Heat recovery system

Abstract

A heat recovery system includes a first air cooler for cooling compressed air from a compressor, a first oil cooler for cooling a lubricant from the compressor, and a second air cooler and/or a second oil cooler serving as a heat recovering heat exchanger. The second air cooler heats water with the heat of the compressed air to be fed to the first air cooler. In contrast, the second oil cooler heats water with the heat of a lubricant to be fed to the first oil cooler.

1 . A heat recovery system comprising:
 a first air cooler for cooling compressed air from a compressor;   a first oil cooler for cooling a lubricant from the compressor; and   a second oil cooler which is disposed on an oil feed path to the first oil cooler and serves as a heat recovering heat exchanger for heating water with the heat of the lubricant to be fed to the first oil cooler.   
     
     
         2 . A heat recovery system according to  claim 1 , further comprising a second air cooler in addition to the second oil cooler,
 wherein the second air cooler is disposed on an air feed path to the first air cooler and serves as a heat recovering heat exchanger for heating water with the heat of the compressed air to be fed to the first air cooler,   the second air cooler and the second oil cooler being disposed in such a manner as to allow the water to pass therethrough in series or parallel.   
     
     
         3 . A heat recovery system according to  claim 1 , further comprising a second air cooler in place of the second oil cooler,
 wherein the second air cooler is disposed on an air feed path to the first air cooler and serves as a heat recovering heat exchanger for heating water with the heat of the compressed air to be fed to the first air cooler.   
     
     
         4 . A heat recovery system according to  claim 1 , wherein feedwater to the heat recovering heat exchanger or its amount is controlled based on a use load of hot water after passing through the heat recovering heat exchanger. 
     
     
         5 . A heat recovery system according to  claim 1 , wherein feedwater to the heat recovering heat exchanger or its amount is controlled based on the temperature of hot water after passing through the heat recovering heat exchanger. 
     
     
         6 . A heat recovery system according to  claim 1 , wherein the compressor is of an oil lubrication type, and
 includes an oil separator for separating the lubricant from the compressed air discharged from the compressor; and   the compressed air, from which the lubricant is separated in the oil separator, is fed to each of the air coolers,   whereas the lubricant from the oil separator is fed to each of the oil coolers.   
     
     
         7 . A heat recovery system according to  claim 1 , wherein the compressor is of a non-lubrication type including a low stage compressor and a high stage compressor,
 the compressed air from the low stage compressor being fed to the high stage compressor through a first inter cooler, and further compressed in the high stage compressor, before being fed to each of the air coolers as after coolers, and   the compressor further includes a second inter cooler which is disposed on an air feed path to the first inter cooler from the low stage compressor and serves as the heat recovering heat exchanger for heating the water with the heat of the compressed air to be fed to the first inter cooler.   
     
     
         8 . A heat recovery system according to  claim 7 , wherein the water is heated to produce steam in the heat recovering heat exchanger, and
 feedwater to the heat recovering heat exchanger or its amount is controlled based on the water level of the heat recovering heat exchanger.   
     
     
         9 . A heat recovery system according to  claim 1 , wherein the compressor is of a water lubrication type,
 lubricating water being used in place of the lubricant, and accordingly, the first oil cooler being replaced with a first water cooler for cooling the lubricating water whereas the second oil cooler being replaced with a second water cooler serving as a heat recovering heat exchanger for heating water with the heat of the lubricating water to be fed to the first water cooler; and   the compressor includes a separator for separating the lubricating water from the compressed air discharged from the compressor; and   no first air cooler is disposed, whereby the compressed air from the compressor is discharged via the separator.