Method and apparatus for evaluating repair and remediation alternatives for heat exchangers

Abstract

A method is provided for evaluating simultaneously the effects of multiple, interdependent heat-exchanger degradation modes for a heat exchanger of a power plant in the context of a series of alternative heat-exchanger remediation strategies. The method includes calculating time-varying predicted future progressions of heat exchanger performance metrics for a plurality of alternative heat-exchanger remediation strategies, and calculating time-varying predicted future progressions of financial metrics describing the accumulated financial benefit of each of the strategies. The calculations may be provided in probabilistic terms. A strategy may then be chosen based, at least in part, on the calculated results.

Claims

1. A method for evaluating simultaneously the effects of multiple, interdependent heat-exchanger degradation modes for a heat exchanger of a power plant in the context of a series of alternative heat-exchanger remediation strategies that include individual options for remedying one or more of the degradation modes, the method comprising: receiving probabilistic time-varying predicted future progressions of heat exchanger performance metrics for a plurality of alternative heat-exchanger remediation strategies, wherein the probabilistic time-varying predicted future progressions are based on a single, integrated probabilistic analysis of the effects of multiple, interdependent heat-exchanger degradation modes, the performance metrics including: a secondary side operating pressure of the heat exchanger, a heat-transfer efficiency of the heat exchanger, a fraction of defective components within the heat exchanger that are subject to one or more heat-exchanger degradation modes, and an electrical power output of the plant; receiving probabilistic time-varying predicted future progressions of financial metrics describing the accumulated financial benefit of each of the plurality of alternative heat-exchanger remediation strategies; and selecting and implementing one of the plurality of alternative heat-exchanger remediation strategies based on the received probabilistic time-varying predicted future progressions of the heat exchanger performance metrics, wherein the time-varying predicted future progressions of heat-exchanger performance metrics for a plurality of alternative heat-exchanger remediation strategies account for routine post-outage heat-transfer transients that result from operating the plant in accordance with each of the plurality of alternative heat-exchanger remediation strategies, and wherein implementing the selected one of the plurality of alternative heat-exchanger remediation strategies includes performing at least one of the following acts: chemical cleaning, applying at least one dilute chemical, lancing tube sheet sludge, in-bundle water-jet lancing, tube bundle flushing, ultrasonic energy cleaning, adding a polymeric dispersant, changing secondary water chemistry, repairing a defective heat-exchanger tube by plugging, repairing a defective heat-exchanger tube by sleeving, lowering a primary fluid temperature, repairing at least one tube moisture separator component; or replacing at least one tube moisture separator component.

2. The method of claim 1, wherein: one of the plurality of alternative heat-exchanger remediation strategies includes a modification of a valve of a high-pressure turbine of the power plant, wherein the turbine is operatively connected to the heat exchanger; and another of the plurality of alternative heat-exchanger remediation strategies does not include the modification of the valve.

3. The method of claim 1, wherein: one of the plurality of alternative heat-exchanger remediation strategies includes an implementation of a feedwater heater bypass configuration; and another of the plurality of alternative heat-exchanger remediation strategies does not include an implementation of a feedwater heater bypass configuration.

4. The method of claim 1, wherein: one of the plurality of alternative heat-exchanger remediation strategies includes a change to the chemistry of water in the secondary plant system; and another of the plurality of alternative heat-exchanger remediation strategies does not include a change to the chemistry of water in the secondary plant system.

5. The method of claim 1, wherein one of the plurality of alternative heat-exchanger remediation strategies includes adding zinc to a primary coolant associated with the heat exchanger, and wherein the time-varying predicted future progression of heat-exchanger performance metrics for the one of the plurality of alternative heat-exchanger remediation strategies accounts for one or more effects of an addition of zinc to the primary coolant.

6. The method of claim 1, wherein the financial metrics account for forced outages associated with the plurality of alternative heat-exchanger remediation strategies.

7. The method of claim 1, wherein the financial metrics account for mid-cycle outages associated with the plurality of alternative heat-exchanger remediation strategies.

8. The method of claim 1, further comprising selecting and implementing one of the plurality of alternative heat-exchanger remediation strategies based on the received time-varying predicted future progressions of financial metrics.

9. The method of claim 1, wherein at least one of the plurality of alternative heat-exchanger remediation strategies includes at least one of the following options for remedying tube deposit heat-transfer fouling: full-height chemical cleaning at at least one specific time and/or frequency, full-height chemical cleaning at a different time and/or frequency than a full-height chemical cleaning according to a different one of the plurality of alternative heat-exchanger remediation strategies, partial-height chemical cleaning at at least one specific time and/or frequency, partial-height chemical cleaning at a different time and/or frequency than a partial-height chemical cleaning according to a different one of the plurality of alternative heat-exchanger remediation strategies, at least one dilute chemical application at at least one specific time and/or frequency, at least one dilute chemical application at a different time and/or frequency than at least one dilute chemical application according to a different one of the plurality of alternative heat-exchanger remediation strategies, tube sheet sludge lancing at at least one specific time and/or frequency, tube sheet sludge lancing at a different time and/or frequency than a tube sheet sludge lancing according to a different one of the plurality of alternative heat-exchanger remediation strategies, in-bundle water jet lancing at at least one specific time and/or frequency, in-bundle water jet lancing at a different time and/or frequency than an in-bundle water-jet lancing according to a different one of the plurality of alternative heat-exchanger remediation strategies, tube bundle flushing at at least one specific time and/or frequency, tube bundle flushing at a different time and/or frequency than a tube bundle flushing according to a different one of the plurality of alternative heat-exchanger remediation strategies, ultrasonic energy cleaning at at least one specific time and/or frequency, ultrasonic energy cleaning at a different time and/or frequency than an ultrasonic energy cleaning according to a different one of the plurality of alternative heat-exchanger remediation strategies, polymeric dispersant addition, other secondary water chemistry changes, and combinations thereof.

10. The method of claim 1, wherein at least one of the plurality of alternative heat-exchanger remediation strategies includes at least one of the following options for remedying heat-exchanger tube corrosion and wear degradation: repairing defective heat-exchanger tubes by plugging, repairing defective heat-exchanger tubes by sleeving, reducing the rate of future occurrence of degraded tubes by lowering the primary fluid temperature, implementing a full-height chemical cleaning at one or more specific times, implementing a full-height chemical cleaning at a different specific time than a full-height chemical cleaning according to a different one of the plurality of alternative heat-exchanger remediation strategies, implementing a partial-height chemical cleaning at a specific time, implementing a partial-height chemical cleaning at a different specific time than a partial-height chemical cleaning according to a different one of the plurality of alternative heat-exchanger remediation strategies, and combinations thereof.

11. The method of claim 1, wherein at least one of the plurality of alternative heat-exchanger remediation strategies includes at least one of the following options for remedying tube support plate broached hole blockage: implementing a full-height chemical cleaning at one or more specific times, implementing a full-height chemical cleaning at a different specific time than a full-height chemical cleaning according to a different one of the plurality of alternative heat-exchanger remediation strategies, implementing at least one dilute chemical application at at least one specific time and/or frequency, implementing at least one dilute chemical application at a different time and/or frequency than a dilute chemical application according to a different one of the plurality of alternative heat-exchanger remediation strategies, in-bundle water-jet lancing at at least one specific time and/or frequency, and in-bundle water-jet lancing at a different time and/or frequency than an in-bundle water-jet lancing according to a different one of the plurality of alternative heat-exchanger remediation strategies.

12. The method of claim 1, wherein at least one of the plurality of alternative heat-exchanger remediation strategies includes at least one of the following options for remedying tube support plate material degradation: implementing a full-height chemical cleaning at one or more specific times, implementing a full-height chemical cleaning at a different specific time than a full-height chemical cleaning according to a different one of the plurality of alternative heat-exchanger remediation strategies, implementing a partial-height chemical cleaning at a specific time, implementing a partial-height chemical cleaning at a different specific time than a partial-height chemical cleaning according to a different one of the plurality of alternative heat-exchanger remediation strategies, implementing at least one dilute chemical application at at least one specific time and/or frequency, implementing at least one dilute chemical application at a different time and/or frequency than a dilute chemical application according to a different one of the plurality of alternative heat-exchanger remediation strategies, in-bundle water-jet lancing at at least one specific time and/or frequency, and in-bundle water-jet lancing at a different time and/or frequency than an in-bundle water-jet lancing according to a different one of the plurality of alternative heat-exchanger remediation strategies.

13. The method of claim 1, wherein at least one of the plurality of alternative heat-exchanger remediation strategies includes at least one of the following options for remedying tube moisture separator component material degradation: weld repairs, separator component replacement, at least one chemical cleaning at a different time and/or frequency than a chemical cleaning according to a different one of the plurality of alternative heat-exchanger remediation strategies, and at least one in-bundle water-jet lancing at a different time and/or frequency than an in-bundle water jet lancing according to a different one of the plurality of alternative heat-exchanger remediation strategies.

14. The method of claim 1, wherein at least one of the plurality of alternative heat-exchanger remediation strategies includes at least one of the following options for remedying one or more heat-exchanger degradation modes: changing the primary fluid temperature; changing a secondary plant structure such as a turbine; changing a valve; implementing a feedwater heater bypass configuration at a time that differs from an implementation of a feedwater heater bypass configuration according to a different one of the plurality of alternative heat-exchanger remediation strategies; replacing the heat exchanger at one or more predetermined times; replacing the heat exchanger at a time that differs from a time of replacement of the heat exchanger according to a different one of the plurality of alternative heat-exchanger remediation strategies; changing the secondary water chemistry; and combinations thereof.

15. The method of claim 1, wherein at least one of the plurality of alternative heat-exchanger remediation strategies includes implementing a thermal power uprate to increase plant electrical power output.

16. The method of claim 1, wherein the time-varying predicted future progressions of heat exchanger performance metrics include predicted metrics for different probabilities of occurrence.

17. The method of claim 1, wherein the time-varying predicted future progressions of financial metrics include predicted metrics for different probabilities of occurrence.

18. The method of claim 1, further comprising: receiving a time-varying predicted future progression of heat exchanger performance metrics for a first alternative heat-exchanger remediation strategy that includes replacing the heat exchanger at a first time; receiving a time-varying predicted future progression of financial metrics describing the accumulated financial benefit of the first alternative heat-exchanger remediation strategy; receiving a time-varying predicted future progression of heat exchanger performance metrics for a second alternative heat-exchanger remediation strategy that includes replacing the heat exchanger at a second time that differs from the first time; and receiving a time-varying predicted future progression of financial metrics describing the accumulated financial benefit of the second alternative heat-exchanger remediation strategy.

19. The method of claim 1, wherein the heat exchanger comprises a heat exchanger of a nuclear power plant.

20. The method of claim 1, wherein the receiving of time-varying predicted future progressions of financial metrics comprises receiving time-varying predicted future progressions of financial metrics based, at least in part, on different power plant lifetimes.

21. The method of claim 1, wherein the evaluation of the effects of multiple, interdependent heat-exchanger degradation modes comprises an evaluation of at least two of the following degradation modes: tube deposit heat-transfer fouling, tube corrosion and wear, support plate broached hole blockage, tube support plate material degradation, and moisture separator component material degradation.

22. The method of claim 1, wherein said implementing one of the plurality of alternative heat-exchanger remediation strategies includes performing at least one of the following acts: remedying tube deposit heat-transfer fouling, wherein said remedying of tube deposit heat-transfer fouling includes performing at least one of the following acts: full-height chemical cleaning, partial-height chemical cleaning, at least one dilute chemical application, tube sheet sludge lancing, in-bundle water-jet lancing, tube bundle flushing, ultrasonic energy cleaning, polymeric dispersant addition, and secondary water chemistry changes, remedying heat-exchanger tube corrosion and wear degradation, wherein said remedying of heat-exchanger tube corrosion and wear degradation includes performing at least one of the following acts: repairing defective heat-exchanger tubes by plugging, repairing defective heat-exchanger tubes by sleeving, reducing the rate of future occurrence of degraded tubes by lowering the primary fluid temperature, implementing a full-height chemical cleaning, and implementing a partial-height chemical cleaning, remedying tube support plate broached hole blockage, wherein said remedying of tube support plate broached hole blockage includes performing at least one of the following acts: implementing a full-height chemical cleaning, implementing at least one dilute chemical application, in-bundle water-jet lancing, remedying tube support plate material degradation, wherein said remedying of tube support plate material degradation includes performing at least one of the following acts: implementing a full-height chemical cleaning, implementing a partial-height chemical cleaning, implementing at least one dilute chemical application, in-bundle water jet lancing, and remedying moisture separator component material degradation, wherein said remedying of tube deposit heat-transfer fouling includes performing at least one of the following acts: making weld repairs, replacing a separator component, at least one chemical cleaning, and at least one in-bundle water jet lancing.

23. A computer-implemented method of evaluating simultaneously the effects of multiple, interdependent heat-exchanger degradation modes for a heat exchanger of a power plant in the context of a series of alternative heat-exchanger remediation strategies that include individual options for remedying one or more of the degradation modes, the method being implemented in a computer comprising electronic storage and one or more physical processors configured to execute one or more computer program modules, the method comprising: calculating probabilistic time-varying predicted future progressions of heat exchanger performance metrics for a plurality of alternative heat-exchanger remediation strategies by evaluating the effects of multiple, interdependent heat-exchanger degradation modes in a single, integrated probabilistic analysis, the performance metrics including: a secondary side operating pressure of the heat exchanger, a heat-transfer efficiency of the heat exchanger, a fraction of defective components within the heat exchanger that are subject to one or more heat-exchanger degradation modes, and an electrical power output of the plant; calculating probabilistic time-varying predicted future progressions of financial metrics describing the accumulated financial benefit of each of the plurality of alternative heat-exchanger remediation strategies; and selecting and implementing one of the plurality of alternative heat-exchanger remediation strategies based on the probabilistic time-varying predicted future progressions of the heat exchanger performance metrics, wherein implementing the selected one of the plurality of alternative heat-exchanger remediation strategies includes performing at least one of the following acts: chemical cleaning, applying at least one dilute chemical, lancing tube sheet sludge, in-bundle water-jet lancing, tube bundle flushing, ultrasonic energy cleaning, adding a polymeric dispersant, changing secondary water chemistry, repairing a defective heat-exchanger tube by plugging, repairing a defective heat-exchanger tube by sleeving, lowering a primary fluid temperature, repairing at least one tube moisture separator component; or replacing at least one tube moisture separator component, wherein the time-varying predicted future progressions of heat-exchanger performance metrics for a plurality of alternative heat-exchanger remediation strategies account for routine post-outage heat-transfer transients that result from operating the plant in accordance with each of the plurality of alternative heat-exchanger remediation strategies.

24. The method of claim 23, wherein evaluating the effects of multiple, interdependent heat-exchanger degradation modes comprises evaluating at least two of the following degradation modes: tube deposit heat-transfer fouling, tube corrosion and wear, support plate broached hole blockage, tube support plate material degradation, and moisture separator component material degradation.

25. A method for evaluating the progression of heat-exchanger tube deposit heat-transfer fouling in the context of a series of alternative heat-transfer fouling remediation strategies, in a single, integrated probabilistic analysis, the method comprising: for each of a plurality of the alternative heat-transfer fouling remediation strategies, receiving calculated probabilities that routine, post-outage heat-transfer performance transients that affect the heat exchanger will result in plant thermal power reductions over a specified time period; receiving calculated accumulated quantities of lost plant production associated with such thermal power reductions calculated over the specified time period; and selecting and implementing one of the plurality of alternative heat-transfer fouling remediation strategies based on the received calculated probability and received calculated accumulated quantity of lost plant production, wherein implementing the selected one of the plurality of alternative heat-exchanger remediation strategies includes performing at least one of the following acts: chemical cleaning, applying at least one dilute chemical, lancing tube sheet sludge, in-bundle water-jet lancing, tube bundle flushing, ultrasonic energy cleaning, adding a polymeric dispersant, changing secondary water chemistry, repairing a defective heat-exchanger tube by plugging, repairing a defective heat-exchanger tube by sleeving, lowering a primary fluid temperature, repairing at least one tube moisture separator component; or replacing at least one tube moisture separator component.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Example embodiments of the methods that may be utilized in practicing the invention are addressed more fully below with reference to the attached drawings in which:

(2) FIG. 1 illustrates an example of predicted future steam generator steam pressure values for a set of 11 hypothetical alternative heat-exchanger remediation strategies according to an example embodiment of the invention;

(3) FIG. 2 illustrates an example of predicted future plant electrical output values for a set of 11 hypothetical alternative heat-exchanger remediation strategies according to an example embodiment of the invention;

(4) FIG. 3 illustrates an example of the median net-present-value (NPV) savings associated with 10 different alternative heat-exchanger remediation strategies, compared to the cost of a “control” strategy (or “baseline alternative”), calculated according to an example embodiment of the invention;

(5) FIG. 4 illustrates an example of a statistical distribution used as an input for calculating probabilistic results according to an example embodiment of the invention;

(6) FIG. 5 illustrates an example of a predicted future progression of steam generator tube deposit thermal resistance (including probabilistic results for various probabilities of occurrence) according to an example embodiment of the invention;

(7) FIG. 6 illustrates an example of the predicted probability that individual heat-exchanger remediation strategies will result in lower NPV costs than a baseline alternative heat-exchanger remediation strategy as calculated by an embodiment of the invention; and

(8) FIG. 7 illustrates an example of the predicted probability that post-outage heat-exchanger performance transients will require a thermal power reduction that would not otherwise have been necessary, as calculated by an embodiment of the invention.

(9) It should be noted that these figures are intended to illustrate the general characteristics of methods with reference to certain example embodiments of the invention and thereby supplement the detailed written description provided below. These drawings are not, however, to scale according to various embodiments, and should not be interpreted as defining or limiting the range of values or properties of embodiments within the scope of this invention. To the contrary, the principles of the present invention are intended to encompass any and all changes, alterations and/or substitutions within the spirit and scope of the following claims.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS OF THE INVENTION

(10) An embodiment of the current invention includes computer-executable instructions (e.g., computer code) that implement an algorithm capable of calculating, with a probabilistic method, time-varying quantities relevant to: a) important plant metrics such as heat-exchanger steam pressure, plant power output (e.g., electrical output as measured, e.g., with MWe), and fraction of in-service heat-exchanger U-tubes, among others, and b) the NPV costs associated with alternative heat-exchanger remediation strategies that include options for addressing individual heat-exchanger degradation modes. Included below are specific examples of embodiments of the invention.

(11) The computer code may be tangibly stored on any suitable electronic storage or computer-readable storage medium (e.g., RAM, ROM, flash, microchip, hard disk drive, solid state drive, etc.) of any suitable computer (e.g., PC, laptop, server computing device, client computing device) running any suitable operating system (e.g., Windows, Unix, Linux, etc.) and including any suitable processor or processors.

(12) Example embodiments of the invention include a computer code capable of evaluating and comparing alternative strategies that include individual options for remedying multiple interdependent heat-exchanger degradation modes such as tube deposit heat-transfer fouling, tube corrosion and wear, tube support plate broached hole blockage, and moisture separator component material degradation, among others. One hypothetical example of such a strategy (among many others) is the following set of options taken together: a) application of a dilute chemical treatment at regular intervals to remove a portion of the tube deposits; b) an increase, of a predetermined magnitude, in the primary fluid temperature; c) use of sleeves to repair corrosion defects at the tube sheet elevation; d) implementation of a thermal power uprate of a predetermined magnitude; and e) replacement of the steam generators at a predetermined time. In this example embodiment, the option for deposit removal in the selected strategy (“a” above) is compared against a control option that comprises operating the steam generator without any removal of tube deposits.

(13) Embodiments of the invention include, for example, an algorithm that predicts for all alternative strategies evaluated the time variation of important plant metrics, including, among others: a) heat-exchanger steam pressure, an example of which is shown in FIG. 1; b) plant production as measured, e.g., by electrical megawatts (MWe), an example of which is shown in FIG. 2; c) fraction of total heat-exchanger U-tubes experiencing service-induced defects; and d) average fraction of tube support plate broached hole flow area blocked by deposits.

(14) Embodiments also include, for example, a computer code that predicts the time-varying NPV cost incurred for all alternative strategies evaluated, where these costs include the costs due to the following causes, among others: a) plant output reductions (decreases in MWe) caused by tube deposit heat-transfer fouling and corrosion- and wear-induced tube defects; b) routine tube inspections required to detect tube defects, including changes in such inspections (and their costs) associated with the type and number of defective tubes detected previously; c) tube repairs by plugging and/or sleeving; d) deposit removal/remediation applications, including chemical cleaning (either through treatment of the entire tube bundle or through treatment of the top-of-tube-sheet region only), dilute chemical applications, top-of-tubesheet water-jet lancing, in-bundle water-jet lancing, ultrasonic energy cleaning, and polymeric dispersant addition, among others; e) repair or replacement of primary separator components due to material degradation; f) steam generator replacement; and g) extensions to plant outages due to, e.g., deposit removal/remediation applications, primary separator component repairs, tube repairs, and steam generator replacement. An example of these costs for 10 alternative deposit removal/remediation strategies, less the same costs for a “control” strategy, as calculated by an embodiment of the invention is shown in FIG. 3.

(15) Embodiments include, for example, a computer code that makes the predictions using a probabilistic method, such as a Monte Carlo method, to calculate results with different probabilities of occurrence. For example, there is a predicted probability of 50% that an actual future result (such as an NPV cost for a given strategy) will be larger than the median (or 50.sup.th percentile) result predicted with a probabilistic method. Similarly, there is a predicted probability of 25% that an actual future result will be larger than the 75.sup.th percentile result predicted with a probabilistic method. Such calculated probabilistic results provide the owner of the heat exchanger with a quantitative understanding of how input uncertainties may affect the actual outcomes (e.g., total NPV cost, secondary steam pressure, plant output, etc.) associated with the alternative remediation strategies evaluated. This is a significant extension beyond the prior art, which produces best-estimate results and/or bounding results with an unquantified probability of occurrence. Examples of 50.sup.th percentile results calculated according to an example embodiment are shown in FIG. 3.

(16) Embodiments include, for example, a computer code which yields direct, pair-wise probabilistic comparisons of NPV costs for alternative strategies, thereby providing calculated probabilities that one strategy will be less costly than another. Examples of such pair-wise comparisons as calculated by an example embodiment of the invention are illustrated by the curves in FIG. 3 and also by the curves in FIG. 6, which show the calculated probability that individual separately numbered strategies will be less costly than a baseline alternative (“control”) strategy.

(17) Example embodiments include a computer code capable of predicting for all alternative strategies the probability that, for example: a) reductions in plant output larger than a specified magnitude will occur, b) remedial measures such as chemical cleaning or dilute chemical treatment will be required to reduce the degree of tube support plate broached hole blockage caused by deposits to restore plant operability, and c) moisture separator component material degradation will be severe enough to require remediation.

(18) Example embodiments include a computer code capable of predicting the time-varying probability that commonly observed post-outage transients in steam generator heat-transfer efficiency will require a reduction in the plant thermal power level. An example of such results calculated with an embodiment of the invention is shown in FIG. 7.

(19) Example embodiments include a computer code that performs the calculations and predictions for the situation in which the heat-exchangers are replaced at a specified future time. In this example embodiment, the costs of heat-exchanger replacement, including vendor cost and the lost plant production associated with the necessary plant outage that accommodates the heat-exchanger replacement, are incorporated into the algorithm's calculations.

(20) Example embodiments also include a computer code that performs the calculations and predictions for the situation in which a plant thermal power uprate is implemented. In this example embodiment, the costs associated with the uprate (such as modifications to plant equipment among others) and the quantity and value of the additional plant production achieved with the power uprate are incorporated into the algorithm's calculations.

(21) Example embodiments include a computer code that performs its probabilistic calculations with statistical distributions (including continuous distributions), rather than fixed values or limited sets of fixed values, for important calculation inputs such as, for example: a) the cost of deposit removal/remediation applications; b) the duration of outage extensions required to accommodate such applications, to accommodate necessary tube repairs, or to accommodate heat-exchanger replacement, for example; c) the cost of replacement power; the average future concentration of impurities such as iron oxide in the feedwater, an example of which is shown in FIG. 4; d) the future progression of the thermal resistance of tube scale deposits on the U-tube outer surfaces, an example of which is shown in FIG. 5; e) the effects of deposit removal/remediation strategies on heat-exchanger heat-transfer efficiency; and f) the difference between the estimated clean thermal resistance of the heat-exchangers and the actual value for this parameter. Use of statistical distributions as inputs to calculations performed with probabilistic methods permits simultaneous quantitative evaluation of the effects of uncertainties in all such inputs on the computed results.

(22) The foregoing illustrated embodiments are provided to illustrate the structural and functional principles of the present invention and are not intended to be limiting. To the contrary, the principles of the present invention are intended to encompass any and all changes, alterations and/or substitutions within the spirit and scope of the invention.