| 摘要 |
<p>In a vapor compression type refrigeration cycle (1) using carbon dioxide as a refrigerant, the carbon dioxide is added with at least one of an odorant and a colorant. It is preferable that the odorant has at least one of methyl mercaptan, ethyl mercaptan, propyl mercaptan, butyl mercaptan, dimethyl thioether, diethyl thioether, picoline, diacetyl, methyl acrylate, ethyl acrylate, propyl acrylate, methyl methacrylate, allyl methacrylate, ethyl propionate, methyl butyrate, butene, vinylacetylene, hexine, o-methoxyphenol, and ammonia. It is also preferable that the colorant has at least one of azo pigments such as beta -naphthol series, beta -oxynaphthoic acid series, naphthol AS series, acetoacetoanilide series, and pyrazolone series. <IMAGE></p> |
