Condensate Monitoring OM0232

Transcription

1 3D TRASAR Boiler Technology 33 Condensate Monitoring Basics Date Version 1.0 Nalco Global Equipment Solutions 1601 West Diehl Road Naperville, IL

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3 Table of Contents 1.0 About This Manual Safety Explanation of Symbols Boiler Condensate System Overview D TRASAR Boiler Condensate Monitoring System Monitoring Condensate Conductivity with a 3D TRASAR Boiler Feedwater System D TRASAR Boiler Condensate Monitor Models Installation D TRASAR Boiler Condensate Monitoring System Sample Point Discharge Line Plumbing Connections Condensate Conductivity Probe Assembly Compensating vs. Non-Compensating Conductivity Probes D TRASAR Condensate Monitor ph and Conductivity Probe Installation Recommended Conductivity Standards D TRASAR Boiler Condensate Monitor Configuration High Temperature Sample Solenoid Valve Setup Conductivity and ph Probe Configuration Specifications Drawings Nalco Global Equipment Solutions 3

4 1.0 About This Manual. This manual provides information unique to the 3D TRASAR Boiler Condensate Monitor System. Refer to Operation Manual OM0227 for general installation instructions, calibration, configuration and troubleshooting that applies to all 3D TRASAR Boiler Automation Systems. Models supplied in some regions require 240 VAC, 50Hz, power instead of 120 VAC, 60Hz. 1.1 Safety Always follow the safety practices listed below: Never perform any installation procedures with electrical power engaged. Never perform any repairs with electrical power engaged. Never open the 3D TRASAR controller box or junction box with electrical power engaged. Maximum water pressure should never exceed 50 psi (3.4 bar). A pressure regulator must be added to the sample inlet for higher pressure samples. Maximum water temperature should not exceed 250 F (122 C) upstream of the sample cooler if equipped with an Nalco Corrosion Monitor (NCM) Sample must be cooled to below 110 F (29 C) downstream of the sample cooler. Always wear the appropriate Personal Protective Equipment (PPE) when working on a 3D TRASAR system (i.e. gloves, protective eyewear, protective shoes, wearing a mask, etc.). Always observe local and facility safety practices beyond those listed in this manual. The 3D TRASAR Boilers system is designed for use in non-hazardous areas. Contact NGES Help Desk for Class 1, Division 2 or Class 1, Division 1 installations. A lockable valve should be installed on the blowdown line to isolate the probe and motorized valve for maintenance. Follow all OSHA lock out, tag out requirements for servicing. WARNING: Always turn off power before making any electrical connections, which includes all interconnecting cables, otherwise permanent damage may occur to system components. SAFETY WARNING: The 3D TRASAR controller does not create sound above the 85 db noise level. Follow plant hearing protection regulations. 1.2 Explanation of Symbols WARNING: Risk of damage to equipment CAUTION-DANGER: High temperature, high pressure or electrical safety risk. SAFETY WARNING: Safety equipment is needed or plant safety procedures must be followed. Nalco Global Equipment Solutions 4

5 2.0 Boiler Condensate System Overview The Value of Condensate as Boiler Feedwater Condensate has a high heat content. Bringing condensate back to the boiler reduces the amount of fuel necessary to convert feedwater to steam. The result is reduced fuel consumption. Properly treated condensate is very pure. Returning condensate to the feedwater will improve feedwater quality and reduce makeup water demand. Pretreatment costs will also be reduced. Better feedwater quality also means more reliable boiler operation. Since condensate is low in dissolved solids, increasing the amount of returned condensate allows a boiler to operate at higher cycles of concentration, thus reducing the volume of blowdown. This will reduce the amount of heat lost from the boiler system through blowdown, and will lower fuel expenditures. Condensate Contamination Condensate can become contaminated with iron, copper, silica, sodium, hardness, organics or other chemicals. Iron and copper are usually present due to corrosion of the condensate/steam system, or inleakage of process water which contains iron or copper. Heavy metals, organics, or oil are usually caused by process contamination. Hardness, sodium, or silica may be caused by boiler water carryover, process contamination, or condenser leaks. Monitoring the quality of condensate being returned to the boiler can identify mechanical, operational or chemical problems. These can then be corrected to return the system to optimum performance levels. In cases where the problems cannot be easily corrected condensate monitoring permits the operator to sewer the condensate rather than return it to the boiler where it may cause serious damage. Condensate Sampling Points Condensate if often collected throughout the system in satellite condensate receiver tanks. When full, the contents are pumped to a larger condensate storage tank. Depending on the complexity of the plant and nature of potential contaminants individual condensate receiver tanks or the main condensate storage tank can be monitored for contamination. See potential sample points on the diagram below. Nalco Global Equipment Solutions 5

6 2.1 3D TRASAR Boiler Condensate Monitoring System 3D TRASAR Boiler Technology Condensate Monitoring Basics The 3D TRASAR Boiler Condensate Monitoring System is design to continuously monitor conductivity and ph. If the condensate does not meet the user-specified conditions a relay is activated. The relay can be wired to a valve to dump the contaminated condensate and/or trigger an alarm. In addition, corrosion (using the optional Nalco Corrosion Monitor) can be monitored. The temperature sensor built into the conductivity probe is used to correct ph and conductivity readings. In addition, it is used by the controller to close the solenoid valve (stop flow) if the temperature of the cooler sample exceed 110ºF (29ºC). Pump Interlock Signal 3D TRASAR Condensate Monitor Valve Control Signal Sample To Drain Sample Take-Off Throttling Valve 3-Way Valve Condensate Receiver Tank Condensate Pump Condensate Dump Condensate Storage Tank CAUTION-DANGER: 3D TRASAR Condensate Monitor must have a pressure below 50 psi (3.4 bar). If the Condensate Monitor is equipped with the optional NCM100 the sample temperature must also be below 250ºF (121ºC). 2.2 Monitoring Condensate Conductivity with a 3D TRASAR Boiler Feedwater System Condensate conductivity can also be monitored with a 3D TRASAR Boiler Feedwater System. If the measurement will be used to dump condensate the system must be equipped with the Blowdown Relay Box. The condensate conductivity probe assembly (P/N 060-BCP100.88) is similar to the blowdown probe assembly except it is designed for measuring lower levels of conductivity (up to 500 µs/cm) and it includes an RTD for temperature compensation. CAUTION-DANGER: DO NOT install the conductivity probe in a condensate line above 392ºF (200ºC) and 250 psig (17.2 bar). Probe failure and serious personal injury will result. Nalco Global Equipment Solutions 6

7 2.3 3D TRASAR for Boilers Condensate Monitor Models 3D TRASAR Boiler System Numbering Convention Model Region Series USA Canada Europe Latin America Asia-Pacific 110 VAC/60 Hz 110 VAC/60 Hz 220 VAC/50 Hz 110 VAC/60 Hz 220 VAC/50 Hz 220 VAC/50 Hz BL50xxx 060-BL50xxx BLC50xxx BLM50xxx BLL50xxx BLLC50xxx BLPC50xxx.88 BL52xxx 060-BL52xx BL52xx BLM52xx BL52xx BL52xx BL52xx.88 BL53xxx 060-BL53xx BLC53xx BLM53xx BLL53xx BLLC53xx BLPC53xx.88 BL54xxx 060-BL54xx BLC54xx BLM54xx BLL54xx BLLC54xx BLPC54xx.88 BL55xxx 060-BL55xx BLC55xx BLM55xx BLL55xx BLLC55xx BLPC55xx.88 BL6xxxx 060-BL6xxx BLC6xxx BLM6xxx BLL6xxx BLLC6xxx BLPC6xxx.88 Note: BL52xxx models do not require a power supply. 3D TRASAR Technology for Boiler Condensate Control Condensate Monitor Controller Fluorometer Nalco Corrosion Monitor Condensate Sample Conditioning System US Nalco Part Mounting Feedwater ph & Conductivity Blowdown Number Relay Box Wall Frame High Purity Low Purity None 115 VAC/60Hz Y NA Y Y Y Y NA NA 060-BL Y NA Y Y Y Y NA NA 060-BL Y NA Y Y Y Y Y NA NA 060-BL Y NA Y Y Y Y Y NA NA 060-BL Nalco Global Equipment Solutions 7

8 3.0 Installation 3.1 3D TRASAR Boiler Condensate Monitor System Condensate sample: cc/min at less than 50 psi (3.4 bar), 250 deg. F 122 deg. C) max. Power 120 VAC, 60Hz, 20A - MUST BE GROUNDED! Lockable valve Condensate pump interlock signal Pressure gauge psi 1/4" MNPT connection (1/4" or 1/2" tubing to unpressurized drain) 1/4" SS tubing (100 ft max) Mustbe 2X insulated! Cooling water to drain Install check valve if there is a chance of backflow Piping isolation valve 1/4" Tubing connection Cooling water supply line (approx gpm) N/O+N/C+Neutral to Motorized Valves Power 120 VAC, 60Hz, 10A (Blowdown Relay Box) 1/2" FNPT cooling water connections Relief valve dischargeto drain Frame Mounted System (29"D x 33"W x 66"H) Nalco Global Equipment Solutions 8

9 3.1.1 Sample Point The condensate sample point should be located downstream of potential contamination sources, where the condensate line will be full. Condensate receiver tanks offer a convenient sampling location. Important Note: The sample point must be located where the pipe will be full of condensate Discharge Line The sample water outlet flow can be plumbed into a containment vessel and pumped to an unpressurized condensate receiver to minimize waste. Plumbing Requirement Sample line Discharge line Cooling water line Condensate Monitor ¼ SS tubing, rate for 50 psi (3 bar), 250 F (121 C) minimum. Pressure tested Flushed prior to system connection Insulated up to system Lockable valve at take-off point Pressure gauge at take-off point ¼ tubing or pipe run to unpressurized drain or flash tank ½ tubing or pipe Plumbing Connections Condensate System Components Connection Type ph & Conductivity NCM100 (optional) Sample Inlet Sample Outlet Cooling Water Inlet & Outlet X ¼ Tube fitting ¼ FNPT ½ FNPT X X ¼ Tube fitting ¼ FNPT ½ FNPT Nalco Global Equipment Solutions 9

10 3.2 Condensate Conductivity Probe Assembly Pump Interlock Signal 3D TRASAR Feedwater System Valve Control Signal Conductivity Probe 3-Way Valve Throttling Valve Condensate Receiver Tank Condensate Pump Condensate Dump Condensate Storage Tank IMPORTANT NOTES: 1. The maximum temperature and pressure the conductivity probe can handle is 392ºF (200ºC) and 250 psig (17.2 bar). If the sample is above these conditions a sample conditioning system must be installed upstream of the conductivity probe to reduce the temperature and pressure. CAUTION-DANGER: DO NOT install the conductivity in a boiler above 392ºF (200ºC) and 250 psig (17.2 bar). Probe failure and serious personal injury will result. 2. The flow control valve downstream of the conductivity probe must be throttled back to maintain backpressure in the lines. The valves cannot be in the wide-open position. Otherwise, flashing in the line will occur if the line discharges to atmospheric pressure. WARNING: Flashing will damage the conductivity probe and valve seals. 3. Restrictions in the piping upstream of the conductivity probe can cause a pressure drop and flashing. This will result in erratic readings and damage the probe and valve seals. All upstream isolation valves should be full-port and set to fully open. 4. The motorized ball valve and flow control valve must be installed downstream from the conductivity probe. DO NOT install the conductivity probe between the valves. Flashing will occur. 5. To ensure the piping remains full at the conductivity probe run a segment of piping downstream of the probe above the level of the probe cross. 6. Likewise, wide spots (small diameter piping bushed up to larger piping) upstream of the probe will cause flashing. Larger diameter piping should transition down to the ¾ cross and probe without reverting to pipe segments of increased diameter. In addition, larger diameter piping should not be installed immediately downstream the ¾ cross. Nalco Global Equipment Solutions 10

11 3D TRASAR Boiler Technology Condensate Monitoring Basics 7. Ensure the flush valve installed on the bottom of the cross and probe closes properly. Leaking will cause flashing at the probe or improper flooding of the conductivity probe. 8. The conductivity probe must be installed so the flow-through hole in the probe is in line with the sample flow. The K-factor is stamped on the probe and is aligned with the hole. 9. Mount the probe cross in a horizontal pipe run at least 2 ft. (0.6 m) downstream of any elbows or fittings that may cause turbulence. DO NOT mount the probe on a vertical pipe run, unless flow in the pipe is upwards. 3.3 Compensating vs. Non-Compensating Conductivity Probes Compensating conductivity probes are used for condensate monitoring because the sample temperature may vary significantly. They have a built-in 4-wire RTD to measure the sample temperature. The controller corrects the conductivity measurement based on its temperature. Additionally, the RTD on the condensate probe mounted on the 3D TRASAR Condensate Monitor is used to close the solenoid valve on the sample line if the temperature exceeds 110ºF (29ºC). A probe with a cell constant of 0.1 (conductivity = µs/cm) is used for all condensate measurements Note: A maximum of 3 RTD s can be connected to the 3D TRASAR Controller (1 is required for the NCSM (RTD 2) and 1 is required for the Sample Conditioning System (RTD 1)). Conductivity Probe Identification Low range probes (K= 0.1) have a large oval-shaped flow-through hole. The entire electrode element is exposed. Range: µs/cm. Conductivity probes rated for high temperature (condensate or blowdown) have 8 Teflon coated leads and high-temperature potting. Maximum Limits: 250 psi (17.2 bar) and 392ºF (200ºC). Conductivity probes rated for lower temperatures/pressures (cooled feedwater/condensate) have 48 PVC coated leads. Maximum Limits: 200 psi (13.8 bar) and 158ºF (70ºC). Both types of probes used for condensate monitoring will have 2 red, 2 black, 2 green and 2 whites wires. Hot Condensate Probe (Compensating) Nalco P/N Nalco Global Equipment Solutions 11

12 3.4 3D TRASAR Condensate Monitor ph and Conductivity Probe Installation The condensate ph and conductivity module piping will be installed on the system at the factory. The probes are shipped in their packaging for protection. They must be installed into the plumbing module before startup. Note: Remember to remove the protective cap from the ph probe before screwing the probe into the tee. 3.5 Recommended Conductivity Calibration Standards The table below lists the conductivity calibration solutions that are available through Nalco. Calibration Standards Part Number 0 µs/cm (dry in Air) µs/cm 460-S µs/cm 460-S µs/cm 460-S µs/cm 460-S µs/cm 001-H ,000 µs/cm 001-H The recommendation for conductivity calibration is to choose two standards that encompass the expected conductivity range of measurement for the system. The tables below list the combinations of standards that are required for boiler feedwater and blowdown applications. Feedwater & Condensate: Blowdown: K = 1.0 K = 0.1 K = 1.0 Calibration Solution #1 Calibration Solution #2 Calibration Solution #1 Calibration Solution #2 Calibration Solution #1 Calibration Solution # , ,000 IMPORTANT NOTE: If combinations other than those listed are used, (i.e., 40 µs/cm and 10,000 µs/cm) the calibration will fail. This is due to the fact that the resulting conductivity counts for the incorrect combination of standards will fall outside of the 3D TRASAR controller s calibration range. Nalco Global Equipment Solutions 12

13 4.0 3D TRASAR Boiler Condensate Monitor System Configuration CAUTION-DANGER: Sample pressure must be below 50 psi (3.4 bar). Cooling water must be supplied to the sample cooler to drop the sample temperature below 110ºF (29ºC). The sample solenoid valve must be configured to close should the sample temperature exceed that limit. 4.1 High Temperature Sample Solenoid Valve Setup On the 3D TRASAR Condensate Monitor the low temperature devices must be protected from a temperature spike above the temperature limitations of the probes. The RTD on the conductivity probe will be used to monitor the temperature. Note: A Fluorometer with SCS must be configured to create the high temperature sample shut off control loop. Once configured the fluorometer portion can be removed. 1. Configure a Fluorometer with SCS. RDT#1 will appear as the default temperature probe. Make sure the control relay output is the same relay connected to the solenoid valve on the sample line. 2. Configure the conductivity (compensating) probe, assigning RTD#1 as the temperature probe. 3. Remove the Fluorometer, leaving the SCS and Conductivity probe configured to use RTD #1. Nalco Global Equipment Solutions 13

14 4.2 Conductivity and ph Probe Configuration The 3D TRASAR Boiler Controller can be configured to control condensate return using a relay. The system can be set up to activate a relay and dump the returning (contaminated) condensate if any of several user-specified conditions are met. Generally, conductivity is used as the primary control, with secondary control from ph, and any 4-20 ma inputs. 1. Using the Configurator add a conductivity probe to the Control and Alarm Settings section. Set the control method to continuous. 2. Open the edit screen for the conductivity probe, and set the output to the relay that you want to control the condensate return. Also, under control settings put in a set point value, and set acting to direct. This will set up the controller to activate the relay if the conductivity rises above the set point. The conductivity must be above the set point + deadband for 5-10 seconds for the relay to switch on. Nalco Global Equipment Solutions 14

15 3. Additional variables can also be used to control the same relay. To add a ph control to the relay, first add the ph probe to the Control and Alarm Settings section in Monitor mode. 4. Then add the ph input to the Control Overrides section. Name the override, and input the value that you want to activate the relay. Next, set the type to low or high. (For example setting the input value to 5, and the type to low will activate the relay if the ph drops below 5). You can set up a high and a low ph override to trip the relay by setting up 2 individual overrides (one for high ph and one for low ph ). 5. For each override click on Edit. Then click the box to activate it, set the output to the same name as the conductivity probe, set the response to fixed failsafe, and the duty to 100%. Control override values will switch the relay on after the value has surpassed the set point for 5 minutes. An analog input (particle monitor) can also be set up as a control override. Nalco Global Equipment Solutions 15

16 Note: If monitoring condensate receiver tanks with an intermittent pump an interlock from the pump must be assigned to the dump valve as an override. 6. Add a digital input (condensate pump on/off interlock signal) and set the control mode to monitor. 7. Add the digital input to the override screen. Set the input value to zero (0) and the type to low. 8. Click the Edit button and check Activate. Set the response to Forced Off. Note: If there are multiple condensate pumps (receiver tanks) the digital inputs can all be wired in parallel to the same digital input. Nalco Global Equipment Solutions 16

17 5.0 Specifications Condensate Monitor System: Maximum Pressure: Minimum Temperature: Maximum Temperature: Sample Flow: Sample Inlet Connection: Sample Outlet Connection: Cooling Water Connections: Wetted Materials: 50 psi (3.4 bar) 200 F (93 C) only if model with optional NCM100 is ordered 250 F (122 C) ml/min ¼ SS tubing ½ FNPT ½ FNPT 316 SS, Teflon, Viton Note: Sample must be cooled to below 158 F (70 C) downstream of the sample cooler (included). 6.0 Drawings Nalco Global Equipment Solutions 17

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20 NALCO COMPANY OPERATIONS North America: Headquarters West Diehl Road Naperville, Illinois USA Energy Services Division 7705 Highway 90-A Sugarland, Texas USA Europe: Ir.GF.Tjalmaweg BV Oegstgeest The Netherlands Asia Pacific: 2 International Business Park #02-20 the Strategy Tower 2 Singapore Latin America: Av das Nações Unidas Andar São Paulo SP Brazil NALCO and the logo, TRASAR, 3D TRASAR, Nalco Corrosion Stress Monitor and VANTAGE are Trademarks of Nalco Company Nalco 2011 Global Nalco Equipment Company Solutions All rights Reserved MANUAL 20