Patent Application
20090090116
1. Technical Field
The present invention relates generally to systems and methods for cooling industrial processing devices and, more particularly, to a system and method for controlling the temperature of industrial processing devices which includes a central liquid supply having a supply-section and a return section and at least one processing device temperature control subsystem for generally maintaining the temperature of liquid being circulated around an industrial processing device at a designated liquid temperature set point which includes a variable-speed pump, control valve and control device which controls the temperature of the liquid in the subsystem by speeding up, slowing down or shutting off the pump to ensure that the subsystem liquid temperature remains approximately equal to the designated liquid temperature set point as determined by the processing device associated with the subsystem.
2. Description of the Prior Art
Many industrial processing devices and applications require cooling and chilling of the units to remove excess heat generated by the device and allow the device to continue to operate normally. Many different systems and methods have been proposed to provide and regulate such cooling capacity, each of which have inherent advantages and disadvantages. One example of the prior art is shown in
Ideally, a system would be devised for cooling such industrial processing devices which takes advantage of already existing systems such as HVAC systems or the like which are already installed in the facility. However, at the current time, there is no known method or system which provides an interface between the already installed system and the industrial processing device cooling system contemplated by the present invention. Therefore, it is an object of the present invention to provide an improved industry processing temperature control system which utilizes an HVAC or other such water delivery system already available in the facility for cooling of the industrial processing devices.
Another object is to provide an improved system for controlling the temperature of industrial processing devices which includes a number of subsystems which are associated with the industrial processing devices, each subsystem connected to a central supply system and including a variable-speed pump, control valve and control device which controls the temperature of the liquid in the subsystem by speeding up, slowing down or shutting off the pump to ensure that the subsystem liquid temperature remains approximately equal to the designated liquid temperature set point as determined by the processing device associated with the subsystem.
A further object of the present invention is to provide an improved system for controlling the temperature of industrial processing devices which does not use solid-state chillers for each subsystem to improve reliability and reduce repair frequency.
Still another object is to provide an improved system for controlling the temperature of industrial processing devices which connects to already existing water chilling systems used for HVAC systems thereby significantly decreasing the installation and maintenance costs associated with the system.
Finally, an object of the present invention is to provide an improved system for controlling the temperature of industrial processing devices which is relatively simple and straightforward in design and construction and is safe, efficient and effective in use.
The present invention provides an industry processing temperature control system including a central liquid supply for providing liquid via a main liquid circulation system having a main liquid supply loop section and a main return section, the liquid being provided at an adjustable set temperature and at least one processing device temperature control subsystem for generally maintaining the temperature of liquid being circulated around an industrial processing device at a designated liquid temperature set point. The processing device temperature control subsystem includes a subsystem liquid circulation loop in liquid transfer connection with the main liquid supply loop section and the main return section of the main liquid circulation means, the subsystem liquid circulation loop operative to circulate liquid in a continuous loop partially adjacent the processing device for alternatively reducing or increasing the temperature of the processing device via thermal transfer therebetween and a first control valve operatively interposed between the main liquid supply loop section and the subsystem liquid circulation loop. A subsystem liquid temperature sensor is operative to obtain the temperature of liquid flowing through the subsystem liquid circulation loop, and a second control valve is operatively interposed in the subsystem liquid circulation loop after the subsystem liquid circulation loop has passed adjacent the processing device. A subsystem variable-speed liquid pump is operatively interposed in the subsystem liquid circulation loop after the second control valve and a subsystem control device is operatively connected to the first control valve, the second control valve and the subsystem variable pump and is in information transmission connection with the subsystem liquid temperature sensor. The subsystem control device is operative to read the current temperature of liquid flowing through the subsystem liquid circulation loop from the subsystem liquid temperature sensor, compare the current temperature with the designated liquid temperature set point, accelerate the liquid pump if the current temperature is lower than the designated liquid temperature set point, decelerate the liquid pump if the current temperature is higher than the designated liquid temperature set point and stop the liquid pump and shut the second control valve if the current temperature is approximately equal to the designated liquid temperature set point.
The present invention thus provides a substantial improvement over those systems and methods found in the prior art which are designed to provide cooling and heating water to industrial processing devices and systems. First of all, the proposed system has the advantage of considerably reducing the initial equipment cost by replacing expensive solid state chillers with commonly available circulation pumps and accessories. Also, the present system guarantees the desired water temperature and water flow with low energy consumption as it is part of the main water supply system, hence not requiring its own dedicated system for operation thereof. Perhaps most importantly from an operational standpoint, however, is that the present invention greatly reduces required maintenance time and expenses as the components of the system are tried and true pumps, valves and pipes, thus eliminating solid-state chillers which are notoriously prone to breakdowns and failures. It is therefore seen that the present invention provides a substantial improvement over those systems and methods found on the prior art.
To overcome the disadvantage of the existing system and also satisfy the different temperature requirements of different processing machines, a new system configuration as shown in
The industry processing temperature control system 10 of the present invention includes a plurality of processing device temperature control subsystems 12, 14, and 16, each of which are generally identical in basic format, and thus the following description of processing device temperature control subsystem 12 should be understood to apply generally to any of the other subsystems, with minor operating variations. The processing device temperature control subsystem 12 would preferably include a subsystem liquid circulation loop 20 which is in liquid transfer connection with the main liquid supply loop section 104, the subsystem liquid circulation loop 20 operative to circulate the chilled water in a continuous loop partially adjacent the processing device 80 in such a manner that the operating temperature of the processing device may be reduced through thermal transfer of excess heat to the liquid circulating within subsystem liquid circulation loop 20. The precise location, size, shape and pipe construction material of the subsystem liquid circulation loop 20 as it threads its way through the processing device 80 will be generally dependent on the particular processing device 80 with which the present invention is to be used, but should be noted that the chilling systems currently available already include preferred layouts of water circulation loops through various types of processing devices 80 and therefore adoption of those preferred circulation loop arrangements for use with the present invention is generally contemplated.
Interposed between the connection of the subsystem liquid circulation loop 20 to the main liquid supply loop section 104 is a first control valve 22 which, in the preferred embodiment, would be two-way control valve which is controlled to maintain water loop differential pressure of the processing machine in the preferred differential pressure range. The first control valve 22 would preferably be a modulating valve which would be selected based on the pressure within main liquid circulation system 102 and the branch water flow into subsystem liquid circulation loop 20, and the selection will generally follow common control valve selection guidelines.
After passing through the first control valve 22, water flow through the subsystem liquid circulation loop 20 enters the inner circulation loop 24 where the temperature of the water within the inner circulation loop 24 prior to encountering the processing device 80 is measured via temperature sensor 26 which, in the preferred embodiment, may be of any appropriate design so long as the temperature of the water circulating within inner circulation loop 24 may be accurately determined. The water within inner circulation loop 24 then passes through and around the processing device 80 and a pressure sensor 28 is operatively associated with inner circulation loop 24 to determine the differential pressure within the inner circulation loop 24, as shown in
Should the temperature of the water within inner circulation loop 24 be determined to be either higher or lower than the designated temperature set point, however, the present invention provides a simple, straightforward and economical system by which the temperature within inner circulation loop 24 may be adjusted. Specifically, inner circulation loop 24 further includes an inner circulation loop return section 25 which includes second control valve 30 and a circulation pump 32 operative such that upon determining that the current water temperature as measured via temperature sensor 26 is lower than the designated liquid temperature set point, the circulation pump 32 is accelerated to accelerate the flow of water through the inner circulation loop 24 thereby increasing the volume of water flowing through the inner circulation loop 24 as controlled by source control valve 22 and thus increasing the thermal transfer rate from the processing device 80 to the water circulating within inner circulation loop 24. Conversely, if the current water temperature as measured by temperature sensor 24 is higher than the designated liquid temperature set point, the circulation pump 32 will be decelerated to decrease the flow of water through inner circulation loop 24, thus decreasing the thermal transfer rate from the processing device 80 thereby maintaining the operating temperature of the processing device 80 within a predetermined temperature range.
Along with the temperature regulation of the water within the inner circulation loop 24, the differential pressure within the inner circulation loop 24 must also be maintained, and this is done by measuring the differential pressure via pressure sensor 28 and if the differential pressure is higher than the designated differential pressure set point, first control valve 22 is gradually closed to restrict water flow through the inner circulation loop 24, and if the differential pressure is lower than the differential pressure set point, the first control valve 22 is gradually opened to increase water flow through the inner circulation loop 24. In this manner, both the differential pressure and temperature of the water within the inner circulation loop 24 of subsystem liquid circulation loop 20 is maintained within preset values, thus optimizing operation of the processing device 80 by maintaining its temperature within a prescribed temperature range.
All of the above-described functions are monitored and controlled by a programmable control device 40 which, in the preferred embodiment, would be a programmable computer system or microchip, depending on the complexity of the system, and which is operatively connected to the first control valve 22, temperature sensor 26, pressure sensor 28, second control valve 30, and circulation pump 32 in order to provide accurate real-time control for each of the elements of the subsystem liquid circulation loop 20. The programming of the control device 40 would be understood by one skilled in the art of such water circulation systems, and therefore detailed description of the particular software programming is deemed unnecessary in this disclosure so long as the decision-making processes as shown in
It is to be understood that numerous additions, modifications and substitutions may be made to the industry processing temperature control system 10 of the present invention which fall within the intended broad scope of the appended claims. For example, the precise needs of each processing device 80 with which the present invention is to be used will be determined on a case-by-case basis and the subsystem liquid circulation loop 20 will be modified to accommodate such requirements by utilizing appropriate control valves 22 and 30 or other such pump and piping system auxiliaries which would be required for proper operation of the subsystem liquid circulation loop 20. Furthermore, the precise nature of the control device 40 is not particularly critical to the present invention so long as the control device 40 can perform the necessary comparisons between current temperature and preferred operating temperature and current differential pressure and preferred operating differential pressure necessary for proper operation of the processing device temperature control subsystem 12. Also, it should be noted that although the present invention has been described as primarily for use with industrial processing devices 80, it may be used in any processing water system which requires accurate temperature and/or differential pressure control, or even may be used for district cooling and district heating systems. In such situations, various motors may be substituted for the circulation pump 32 and motor associated therewith, such as substituting an AC motor with a variable frequency drive for larger horsepower pumps for the direct current motor currently proposed for use with the present invention. Finally, the specific operating speeds and pressures utilized in connection with the subsystem liquid circulation loop 20 may be modified or changed depending on the processing device 80 with which the system is to be used, and such adjustments and modifications will be understood by those skilled in the art of such cooling systems.
There has therefore been shown and described an industry processing temperature control system 10 which accomplishes at least all of its intended objectives.
