TWI769837B

TWI769837B - Waste heat recovery system and control method thereof

Info

Publication number: TWI769837B
Application number: TW110119392A
Authority: TW
Inventors: 謝瑞青; 賴俊杰
Original assignee: 國立勤益科技大學
Priority date: 2021-05-28
Filing date: 2021-05-28
Publication date: 2022-07-01
Also published as: TW202246638A

Abstract

A waste heat recovery system includes an organic Rankine cycle system and an intermediate heating system. The organic Rankine cycle system includes a first working fluid, an evaporator and a first pump. The evaporator vaporizes the first working fluid at a high pressure, and the first working fluid has an evaporation temperature in the evaporator. The first pump delivers the first working fluid to the evaporator. The intermediate heating system is connected to the organic Rankine cycle system. The intermediate heating system includes a heat exchanger, a second working fluid and a second pump. A flue gas flows through the heat exchanger to perform heat exchange. The second working fluid flows through the heat exchanger to absorb heat energy of the flue gas and has an inlet temperature. The second pump delivers the second working fluid from the evaporator to the heat exchanger. The flue gas has a mass flow rate. The first pump and the second pump control the evaporation temperature of the first working fluid and the inlet temperature of the second working fluid according to a comparison result of the mass flow rate of the flue gas and a predetermined mass flow rate. Therefore, the waste heat recovery system of the present disclosure can adjust the evaporation temperature of the first working fluid and the inlet temperature of the second working fluid, so that it could have better economic benefits than a conventional waste heat recovery system when the flue gas has an unstable mass flow rate.

Description

廢熱回收系統及其控制方法Waste heat recovery system and control method thereof

本發明是關於一種廢熱回收系統及其控制方法，特別是關於一種可隨煙氣流量變動而調整之廢熱回收系統及其控制方法。The present invention relates to a waste heat recovery system and a control method thereof, in particular to a waste heat recovery system and a control method thereof which can be adjusted with the flue gas flow rate.

工業廢熱多以煙氣形式排放至環境中，導致能源使用效率降低且溫室效應加劇，而利用有機朗肯循環(Organic Rankine Cycle，ORC)回收廢熱轉換成電能可有效緩解此情況。然而，煙氣常夾雜汙染物質，若直接進入有機朗肯蒸發器與工作流體進行熱交換，會腐蝕有機朗肯蒸發器，造成系統安全上的疑慮。此外，煙氣為不穩定之熱源，其流量會隨著每天產能的不同或是燃燒廢棄物的多寡而有所浮動，故容易產生較差的發電量及較高的電力生產成本(Electricity Production Cost，EPC)之問題。由此可知，目前市場上缺乏一種安全性高、具有較佳發電量及較低電力生產成本的廢熱回收系統及其控制方法，故相關業者均在尋求其解決之道。Industrial waste heat is mostly discharged into the environment in the form of flue gas, which reduces energy efficiency and intensifies the greenhouse effect. Using the Organic Rankine Cycle (ORC) to recover waste heat and convert it into electricity can effectively alleviate this situation. However, the flue gas is often mixed with pollutants. If it directly enters the organic Rankine evaporator for heat exchange with the working fluid, it will corrode the organic Rankine evaporator and cause system safety concerns. In addition, flue gas is an unstable heat source, and its flow rate will fluctuate with the daily production capacity or the amount of burning waste, so it is easy to generate poor power generation and high power production cost (Electricity Production Cost, EPC) problem. From this, it can be seen that there is currently a lack of a waste heat recovery system and its control method with high safety, better power generation and lower power production cost in the market, so the relevant industry is looking for its solution.

因此，本發明之目的在於提供一種廢熱回收系統及其控制方法，其透過有機朗肯泵浦與熱水迴路泵浦之間的交互作用有效控制熱水入口溫度與工作流體蒸發溫度，使系統在不穩定之煙氣熱源下能具有較佳的發電量及較低的電力生產成本。Therefore, the purpose of the present invention is to provide a waste heat recovery system and a control method thereof, which can effectively control the hot water inlet temperature and the working fluid evaporation temperature through the interaction between the organic Rankine pump and the hot water circuit pump, so that the system can be Under the unstable flue gas heat source, it can have better power generation and lower power production cost.

依據本發明的結構態樣之一實施方式提供一種廢熱回收系統，其用以回收煙氣之煙氣熱能。廢熱回收系統包含有機朗肯循環系統以及熱水迴路系統。其中有機朗肯循環系統包含第一工作流體、有機朗肯蒸發器及有機朗肯泵浦。有機朗肯蒸發器將第一工作流體高壓汽化，第一工作流體於有機朗肯蒸發器內具有一工作流體蒸發溫度。有機朗肯泵浦將第一工作流體傳送至有機朗肯蒸發器。再者，熱水迴路系統連接有機朗肯循環系統，熱水迴路系統包含熱交換器、第二工作流體及熱水迴路泵浦。煙氣流經熱交換器而進行熱交換。第二工作流體流經熱交換器而吸收煙氣熱能且具有一熱水入口溫度。熱水迴路泵浦將第二工作流體從有機朗肯蒸發器傳送至熱交換器。煙氣具有煙氣流量，有機朗肯泵浦與熱水迴路泵浦依據煙氣流量與煙氣流量預設值之比對結果控制工作流體蒸發溫度與熱水入口溫度。According to one embodiment of the structural aspect of the present invention, a waste heat recovery system is provided for recovering the heat energy of flue gas. The waste heat recovery system includes an organic Rankine cycle system and a hot water loop system. The organic Rankine cycle system includes a first working fluid, an organic Rankine evaporator and an organic Rankine pump. The organic Rankine evaporator vaporizes the first working fluid under high pressure, and the first working fluid has a working fluid evaporation temperature in the organic Rankine evaporator. The organic Rankine pump delivers the first working fluid to the organic Rankine evaporator. Furthermore, the hot water circuit system is connected to the organic Rankine cycle system, and the hot water circuit system includes a heat exchanger, a second working fluid and a hot water circuit pump. The flue gas flows through the heat exchanger for heat exchange. The second working fluid flows through the heat exchanger to absorb the thermal energy of the flue gas and has a hot water inlet temperature. The hot water loop pump delivers the second working fluid from the organic Rankine evaporator to the heat exchanger. The flue gas has a flue gas flow, and the organic Rankine pump and the hot water circuit pump control the evaporation temperature of the working fluid and the hot water inlet temperature according to the comparison result of the flue gas flow and the preset value of the flue gas flow.

藉此，本發明的廢熱回收系統透過有機朗肯泵浦與熱水迴路泵浦之間的交互作用有效控制熱水入口溫度與工作流體蒸發溫度，使系統在不穩定之煙氣熱源下能具有較佳的發電量及較低的電力生產成本。Thereby, the waste heat recovery system of the present invention effectively controls the inlet temperature of the hot water and the evaporation temperature of the working fluid through the interaction between the organic Rankine pump and the hot water circuit pump, so that the system can have a stable flue gas heat source. Better power generation and lower electricity production costs.

依據本發明的方法態樣之一實施方式提供一種廢熱回收系統之控制方法，用以回收煙氣之煙氣熱能，廢熱回收系統之控制方法包含以下步驟：參數獲得步驟與泵浦控制步驟。其中參數獲得步驟係驅動廢熱回收系統獲得煙氣之煙氣流量、煙氣流量預設值、工作流體蒸發溫度及熱水入口溫度。而泵浦控制步驟係驅動有機朗肯泵浦與熱水迴路泵浦依據煙氣流量與煙氣流量預設值之比對結果控制熱水入口溫度與工作流體蒸發溫度。According to an embodiment of the method aspect of the present invention, there is provided a control method of a waste heat recovery system for recovering flue gas heat energy of flue gas. The control method of the waste heat recovery system includes the following steps: a parameter acquisition step and a pump control step. The parameter obtaining step is to drive the waste heat recovery system to obtain the flue gas flow of the flue gas, the preset value of the flue gas flow, the evaporation temperature of the working fluid and the inlet temperature of the hot water. The pump control step is to drive the organic Rankine pump and the hot water circuit pump to control the hot water inlet temperature and the working fluid evaporation temperature according to the comparison result of the flue gas flow and the preset value of the flue gas flow.

藉此，本發明的廢熱回收系統之控制方法透過有機朗肯泵浦與熱水迴路泵浦之間的交互作用有效控制熱水入口溫度與工作流體蒸發溫度，使系統在不穩定之煙氣熱源下能具有較佳的發電量及較低的電力生產成本。Thereby, the control method of the waste heat recovery system of the present invention effectively controls the inlet temperature of the hot water and the evaporation temperature of the working fluid through the interaction between the organic Rankine pump and the hot water circuit pump, so that the system can be used in an unstable flue gas heat source. Lower energy has better power generation and lower power production cost.

請參閱第1圖，第1圖係繪示本發明第一實施例的廢熱回收系統100的示意圖。廢熱回收系統100用以回收煙氣110之煙氣熱能。廢熱回收系統100包含有機朗肯循環系統200、熱水迴路系統300及冷卻循環系統400。Please refer to FIG. 1. FIG. 1 is a schematic diagram of a waste heat recovery system 100 according to a first embodiment of the present invention. The waste heat recovery system 100 is used to recover the heat energy of the flue gas from the flue gas 110 . The waste heat recovery system 100 includes an organic Rankine cycle system 200 , a hot water circuit system 300 and a cooling cycle system 400 .

有機朗肯循環系統200包含第一工作流體210、有機朗肯蒸發器220、有機朗肯泵浦230、有機朗肯膨脹器240及有機朗肯冷凝器250。其中第一工作流體210可為臨界溫度低於200°C之冷媒，例如：R245fa、R123、R1234ze(Z)，但本發明不以此為限。有機朗肯蒸發器220將第一工作流體210高壓汽化，第一工作流體210於有機朗肯蒸發器220內具有工作流體蒸發溫度T _eva，工作流體蒸發溫度T _eva可藉由有機朗肯泵浦230所提供之壓力(亦稱為蒸發壓力，P _eva)所調整。有機朗肯泵浦230連接有機朗肯蒸發器220並將第一工作流體210傳送至有機朗肯蒸發器220。有機朗肯膨脹器240連接於有機朗肯蒸發器220，有機朗肯膨脹器240接收高壓汽化後之第一工作流體210，以使高壓汽化後之第一工作流體210膨脹並且降壓，有機朗肯膨脹器240被第一工作流體210驅動以產生旋轉軸功。有機朗肯冷凝器250連接於有機朗肯膨脹器240與有機朗肯泵浦230之間，有機朗肯冷凝器250接收降壓後之第一工作流體210，以使降壓後之第一工作流體210液化。換言之，有機朗肯泵浦230是將液化後之第一工作流體210從有機朗肯冷凝器250傳送至有機朗肯蒸發器220，第一工作流體210流經有機朗肯泵浦230、有機朗肯蒸發器220、有機朗肯膨脹器240及有機朗肯冷凝器250以形成迴路。此外，有機朗肯泵浦230包含有機朗肯變頻器，有機朗肯變頻器具有第一頻率，第一工作流體210具有第一流量ṁ _wf(mass flow rate of working fluid)，且第一頻率與第一流量ṁ _wf及工作流體蒸發溫度T _eva為正相關。 The organic Rankine cycle system 200 includes a first working fluid 210 , an organic Rankine evaporator 220 , an organic Rankine pump 230 , an organic Rankine expander 240 and an organic Rankine condenser 250 . The first working fluid 210 may be a refrigerant with a critical temperature lower than 200°C, such as R245fa, R123, R1234ze(Z), but the invention is not limited to this. The organic Rankine evaporator 220 vaporizes the first working fluid 210 at high pressure. The first working fluid 210 has a working fluid evaporation temperature T _eva in the organic Rankine evaporator 220 , and the working fluid evaporation temperature T _eva can be pumped by the organic Rankine pump. The pressure provided by 230 (also known as the evaporative pressure, P _eva ) is adjusted. The organic Rankine pump 230 is connected to the organic Rankine evaporator 220 and delivers the first working fluid 210 to the organic Rankine evaporator 220 . The organic Rankine expander 240 is connected to the organic Rankine evaporator 220. The organic Rankine expander 240 receives the first working fluid 210 after high pressure vaporization, so as to expand and depressurize the first working fluid 210 after the high pressure vaporization. The Ken expander 240 is driven by the first working fluid 210 to generate rotational shaft work. The organic Rankine condenser 250 is connected between the organic Rankine expander 240 and the organic Rankine pump 230, and the organic Rankine condenser 250 receives the depressurized first working fluid 210, so as to make the depressurized first working fluid 210 Fluid 210 liquefies. In other words, the organic Rankine pump 230 transfers the liquefied first working fluid 210 from the organic Rankine condenser 250 to the organic Rankine evaporator 220 , and the first working fluid 210 flows through the organic Rankine pump 230 and the organic Rankine pump 230 . A Ken evaporator 220, an organic Rankine expander 240 and an organic Rankine condenser 250 form a loop. In addition, the organic Rankine pump 230 includes an organic Rankine inverter, the organic Rankine inverter has a first frequency, the first working fluid 210 has a first mass flow rate _ṁwf (mass flow rate of working fluid), and the first frequency is the same as The first flow rate ṁ _wf and the working fluid evaporation temperature T _eva are positively correlated.

熱水迴路系統300連接有機朗肯循環系統200，熱水迴路系統300包含熱交換器310、第二工作流體320及熱水迴路泵浦330。煙氣110流經熱交換器310而進行熱交換。第二工作流體320流經熱交換器310而吸收煙氣熱能且具有熱水入口溫度T _{hw_in}，然後第二工作流體320會流經有機朗肯蒸發器220。第二工作流體320進入有機朗肯蒸發器220的溫度為熱水入口溫度T _{hw_in}，第二工作流體320離開有機朗肯蒸發器220的溫度為熱水出口溫度T _{hw_out}。熱水迴路泵浦330將第二工作流體320從有機朗肯蒸發器220傳送至熱交換器310。煙氣110具有煙氣流量ṁ _f，有機朗肯泵浦230與熱水迴路泵浦330依據煙氣流量ṁ _f與煙氣流量預設值之比對結果控制工作流體蒸發溫度T _eva與熱水入口溫度T _{hw_in}。此外，熱水迴路泵浦330包含熱水迴路變頻器，熱水迴路變頻器具有第二頻率，第二工作流體320具有第二流量ṁ _hw(mass flow rate of hot water)，且第二頻率與第二流量ṁ _hw為正相關。在一實施例中，熱交換器310可為鰭管式熱交換器或熱管熱交換器。煙氣110進入熱交換器310的煙氣入口溫度T _{f_in}可為500°C，煙氣110離開熱交換器310的煙氣出口溫度T _{f_out}可為179°C至182°C。煙氣流量預設值可為10kg/s，但本發明不以此為限。 The hot water circuit system 300 is connected to the organic Rankine cycle system 200 , and the hot water circuit system 300 includes a heat exchanger 310 , a second working fluid 320 and a hot water circuit pump 330 . The flue gas 110 flows through the heat exchanger 310 for heat exchange. The second working fluid 320 flows through the heat exchanger 310 to absorb the thermal energy of the flue gas and has a hot water inlet temperature T _hw — in , and then the second working fluid 320 flows through the organic Rankine evaporator 220 . The temperature of the second working fluid 320 entering the organic Rankine evaporator 220 is the hot water inlet temperature T _{hw_in} , and the temperature of the second working fluid 320 leaving the organic Rankine evaporator 220 is the hot water outlet temperature T _{hw_out} . The hot water circuit pump 330 delivers the second working fluid 320 from the organic Rankine evaporator 220 to the heat exchanger 310 . The flue gas 110 has a flue gas flow rate ṁ _f , and the organic Rankine pump 230 and the hot water circuit pump 330 control the working fluid evaporation temperature T _eva and the hot water according to the comparison result of the flue gas flow rate ṁ _f and a preset value of the flue gas flow rate Inlet temperature T _{hw_in} . In addition, the hot water circuit pump 330 includes a hot water circuit frequency converter, the hot water circuit frequency converter has a second frequency, the second working fluid 320 has a second mass flow rate ṁ _hw (mass flow rate of hot water), and the second frequency is the same as The second flow ṁ _hw is positively correlated. In one embodiment, the heat exchanger 310 may be a fin-and-tube heat exchanger or a heat-pipe heat exchanger. The flue gas inlet temperature T _{f_in} of the flue gas 110 entering the heat exchanger 310 may be 500°C, and the flue gas outlet temperature T _{f_out} of the flue gas 110 leaving the heat exchanger 310 may be 179°C to 182°C. The preset value of the flue gas flow rate may be 10kg/s, but the present invention is not limited to this.

冷卻循環系統400連接有機朗肯循環系統200。冷卻循環系統400包含一冷卻流體410、冷卻水塔420、冷卻泵浦430及發電機440，其中冷卻流體410流經有機朗肯冷凝器250並吸收第一工作流體210液化所放出之熱能。冷卻水塔420接收經過吸收熱能後之冷卻流體410，以使吸收熱能後之冷卻流體410冷卻。冷卻泵浦430將冷卻後之冷卻流體410傳送至有機朗肯冷凝器250。冷卻泵浦430可依需求透過變頻器調整冷卻流體410之流量。此外，發電機440透過軸連接器連接有機朗肯膨脹器240，發電機440接收有機朗肯膨脹器240之旋轉軸功而發電。The cooling cycle system 400 is connected to the organic Rankine cycle system 200 . The cooling circulation system 400 includes a cooling fluid 410 , a cooling water tower 420 , a cooling pump 430 and a generator 440 , wherein the cooling fluid 410 flows through the organic Rankine condenser 250 and absorbs the heat energy released by the liquefaction of the first working fluid 210 . The cooling water tower 420 receives the cooling fluid 410 after absorbing thermal energy to cool the cooling fluid 410 after absorbing thermal energy. The cooling pump 430 delivers the cooled cooling fluid 410 to the organic Rankine condenser 250 . The cooling pump 430 can adjust the flow rate of the cooling fluid 410 through the frequency converter as required. In addition, the generator 440 is connected to the organic Rankine expander 240 through a shaft connector, and the generator 440 receives the rotating shaft work of the organic Rankine expander 240 to generate electricity.

舉例來說，當比對結果為煙氣流量ṁ _f高於煙氣流量預設值時，有機朗肯泵浦230之第一頻率可維持不變，熱水迴路泵浦330之第二頻率可增加，使工作流體蒸發溫度T _eva維持在一蒸發溫度預設值，第二流量ṁ _hw增加而高於一第二流量預設值，且熱水入口溫度T _{hw_in}維持於一熱水溫度預設值。再者，當比對結果為煙氣流量ṁ _f低於煙氣流量預設值時，第一頻率與第二頻率可均維持不變，使工作流體蒸發溫度T _eva維持在蒸發溫度預設值，第二流量ṁ _hw維持在第二流量預設值，且熱水入口溫度T _{hw_in}低於熱水溫度預設值。另外，當比對結果為煙氣流量ṁ _f低於煙氣流量預設值時，第一頻率可降低，第二頻率可維持不變，使第一流量ṁ _wf降低而低於第一流量預設值，工作流體蒸發溫度T _eva降低而低於蒸發溫度預設值，第二流量ṁ _hw維持在第二流量預設值，且熱水入口溫度T _{hw_in}維持於熱水溫度預設值。換言之，透過減少有機朗肯蒸發器220取熱量，以有效保持系統的經濟效益。上述之蒸發溫度預設值可為105°C，熱水溫度預設值可為160°C，但本發明不以此為限。 For example, when the comparison result is that the flue gas flow ṁ _{f is} higher than the preset value of flue gas flow, the first frequency of the organic Rankine pump 230 can remain unchanged, and the second frequency of the hot water circuit pump 330 can be increase, so that the working fluid evaporation temperature T _eva is maintained at a predetermined evaporation temperature value, the second flow rate ṁ _hw is increased to be higher than a second predetermined flow rate value, and the hot water inlet temperature T _{hw_in is} maintained at a predetermined hot water temperature value. Furthermore, when the comparison result is that the flue gas flow rate ṁ _f is lower than the preset value of the flue gas flow rate, the first frequency and the second frequency can both remain unchanged, so that the evaporation temperature T _eva of the working fluid is maintained at the preset value of the evaporation temperature. , the second flow rate ṁ _hw is maintained at the second preset flow rate value, and the hot water inlet temperature T _{hw_in} is lower than the hot water temperature preset value. In addition, when the comparison result is that the flue gas flow rate ṁ _f is lower than the preset value of the flue gas flow rate, the first frequency can be reduced, and the second frequency can be maintained unchanged, so that the first flow rate ṁ _wf is decreased and is lower than the first flow rate preset value. The setting value, the working fluid evaporation temperature T _eva is decreased and is lower than the predetermined value of the evaporation temperature, the second flow rate ṁ _hw is maintained at the second predetermined flow rate value, and the hot water inlet temperature T _{hw_in is} maintained at the predetermined value of the hot water temperature. In other words, the economic benefits of the system can be effectively maintained by reducing the amount of heat taken by the organic Rankine evaporator 220 . The above-mentioned preset value of the evaporation temperature may be 105°C, and the preset value of the hot water temperature may be 160°C, but the present invention is not limited thereto.

藉此，本發明之廢熱回收系統100透過有機朗肯泵浦230與熱水迴路泵浦330之間的交互作用有效控制熱水入口溫度T _{hw_in}與工作流體蒸發溫度T _eva，使系統在不穩定之煙氣110熱源下能具有較佳的發電量及較低的電力生產成本。 Thereby, the waste heat recovery system 100 of the present invention effectively controls the hot water inlet temperature T _{hw_in} and the working fluid evaporation temperature T _eva through the interaction between the organic Rankine pump 230 and the hot water circuit pump 330 , so that the system is unstable in The heat source of the flue gas 110 can have better power generation and lower power production cost.

請一併參閱第1圖與第2圖，第2圖係繪示本發明第二實施例的廢熱回收系統之控制方法500的流程示意圖。廢熱回收系統之控制方法500用以回收煙氣110之煙氣熱能，廢熱回收系統之控制方法500包含參數獲得步驟S2與泵浦控制步驟S4。Please refer to FIG. 1 and FIG. 2 together. FIG. 2 is a schematic flowchart illustrating a control method 500 of a waste heat recovery system according to a second embodiment of the present invention. The control method 500 of the waste heat recovery system is used for recovering the heat energy of the flue gas 110 . The control method 500 of the waste heat recovery system includes a parameter obtaining step S2 and a pump control step S4 .

參數獲得步驟S2係驅動廢熱回收系統100獲得煙氣110之煙氣流量ṁ _f、煙氣流量預設值、工作流體蒸發溫度T _eva及熱水入口溫度T _{hw_in}。在一實施例中，廢熱回收系統100可包含感測器模組與控制處理器，感測器模組包含煙氣感測器、第一溫度感測器、壓力感測器及第二溫度感測器，其中煙氣感測器用以感測煙氣110之煙氣流量ṁ _f，第一溫度感測器用以感測工作流體蒸發溫度T _eva，壓力感測器用以感測壓力P _eva，第二溫度感測器用以感測熱水入口溫度T _{hw_in}。控制處理器電性連接感測器模組、有機朗肯泵浦230及熱水迴路泵浦330，控制處理器依據煙氣流量ṁ _f控制有機朗肯泵浦230及熱水迴路泵浦330。控制處理器可為電腦、微處理器或其他電子處理裝置。 The parameter obtaining step S2 is to drive the waste heat recovery system 100 to obtain the flue gas flow ṁ _f of the flue gas 110 , the preset value of the flue gas flow, the working fluid evaporation temperature T _eva and the hot water inlet temperature T _{hw_in} . In one embodiment, the waste heat recovery system 100 may include a sensor module and a control processor. The sensor module includes a flue gas sensor, a first temperature sensor, a pressure sensor, and a second temperature sensor. The flue gas sensor is used for sensing the flue gas flow rate ṁ _f of the flue gas 110 , the first temperature sensor is used for sensing the working fluid evaporation temperature T _eva , the pressure sensor is used for sensing the pressure P _eva , the second Two temperature sensors are used for sensing the hot water inlet temperature T _{hw_in} . The control processor is electrically connected to the sensor module, the organic Rankine pump 230 and the hot water circuit pump 330, and the control processor controls the organic Rankine pump 230 and the hot water circuit pump 330 according to the flue gas flow _ṁf . The control processor may be a computer, microprocessor or other electronic processing device.

泵浦控制步驟S4係驅動有機朗肯泵浦230與熱水迴路泵浦330依據煙氣流量ṁ _f與煙氣流量預設值之比對結果控制熱水入口溫度T _{hw_in}與工作流體蒸發溫度T _eva。藉此，本發明的廢熱回收系統之控制方法500透過有機朗肯泵浦230與熱水迴路泵浦330之間的交互作用有效控制熱水入口溫度T _{hw_in}與工作流體蒸發溫度T _eva，使系統在不穩定之煙氣110熱源下能具有較佳的發電量及較低的電力生產成本。 The pump control step S4 is to drive the organic Rankine pump 230 and the hot water circuit pump 330 to control the hot water inlet temperature T _{hw_in} and the working fluid evaporation temperature T according to the comparison result of the flue gas flow ṁ _f and the preset value of the flue gas flow _eva . Thereby, the control method 500 of the waste heat recovery system of the present invention effectively controls the hot water inlet temperature T _{hw_in} and the working fluid evaporation temperature T _eva through the interaction between the organic Rankine pump 230 and the hot water loop pump 330 , so that the system Under the unstable heat source of flue gas 110, it can have better power generation and lower power production cost.

由上述實施方式可知，本發明具有下列優點：其一，透過有機朗肯泵浦與熱水迴路泵浦之間的交互作用有效控制熱水入口溫度與工作流體蒸發溫度，使系統在不穩定之煙氣熱源下能具有較佳的發電量及較低的電力生產成本。其二，利用熱水迴路系統與煙氣廢熱進行熱交換，可有效緩衝煙氣對系統的影響，大幅增加安全性。其三，有機朗肯泵浦、熱水迴路泵浦及鰭管式熱交換器之搭配可實現最佳之有效度，並保持系統的經濟效益。It can be seen from the above-mentioned embodiments that the present invention has the following advantages: firstly, through the interaction between the organic Rankine pump and the hot water circuit pump, the hot water inlet temperature and the working fluid evaporation temperature are effectively controlled, so that the system can be stabilized under unstable conditions. The flue gas heat source can have better power generation and lower power production cost. Second, the use of the hot water circuit system to exchange heat with the waste heat of the flue gas can effectively buffer the impact of the flue gas on the system and greatly increase the safety. Third, the combination of organic Rankine pump, hot water circuit pump and fin-and-tube heat exchanger can achieve the best efficiency and maintain the economic benefits of the system.

雖然本發明已以實施方式揭露如上，然其並非用以限定本發明，任何熟習此技藝者，在不脫離本發明之精神和範圍內，當可作各種之更動與潤飾，因此本發明之保護範圍當視後附之申請專利範圍所界定者為準。Although the present invention has been disclosed in the above embodiments, it is not intended to limit the present invention. Anyone skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection of the present invention The scope shall be determined by the scope of the appended patent application.

100:廢熱回收系統100: Waste Heat Recovery System

110:煙氣110: Smoke

200:有機朗肯循環系統200: Organic Rankine Cycle System

210:第一工作流體210: First working fluid

220:有機朗肯蒸發器220: Organic Rankine Evaporator

230:有機朗肯泵浦230: Organic Rankine Pump

240:有機朗肯膨脹器240: Organic Rankine Expander

250:有機朗肯冷凝器250: Organic Rankine Condenser

300:熱水迴路系統300: Hot water circuit system

310:熱交換器310: Heat Exchanger

320:第二工作流體320: Second working fluid

330:熱水迴路泵浦330: Hot water circuit pump

400:冷卻循環系統400: Cooling Circulation System

410:冷卻流體410: Cooling Fluid

420:冷卻水塔420: Cooling water tower

430:冷卻泵浦430: Cooling Pump

440:發電機440: Generator

500:廢熱回收系統之控制方法500: Control method of waste heat recovery system

S2:參數獲得步驟S2: Parameter acquisition step

S4:泵浦控制步驟S4: Pump Control Step

ṁ _f:煙氣流量ṁ _f : flue gas flow

ṁ _hw:第二流量ṁ _hw : second flow

ṁ _wf:第一流量ṁ _wf : first traffic

T _eva:工作流體蒸發溫度T _eva : working fluid evaporation temperature

T _{f_in}:煙氣入口溫度T _{f_in} : flue gas inlet temperature

T _{f_out}:煙氣出口溫度T _{f_out} : flue gas outlet temperature

T _{hw_in}:熱水入口溫度T _{hw_in} : hot water inlet temperature

T _{hw_out}:熱水出口溫度T _{hw_out} : hot water outlet temperature

第1圖係繪示本發明第一實施例的廢熱回收系統的示意圖；以及第2圖係繪示本發明第二實施例的廢熱回收系統之控制方法的流程示意圖。 FIG. 1 is a schematic diagram illustrating a waste heat recovery system according to a first embodiment of the present invention; and FIG. 2 is a schematic flow chart illustrating a control method of a waste heat recovery system according to a second embodiment of the present invention.

100:廢熱回收系統 100: Waste Heat Recovery System

110:煙氣 110: Smoke

200:有機朗肯循環系統 200: Organic Rankine Cycle System

210:第一工作流體 210: First working fluid

220:有機朗肯蒸發器 220: Organic Rankine Evaporator

230:有機朗肯泵浦 230: Organic Rankine Pump

240:有機朗肯膨脹器 240: Organic Rankine Expander

250:有機朗肯冷凝器 250: Organic Rankine Condenser

300:熱水迴路系統 300: Hot water circuit system

310:熱交換器 310: Heat Exchanger

320:第二工作流體 320: Second working fluid

330:熱水迴路泵浦 330: Hot water circuit pump

400:冷卻循環系統 400: Cooling Circulation System

410:冷卻流體 410: Cooling Fluid

420:冷卻水塔 420: Cooling water tower

430:冷卻泵浦 430: Cooling Pump

440:發電機 440: Generator

:煙氣流量

: flue gas flow

:第二流量

: second flow

:第一流量

: first flow

T_eva:工作流體蒸發溫度 T _eva : working fluid evaporation temperature

T_{f_in}:煙氣入口溫度 T _{f_in} : flue gas inlet temperature

T_{f_out}:煙氣出口溫度 T _{f_out} : flue gas outlet temperature

T_{hw_in}:熱水入口溫度 T _{hw_in} : hot water inlet temperature

T_{hw_out}:熱水出口溫度 T _{hw_out} : hot water outlet temperature

Claims

一種廢熱回收系統，用以回收一煙氣之一煙氣熱能，該廢熱回收系統包含：一有機朗肯循環系統，包含：一第一工作流體；一有機朗肯蒸發器，將該第一工作流體高壓汽化，該第一工作流體於該有機朗肯蒸發器內具有一工作流體蒸發溫度；及一有機朗肯泵浦，將該第一工作流體傳送至該有機朗肯蒸發器；以及一熱水迴路系統，連接該有機朗肯循環系統，該熱水迴路系統包含：一熱交換器，該煙氣流經該熱交換器而進行熱交換；一第二工作流體，流經該熱交換器而吸收該煙氣熱能且具有一熱水入口溫度；及一熱水迴路泵浦，將該第二工作流體從該有機朗肯蒸發器傳送至該熱交換器；其中，該煙氣具有一煙氣流量，該有機朗肯泵浦與該熱水迴路泵浦依據該煙氣流量與一煙氣流量預設值之一比對結果控制該工作流體蒸發溫度與該熱水入口溫度；其中，該有機朗肯泵浦包含一有機朗肯變頻器，該有機朗肯變頻器具有一第一頻率，該第一工作流體具有一第一流量，且該第一頻率與該第一流量及該工作流體蒸發溫度為正相關；其中，該熱水迴路泵浦包含一熱水迴路變頻器，該熱水迴路變頻器具有一第二頻率，該第二工作流體具有一第二流量，且該第二頻率與該第二流量為正相關；其中，當該比對結果為該煙氣流量高於該煙氣流量預設值時，該第一頻率維持不變，該第二頻率增加，該工作流體蒸發溫度維持在一蒸發溫度預設值，該第二流量增加而高於一第二流量預設值，且該熱水入口溫度維持於一熱水溫度預設值。 A waste heat recovery system is used to recover the thermal energy of a flue gas, the waste heat recovery system includes: an organic Rankine cycle system, including: a first working fluid; an organic Rankine evaporator, the first working fluid high pressure vaporization of fluid, the first working fluid has a working fluid vaporization temperature in the organic Rankine evaporator; and an organic Rankine pump to deliver the first working fluid to the organic Rankine evaporator; and a heat A water circuit system is connected to the organic Rankine cycle system, the hot water circuit system includes: a heat exchanger, the flue gas flows through the heat exchanger for heat exchange; a second working fluid flows through the heat exchanger to Absorbing the thermal energy of the flue gas and having a hot water inlet temperature; and a hot water circuit pump to transmit the second working fluid from the organic Rankine evaporator to the heat exchanger; wherein the flue gas has a flue gas flow, the organic Rankine pump and the hot water circuit pump control the evaporation temperature of the working fluid and the inlet temperature of the hot water according to a comparison result between the flue gas flow and a preset value of the flue gas flow; The Rankine pump includes an organic Rankine frequency converter, the organic Rankine frequency converter has a first frequency, the first working fluid has a first flow rate, and the first frequency is related to the first flow rate and the evaporation temperature of the working fluid is positively correlated; Wherein, the hot water circuit pump includes a hot water circuit frequency converter, the hot water circuit frequency converter has a second frequency, the second working fluid has a second flow rate, and the second frequency and the second flow rate are positive wherein, when the comparison result is that the flue gas flow rate is higher than the preset value of the flue gas flow rate, the first frequency remains unchanged, the second frequency increases, and the evaporation temperature of the working fluid is maintained at a predetermined evaporation temperature A set value, the second flow rate increases and is higher than a second flow rate preset value, and the hot water inlet temperature is maintained at a hot water temperature preset value.

如請求項1所述之廢熱回收系統，其中該有機朗肯循環系統更包含：一有機朗肯膨脹器，連接於該有機朗肯蒸發器，該有機朗肯膨脹器接收高壓汽化後之該第一工作流體，以使高壓汽化後之該第一工作流體膨脹降壓，該有機朗肯膨脹器被該第一工作流體驅動以產生一旋轉軸功；及一有機朗肯冷凝器，連接於該有機朗肯膨脹器與該有機朗肯泵浦之間，該有機朗肯冷凝器接收降壓後之該第一工作流體，以使降壓後之該第一工作流體液化；其中，該有機朗肯泵浦將液化後之該第一工作流體從該有機朗肯冷凝器傳送至該有機朗肯蒸發器，該第一工作流體流經該有機朗肯泵浦、該有機朗肯蒸發器、該有機朗肯膨脹器及該有機朗肯冷凝器以形成迴路。 The waste heat recovery system according to claim 1, wherein the organic Rankine cycle system further comprises: an organic Rankine expander connected to the organic Rankine evaporator, and the organic Rankine expander receives the first organic Rankine after high-pressure vaporization. a working fluid to expand and depressurize the first working fluid after high-pressure vaporization, the organic Rankine expander is driven by the first working fluid to generate a rotating shaft work; and an organic Rankine condenser connected to the Between the organic Rankine expander and the organic Rankine pump, the organic Rankine condenser receives the depressurized first working fluid to liquefy the depressurized first working fluid; wherein the organic Rankine condenser The first working fluid after liquefaction is transferred from the organic Rankine condenser to the organic Rankine evaporator, and the first working fluid flows through the organic Rankine pump, the organic Rankine evaporator, and the organic Rankine evaporator. The organic Rankine expander and the organic Rankine condenser form a loop.

如請求項2所述之廢熱回收系統，更包含：一冷卻循環系統，連接該有機朗肯循環系統，該冷卻循環系統包含：一冷卻流體，流經該有機朗肯冷凝器並吸收該第一工作流體液化所放出之熱能；一冷卻水塔，接收吸收熱能後之該冷卻流體，以使吸收熱能後之該冷卻流體冷卻；及一冷卻泵浦，將冷卻後之該冷卻流體傳送至該有機朗肯冷凝器。 The waste heat recovery system as described in claim 2, further comprising: A cooling cycle system, connected to the organic Rankine cycle system, the cooling cycle system includes: a cooling fluid, flowing through the organic Rankine condenser and absorbing the heat energy released by the liquefaction of the first working fluid; a cooling water tower, receiving and absorbing The cooling fluid after thermal energy is used to cool the cooling fluid after absorbing thermal energy; and a cooling pump sends the cooled cooling fluid to the organic Rankine condenser.

如請求項1所述之廢熱回收系統，其中，當該比對結果為該煙氣流量低於該煙氣流量預設值時，該第一頻率與該第二頻率均維持不變，使該工作流體蒸發溫度維持在該蒸發溫度預設值，該第二流量維持在該第二流量預設值，且該熱水入口溫度低於該熱水溫度預設值。 The waste heat recovery system according to claim 1, wherein when the comparison result is that the flue gas flow rate is lower than the preset value of the flue gas flow rate, both the first frequency and the second frequency remain unchanged, so that the The evaporation temperature of the working fluid is maintained at the preset value of the evaporation temperature, the second flow rate is maintained at the preset value of the second flow rate, and the inlet temperature of the hot water is lower than the preset value of the hot water temperature.

如請求項4所述之廢熱回收系統，其中，當該比對結果為該煙氣流量低於該煙氣流量預設值時，該第一頻率降低，該第二頻率維持不變，使該第一流量降低而低於該第一流量預設值，該工作流體蒸發溫度降低而低於該蒸發溫度預設值，該第二流量維持在該第二流量預設值，且該熱水入口溫度維持於該熱水溫度預設值。 The waste heat recovery system according to claim 4, wherein when the comparison result is that the flue gas flow rate is lower than the preset value of the flue gas flow rate, the first frequency is decreased, and the second frequency is maintained unchanged, so that the The first flow rate decreases and is lower than the first preset value of the flow rate, the evaporation temperature of the working fluid decreases and is lower than the preset value of the evaporation temperature, the second flow rate is maintained at the preset value of the second flow rate, and the hot water inlet The temperature is maintained at the hot water temperature preset value.

一種使用如請求項1所述之廢熱回收系統之控制方法，用以回收一煙氣之一煙氣熱能，該廢熱回收系統之控制方法包含以下步驟：一參數獲得步驟，係驅動該廢熱回收系統獲得該煙氣之該煙氣流量、該煙氣流量預設值、該工作流體蒸發溫度及該熱水入口溫度；以及一泵浦控制步驟，係驅動該有機朗肯泵浦與該熱水迴路泵浦依據該煙氣流量與該煙氣流量預設值之該比對結果控制該熱水入口溫度與該工作流體蒸發溫度；其中，該有機朗肯泵浦包含該有機朗肯變頻器，該有機朗肯變頻器具有該第一頻率，該第一工作流體具有該第一流量，且該第一頻率與該第一流量及該工作流體蒸發溫度為正相關；其中，該熱水迴路泵浦包含該熱水迴路變頻器，該熱水迴路變頻器具有該第二頻率，該第二工作流體具有該第二流量，且該第二頻率與該第二流量為正相關；其中，當該比對結果為該煙氣流量高於該煙氣流量預設值時，該第一頻率維持不變，該第二頻率增加，該工作流體蒸發溫度維持在該蒸發溫度預設值，該第二流量增加而高於該第二流量預設值，且該熱水入口溫度維持於該熱水溫度預設值。 A control method using the waste heat recovery system as claimed in claim 1 to recover a flue gas to heat energy of a flue gas, the waste heat recovery system The control method of the system includes the following steps: a parameter obtaining step, which drives the waste heat recovery system to obtain the flue gas flow rate of the flue gas, the preset value of the flue gas flow rate, the evaporation temperature of the working fluid and the inlet temperature of the hot water; and a pump control step, driving the organic Rankine pump and the hot water circuit pump to control the hot water inlet temperature and the evaporation of the working fluid according to the comparison result between the flue gas flow rate and the preset value of the flue gas flow rate temperature; wherein, the organic Rankine pump includes the organic Rankine frequency converter, the organic Rankine frequency converter has the first frequency, the first working fluid has the first flow rate, and the first frequency and the first frequency The flow rate and the evaporation temperature of the working fluid are positively correlated; wherein, the hot water circuit pump includes the hot water circuit frequency converter, the hot water circuit frequency converter has the second frequency, and the second working fluid has the second flow rate, And the second frequency is positively correlated with the second flow; wherein, when the comparison result is that the flue gas flow is higher than the preset value of the flue gas flow, the first frequency remains unchanged, and the second frequency increases , the evaporation temperature of the working fluid is maintained at the preset value of the evaporation temperature, the second flow rate is increased to be higher than the preset value of the second flow rate, and the inlet temperature of the hot water is maintained at the preset value of the hot water temperature.

如請求項6所述之廢熱回收系統之控制方法，其中，當該比對結果為該煙氣流量低於該煙氣流量預設值時，該第一頻率與該第二頻率均維持不變，該工作流體蒸發溫度維持在該蒸發溫度預設值，該第二流量維持在該第二流量預設值，且該熱水入口溫度低於該熱水溫度預設值。 The control method of the waste heat recovery system according to claim 6, wherein when the comparison result is that the flue gas flow rate is lower than the preset value of the flue gas flow rate, the first frequency and the second frequency remain unchanged , the working fluid evaporation temperature The temperature is maintained at the preset value of the evaporating temperature, the second flow rate is maintained at the preset value of the second flow rate, and the inlet temperature of the hot water is lower than the preset value of the hot water temperature.

如請求項7所述之廢熱回收系統之控制方法，其中，當該比對結果為該煙氣流量低於該煙氣流量預設值時，該第一頻率降低，該第二頻率維持不變，使該第一流量降低而低於該第一流量預設值，該工作流體蒸發溫度降低而低於該蒸發溫度預設值，該第二流量維持在該第二流量預設值，且該熱水入口溫度維持於該熱水溫度預設值。 The control method for a waste heat recovery system according to claim 7, wherein when the comparison result is that the flue gas flow rate is lower than the preset value of the flue gas flow rate, the first frequency is decreased, and the second frequency is maintained unchanged , the first flow rate is decreased to be lower than the first preset value of the flow rate, the evaporation temperature of the working fluid is decreased to be lower than the preset value of the evaporation temperature, the second flow rate is maintained at the preset value of the second flow rate, and the The hot water inlet temperature is maintained at the hot water temperature preset value.