Heat recovery apparatus

A heat recovery apparatus comprising a first heat exchange device, a compression device, a second heat exchange device and at least two pressure drop devices, which are fluidically connected through pipes that refrigerants flow,

• wherein at least two refrigerant streams including a first refrigerant stream and a second refrigerant stream flow into said first heat exchange device,
• said first refrigerant stream flowing into said first heal exchange device is heat exchanged with a first fluid stream flowing into said first heat exchange device, and said first fluid stream heat exchanged with said first refrigerant stream is heat exchanged with said second refrigerant stream,
• the at least two refrigerant streams including the first and second refrigerant streams flowing out from said first heat exchange device flow into said compression device,
• the at least two refrigerant streams including the first and second refrigerant streams flowing out from said compression device flow into said second heat exchange device,
• the at least two refrigerant streams including the first and second refrigerant streams flowing into said second heat exchange device are heat exchanged with a second fluid stream flowing into said second heat exchange device,
• the at least two refrigerant streams including the first and second refrigerant streams flowing out from said second heat exchange device flow into said at least two pressure drop devices, respectively,
• the at least two refrigerant streams including the first refrigerant stream and the second refrigerant stream, flowing out from said at least two pressure drop devices, respectively, flow into said first heat exchange device,
• wherein the first heat exchange device comprises at least two heat exchangers, the compression device comprises at least two compressors, the second heat exchange device composes of only one heat exchanger, and the pressure drop device is a control valve or a turbine,
• wherein the first heat exchange device comprises a first-first heat exchanger and a first-second heat exchanger, the compression device comprises a first compressor and a second compressor, and the pressure drop device comprises a first pressure drop device and a second pressure drop device, and
• wherein the first fluid stream flows into said first-first heat exchanger and the first fluid stream flowing out from said first-first heat exchanger flows into said first-second heat exchanger,
• the first refrigerant stream flows into said first-first heat exchanger and the second refrigerant stream flows into said first-second heat exchanger,
• the first refrigerant stream flowing into said first-first heat exchanger is heat exchanged with the first fluid stream flowing into said first-first heat exchanger and the second refrigerant stream flowing into said first-second heat exchanger is heat exchanged with the first fluid stream flowing out from said first-first heat exchanger and flowing into said first-second heat exchanger,
• the first refrigerant stream flowing out from said first-first heat exchanger flows into said first compressor and the second refrigerant stream flowing out from said second heat exchange device flows into said second compressor,
• the first refrigerant stream flowing out from said first compressor and the second refrigerant stream flowing out from said second compressor flow into said second heat exchange device,
• the first and second refrigerant streams flowing into said second heat exchange device are heat exchanged with the second fluid stream flowing into said second heat exchange device, and the first refrigerant stream flowing out from said second heat exchange device flows into said first pressure drop device and the second refrigerant stream flowing out from said second heat exchange device flows into said second pressure drop device, and
• the first refrigerant stream flowing out from said first pressure drop device flows into said first-first heat exchanger and the second refrigerant stream flowing out from said second pressure drop device flows into said first-second heat exchanger.