Abstract:
The present invention discloses a fuel-cell-based cogeneration system with radio frequency identification (RFID) sensors. The fuel-cell-based cogeneration system with RFID sensors includes the fuel-cell-based cogeneration system and an RFID data processing system. The RFID data processing system captures data of the temperature and flow rate from the RFID sensors, while the system data are in turn converted into RFID signals. The RFID data processing system transmits a control signal generated from the RFID signal to control the operation of the fuel-cell-based cogeneration system. Since the RFID transmission technology, the sensor error caused by wires is consequently reduced. Furthermore, overall sensitivity and accuracy of the RFID sensors are increased, which leads to an accompanying increase in the stability of the operating system.

Description:
BACKGROUND OF THE INVENTION 
     1. Technical Field 
     The present invention relates to fuel-cell-based cogeneration systems, and more particularly, to a fuel-cell-based cogeneration system with radio frequency identification sensors wherein the RFID technology is applied to the fuel-cell-based cogeneration system. 
     2. Description of Related Art 
     With the recent economic development, demand for electricity is increasingly growing, and power shortage happens frequently in peak hours. Although power brownouts have been conducted as an expedient, this approach brings serious inconvenience to the people&#39;s livelihood and industries. Other approaches to improving power shortage include building new power plants and enhancing energy efficiency. However, the increasing environmental consciousness and the limited natural resources make building new power plants an unwise choice. Therefore, the most feasible way nowadays to remedy power shortage seems being enhancing energy efficiency. 
     Fuel-cell-based cogeneration systems have been introduced as a part of green industry. Such a system is composed of a fuel cell and a combined heat and power system, wherein the combined heat and power system retrieves the waste heat generated by the operating fuel cell and stores the same in the form of hot water in an isolating device, so as to provide electricity and hot water simultaneously, thereby reusing and leveraging energy. 
     However, for operating the fuel cell, it is necessary to introduce water with constant flow rate and constant temperature so as to bring out the waste heat. Thus, the water routes in the system have to be equipped with sensors for flow and temperature, so as to monitor and adjust the system timely, and in turn ensure the stable operation of the overall system. 
     Conventionally, for fitting the sensors to the configuration and layout of the system, the shielding wires of the sensors are likely to be bent, and this may cause measuring errors of the sensors. Moreover, the impedance of sensors is subject to the lengths of the shielding wires, so the shielding wires may not be trimmed without problem. If one tries to extend the shielding wires with compensating wires, the impedance can consequently become larger and significantly affect the measuring accuracy. Therefore, the length of the shielding wires is not flexible. In addition, the system is to be packaged in a confined housing and this also adds difficulty in wiring. 
     To sum up, since the accuracy of the sensors highly depends on the numerous sensor wires that cannot be bent, trimmed or extended, in the mass production of a fuel-cell-based cogeneration system, there is no choice but manual wiring. This not only increases labor costs, but also hinders the system from putting into modulization. 
     SUMMARY OF THE INVENTION 
     The present invention provides a fuel-cell-based cogeneration system with radio frequency identification sensors, wherein by using the RFID sensors, the sensor error caused by bent, extended or trimmed wires is consequently reduced so that overall sensitivity to temperature and flow of the system can be enhanced, and the stability of the system can be in turn improved. 
     The present invention provides a fuel-cell-based cogeneration system with radio frequency identification sensors, wherein the RFID sensors help to simplify wiring and lower the costs of manual wiring, so as to allow modular production of the fuel-cell-based cogeneration system. 
     To achieve the above effects, the present invention provides a fuel-cell-based cogeneration system with radio frequency identification sensors, comprising: the fuel-cell-based cogeneration system that includes a fuel cell having a first output end and a first input end; a first heat exchange pipe communicating the first output end and the first input end, and having a heat-dissipating motor, a first RFID sensor, a second RFID sensor, a first lateral of a heat exchanger and a third RFID sensor connected successively in series along the direction of water flows therein; an isolating device having a chamber, which comprises a second output end, a second input end and at least one opening; and a fourth RFID sensor that is combined with the isolating device for detecting a water temperature in the chamber; and a second heat exchange pipe communicating the second output end and the second input end, and having a heat-storing motor, a fifth RFID sensor and a second lateral of the heat exchanger connected successively in series along the direction of water flows therein; and an RFID data processing system that includes: an RFID reader, when enabled, transmitting a first RFID signal to each said RFID sensor, and receiving a second RFID signal transmitted by each said RFID sensor; and a microprocessor enabling the RFID reader, and generating a control signal according to the second RFID signal for controlling the heat-dissipating motor and the heat-storing motor. 
     By implementing the present invention, at least the following progressive effects can be achieved: 
     1. Since the sensor error caused by wires is improved, the overall sensitivity of the fuel-cell-based cogeneration system to temperature and flow can be enhanced, so that the accuracy of the system can be increased and the stability of the system can be in turn ensured. 
     2. Since the wiring is simplified, the modular production of the fuel-cell-based cogeneration system becomes feasible to ensure the productive efficiency. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention as well as a preferred mode of use, further objectives and advantages thereof will be best understood by reference to the following detailed description of illustrative embodiments when read in conjunction with the accompanying drawings, wherein: 
         FIG. 1  is a schematic drawing of a fuel-cell-based cogeneration system with radio frequency identification sensors according to one embodiment of the present invention; 
         FIG. 2  is a schematic drawing of an RFID package according to the embodiment of the present invention; 
         FIG. 3  is a schematic drawing of the RFID sensor according to the embodiment of the present invention; and 
         FIG. 4  and  FIG. 5  are schematic drawings of an RFID reader and its peripheral interface according to the embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIG. 1  is a schematic drawing of a fuel-cell-based cogeneration system  100  with RFID sensors  60  according to one embodiment of the present invention. FIG.  2  is a schematic drawing of an RFID package  301  according to the embodiment of the present invention.  FIG. 3  is a schematic drawing of one of the RFID sensors  60  according to the embodiment of the present invention.  FIG. 4  and  FIG. 5  are schematic drawings of an RFID reader  80  and its peripheral interface  86  according to the embodiment of the present invention. 
     Referring to  FIG. 1 , the present embodiment is the fuel-cell-based cogeneration system  100  with the RFID sensors  60 . It comprises the fuel-cell-based cogeneration system  100  and an RFID data processing system  200 . Therein, the RFID data processing system  200  captures the operational status of the fuel-cell-based cogeneration system  100  by means of the RFID technology, so as to monitor the system in a real-time manner. 
     The fuel-cell-based cogeneration system  100  includes a fuel cell  10 , a first heat exchange pipe  20 , an isolating device  30  and a second heat exchange pipe  40 . 
     The fuel cell  10  has a first output end  11  and a first input end  12 . Water drained out of the fuel cell  10  through the first output end  11 , and flows through the first heat exchange pipe  20  before returning to the fuel cell  10  via the first input end  12 . 
     The first heat exchange pipe  20  communicates the first output end  11  with the first input end  12  so as to form a water loop. The waste heat generated by the fuel cell  10  as a result of power generation is brought away from the fuel cell  10  by water. Afterward, the water can be drained out at the first output end  11  and flows through the first heat exchange pipe  20  which the water after heat exchange can be guided back to the fuel cell  10  through the first input end  12 . 
     The first heat exchange pipe  20  has, along the direction of water flows, a heat-dissipating motor  50   a , a first RFID sensor  60   a , a second RFID sensor  60   b , a first lateral of a heat exchanger  70  and a third RFID sensor  60   c  that are connected in series. The heat-dissipating motor  50   a  serves to push water to flow in the first heat exchange pipe  20 . Thus, by adjusting the rotation speed of the heat-dissipating motor  50   a , the flow of water in the first heat exchange pipe  20  can be controlled. 
     The first RFID sensor  60   a  is a flow sensor capable of RFID transmission, for detecting the flow of water in the first heat exchange pipe  20 , so as to ensure there is sufficient water stably flowing along the first heat exchange pipe  20 . The second RFID sensor  60   b  and the third RFID sensor  60   c  are temperature sensors, also being capable of RFID transmission. They serve to monitor the temperatures of the water coming into and leaving the heat exchanger  70 , respectively. 
     The isolating device  30  has a chamber  31  and a fourth RFID sensor  60   d . The chamber  31  has a second output end  311 , a second input end  312  and at least one opening  313 , which makes the hot water stored in the isolating device  30  accessible to users. The fourth RFID sensor  60   d  is a temperature sensor capable of RFID transmission. It is combined with the isolating device  30  for detecting the water temperature in the chamber  31 . 
     The second heat exchange pipe  40  communicates the second output end  311  with the second input end  312 , so that the water inside the isolating device  30  is guided out to the heat exchanger  70  through the second output end  311 , and the hot water after heat exchange is led back to the isolating device  30  for storage through the second input end  312 . Therein, the second heat exchange pipe  40  has, along the direction of water flows, a heat-storing motor  50   b , a fifth RFID sensor  60   e  and a second lateral of the heat exchanger  70  that are connected in series. 
     The heat-storing motor  50   b  also serves to push water in the second heat exchange pipe  40  to flow, so the heat-storing motor  50   b  is usable to control the water flow. The fifth RFID sensor  60   e  is a flow sensor capable of RFID transmission, for detecting the flow rate of water in the second heat exchange pipe  40 . 
     As shown in  FIG. 1 , the RFID data processing system  200  comprises an RFID reader  80  and a microprocessor  90 . 
     The RFID reader  80  serves to enable each said RFID sensor  60  and read a signal therefrom. The RFID reader  80  is configured to transmit a first RFID signal. When the RFID sensor  60  is within the transmission range of the RFID reader  80 , the RFID sensor  60  receives the first RFID signal and gets enabled, and then sends back a second RFID signal. After receiving the second RFID signal transmitted by any of the RFID sensors  60 , the RFID reader  80  is informed of the flow and temperature detected by the corresponding RFID sensor  60 . 
     The microprocessor  90  enables the RFID reader  80 , so that the RFID reader  80  transmits the first RFID signal to enable the RFID sensors  60 . In addition, the microprocessor  90  may generate a control signal according to the second RFID signal, so as to control the corresponding heat-dissipating motor  50   a  and heat-storing motor  50   b , and thereby adjust water flows to obtain improved heat exchange effect. 
     As shown in  FIG. 2 , in the present embodiment, the package  301  of RFID signals and digital signals is composed of addresses and information of the RFID sensors. Thus, as to information transmission, the information source can be identified in virtue of the addresses. Furthermore, bits of each said package  301  may vary with the number of the RFID sensors  60 . 
     Referring to  FIG. 3 , each of the RFID sensors  60  of the embodiment comprises a detecting module  61  and a data-capturing RFID module  62 . The detecting module  61  serves to capture a status signal of the fuel cell  10 . The detecting module  61  is composed of a temperature detecting module and a flow detecting module. 
     According to the present embodiment, the detecting modules  61  in the first and fifth RFID sensors  60   a  and  60   e  are flow detecting module. When the flow detecting module detects that there is no water flowing or there is abnormal water level in the first heat exchange pipe  20  or the second heat exchange pipe  40 , the system generates a warning of abnormal operation. 
     The detecting modules  61  in the second, third and fourth RFID sensors  60   b ,  60   c ,  60   d  are temperature detecting module, and the temperatures detected by the second and third RFID sensors  60   b ,  60   c  are used as a basis for determining the rotation speed of the heat-dissipating motor  50   a  and the heat-storing motor  50   b.    
     The data-capturing RFID module  62  comprises a capturing-and-amplifying unit  621 , a first digital data processing unit  622 , a first antenna  623  and a first RFID unit  624 . 
     The capturing-and-amplifying unit  621  is electrically connected between the detecting module  61  and the first digital data processing unit  622 . The capturing-and-amplifying unit  621  converts the status signal of the fuel cell  10  received by the detecting module  61  into a first digital signal, and then the first digital data processing unit  622  converts the first digital signal into a second RFID signal. 
     The first RFID unit  624  is electrically connected between the first digital data processing unit  622  and the first antenna  623 . The first RFID unit  624  transmits the second RFID signal by means of the first antenna  623 . In addition, the first RFID unit  624  also receives the first RFID signal by means of the first antenna  623 , and then according to the first RFID signal enables the data-capturing RFID module  62  to capture the status signal of the fuel cell  10 . 
     As shown in  FIG. 4  and  FIG. 5 , the RFID reader  80  includes a second antenna  81 , a second RFID unit  82 , a second digital data processing unit  83  and a data collecting unit  84 . 
     The second antenna  81  serves to transmit the first RFID signal and to receive the second RFID signal. The second RFID unit  82  is electrically connected to the second antenna  81  and the second digital data processing unit  83 . After the second antenna  81  receives the second RFID signal, the second RFID unit  82  receives the second RFID signal output by the second antenna  81 . Then the second digital data processing unit  83  converts the received second RFID signal into a second digital signal. Moreover, the second RFID unit  82  also transmits the first RFID signal by means of the second antenna  81 . 
     The data collecting unit  84  is electrically connected to the second digital data processing unit  83 , and stores a predetermined data signal as a criterion indicating the system&#39;s normal operation. The predetermined data signal includes the relation between the water temperature and the rotation speed of the motors  50   a ,  50   b  in normal operation. The microprocessor  90  compares the second digital signal with the predetermined data signal so as to generate a control signal for controlling the heat-dissipating motor  50   a  and the heat-storing motor  50   b , thereby allowing the motors  50   a ,  50   b  to operate corresponding to the water temperature, and in turn optimizing the heat energy conversion rate. 
     Therein, basing on the comparison between the second digital signals generated by the second and third RFID sensors  60   b ,  60   c  and the predetermined data signal, when the second RFID sensor  60   b  detects an elevated water temperature, meaning that the water flowing into the heat exchanger  70  is warmer, the rotation speed of the heat-dissipating motor  50   a  has to be increased to make the hot water generated by the fuel cell  10  enter the heat exchanger  70  quickly, thereby accelerating heat exchange. Similarly, when the second digital signal of the third RFID sensor  60   c  indicates that the water flowing out the heat exchanger  70  becomes warmer, the rotation speed of the heat-storing motor  50   b  has to be increased, so as to prompt the water in the second heat exchange pipe  40  to enter the heat exchanger  70 , thereby improving heat exchange speed and lowering the water temperature detected by the third RFID sensor  60   c.    
     Referring to  FIG. 4 , the RFID reader  80  may further comprise a first memory device  85   a , which is electrically connected to the data collecting unit  84 , so that the data collecting unit  84  is allowed to store the second digital signal in the first memory device  85   a.    
     Moreover, the RFID reader  80  may further comprise a peripheral interface  86 , which is electrically connected to the data collecting unit  84 . The peripheral interface  86  may be a serial port, a parallel port or a universal serial bus, and the second digital signal may be output through the peripheral interface  86 . As shown in  FIG. 5 , the peripheral interface  86  may be further electrically connected to a second memory device  85   b , which similarly serves to store the second digital signal. 
     The present invention has been described with reference to the preferred embodiments and it is understood that the embodiments are not intended to limit the scope of the present invention. Moreover, as the contents disclosed herein should be readily understood and can be implemented by a person skilled in the art, all equivalent changes or modifications which do not depart from the concept of the present invention should be encompassed by the appended claims.