Heat transfer apparatus and method

Abstract

In one aspect, a heat transfer apparatus including a process fluid heat exchange circuit having a mechanical cooler with hot and cold side heat exchangers and a hybrid cooler to receive process fluid from the hot side heat exchanger and provide cooled process fluid to the cold side heat exchanger. The hybrid cooler includes direct and indirect heat exchangers. The hybrid cooler has a dry mode and a hybrid mode. The heat transfer apparatus includes a controller configured to operate the process fluid heat exchange circuit in one of a plurality of modes based at least in part upon a determination of a thermal duty of the heat transfer apparatus.

1 . A heat transfer apparatus for an industrial process that requires process fluid at a process fluid set temperature, the heat transfer apparatus comprising:
 a process fluid heat exchange circuit to receive a process fluid at a temperature different than the process fluid set temperature and provide the process fluid at the process fluid set temperature, the process fluid heat exchange circuit comprising:
 a mechanical cooler having a hot side heat exchanger and a cold side heat exchanger; 
 a hybrid cooler to receive process fluid from the hot side heat exchanger of the mechanical cooler and provide cooled process fluid to the cold side heat exchanger of the mechanical cooler; 
 an airflow generator operable to cause air to contact the hybrid cooler; 
 the hybrid cooler comprising a direct heat exchanger and an indirect heat exchanger, the hybrid cooler having a dry mode wherein the indirect heat exchanger transfers heat from the process fluid to the air and a hybrid mode wherein the indirect heat exchanger and the direct heat exchanger transfer heat from the process fluid to the air; 
   the process fluid heat exchange circuit having a plurality of modes including:
 a first mode wherein the process fluid bypasses the mechanical cooler and the hybrid cooler is in the dry mode; 
 a second mode wherein the mechanical cooler removes heat from the process fluid and the hybrid cooler is in the dry mode; 
 a third mode wherein the process fluid bypasses the mechanical cooler and the hybrid cooler is in the hybrid mode; and 
 a fourth mode wherein the mechanical cooler removes heat from the process fluid and the hybrid cooler is in the hybrid mode; and 
   a controller operatively connected to the process fluid heat exchange circuit, the controller configured to operate the process fluid heat exchange circuit in one of the plurality of modes based at least in part upon a determination of a thermal duty of the heat transfer apparatus.   
     
     
         2 . The heat transfer apparatus of  claim 1  wherein, with the process fluid heat exchange circuit in the first mode and the second mode, the process fluid bypasses the direct heat exchanger. 
     
     
         3 . The heat transfer apparatus of  claim 1  wherein the hybrid cooler has a wet mode wherein the direct heat exchanger transfers heat from the process fluid to the air;
 wherein the plurality of modes of the process fluid heat exchange circuit includes: 
 a fifth mode wherein the process fluid bypasses the mechanical cooler and the hybrid cooler is in the wet mode; and 
 a sixth mode wherein the mechanical cooler removes heat from the process fluid and the hybrid cooler is in the wet mode. 
 
     
     
         4 . The heat transfer apparatus of  claim 3  wherein, with the process fluid heat exchange circuit in the fifth mode and the sixth mode, the process fluid bypasses the indirect heat exchanger. 
     
     
         5 . The heat transfer apparatus of  claim 1  wherein the direct heat exchanger comprises:
 a heat exchanger to transfer heat between the process fluid and a liquid; 
 a heat transfer medium; and 
 a liquid distribution system operable to distribute the liquid onto the heat transfer medium. 
 
     
     
         6 . The heat transfer apparatus of  claim 5  wherein the heat transfer medium comprises fill sheets and/or fill blocks. 
     
     
         7 . The heat transfer apparatus of  claim 1  wherein the hybrid cooler further comprises an adiabatic cooler operable to cool the air upstream of the indirect heat exchanger. 
     
     
         8 . The heat transfer apparatus of  claim 1  wherein the hybrid cooler has a wet mode wherein the direct heat exchanger transfers heat from the process fluid to the air;
 wherein the plurality of modes of the process fluid heat exchange circuit includes:
 a fifth mode wherein the process fluid bypasses the mechanical cooler and the hybrid cooler is in the wet mode; and 
 a sixth mode wherein the mechanical cooler removes heat from the process fluid and the hybrid cooler is in the wet mode; 
 
 wherein the hybrid cooler comprises:
 a secondary indirect heat exchanger; 
 a heat transfer medium below the secondary indirect heat exchanger; and 
 a liquid distribution system operable to distribute liquid onto the secondary indirect heat exchanger and the heat transfer medium therebelow with the hybrid cooler in either the wet mode or the hybrid mode; 
 
 wherein, with the process fluid heat exchange circuit in the first mode and the second mode, the hybrid cooler is in the dry mode and the secondary indirect heat exchanger transfers heat between the process fluid and the air; 
 wherein, with the process fluid heat exchange circuit in the fifth mode and the sixth mode, the hybrid cooler is in the wet mode and the liquid distribution system distributes the liquid onto the secondary indirect heat exchanger and the heat exchange medium; and 
 wherein, with the process fluid heat exchange circuit in the third mode and the fourth mode, the hybrid cooler is in the hybrid mode and the liquid distribution system distributes liquid onto the secondary indirect heat exchanger and the heat exchange medium. 
 
     
     
         9 . The heat transfer apparatus of  claim 1  wherein the direct heat exchanger comprises a heat transfer medium below the indirect heat exchanger and a liquid distribution system operable to distribute a liquid onto the indirect heat exchanger so that the liquid travels from the indirect heat exchanger toward the direct heat exchanger; and
 wherein, with the process fluid heat exchange circuit in the third mode, the liquid distribution system distributes liquid onto the indirect heat exchanger; and 
 wherein, with the process fluid heat exchange circuit in the first mode, the liquid distribution system distributes less liquid onto the indirect heat exchanger than in the third mode. 
 
     
     
         10 . The heat transfer apparatus of  claim 1  wherein the process fluid heat exchange circuit further comprises a heat exchanger operatively connected to a cooling load;
 wherein the process fluid comprises a first process fluid and a second process fluid; 
 wherein the process fluid heat exchange circuit comprises a first process fluid loop that includes the mechanical cooler, the hybrid cooler, and a first portion of the heat exchanger; and 
 a second process fluid loop including the cooling load and a second portion of the heat exchanger, the heat exchanger configured to transfer heat between the first process fluid and the second process fluid. 
 
     
     
         11 . The heat transfer apparatus of  claim 1  wherein the process fluid heat exchange circuit does not include a thermal energy storage. 
     
     
         12 . The heat transfer apparatus of  claim 1  wherein the determination of the thermal duty of the heat transfer apparatus comprises a determination of whether the process fluid heat exchange circuit is able to provide the process fluid at the process fluid set temperature. 
     
     
         13 . The heat transfer apparatus of  claim 1  wherein the determination of the thermal duty of the heat transfer apparatus is based at least in part upon a temperature of process fluid supplied by the process fluid heat exchange circuit, the process fluid set temperature, and a control range parameter. 
     
     
         14 . The heat transfer apparatus of  claim 1  wherein the controller is configured to operate the process fluid heat exchange circuit in one of the operating modes upon startup of the heat transfer apparatus based at least in part upon a dry bulb temperature and dry bulb temperature set points associated with the operating modes. 
     
     
         15 . The heat transfer apparatus of  claim 1  further comprising an outer structure; and
 wherein the mechanical cooler, the direct heat exchanger, and the indirect heat exchanger are in the outer structure. 
 
     
     
         16 . The heat transfer apparatus of  claim 1  wherein the mechanical cooler comprises a chiller;
 wherein the hot side heat exchanger comprises a condenser; and 
 wherein the cold side heat exchanger comprises an evaporator. 
 
     
     
         17 . The heat transfer apparatus of  claim 1  wherein the process fluid heat exchange circuit in the first mode and the third mode is configured to cause the process fluid to bypass the mechanical cooler by:
 directing the process fluid around the mechanical cooler; or 
 not operating the mechanical cooler while the process fluid flows through the mechanical cooler. 
 
     
     
         18 . A heat transfer apparatus for an industrial process that requires process fluid at a process fluid set temperature, the heat transfer apparatus comprising:
 a process fluid heat exchange circuit to receive a process fluid at a temperature different than the process fluid set temperature, the process fluid heat exchange circuit comprising:
 a mechanical cooler having a hot side heat exchanger and a cold side heat exchanger; 
 a fluid cooler to receive the process fluid from the hot side heat exchanger and provide cooled process fluid to the cold side heat exchanger; 
 an airflow generator operable to cause air to contact the fluid cooler; 
 the fluid cooler having a wet mode wherein the fluid cooler utilizes a liquid to facilitate heat transfer from the process fluid to the air and a dry mode wherein the fluid cooler utilizes less liquid to facilitate heat transfer from the process fluid to the air than in the wet mode; 
   the process fluid heat exchange circuit operable in a plurality of modes including:
 a first mode wherein the process fluid bypasses the mechanical cooler and the fluid cooler in the dry mode thereof removes heat from the process fluid; 
 a second mode wherein the mechanical cooler and the fluid cooler in the dry mode thereof remove heat from the process fluid; 
 a third mode wherein the process fluid bypasses the mechanical cooler and the fluid cooler in the wet mode thereof removes heat from the process fluid; and 
 a fourth mode wherein the mechanical cooler and the fluid cooler in the wet mode thereof remove heat from the process fluid; and 
   a controller operatively connected to the process fluid heat exchange circuit, the controller configured to change the process fluid heat exchange circuit between the operating modes based at least in part upon a determination of whether the process fluid heat exchange circuit is able to provide the process fluid at the process fluid set temperature.   
     
     
         19 . The heat transfer apparatus of  claim 18  wherein the determination of the whether the process fluid heat exchange circuit is able to provide the process fluid at the process fluid set temperature is based at least in part upon a temperature of the process fluid supplied by the process fluid heat exchange circuit, the process fluid set temperature, and a control range parameter. 
     
     
         20 . The heat transfer apparatus of  claim 19  wherein the controller, with the process fluid heat exchange circuit in the first mode, is configured to change the process fluid heat exchange circuit to the second mode based at least in part upon the temperature of the process fluid supplied by the process fluid heat exchange circuit being greater than a sum of the process fluid set temperature and the control range parameter. 
     
     
         21 . The heat transfer apparatus of  claim 19  wherein the controller has an energy saving mode wherein the controller, with the process fluid heat exchange circuit in the second mode, is configured to change the process fluid heat exchange circuit to the third mode based at least in part upon a dry bulb temperature satisfying a dry switch point condition. 
     
     
         22 . The heat transfer apparatus of  claim 19  wherein the controller, with the process fluid heat exchange circuit in the second mode, is configured to change the process fluid heat exchange circuit to the third mode based at least in part upon the temperature of the process fluid supplied by the process fluid heat exchange circuit being greater than a sum of the process fluid set temperature and the control range parameter. 
     
     
         23 . The heat transfer apparatus of  claim 19  wherein the controller, with the process fluid heat exchange circuit in the third mode, is configured to change the process fluid heat exchange circuit to the fourth mode based at least in part upon the temperature of the process fluid supplied by the process fluid heat exchange circuit being greater than a sum of the process fluid set temperature and the control range parameter. 
     
     
         24 . The heat transfer apparatus of  claim 19  wherein the controller is configured to change the process fluid heat exchange circuit from the fourth mode to the third mode, change the process fluid heat exchange circuit from the third mode to the second mode, or change the process fluid heat exchange circuit from the second mode to the first mode based at least in part upon the temperature of the process fluid supplied by the process fluid heat exchange circuit being less than a difference between the process fluid supply temperature and the control range parameter. 
     
     
         25 . The heat transfer apparatus of  claim 19  wherein the controller has an energy saving mode and a water saving mode; and
 wherein the control range parameter comprises a first control range parameter for the energy saving mode and a different, second control range parameter for the water saving mode. 
 
     
     
         26 . The heat transfer apparatus of  claim 18  wherein the controller is configured to operate the process fluid heat exchange circuit in the first, second, third, or fourth mode based at least in part upon a dry bulb temperature and dry bulb temperature set points associated with the first, second, third, and fourth modes. 
     
     
         27 . The heat transfer apparatus of  claim 26  wherein the fluid cooler comprises an indirect heat exchanger and an adiabatic cooler operable to cool air upstream of the indirect heat exchanger; and
 wherein the dry bulb temperature comprises a dry bulb temperature of the air after the adiabatic cooler and before the indirect heat exchanger. 
 
     
     
         28 . The heat transfer apparatus of  claim 18  wherein the wherein the controller is configured to select one of the operating modes for initial operation of the process fluid heat exchange circuit based at least in part upon a temperature of the air, a relative humidity of the air, a return temperature of the process fluid, and the flow rate of the process fluid. 
     
     
         29 . The heat transfer apparatus of  claim 18  wherein the determination of whether the process fluid heat exchange circuit is able to provide the process fluid at the process fluid set temperature is based at least in part upon:
 a dry bulb temperature; and 
 a threshold dry bulb temperature for operating the fluid cooler in the wet mode. 
 
     
     
         30 . The heat transfer apparatus of  claim 18  wherein the fluid cooler comprises an indirect heat exchanger and an adiabatic cooler operable to cool air upstream of the indirect heat exchanger. 
     
     
         31 . The heat transfer apparatus of  claim 18  wherein the fluid cooler comprises a hybrid cooler having a direct heat exchanger and an indirect heat exchanger;
 wherein, with fluid cooler in the wet mode, the process fluid bypasses the indirect heat exchanger and the direct heat exchanger removes heat from the process fluid; 
 wherein, with the fluid cooler in the dry mode, the process fluid bypasses the direct heat exchanger and the indirect heat exchanger removes heat from the process fluid; 
 wherein the fluid cooler has a hybrid mode wherein the direct heat exchanger and the indirect heat exchanger remove heat from the process fluid. 
 
     
     
         32 . The heat transfer apparatus of  claim 18  further comprising an outer structure; and
 wherein the mechanical cooler and the fluid cooler are in the outer structure. 
 
     
     
         33 . The heat transfer apparatus of  claim 18  wherein the mechanical cooler comprises a chiller;
 wherein the hot side heat exchanger comprises a condenser; and 
 wherein the cold side heat exchanger comprises an evaporator. 
 
     
     
         34 . The heat transfer apparatus of  claim 18  wherein the process fluid heat exchange circuit further comprises a heat exchanger for being operatively connected to a cooling load;
 wherein the process fluid comprises a first process fluid and a second process fluid; 
 wherein the process fluid heat exchange circuit comprises a first process fluid loop that includes the mechanical cooler, the fluid cooler, and a first portion of the heat exchanger; and 
 a second process fluid loop including the cooling load and a second portion of the heat exchanger, the heat exchanger configured to transfer heat between the first process fluid and the second process fluid. 
 
     
     
         35 . The heat transfer apparatus of  claim 18  wherein the fluid cooler comprises a hybrid cooler having a direct heat exchanger and an indirect heat exchanger;
 wherein, with the fluid cooler in the dry mode, the process fluid bypasses the direct heat exchanger and the indirect heat exchanger removes heat from the process fluid; 
 wherein, with the fluid cooler in the wet mode, the process fluid bypasses the indirect heat exchanger and the direct heat exchanger removes heat from the process fluid; 
 wherein the fluid cooler has a hybrid mode wherein the direct heat exchanger and the indirect heat exchanger remove heat from the process fluid; 
 wherein the process fluid heat exchange circuit has a fifth mode wherein the process fluid bypasses the mechanical cooler and the fluid cooler is in the hybrid mode; and 
 wherein the process fluid heat exchange circuit has a sixth mode wherein the mechanical cooler and the fluid cooler in the hybrid mode thereof remove heat from the process fluid. 
 
     
     
         36 - 52 . (canceled)