HEAT TRANSFER APPARATUS AND METHOD
In one aspect, a heat transfer apparatus for an industrial process that requires process fluid at a process fluid set temperature. The heat transfer apparatus includes a process fluid heat exchange circuit having a heat exchanger, an airflow generator, and a thermal energy storage. The controller is configured to operate the process fluid heat exchange circuit in a second mode wherein the thermal energy storage transfers heat between the process fluid and the thermal energy storage and the heat exchanger transfers heat between the process fluid and the air based at least in part upon a parameter of the air and a determination of the process fluid heat exchange circuit in a first mode, wherein the process fluid bypasses the thermal energy storage, being unable to provide the process fluid at the process fluid set temperature.
1 . A heat transfer apparatus comprising:
a process fluid inlet;
a process fluid outlet;
a process fluid heat exchange circuit connecting the process fluid inlet to the process fluid outlet, the process fluid heat exchange circuit configured to receive a process fluid at a first temperature via the process fluid inlet and return the process fluid at a second temperature lower than the first temperature via the process fluid outlet, the process fluid heat exchange circuit comprising:
a heat exchanger;
a fan operable to cause airflow to contact the heat exchanger; and
a mechanical cooler having a condenser and an evaporator;
the heat exchanger to receive process fluid from the condenser of the mechanical cooler and provide cooled process fluid to the evaporator;
the process fluid heat exchange circuit having a plurality of modes including:
a first mode wherein the heat exchanger transfers heat between the process fluid and the airflow; and
a second mode wherein the heat exchanger transfers heat between the process fluid and the airflow and the evaporator of the mechanical cooler removes heat from the process fluid; 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, in the second mode, the process fluid heat exchange circuit directs at least a portion of the process fluid from the heat exchanger to the evaporator of the mechanical cooler to enable the evaporator to cool the at least a portion of the process fluid from the heat exchanger.
3 . The heat transfer apparatus of claim 1 wherein, in the second mode, the condenser of the mechanical cooler transfers heat to at least a portion of the process fluid and the process fluid heat exchange circuit directs the at least a portion of the process fluid to the heat exchanger to enable the heat exchanger to cool the at least a portion of the process fluid from the condenser.
4 . The heat transfer apparatus of claim 1 wherein the controller is configured to determine thermal duty based at least in part on ambient air temperature.
5 . The heat transfer apparatus of claim 4 wherein the controller is configured to operate the process fluid heat exchange circuit in the first mode based at least in part upon the ambient air temperature being a first ambient air temperature; and
wherein the controller is configured to operate the process fluid heat exchange circuit in the second mode based at least in part upon the ambient air temperature being a second ambient air temperature greater than the first ambient air temperature.
6 . The heat transfer apparatus of claim 5 wherein the heat exchanger comprises an adiabatic cooler operable in a wet mode or a dry mode with the process fluid heat exchange circuit in the second mode; and
wherein the controller is configured to operate the process fluid heat exchange circuit in the second mode and operate the adiabatic cooler in the wet mode based at least in part upon the ambient air temperature being a third ambient air temperature greater than the second ambient air temperature.
7 . The heat transfer apparatus of claim 1 wherein the thermal duty comprises one of a plurality of thermal duties including an easier thermal duty and a harder thermal duty; and
wherein the controller is configured to operate the process fluid heat exchange circuit in the first mode based at least in part upon the thermal duty being the easier thermal duty; and
wherein the controller is configured to operate the process fluid heat exchange circuit in the second mode based at least in part upon the thermal duty being the harder thermal duty.
8 . The heat transfer apparatus of claim 1 wherein the process fluid heat exchange circuit in the first mode is configured to cause process fluid to bypass the mechanical cooler.
9 . The heat transfer apparatus of claim 1 wherein the process fluid heat exchange circuit includes a valve upstream of the mechanical cooler; and
wherein the valve is configured to direct process fluid away from the mechanical cooler with the process fluid heat exchange circuit in the first mode.
10 . The heat transfer apparatus of claim 1 wherein the process fluid heat exchange circuit in the first mode is configured to direct the process fluid around at least one of the evaporator and the condenser of the mechanical cooler.
11 . The heat transfer apparatus of claim 1 wherein the mechanical cooler is inactive with the process fluid heat exchange circuit in the first mode.
12 . The heat transfer apparatus of claim 1 wherein, with the process fluid heat exchange circuit in the first mode, the evaporator of the mechanical cooler is configured to remove less heat from the process fluid than with the process fluid heat exchange circuit in the second mode.
13 . The heat transfer apparatus of claim 1 wherein the heat exchanger has a wet mode and a dry mode; and
wherein the heat exchanger is operable in either the wet mode or the dry mode with the process fluid heat exchange circuit in the second mode.
14 . The heat transfer apparatus of claim 1 wherein the heat exchanger comprises a coil, an adiabatic pad, and a liquid distribution system configured to distribute liquid to the adiabatic pad;
wherein the heat exchanger is operable in either a wet mode or a dry mode with the process fluid heat exchange circuit in the second mode; and
wherein the liquid distribution system distributes more liquid to the adiabatic pad with the heat exchanger in the wet mode than in the dry mode.
15 . The heat transfer apparatus of claim 1 wherein the heat exchanger includes an indirect heat exchanger and an adiabatic precooler.
16 . The heat transfer apparatus of claim 1 wherein the controller is configured to determine thermal duty based at least in part on:
ambient air temperature;
ambient air humidity; and/or
a process fluid temperature.
17 . The heat transfer apparatus of claim 1 wherein the mechanical cooler includes a chiller.
18 . The heat transfer apparatus of claim 1 wherein the process fluid heat exchange circuit includes one or more process fluid pumps.
19 . A system comprising:
a cooling load;
a process fluid heat exchange circuit connected to the cooling load to receive hot process fluid from the cooling load and return cooled process fluid to the cooling load, the process fluid heat exchange circuit comprising:
a heat exchanger;
a fan operable to cause airflow to contact the heat exchanger; and
a mechanical cooler having a condenser and an evaporator;
the heat exchanger to receive process fluid from the condenser of the mechanical cooler and provide cooled process fluid to the evaporator;
the process fluid heat exchange circuit having a plurality of modes including:
a first mode wherein the heat exchanger transfers heat between the process fluid and the airflow; and
a second mode wherein the heat exchanger transfers heat between the process fluid and the airflow and the evaporator of the mechanical cooler removes heat from the process fluid; 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 thermal duty determination.
20 . The system of claim 19 wherein, in the second mode, the process fluid heat exchange circuit directs at least a portion of the process fluid from the heat exchanger to the evaporator of the mechanical cooler to enable the evaporator to cool the at least a portion of the process fluid from the heat exchanger.
21 . The system of claim 19 wherein, in the second mode, the condenser transfers heat to at least a portion of the process fluid and the process fluid heat exchange circuit directs the at least a portion of the process fluid to the heat exchanger to enable the heat exchanger to cool the at least a portion of the process fluid from the condenser.
22 . The system of claim 19 wherein the controller is configured to make the thermal duty determination based at least in part on ambient air temperature.
23 . The system of claim 22 wherein the controller is configured to operate the process fluid heat exchange circuit in the first mode based at least in part upon the ambient air temperature being a first ambient air temperature; and
wherein the controller is configured to operate the process fluid heat exchange circuit in the second mode based at least in part upon the ambient air temperature being a second ambient air temperature greater than the first ambient air temperature.
24 . The system of claim 23 wherein the heat exchanger comprises an adiabatic cooler operable in a wet mode or a dry mode with the process fluid heat exchange circuit in the second mode; and
wherein the controller is configured to operate the process fluid heat exchange circuit in the second mode and operate the adiabatic cooler in the wet mode based at least in part upon the ambient air temperature being a third ambient air temperature greater than the second ambient air temperature.
25 . The system of claim 19 wherein the thermal duty comprises a plurality of thermal duties including an easier thermal duty and a harder thermal duty; and
wherein the controller is configured to operate the process fluid heat exchange circuit in the first mode based at least in part upon the thermal duty being the easier thermal duty; and
wherein the controller is configured to operate the process fluid heat exchange circuit in the second mode based at least in part upon the thermal duty being the harder thermal duty.
26 . The system of claim 19 wherein the process fluid heat exchange circuit in the first mode is configured to cause process fluid to bypass the mechanical cooler.
27 . The system of claim 19 wherein the process fluid heat exchange circuit includes a valve upstream of the mechanical cooler; and
wherein the valve is configured to direct process fluid away from the mechanical cooler with the process fluid heat exchange circuit in the first mode.
28 . The system of claim 19 wherein the process fluid heat exchange circuit in the first mode is configured to direct the process fluid around at least one of the evaporator and the condenser of the mechanical cooler.
29 . The system of claim 19 wherein the mechanical cooler is inactive with the process fluid heat exchange circuit in the first mode.
30 . The system of claim 19 wherein the heat exchanger has a wet mode and a dry mode; and
wherein the heat exchanger is operable in either the wet mode or the dry mode with the process fluid heat exchange circuit in the second mode.
31 . The system of claim 19 wherein the heat exchanger comprises a coil, an adiabatic pad, and a liquid distribution system configured to distribute liquid to the adiabatic pad;
wherein the heat exchanger is operable in either a wet mode or a dry mode with the process fluid heat exchange circuit in the second mode; and
wherein the liquid distribution system distributes more liquid to the adiabatic pad with the heat exchanger in the wet mode than in the dry mode.
32 . The system of claim 19 wherein the cooling load comprises an air handling unit.