成果報告書詳細
管理番号20120000000285
タイトル*平成23年度中間年報 イットリウム系超電導電力機器技術開発 超電導変圧器の技術開発 冷却システム技術開発
公開日2012/5/10
報告書年度2011 - 2011
委託先名大陽日酸株式会社
プロジェクト番号P08016
部署名省エネルギー部
和文要約和文要約等以下本編抜粋:
1. 研究開発の内容及び成果等
(1)小型膨張タービンの高効率化
平成23 年度の実施計画に従い、膨張タービンの性能向上に向けた改良と評価試験を実施した。改良点はインペラと固定壁との隙間(シュラウドクリアランス)の最適化による損失低減である。その結果、タービン効率は平成22 年度の72%から1 ポイント向上し、73%を得ることができた。今後は侵入熱の低減による性能向上を目指して、制動モータなどの発熱部の温度上昇抑制のための改良検討に取り組む。
英文要約Title: Technological Development of Yttrium-based Superconducting Power Equipment (FY2008-FY2012) FY2011 Annual Report
Brayton cycle Neon refrigerator is being developed and will be installed in a cooling system for High Temperature Superconducting power machines. The refrigerator is required high COP (coefficient of performance) and compactness.
The turbo-expander performance was improved by adjusting its shroud clearance, and its isentropic efficiency was increased up to 73 %. In the next stage, we try to decrease heat in-leak into the cold parts and improve cooling performance of the turbine motor.
In the Brayton cycle Neon refrigerator, cryogenic compression technology is very useful for improving its COP, because a compression work at low temperature is smaller than at room temperature. A liquefied gas like LNG can be utilized as a cold resource and compression heat of the turbo-compressor can be adsorbed by it. A cryogenic compression test for our new turbo-compressor was carried out. The test was done by using cold air at temperature of -100 ~C. Compressor body temperatures and temperature distribution, and magnetic bearings stability were checked in the test. The test results showed that there is no issue about operating our turbo-compressor at cryogenic circumstance. We will investigate actual compression performance of our turbo-compressor at low temperature and calculate expected COP by cryogenic compression technology.
We assembled a test refrigerator with the compact turbo-expander, the compact turbo-compressor and 4 blocks heat exchanger. Refrigerator performance tests were carried out and we got 2.2 kW cooling power at 65 K and 0.06 COP at 80 K. Those values are superior to our final targets (cooling power 2.0 kW at 65 K and COP 0.06 at 80 K) of this project.
A temperature control of a refrigerator is usually performed by an electric heater and this method makes refrigerator efficiency worse. We are considering a new method that a refrigeration temperature is controlled by a compressor rotational speed. We checked relations between compressor rotational speed and cooling power about our refrigerator. It is confirmed that our refrigerator has preferable performance. Its cooling power variation at 65 K is 0.5 kW to 2 kW without an electric heater.
In the other hands, we designed and made a new test refrigerator which has a liquid nitrogen sub-cooler. The sub-cooler is a heat exchanger between cold neon gas and liquid nitrogen. It produces sub-cooled liquid nitrogen in the cold box of the refrigerator.
We will start performance tests of our new refrigerator and also check the sub-cooler efficiency. In this autumn, cooling system having the neon refrigerator and a sub-cooled liquid nitrogen circulation device is built, and it is used for cooling a superconducting power transformer.
ダウンロード成果報告書データベース(ユーザ登録必須)から、ダウンロードしてください。

▲トップに戻る