate  56 , where the control rod  431  can drive the rotatable plate  56  to rotate on the fixed plate  55 . The bottom cover  54  is provided with a cold water inlet  541  and a cold water outlet  542 , which are in communication with the cold water inlet  414  and the cold water outlet  415  of the housing  41  respectively through the connector  44  (see  FIG. 3  and  FIG. 4 ). A cold water inlet hole  551  and a cold water outlet hole  552  are disposed as spaced apart on the fixed plate  55 , and are in communication with the cold water inlet  541  and the cold water outlet  542  on the bottom cover  54  respectively. A surface (plane) of the fixed plate  55  to which the rotatable plate  56  faces is formed with a groove  561 , which is disposed to selectively communicate with the cold water inlet  414  and the cold water outlet  415  with different degrees depending on the rotation of the rotatable plate  56  so as to control the amount of cold water of the cold water outlet  415  of the housing  41 . 
         [0071]      FIG. 8  and  FIG. 9  illustrate state changes generated by rotation of the rotatable plate  56  relative to the fixed plate  55 . In an initial state shown in  FIG. 8 , that is, when the flow regulating valve  43  is in an off state, the groove  561  does not cover the cold water inlet hole  551  or the cold water outlet hole  552 , so that the cold water inlet hole  551  and the cold water outlet hole  552  are spaced apart from each other but are not in communication. 
         [0072]    When the flow regulating knob  45  is used to rotate the control rod  431  to drive the rotatable plate  56  to rotate on the fixed plate  55 , the flow regulating valve  43  enters a on state shown in  FIG. 9 . In this case, as shown in  FIG. 10 , cold water supplied by a cold water source enters the cold water outlet hole  552  through the cold water inlet hole  551  and the groove  561 , that is, the cold water is output to the cold water outlet  415  of the housing  41  through the cold water inlet  414  of the housing  41  and further supplied to a heat exchanger  3 . The cold water exchanges heat with hot water from an application device (for example, a washing facility) within the heat exchanger  3  to become tepid water, and part of the tepid water is directly communicated with the tepid water inlet  416  of the valve assembly  4  through a pipeline, part of the tepid water is communicated with a heater and is heated into a hot water source to be communicated with the hot water inlet  419  of the valve assembly  4 , and provides hot water with a stable water temperature at the temperature preset by the temperature regulating knob  46  by means of the control rod  424  for the tepid water outlet  417  through the thermostat  42  so as to be supplied to the application device. 
         [0073]    The fixed plate  55  and the rotatable plate  56  in the valve assembly of the present invention may be made of metal or ceramics. 
         [0074]      FIG. 10  illustrates a structural block diagram of a heat energy recovery device including the said fluid control device according to the present invention. As shown in the figure, said heat energy recovery device comprises valve assembly  4  and heat exchanger. As shown in the figure, the water from the cold water source enters the heat exchanger through valve assembly  4 . One skilled in the art would understand that water from the cold water may also enter heat exchange directly without passing through valve assembly  4 . Upon passing through the heat exchanger to absorb the heat energy of waste water, the water reaches a higher temperature and becomes tepid water. Tepid water may enter valve assembly  4  through tepid water inlet and mix with the hot water entering valve assembly  4  from hot water inlet within the mixing cavity. For detailed description please refer to the aforementioned disclosure and it would not be reiterated here. It should be explained here that the hot water from the heat exchanger may also be heated to become hot water by a heater, and introduced into valve assembly through hot water inlet  419 . 
         [0075]    When valve assembly  4  is in off state, it separates the clean water within heat exchanger  3  and water heater from the cold water source of the building, such that heat exchanger  3  is not borne with any pressure from the cold water source under circumstances of no water usage, and even if there may exists any water leakage with heat exchanger  3 , precious drinking water would not endlessly leak into waster water conduit and causes waste; 
         [0076]    When valve assembly  4  is in on state, cold water enters heat exchanger  3  through valve assembly  4  upon entering cold water conduit, and further enters valve assembly  4  through hot water inlet  419  and warm water inlet  416  and finally out from warm water outlet  417 . During water usage, the pressure of the cold water source is released through the warm water out from the warm water outlet  417 . Thus, the conduit between the valve assembly  4  and the heat exchanger  3 , the conduit between heat exchanger  3  and heater, the conduit between cold outlet  415  and heat exchanger, and the conduit between heat exchanger  3  and warm water inlet  416  would not subject to excessive pressure under on or off circumstances, and such that it may utilize soft plastic conduit instead of metal tube to reduce material and installation cost. Meanwhile, as heat exchanger  3  bears a lower water pressure, it may be made of thinner material to enhance heat exchange efficiency.  FIG. 11  to  FIG. 15  illustrate a structure of a second embodiment of a valve assembly with a thermostatic function according to the present invention, and  FIG. 16  is a structural block diagram of a heat energy recovery device including the valve assembly with a thermostatic function according to the present invention. The structure of the valve assembly  6  with a thermostatic function in the second embodiment is roughly identical with that of the valve assembly  4  with a thermostatic function in the first embodiment, and the only different exist within the structures of a flow regulating valve  63 . Detailed description about the same components is omitted herein. 
         [0077]    As shown in  FIG. 11  and  FIG. 12 , the valve assembly  6  includes a housing  41 , a flow regulating knob  45 , a water-temperature regulating knob  46 , a thermostat  42  disposed in the housing  41 , a flow regulating valve  63 , and a connector  64  and connecting pipes  67 ,  68  for communicating with the flow regulating valve  63  and the housing  41 . The housing  41  is formed with a cavity  418  therein and is externally formed with a cold water inlet  414 , a cold water outlet  415 , a hot water inlet  419 , a tepid water inlet  416 , and a tepid water outlet  417  that are in communication with the cavity  418 . 
         [0078]    As shown in  FIG. 11  and  FIG. 12 , the flow regulating valve  63  is disposed within the cavity  418  of the housing  41 , and by means of a control rod  631  through which the flow regulating valve  63  is connected with the flow regulating knob  45 , the flow regulating valve  63  can regulate water quantity. 
         [0079]      FIG. 13  is an exploded perspective view of the flow regulating valve  63 . The flow regulating valve  63  includes a housing  73  with a cavity formed therein, a bottom cover  74  snapped to the housing  73  in a sealing manner, a fixed plate  75  fixedly disposed on the bottom cover  74  in the cavity of the housing  73 , a rotatable plate  76  relatively rotatably disposed on the fixed plate  75 , and a control rod  631  passing through the housing  73  and connecting to the rotatable plate  76 , where the control rod  631  can drive the rotatable plate  76  to rotate on the fixed plate  75 . In addition to being provided with a cold water inlet  741  and a cold water outlet  742 , the bottom cover  74  is further provided with a hot water inlet  743  and a hot water outlet  744 , which, by means of the connector  64  and the connecting pipe  67  (see  FIG. 12 ), such that the cold water inlet  741  communicate with the cold water inlet  414  of the housing  41 , the cold water outlet  742  communicate with the cold water outlet  415  of the housing  41 , the hot water inlet  743  communicate with the hot water inlet  419  of the housing  41 , and the hot water outlet  744  communicate with the hot water inlet  429  of the thermostat  42 . 
         [0080]    In addition to a cold water inlet hole  751  and a cold water outlet hole  752  as provided in a spaced manner on the fixed plate  75 , the fixed plate  75  is further provided with a hot water inlet hole  753  and a hot water outlet hole  754 , which are in communication with the cold water inlet  741 , the cold water outlet  742 , the hot water inlet  743  and the hot water outlet  744  on the bottom cover  74  respectively. 
         [0081]    A surface (plane) on the fixed plate  75  to which the rotatable plate  76  faces is formed with two grooves, a first groove  761  and a second groove  762 , which are disposed to selectively synchronously communicate the cold water inlet  741  with the cold water outlet  742  and communicate the hot water inlet  743  with the hot water outlet  744  with different degrees depending on the rotation of the rotatable plate  76 . 
         [0082]      FIG. 14  and  FIG. 15  illustrate state changes generated by rotation of the rotatable plate  76  relative to the fixed plate  75 . In an initial state shown in  FIG. 14 , that is, when the flow regulating valve  63  is in an off state, the first groove  761  does not cover the cold water inlet hole  751  or the cold water outlet hole  752 , and the second groove  762  does not cover the hot water inlet hole  753  and the hot water outlet hole  754 , so that the cold water inlet hole  751  and the cold water outlet hole  752  are spaced apart from each other but are not in communication, and the hot water inlet hole  753  and the hot water outlet hole  754  are spaced apart from each other but are not in communication. 
         [0083]    When the flow regulating knob  45  is used to rotate the control rod  631  to drive the rotatable plate  76  to rotate on the fixed plate  75 , the flow regulating valve  63  gradually enters a full-on state shown in  FIG. 15 . In this case, as shown in  FIG. 16 , cold water supplied by a cold water source enters the cold water outlet hole  752  through the cold water inlet hole  751  and the first groove  761 , that is, the cold water is output to the cold water outlet  415  of the housing  41  through the cold water inlet  414  of the housing  41  and to be further supplied to a heat exchanger  3 . The cold water exchanges heat with hot water from an application device (for example, a washing facility) in the heat exchanger  3  to become tepid water, and is then communicated with the tepid water inlet  416  of the housing  41 ; meanwhile, hot water supplied by a hot water source enters the hot water outlet hole  754  through the hot water inlet hole  753  and the second groove  762 , that is, the hot water is communicated with the hot water inlet  429  of the thermostat  42  through the hot water inlet  419  of the housing  41 . The tepid water and the hot water, by means of the thermostat  42 , provide hot water with a stable water temperature at the temperature preset by the temperature regulating knob  46  by means of the control rod  424  for the tepid water outlet  416 , so as to be supplied to the application device. 
         [0084]      FIG. 16  illustrates a structural block diagram of a heat energy recovery device including the fluid control device of a second embodiment according to the present invention. As  FIG. 16  is substantially similar to  FIG. 10 , the description is omitted herein. 
         [0085]      FIG. 17  to  FIG. 24  illustrate a structure of a third embodiment of a valve assembly with a thermostatic function according to the present invention, and  FIG. 25  is a structural block diagram of a heat energy recovery device including the valve assembly with a thermostatic function according to the present invention. As shown in  FIG. 17 , the valve assembly  8  is fastened onto a table surface  21  by means of fasteners  22  and  23 . 
         [0086]    As shown in  FIG. 17  and  FIG. 18 , the valve assembly  8  includes a housing  81  which consists of a top shell  811 , a bottom shell  812 , and a screw cap  813 , which form a cavity  818  therein, where the cavity  818  is in communication with a cold water inlet  814 , a cold water outlet  815 , a hot water inlet  819 , a tepid water inlet  816 , and a tepid water outlet  817  on the bottom cover  812 . The valve assembly  8  further includes a thermostat  82  disposed within the cavity  818 , a flow regulating valve  83 , a flow regulating knob  85 , and a water-temperature regulating knob  84 . The water-temperature regulating knob  84  and the flow regulating knob  85  are located on the same end of the housing  81 . 
         [0087]      FIG. 19  is an exploded perspective view of the flow regulating valve  83 . The flow regulating valve  83  includes a housing  831  with a cavity formed therein, a bottom cover  832  sealingly engaged to the housing  831 , a first fixed plate  833  and a second fixed plate  835  fixedly disposed in the cavity  818  of the housing  831 , and a rotatable plate  834  relatively rotatably disposed between the first fixed plate  833  and the second fixed plate  835 . In particular, a contact surface between the first fixed plate  833  and the rotatable plate  834 , and a contact surface between the second fixed plate  835  and the rotatable plate  834  are planes. The bottom cover  832  is provided with a cold water inlet  8321 , a cold water outlet  8322 , a tepid water inlet  8323 , a hot water inlet  8325 , and a tepid water outlet  8324 , which are in communication with the cold water inlet  814 , the cold water outlet  815 , the hot water inlet  819 , the tepid water inlet  816 , and the tepid water outlet  817  of the housing  81  respectively. 
         [0088]    In addition to the cold water inlet hole  8331  and a cold water outlet hole  8332  that are in communication with the cold water inlet  8321  and the cold water outlet  8322  respectively as provided on the bottom cover  832 , the first fixed plate  833  is further provided with a hot water inlet hole  8333  that is in communication with the hot water inlet  8325  on the bottom cover  832 , and a tepid water input hole  8335  and a tepid water output hole  8334  that are in communication with the tepid water inlet  8323  and the tepid water outlet  8324  respectively. 
         [0089]    The second fixed plate  835  is provided with a hot water inlet hole  8353 , a tepid water input hole  8355 , and a tepid water output hole  8354  that are aligned with the hot water inlet hole  8333 , the tepid water input hole  8335 , and the tepid water output hole  8334  of the first fixed plate respectively. 
         [0090]    In addition to a groove  8341  is provided to the rotatable plate  834 , the rotatable plate  834  is further provided with a hot water hole  8343 , a tepid water input hole  8345 , and a tepid water output hole  8344 , which are disposed to be as follows: rotatable plate not only the groove  8341  can communicate with the cold water inlet hole  8331  and the cold water outlet hole  8332  of the first fixed plate  833  in different degrees, the hot water hole  8343  also synchronously communicates with the hot water inlet hole  8333  of the first fixed plate  833  and the hot water inlet hole  8353  of the second fixed plate  835  in different degrees depending on the rotation of the rotatable plate  834 . 
         [0091]    As shown in  FIG. 20  to  FIG. 21 , the thermostat  82  has a tepid water inlet  821 , a hot water inlet  822 , and a mixing chamber  828 . The mixing chamber  828  of the thermostat  82  is provided with a thermostatic element  823  and a slider  825  therein. Substance in the thermostatic element  823  can automatically change the length of a tail  8231  of the thermostatic element  823  based on the water temperature in the mixing chamber  828  according to the principle of thermal expansion and contraction. When the water temperature in the mixing chamber  828  is higher than a temperature preset by the water-temperature regulating knob  85  by means of a control rod  824 , the tail  8231  of the thermostatic element  823  may lengthen to press the slider  825  downwards so as to narrow a hot water channel  8221  between the hot water inlet  822  and the mixing chamber  828  and widen a tepid water channel  8211  between the cold water inlet  821  and the mixing chamber  828  to increase the amount of tepid water in the mixing chamber  828  and decrease the amount of hot water, thereby lowering the water temperature in the mixing chamber  828 . However, when the water temperature in the mixing chamber  828  is lower than the temperature preset by the water-temperature regulating knob  85  by means of the control rod  824 , the tail  8231  of the thermostatic element  823  may shorten, a spring  827  may push the slider  825  upwards so as to widen the hot water channel  8221  and narrow the tepid water channel  8211 , to increase the amount of hot water in the mixing chamber  828  and decrease the amount of tepid water, thereby raising the water temperature in the mixing chamber  828 . The thermostat  82  is further internally provided with a flow regulating rod  836 , which is connected to a connector  837  and a connector  838 , to enable the connector  838  to synchronously rotate with the flow regulating knob  86 . The flow regulating rod  836 , the connector  837 , and the connector  838  pass through the interior of the thermostat  82 , and one end  8381  of the connector  838  protrudes from the thermostat  82 , and is inserted into a tepid water output hole  8344  in the center of the rotatable plate  834  of the flow regulating valve  83  so as to drive the rotatable plate  834  to synchronously rotate with the flow regulating knob  86 . 
         [0092]      FIG. 22  and  FIG. 23  illustrate state changes generated by rotation of the rotatable plate  834  relative to the first fixed plate  833  and the second fixed plate  835 . In an initial state shown in  FIG. 22 , that is, when the flow regulating valve  83  is in an off state, the groove  8341  of the rotatable plate  834  does not cover the cold water inlet  8331  and the cold water outlet  8332  of the first fixed plate  833 , and the hot water hole  8343  of the rotatable plate  834  does not cover the hot water inlet hole  8333  of the first fixed plate  833 , so that the cold water inlet hole  8331  and the cold water outlet hole  8332  are spaced apart from each other but are not in communication, and the hot water inlet hole  8333  of the first fixed plate  833  and the hot water inlet hole  8353  of the second fixed plate  835  are also spaced apart from each other but are not in communication. 
         [0093]    When the flow regulating knob  85  is used to rotate the rotatable plate  834 , the rotatable plate  834  gradually enters a full-on state as shown in  FIG. 23 . In this case, as shown in  FIG. 23  to  FIG. 25 , the groove  8341  of the rotatable plate  834  completely covers the cold water inlet  8331  and the cold water outlet  8332 , and the hot water hole  8343  of the rotatable plate  834  completely covers the hot water inlet hole  8333  of the first fixed plate  833 , so as to be completely communicated with the hot water inlet hole  8353  of the second fixed plate  835 . Cold water supplied by a cold water source enters the cold water outlet hole  8332  through the cold water inlet hole  8331  and the groove  8341 , that is, the cold water is output to the cold water outlet  815  of the housing  81  through the cold water inlet  814  of the housing  81  to be supplied to a heat exchanger  3 . The cold water exchanges heat with hot wastewater from an application device (for example, a washing facility) in the heat exchanger  3 , so that the cold water becomes tepid water and is then communicated with the tepid water inlet  816  of the housing  81 ; meanwhile, hot water supplied by a hot water source is communicated with the hot water inlet  822  of the thermostat  82  through the hot water inlet aperture  819 , and the hot water inlet holes  8333 ,  8343  and  8353  of the first fixed plate  833 , the rotatable plate  834  and the second fixed plate  835 . The tepid water and the hot water enter an hole  8371  of the connector  837  and a central hole  8381  of the connector  838  through the cavity  828  by means of the thermostat  82 , and then provide hot water with a stable water temperature at the temperature preset by the temperature regulating knob  86  by means of the control rod  824  for the tepid water outlet  817  of the housing  81  through tepid water output holes  8354 ,  8344  and  8334  in the center of the second fixed plate  835 , the rotatable plate  834  and the first fixed plate  833  so as to be supplied to the application device. 
         [0094]    The working principle of the heat energy recycle device of  FIG. 25  is substantially similar to that of the heat energy recycle device shown in  FIG. 10  and thus omitted herein. 
         [0095]    In the above examples, the rotatable plates  56 ,  76  and  834  regulate the fluid flow passing through the fluid control device of the present invention by means of rotation. It should be understood by one skilled in the art that this could be achieved by other means of movement such as linear movement etc to regulate the fluid flow control. Such variations fall within the spirit and scope of the present invention. 
         [0096]    Although various embodiments of the present invention have been described above in detail, variations and improvements to the present invention may be further made by a person skilled in the art. It should be understood that such variations and improvements shall fall within the spirit and scope of the present invention. It should be noted that although the aforementioned embodiments have exemplified with water as an example of fluids to illustrate the structure and operation of the present invention, one person skilled in the art should appreciate that the embodiments of the present invention is not limited to the usage of water, but also fit for all other suitable fluids.