Recovery and re-use of waste energy in industrial facilities

A method implemented in a crude oil refining facility, the method comprising:

• in a crude oil refining facility comprising a plurality of oil refining plants, each oil refining plant configured to perform at least one oil refining process, each oil refining plant comprising a plurality of interconnected oil refining sub-systems, wherein a plurality of streams at respective temperatures flow between the plurality of oil refining sub-systems:
• flowing a hydrocracking plant stream, a low temperature shift (LTS) converter product stream and a diesel hydro-treating plant stream of a hydrocracking plant, a steam reforming hydrogen plant and a diesel hydro-treating plant, respectively, of the plurality of oil refining plants to one or more heat exchangers, the hydrocracking plant stream comprising at least one of a feed stream to a first reaction stage cold high pressure separator, a feed stream to a second reaction stage cold high pressure separator, a product stripper overhead stream, a diesel product stream, a kerosene pumparound stream, and a kerosene product stream;
• flowing a stream from a first oil refining plant of the plurality of oil refining plants to the one or more heat exchangers, the first oil refining plant being different from the hydrocracking plant, the steam reforming hydrogen plant and the diesel hydro-treating plant and comprising a naphtha hydro-treating plant, a sour water stripper plant, an amine regeneration plant separation section, a sulfur recovery plant and a gas separation plant through which a gas separation plant stream comprising at least one of C2 to C4 flows, wherein the one or more heat exchangers transfer heat from one or more of the hydrocracking plant stream, the low temperature shift (LTS) converter product stream and the diesel hydro-treating plant stream to the stream from the first oil refining plant;
• and
• utilizing the stream from the first oil refining plant heated by one or more of the hydrocracking plant stream, the low temperature shift (LTS) converter product stream and the diesel hydro-treating plant stream in an oil refining process at the first oil refining plant.