Method of monitoring condenser performance and system therefor

• US 4,390,058 A
• Filed: 12/04/1980
• Issued: 06/28/1983
• Est. Priority Date: 12/05/1979
• Status: Expired due to Term

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Otake, Katsumoto, Okouchi, Isao, Mukai, Yasuteru, Miyai, Masahiko
• Primary Examiner(s): Richter, Sheldon J.
• Application Number:
  US06/213,095
• Time in Patent Office: 936 Days
• Field of Search: 165/95, 165/11 A, 165/1, 165/11 R, 165/32
• US Class Current: 165/11.1
• CPC Class Codes: F28B 11/00 Controlling arrangements with features specially adapted for condensers control arrangements in general G05
• CPC Class Codes: F28G 1/12 Fluid-propelled scrapers, bullets, or like solid bodies

Abstract

A method of monitoring the performance of a condenser and a system for carrying such method into practice, wherein a cooling water temperature, a cooling water flow rate, a condenser temperature and/or a heat flux through walls of cooling water tubes of the condenser are sensed by sensors to obtain values representing the operating conditions of the condenser, and an overall heat transmission coefficient or a heat transfer rate of the cooling water tubes is calculated at an arithmetic unit from the values representing the operating conditions. The cleanness of the cooling water tubes is calculated by an arithmetic unit from the value of the overall heat transmission coefficient or the heat transfer rate, and the performance of the condenser is judged by a performance judging unit based on the cleanness of the cooling water tubes.

Claims

1. A method of monitoring the performance of a condenser comprising the steps of:

sensing the operating conditions of the condenser and obtaining values representing the operating conditions;

calculating the cleanness of cooling water tubes of the condenser based on at least one of the variables of the overall condenser heat transmission coefficient and a heat transfer rate according to the values obtained in the first step; and

controlling the performance of the condenser with special reference to the values representing the cleanness of the cooling water tubes.

2. A method as set forth in claim 1, wherein values of cooling water temperature, cooling water flow rate and steam temperature in the condenser are sensed as representing the operating conditions of the condenser, and the cleanness of the cooling water tubes is calculated from an overall heat transmission coefficient of the cooling water tubes calculated from the obtained values representing the operating conditions of the condenser.

3. A method as set forth in claim 2, wherein a total heat load is calculated from the cooling water temperature and the cooling water flow rate and a logarithmic mean temperature differential is calculated from the cooling water temperature and the steam temperature in the condenser, and the overall heat transmission coefficient is calculated from the total heat load and the logarithmic mean temperature differential.

4. A method as set forth in claim 2, wherein the performance of the condenser is controlled based on the value of the overall heat transmission coefficient or the cleanness of the cooling water tubes.

5. A method as set forth in claim 4, wherein the step of controlling the performance of the condenser includes effecting cleaning of the cooling water tubes of the condenser.

6. A method as set forth in claim 1, wherein values of cooling water temperature, steam temperature in the condenser and heat flow through walls of the cooling water tubes are sensed as representing the operating conditions of the condenser, and the cleanness of the cooling water tubes is calculated from a heat flux and a heat transfer rate calculated from the obtained values representing the operating conditions of the condenser.

7. A method as set forth in claim 3, wherein the heat flux is calculated from the heat flow through the walls of the cooling water tubes and a logarithmic mean temperature differential is calculated from the cooling water temperature and the steam temperature in the condenser, and the cleanness of the cooling water tubes is calculated from the heat transfer rate calculated from the heat flux and the logarithmic mean temperature differential.

8. A method as set forth in claim 6, wherein the performance of the condenser is judged based on the value of the cleanness of the cooling water tubes.

9. A method as set forth in claim 8, wherein the step of controlling the performance of the condenser includes effecting cleaning of the cooling water tubes of the condenser.

10. A method of monitoring the performance of a condenser having a plurality of cooling tubes, comprising the steps of:

(i) sensing the inlet and outlet temperatures and the flow rate of the cooling water supplied into the condenser while sensing steam pressure or stem temperature in the condenser;

(ii) calculating the total heat load of the total cooling water tubes based on the inlet and outlet temperatures and the flow rate of the cooling water respectively obtained in the first step;

(iii) calculating the overall heat transmission coefficient of the total cooling water tubes based on said total heat load and said sensed values;

(iv) calculating the cleanness of the cooling water tubes of the condenser based on said overall heat transmission coefficient; and

(v) controlling the performance of the condenser based on the values representing the cleanness of the total cooling water tubes.

11. A method as set forth in claim 10, comprising the steps of:

(i) calculating the logarithmic mean temperature differential of the total cooling water tubes based on the sensed inlet and outlet temperatures and the steam pressure or steam temperature in the condenser; and

(ii) calculating said overall heat transmission coefficient based on said total heat load and said logarithmic mean temperature differential.

12. A method as set forth in claim 10, wherein the step of controlling the performance of the condenser includes effecting cleaning of the cooling water tubes of the condenser.

13. A method of monitoring the performance of a condenser comprising the steps of:

(i) sensing the value of the heat flow of the cooling water tubes transmitted through the walls of the cooling water tubes of the condenser, and sensing the inlet and outlet temperatures of the cooling water flowing in the cooling water tubes of the condenser, the cooling water flow rate and a steam pressure or steam temperature in the condenser;

(ii) calculating the heat flux based on the values of the sensed heat flow of the cooling water tubes;

(iii) calculating the heat transfer rate of the cooling water tubes based on said heat flux value and said sensed values;

(iv) calculating the cleanness of the cooling water tubes of the condenser based on said heat transfer rate of the cooling water tubes; and

(v) controlling the performance of the condenser based on the values representing the cleanness of the cooling water tubes of the condenser.

14. A method as set forth in claim 13, comprising the steps of:

(i) calculating the logarithmic mean temperature differential based on the sensed inlet and outlet temperatures of the cooling water and the steam pressure or steam temperature in the condenser; and

(ii) calculating the heat transfer rate based on said heat flux and the logarithmic mean temperature differential.

15. A method as set forth in claim 13, wherein the step of controlling the performance of the condenser includes effecting cleaning of the cooling water tubes of the condenser.

16. A system for monitoring the performance of a condenser, comprising:

a plurality of sensors for sensing the operating conditions of the condenser and for generating signals having values representing said operating conditions including cooling water temperature sensors and means including a condenser steam temperature sensor or condenser steam pressure sensor; and

a monitoring device connected to said sensors and comprising first arithmetic means for calculating the overall condenser heat transmission coefficient which is a measure of the cleanness of cooling water tubes of the condenser based on signals from said sensors representing the variables of a least one of heat flux and heat transfer rate according to the values representing the operating conditions obtained by said sensors, to thereby monitor the performance of the condenser.

17. A system as set forth in claim 16, wherein said plurality of sensors further include cooling water flow rate sensors, and said monitoring device further comprises second arithmetic means for calculating an overall heat transmission coefficient necessary for determining the cleanness of the cooling water tubes calculated from values representing the operating conditions obtained by said sensors.

18. A system as set forth in claim 17, wherein said monitoring device further comprises third arithmetic means for calculating a total heat load from values obtained by said cooling water temperature sensors and said cooling water flow rate sensors, and fourth arithmetic means for calculating a logarithmic mean temperature differential from values obtained by said cooling water temperature detectors and means including said condenser steam temperature sensor or said condenser steam pressure sensor, and wherein the overall heat transmission coefficient is calculated at said second arithmetic means from values obtained by calculations done at said third and fourth arithmetic means.

19. A system as set forth in claim 17, wherein said monitoring device further comprises performance judging means for judging the performance of the condenser based on the cleanness of the cooling water tubes determined by said first arithmetic means and the overall heat transmission coefficient determined by said second arithmetic means.

20. A system as set forth in claim 19, further comprising a cleaning device for cleaning the cooling water tubes of the condenser by means of resilient spherical members introduced into said cooling water tubes, and a controller for actuating said cleaning device by an actuating signal supplied by said performance judging means.

21. A system as set forth in claim 16, wherein said plurality of sensors comprise further include sensors for detecting heat flows through walls of the cooling water tubes, and said monitoring device further comprises second arithmetic means for calculating the heat flux necessary for determining the cleanness of the cooling water tubes calculated from values representing the operating conditions obtained by said sensors, and third arithmetic means for calculating the heat transfer rate necessary for determining the cleanness of the cooling water tubes calculated from the values representing the operating conditions obtained by said sensors.

22. A system as set forth in claim 21, wherein said monitoring device further comprises a fourth arithmetic unit for calculating a logarithmic mean temperature differential from values obtained by said cooling water temperature sensors, said condenser steam temperature sensor or said condenser steam pressure sensor, and the heat transfer rate is calculated at said third arithmetic means from values obtained by calculations done at said second arithmetic means and said fourth arithmetic means.

23. A system as set forth in claim 21, wherein said monitoring device further comprises another performance judging means for judging the performance of the condenser based on the cleanness of the cooling water tubes determined by said first arithmetic means.

24. A system as set forth in claim 23, further comprising a cleaning device for cleaning the cooling water tubes of the condenser by means of resilient spherical members introduced into said cooling water tubes, and a controller for actuating said cleaning device by an actuating signal supplied by said another performance judging means.

25. A system for monitoring the performance of a condenser comprising:

means including a plurality of cooling water temperature sensors for respectively sensing the inlet temperature and the outlet temperature of the cooling water supplied in the condenser having cooling water tubes, cooling water flow rate sensor means for sensing the flow rate of said cooling water, a condenser steam temperature sensor or condenser steam pressure sensor, and total heart load calculating means for calculating the total heat load of the total cooling water tubes of the condenser based on the values obtained by said cooling water temperature sensors and the cooling water flow rate sensor means;

overall heat transmission coefficient calculating means for calculating the overall heat transmission coefficient of the total cooling water tubes of the condenser based on the total heat load of the total cooling tubes calculated by said total heat load calculating means and the values obtained by said plurality of sensors; and

tube cleanness calculating means for calculating the cleanness of the total cooling water tubes based on the overall heat transmission coefficient obtained by said overall heat transmission coefficient calculating means.

26. A system as set forth in claim 25, further comprising logarithmic mean temperature differential calculating means for calculating the logarithmic mean temperature differential of the total cooling water tubes based on the values obtained by said cooling water temperature sensors and the condenser steam pressure sensor or the condenser steam temperature sensors;

whereby said overall heat transmission coefficient calculating means is capable of calculating the overall heat transmission coefficient based on the values representing the total heat load obtained by the total heat load calculating means and the logarithmic mean temperature differential obtained by said logarithmic mean temperature differential calculating means.

27. A system as set forth in claim 25, comprising performance judging means for judging the performance of the condenser based on the tube cleanness determined by said tube cleanness calculating means.

28. A system as set forth in claim 25, further comprising a cleaning device for cleaning the cooling water tubes of the condenser by means of resilient spherical members introduced into said cooling water tubes, and a controller for actuating said cleaning device by an actuating signal supplied by said performance judging means.

29. A system for monitoring the performance of a condenser comprising:

heat flow sensor means provided on the cooling water tubes of the condenser for sensing the heat flow transmitted through walls of the cooling water tubes, means including a plurality of cooling water temperature sensors for respectively sensing the inlet and outlet temperatures of the cooling water flowing through the cooling water tubes of the condenser, flow rate sensor means for sensing the flow rate of said cooling water, means including a steam pressure or steam temperature sensor for sensing the steam pressure of the steam temperature in the condenser;

heat flux calculating means for calculating the heat flux of the cooling water tubes based on the value of the heat flow determined by said heat flow sensor means;

heat transfer rate calculating means for calculating the heat transfer rate of the cooling water tubes based on the values obtained by said plurality of sensors; and

tube cleanness calculating means for calculating the tube cleanness based on the heat transfer rate obtained by said heat transfer rate calculating means.

30. A system as set forth in claim 29, further comprising a logarithmic mean temperature differential calculating means for calculating the logarithmic mean temperature differential of the cooling water tubes based on the values obtained by said cooling water temperature sensors and the condenser steam pressure or condenser steam temperature sensors, whereby said heat transfer rate calculating means is capable of calculating the heat transfer rate based on the heat flux obtained by said heat flux calculating means and the logarithmic means temperature differential obtained by said logarithmic means temperature differential calculating means.

31. A system as set forth in claim 29, comprising performance judging means for judging the performance of the condenser based on the tube cleanness determined by said tube cleanness calculating means.

32. A system as set forth in claim 31, comprising a cleaning device for cleaning the cooling water tubes by introducing cleaning medium into the cooling water tubes of the condenser based on the actuating signal from the performance judging means.