This disclosure relates generally to process control systems and, more specifically, to vortex tube temperature control for process control devices.
Process control systems typically include numerous process control field devices, some of which may be exposed to operating environments in which the ambient temperature is relatively high or low, and/or varies widely. Such temperature conditions may have an adverse effect on the operation of the field devices because many of the components of these field devices are designed to work in more moderate environments. Some field devices may be enclosed in protective housings. However, these housings are not effective to prevent the field devices from being affected by extreme temperatures or temperature changes.
An example apparatus comprises a housing, a process control device disposed in the housing, and a vortex tube coupled to the housing to regulate an operating temperature of the process control device. The vortex tube has a fluid inlet to receive a fluid, a first fluid outlet and a second fluid outlet. A temperature of a first portion of the fluid at the first fluid outlet is greater than a temperature of the second portion of the fluid at the second fluid outlet and a temperature of a fluid at the fluid inlet. The first fluid outlet discharges the first portion of the fluid to regulate the operating temperature of the process control device.
An example method comprises measuring a temperature of at least one of a process control device disposed in a housing or an interior of the housing, delivering a fluid to the housing via a vortex tube and adjusting, based on the measured temperature, a flow of the fluid through the vortex tube to maintain a substantially constant operating temperature of the device and/or the interior of the housing.
The example apparatus disclosed herein includes a vortex tube coupled to a housing containing a process control field device. The vortex tube described herein has a fluid inlet, a hot fluid outlet and a cold fluid outlet. The fluid from the hot fluid outlet is used to heat an interior cavity of the process control device housing to maintain a substantially constant, moderate local ambient temperature surrounding the process control device, even in extremely cold environments. The temperature of the fluid exiting the hot fluid outlet of the vortex tube can be adjusted by changing a flow of fluid entering the inlet of the vortex tube and/or changing the flow of fluid exiting the hot fluid outlet.
An example apparatus 100 described in
Referring to
In the example apparatus 100, a vortex tube 116 is disposed in the housing 102, but may also be located elsewhere, as described below. As shown in the example apparatus 100 of
The vortex tube 116 of example apparatus 100 has a fluid inlet 118, a first fluid outlet 120, and a second fluid outlet 122. A fluid supply 124 provides a compressed or pressurized fluid to the fluid inlet 118 and enters the vortex tube 116 perpendicular to a body 126 of the vortex tube 116. The fluid supply 124 may be a system dedicated to provide compressed or pressurized fluid to the vortex tube 116. Alternatively, the fluid supply 124 may also provide compressed or pressurized fluid elsewhere in the process control system.
Fluid exiting the first fluid outlet 120 has a temperature higher than that of fluid exiting the second fluid outlet 122. In the example apparatus 100, the fluid exiting the first fluid outlet 120 is directed to heat the interior cavity 114 of the housing 102 and/or the process control device 104. The fluid from the first fluid outlet 120 may be divided, via fluid passageways or ducts, into multiple portions or streams upon exiting the first fluid outlet 120. These fluid streams may also be used to heat one or more additional components 106 within the housing 102. The fluid from the second fluid outlet 122 is exhausted external to the housing 102. As shown in
The example apparatus 100 includes a controller 128 coupled to one or more sensors 130 to measure a temperature of the interior cavity 114 of the housing 102, an operating temperature of the process control device 104, and/or the temperatures of the one or more additional components 106. In operation, the controller 128 may adjust the flow of fluid through the fluid inlet 118 of the vortex tube 116, via the fluid supply 124, to adjust, control or regulate the temperature of the fluid exiting the first fluid outlet 120 of the vortex tube 116. The temperature of the fluid and the flow rate of fluid from the first fluid outlet 120 of the vortex tube 116 into the interior cavity 114 of the housing 102 may also be adjusted by adjusting a valve 132 at the first fluid outlet. Decreasing the flow rate of fluid at the first fluid outlet 120 of the vortex tube 116 increases the temperature of the fluid, while increasing the flow rate of the fluid at the first fluid outlet 120 of the vortex tube 116 decreases the temperature of the fluid.
The example apparatus 200 of
The example apparatus of 300 of
The example controller 128 of
Additionally, the example controller 128 of
The controller 128 measures the temperature of at least the process control device 104 and/or the interior cavity 114 of the housing 102 (block 404). The controller 128 then determines if the temperature of the process control device 104 or the interior cavity 114 of the housing 102 is substantially equal to a set point temperature (block 406) by comparing the measured temperature to the set point temperature. If the measured temperature is not substantially equal to (e.g. within a 10° C. differential of) the set point temperature, the flow through the vortex tube 116 is adjusted (block 408) before being directed toward the process control device 104 or the interior cavity 114 of the housing 102 (block 410). The flow can be adjusted by changing a pressure of the fluid at the fluid inlet 118 of the vortex tube 116 and/or by changing a flow of the fluid at the first fluid outlet 120 of the vortex tube 116 using, for example, the valve 132.
If the measured temperature and the set point temperature are substantially equal at block 406, the fluid from the first fluid outlet 120 is directed to at least the process control device 104 or the interior cavity 114 of the housing 102 (block 410) without first adjusting the flow of the fluid through the vortex tube 116. The fluid from the first fluid outlet 120 may be divided into multiple portions, at least one of which is diverted process control device 104 or the interior cavity 114 of the housing 102. One or more of the other portions may be diverted to other components 106 of the process control device 104.
In this example, at least a portion of the method represented by the flowchart in
As mentioned above, at least a portion of the example method of
The processor platform 500 of the illustrated example includes a processor 512. The processor 512 of the illustrated example is hardware. For example, the processor 512 can be implemented by one or more integrated circuits, logic circuits, microprocessors or controllers from any desired family or manufacturer.
The processor 512 of the illustrated example includes a local memory 513 (e.g., a cache). The processor 512 of the illustrated example is in communication with a main memory including a volatile memory 514 and a non-volatile memory 516 via a bus 518. The volatile memory 514 may be implemented by Synchronous Dynamic Random Access Memory (SDRAM), Dynamic Random Access Memory (DRAM), RAMBUS Dynamic Random Access Memory (RDRAM) and/or any other type of random access memory device. The non-volatile memory 516 may be implemented by flash memory and/or any other desired type of memory device. Access to the main memory 514, 516 is controlled by a memory controller.
The processor platform 500 of the illustrated example also includes an interface circuit 520. The interface circuit 520 may be implemented by any type of interface standard, such as an Ethernet interface, a universal serial bus (USB), and/or a PCI express interface.
In the illustrated example, one or more input devices 522 are connected to the interface circuit 520. The input device(s) 522 permit(s) a user to enter data and commands into the processor 512. The input device(s) 522 can be implemented by, for example, an audio sensor, a microphone, a camera (still or video), a keyboard, a button, a mouse, a touchscreen, a track-pad, a trackball, isopoint and/or a voice recognition system.
One or more output devices 524 are also connected to the interface circuit 520 of the illustrated example. The output devices 524 can be implemented, for example, by display devices (e.g., a light emitting diode (LED), an organic light emitting diode (OLED), a liquid crystal display, a cathode ray tube display (CRT), a touchscreen, a tactile output device, a printer and/or speakers). The interface circuit 520 of the illustrated example, thus, typically includes a graphics driver card, a graphics driver chip or a graphics driver processor.
The interface circuit 520 of the illustrated example also includes a communication device such as a transmitter, a receiver, a transceiver, a modem and/or network interface card to facilitate exchange of data with external machines (e.g., computing devices of any kind) via a network 526 (e.g., an Ethernet connection, a digital subscriber line (DSL), a telephone line, coaxial cable, a cellular telephone system, etc.).
The processor platform 500 of the illustrated example also includes one or more mass storage devices 528 for storing software and/or data. Examples of such mass storage devices 528 include floppy disk drives, hard drive disks, compact disk drives, Blu-ray disk drives, RAID systems, and digital versatile disk (DVD) drives.
Coded instructions 532 to implement at least a portion of the method 400 of
Although certain example methods, apparatus and articles of manufacture have been disclosed herein, the scope of coverage of this patent is not limited thereto. On the contrary, this patent covers all methods, apparatus and articles of manufacture fairly falling within the scope of the claims of this patent.