- 期刊
提昇天然氣(NG1)混合熱值穩定度之研究
The Study on Improving the Blending Stability of Calorific Value of NG1 Natural Gas
摘要
台灣中北部市場所使用之天然氣NG1，係經由鐵砧山礦場自產較高熱值約9,750Kcal/sm^3天然氣摻入進口高熱值約9,950Kcal/sm^3天然氣NG2後，再與自產低熱值約5,350Kcal/sm^3LTS氣互相混合為8,900Kcal/sm^3所得之摻混氣。 鐵砧山礦場約9,750Kcal/sm^3天然氣產量約10%，與進口約9,950Kcal/sm^3天然氣約佔67%，在南勢配氣站作第一階段混合，混合後氣體稱為高熱值氣（熱值約9,800Kcal/sm^3），再輸至中平配氣站作第二階段摻混，其以自產低熱值5,350Kcal/sm^3之LTS氣與經第一階段高熱值9,800Kcal/sm^3氣摻混完成8,900Kcal/sm^3NG1成品氣。自產低熱值氣體與高熱值氣體於配氣頭依等比例摻混，下游管路設有混合器(Mixer)、四組彎頭供作攪拌、混合，混合之後的NG1天然氣隨即供應市場使用。所有操作控制以使用電腦設備，取代人工粗糙操作，並以電腦軟體技術整合天然氣計量、類比信號輸入／輸出、電動閥開／關控制、JET調壓設備操作、流量控制閥開度操作摻配混合、以及遠端遙控南勢配氣站自動升／降壓操作等繁瑣操作程序。 NG1天然氣主要供應台灣中北部工業與家庭用，其用氣特性與氣溫有顯著關聯，天氣越冷，用氣量越多，相對的市場不需用氣時之回壓也會非常迅速。若以用氣時段來區分，則以工廠上班之週一至週五使用量最大。以用氣時間來區分，因商業、家庭用氣集中於每日下午6時起至晚上11時這段時間達到供氣高峰。本文是以改善製程設備與方法，探討兩種不同熱值氣體摻配控制，則即使氣源不同，控制混合後熱值在規定穩定範圍內。
並列摘要
The NG1 calorific value of 8,900 Kcal/sm^3, consumed in the central and northern market, is the mixture of the following: (1). indigenous gas from TCS with higher calorific value of 9,750 Kcal/sm^3, (2). Imported gas with higher calorific value of 9,950 Kcal/sm^3 (NG2), and (3). indigenous LTS gas with lower calorific value of 5,350 Kcal/sm^3. The blended gas after the first phase blending of indigenous gas from TCS and imported gas at Nan Shi distributional gas station is called ”high calorific value gas” (about 9,800 Kcal/sm^3). This ”high calorific value gas” is then sent to Chung Ping distributional gas station for the second phase blending. The blended gas of ”high calorific value gas” (about 9,800 Kcal/sm^3) and indigenous gas LTS with calorific value of 5,350 Kcal/sm^3 is the final product called NG1 natural gas. The indigenous gas with low calorific value and imported gas with high calorific value were blended proportionally at distributional gas header. The downstream pipelines were equipped with mixer and four sets of angle heads for stirring and mixing of gas. The NG1 after above mentioned mixing was then sent out for the market. All the operational controls were through computerized equipments instead of manual operations. In addition, it is applied to integrate gas measurement, input/output of analogue signals, open/close control of MOV, operation of JET pressure adjustment equipment, flow control valve operation, and remote control of automatic increase/reduction of pressure at Nan Shi distributional gas station, etc. The NG1 is mainly for industrial and household users in central and northern Taiwan. The demand pattern is closely related to temperatures. The colder it is, the more the gas consumption becomes. Gas consumption is more on weekdays, from Monday to Friday. In terms of the time of gas consumption in a day, it reaches peak around 6 pm-11 pm as industrial and household users consume more during this period. This paper examines the control of gas blending of different calorific values. With the different gas sources, the calorific value after blending could still be controlled within the required range.