Patent Application
20080022757
The accompanying figures, in which like reference numerals refer to identical or functionally-similar elements throughout the separate views and which are incorporated in and form a part of the specification, further illustrate the embodiments and, together with the detailed description, serve to explain the embodiments disclosed herein.
The particular values and configurations discussed in these non-limiting examples can be varied and are cited merely to illustrate at least one embodiment and are not intended to limit the scope thereof.
For ease of illustration, the embodiments disclosed herein are described with respect to motor/engine lubricating. One skilled in the art will understand that the embodiments disclosed herein can also be employed to manage the condition of other oil products in other contexts, in some cases with minor or no modification. For example, the systems and/or methods disclosed herein can be applied equally well to cooking oil, food oil, or other oil, whether edible or not.
In the illustrated embodiment,
In the illustrated embodiment, sensor module 110 couples to oil reservoir 104 and is described in more detail below. In an alternate embodiment, sensor module 110 is coupled to engine 102. One skilled in the art will understand that other configurations can also be employed.
Generally, system 100 can be configured to conform to proactive and/or predictive maintenance standards and/or goals. Broadly, predictive maintenance targets detection of incipient failure of both the fluids' properties and certain machine components (e.g., bearings, gears, etc.). Predictive maintenance looks for failure symptoms and faults, employing technologies such as, for example, wear debris analysis, vibration analysis, thermography, and motor current analysis. Predictive maintenance is typically directed towards early detection of faults and/or failure.
Generally, proactive maintenance involves continuous monitoring and controlling of machine failure root causes. Proactive maintenance looks for root causes, employing technologies such as, for example, contaminant monitoring, balancing and alignment tools, viscosity and “AN” monitoring. Typical implementations of proactive maintenance involve three broad steps or stages. In a first step or stage, a target, or standard, associated with each root cause is identified. In a second step or stage, the fluids' conditions are maintained within these targets. In a third step or stage, a feedback loop of an oil analysis program is provided. Proactive maintenance is typically directed towards fault free machines and machine life extension.
There is no single marker typically employed that independently identifies when an oil is no longer usable. Modern oil analysis labs generally observe a combination of markers to determine oil degradation status, but the importance assigned to individual markers, as well as their limits, varies in industrial practices. Many oil analysis labs use the following physical/chemical markers for oil deterioration:
TAN limits: 4-7 mg KOH/g sample
TBN limits: 1-2 mg KOH/g sample
Viscosity change limits: 20-50%
DSC limits: 2-5 minutes (onset time of oxidation).
Further, there are a number of oil acidity (i.e., pH) related measurements. Generally oil deterioration monitoring can include base oil oxidation monitoring, anti-oxidant and corrosion inhibitors degradation monitoring, and/or detergent/dispersant degradation monitoring. Further, oil acidity can be measured directly, through a variety of pH tests, or indirectly, through a variety of TAN/TBN measurements. Additionally, corrosion/etch rate can be measured through application to sacrificial metals.
In the illustrated embodiments, sensor module 110 (and subsequent embodiments) is configured to measure oxidation stability. In particular, illustrated embodiments are configured to measure oxygen stability through evaluation of an oxygen induction time (OIT). In order to illustrate certain details of the sensor module 110 embodied in the above exemplary embodiment, reference is now made to
In particular,
In one embodiment, test array 204 is configured as a disposable module. So configured, test array 204 can be constructed as a replaceable cartridge. Additionally, so configured, system 200 can be adapted for portable use. This embodiment is preferred for applications wherein the oil to be tested does not require repeated real-time monitoring, such as, for example, food oil testing, or wherein a plurality of oils are to be tested, in a variety of physical locations. In an alternate embodiment, test array 204 is configured as a non-disposable module, permanently coupled to CAI module 206. This embodiment is preferred for applications wherein it is desired that the oil to be tested be measured frequently, in real-time, or otherwise repeatedly. One skilled in the art will understand that other configurations can also be employed.
Test array 204 includes housing chamber 210. Housing chamber 210 can be configured to conform to any number of suitable shapes, including custom shapes, to suit the broader system in which system 200 is employed. Housing chamber 210 includes and envelops testing chamber 212. Generally, testing chamber 212 receives an oil sample to be tested (oil 214) through an inlet 216. Testing chamber 212 couples to CAI module 206 through outlet 222.
In the illustrated embodiment, inlet 216 couples to testing chamber 212 through one-way seal 218. Inlet 216 is configured to receive oil 214 from, for example, an oil reservoir 104 of
Oil 214 is held in testing chamber 212 and heated by first heater 220. In one embodiment, first heater 220 comprises a heater and a temperature sensor. In a preferred embodiment, first heater 220 is a microheater. In an alternate embodiment, first heater 220 is a microbrick. In an alternate embodiment, first heater 220 is a microbridge.
Housing chamber 210 includes reagent module 230. Reagent module 230 includes reagent chamber 232, which holds reagent 234. In one embodiment, reagent chamber 232 is an oxygen flux chamber, described in more detail below. Reagent 234 is held in reagent chamber 232 and heated by second heater 236. In a preferred embodiment, second heater 236 is a microheater. In an alternate embodiment, second heater 236 is a microbrick. In an alternate embodiment, second heater 236 is a microbridge.
Reagent module 230 couples to testing chamber 212 through port 240 and one-way seal 242. In the illustrated embodiment, one-way seal 242 and port 240 are together configured to deliver a particular quantity of oxygen flux to testing chamber 212, as described in more detail below. In a preferred embodiment, port 240 and one-way seal 242 together comprise an oxygen flux probe configured to deliver a regulated amount of oxygen flux into testing chamber 212.
Generally, reagent 234 is a single substance or a group (whether composite or otherwise) of substances that release oxygen. In the illustrated embodiment, reagent 234 is configured to release oxygen when heated. In a preferred embodiment, reagent 234 is configured to release a stable and predictable amount of oxygen, or oxygen flux, under constant environmental conditions. In one embodiment, reagent 234 is any type of oxygen source that can release oxygen upon heating. Reagent 234 may be one or more of any number of substances, including, for example, inorganic superoxide, chlorate, and/or perclorate, as well as inorganic or organic Ozonide or other suitable substances. One skilled in the art will understand that a variety of oxygen releasing substances can be employed. In particular, the following are suitable reagents 234: inorganic compounds such as KMnO4, La(NO3)3, CeO2, MgO2 and organic compounds such as benzoyl peroxide (BPO). In a preferred embodiment, reagent 234 is KMnO4.
Generally, in operation, system 200 is configured as follows. A sample of oil 214 is added to testing chamber 212 through inlet 216 and one-way seal 218. Testing chamber 212 is heated to and kept at a stable temperature by first heater 220. In one embodiment, the stable temperature is 150 degrees Celsius. In an alternate embodiment, the stable temperature is 80 degrees Celsius. In an alternate embodiment, testing chamber 212 is heated to different temperatures in a measurement panel, such as 80, 100, 125 and 150 degrees Celsius. One skilled in the art will understand that other configurations, particularly other specific temperatures, can also be employed.
Reagent chamber 232 is heated by second heater 236, causing reagent 234 to produce stable oxygen flux, which is delivered to testing chamber 212 through port 240 and one-way seal 242. The oxidation induction time (OIT) is measured. In one embodiment, the OIT starts from the point that the oxygen releasing reagents 234 were heated and ends upon the point that the temperature sensor in first heater 220 detects a specified value of temperature increase in testing chamber 212. In one embodiment, the temperature increase can be measured as a temperature increase in the oil 214.
Thus, in one embodiment, the OIT is calculated from the first introduction of oxygen flux into testing chamber 212 from reagent chamber 232, to the detection of a pre-determined increase in temperature of the testing chamber 212. In one embodiment, the first introduction of oxygen flux is set at the point where heat is applied by second heater 236 to reagent chamber 232. One skilled in the art will understand that as the first heater 220 is kept at stable operating parameters once the testing chamber 212 reaches the initial stable temperature, the increase in temperature in testing chamber 212 is a function of the stable oxygen flux entering testing chamber 212 from reagent chamber 232, and thus is a function of the oil oxidation induction. The measured OIT is then used to calculate the oxidation stability of the sample oil 214. As described above, the oxidation stability of an oil sample can be employed as a measure of the quality of the oil sample. Thus, generally, in one embodiment, system 200 provides an improved system for measuring oil quality as a function of oxidation induction time.
Referring now to
Additionally, in the illustrated embodiment, system 250 is depicted with an independent conduit 222(a-n) between each testing chamber and CAI module 206. In an alternate embodiment, CAI module 206 can be coupled to the array of testing chambers through a single conduit 222. One skilled in the art will understand that other configurations can also be employed.
As described thereafter at block 315, the embedded heater output is locked. This operation can be performed by, for example, CAI module 206 maintaining at a constant heat output first heater 220
As indicated thereafter at block 325, a first OIT start point is marked at a pre-determined ORR chamber temperature. The operation depicted at block 325 can be performed by, for example, CAI module 206 of
Next, as depicted at decisional block 330, a determination is made whether the testing chamber is at a pre-determined temperature increase. The operation depicted at block 330 can be performed by, for example, CAI module 206 and/or first heater 220 of
As depicted next at block 335, an OIT end point is marked at the pre-determined temperature increase. The operation depicted at block 335 can be performed by, for example, CAI module 206 and/or first heater 220 of
Next, as depicted at block 345, the oxidation stability of the oil sample is evaluated based on the calculated OIT. The operation depicted at block 345 can be performed by, for example, CAI module 206 of
Accordingly, the embodiments provide for a system, apparatus, and method for improved measurement of oil quality through thermal analysis of oil oxidation stability. In particular, stable microfabricated devices, such as, for example, a microbrick and/or microbridge, are configured for oil oxidation stability monitoring in a novel, in-line sensor configuration. Thus, improved accuracy and reliability in sensing and measurement of oil oxidation stability are provided.
It will be appreciated that variations of the above-disclosed and other features and functions, or alternatives thereof, may be desirably combined into many other different systems or applications. Also that various presently unforeseen or unanticipated alternatives, modifications, variations or improvements therein may be subsequently made by those skilled in the art which are also intended to be encompassed by the following claims.
