JP5369831B2 - Cooling water state measuring device and cooling tower - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a measuring device of properties of cooling water for precisely detecting deposits in a cooling tower by easily installing in the cooling tower, and to provide the cooling tower including the measuring device of properties of cooling water. <P>SOLUTION: Water in the cooling tower 30 passes through a pump 32 and a heat exchanger 34 and returns to the cooling tower 30, and is poured to a filler 40 from a water supply pipe 36. Water traveling and falling from the filler 40 is collected by a water collecting section 41 in an upper opening container shape, is poured to a water reception section 43 in an upper opening container shape via piping 42, is introduced to a measurement chamber 45 from piping 44, and flows out via the piping 46. A sensor 1 is installed in the measurement chamber 45 and abuts on cooling water introduced into the measurement chamber 45. A slime occurrence situation in the circulation cooling water system is detected by detection temperatures T<SB>1</SB>, T<SB>2</SB>of the sensor 1. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a cooling water state measuring device suitably used for detecting slime and scale in a cooling tower such as a circulating cooling water system, and a cooling tower equipped with this cooling water state measuring device.

  As a method for detecting an increase in the thickness of a microorganism film formed on a wall surface of a heat exchanger or a pipe by microorganisms generated in circulating water such as a cooling tower, Japanese Patent Application Laid-Open No. 61-26809 discloses in the pipe and pipe. Heat generation is performed from the temperature of the heat transfer section measured by the temperature sensing section (thermocouple, etc.) provided around the pipe and the fluid temperature in the pipe measured in advance. A method is described in which heat transfer inhibition due to microbial films (slime), precipitates (scale), etc. adhering to the inner wall surface of the pipe is detected from changes in the heat transfer amount.

  The method disclosed in Japanese Patent Laid-Open No. 61-26809 is a method for detecting the heat transfer inhibition caused by the deposits adhering to the inner wall surface of the pipe by the temperature rise of the temperature measuring element embedded in the pipe pipe wall. It is a method that can detect adhesion in a short time. However, (1) it is necessary to prepare a measuring unit for measuring the water temperature. (2) It is necessary to prepare a special piping with a temperature sensor embedded in addition to the normal piping. (3) In order to stabilize the heat supply amount to the pipe side by embedding the heating part in the pipe or fixing it outside the pipe, keep the heat radiation outside the pipe constant. It is not easy to prepare a means for measurement.

  In Japanese Patent Laid-Open No. 10-332610, a decrease in the amount of heat dissipated by the slime formed on the flat plate is caused by a resistance change when a heater in which a resistor such as platinum is formed in a pattern on the flat plate is heated. Is described by measuring the temperature rise (increase in resistance value). According to this method, a small measuring unit can be immersed in the circulating water system, and the measurement operation is facilitated as compared with the rubber plate method and the method disclosed in Japanese Patent Application Laid-Open No. 61-26809. However, in Japanese Patent Laid-Open No. 10-332610, since the water temperature and the water flow velocity are not measured, it is impossible to distinguish the change in the heat release amount due to the fluctuation of the water temperature or the flow velocity and the change in the heat release amount due to the slime adhesion. It was necessary to provide a means for separately measuring changes in water temperature and flow velocity.

JP 61-26809 A JP-A-10-332610

  As described in Japanese Patent Laid-Open No. Sho 61-26809, piping is measured by a method of measuring the amount of heat radiation from the output of the temperature measuring element embedded in the piping when the heater is heated and the temperature of the fluid flowing in the piping measured in advance. It is possible to always detect deposits on the wall surface. However, in the circulating water system, the water in the cooling tower is passed through the heat exchanger by the circulating water pump and returned to the cooling tower, and the cooling tower as described in JP-A-61-26809 is used. If it is attempted to install the sensor by this method, a construction for adding a new pipe in which the sensor is embedded is required.

  In JP-A-61-26809 and JP-A-10-332610, when the amount of heat release due to flow velocity changes due to flow rate fluctuations, it is difficult to distinguish between temperature fluctuations due to deposits and fluctuations due to flow rates, It is necessary to reduce the influence of water flow for stable measurement. In particular, when using the measuring means of Japanese Patent Laid-Open No. 10-332610, when the flow of water directly hits the measuring means, it is directly affected by the change in the water flow velocity.

  The present invention solves the above-mentioned problems of the prior art, and includes a cooling water state measuring device that can be easily installed in a cooling tower and can accurately detect deposits on the cooling tower, and this cooling water state measuring device. An object is to provide a cooling tower.

The cooling water state measuring device according to claim 1 is installed in a water collecting part for collecting cooling water flowing down inside the cooling tower, a water passing part through which cooling water from the water collecting part passes, and the water passing part. And a sensor for measuring the properties of the cooling water, and the water passing portion receives the cooling water from the water collecting portion while maintaining a full or overflow state, and a water receiving portion having an open top, A measuring chamber through which cooling water from the water receiving section passes, and the sensor is installed in the measuring chamber.

Cooling aqueous shape measuring apparatus according to claim 2, Oite to claim 1, wherein the sensor is a metal tube and a heating element and temperature sensing element is inserted into the metal tube, the heat generating body and the temperature sensing element and said It is characterized by comprising a filler filled between the inner surface of the metal tube.

According to a third aspect of the present invention, there is provided the cooling water state measuring apparatus according to the second aspect , wherein the energization control means for the heating element, and the judgment means for judging the adhesion of the deposit on the outer surface of the metal tube from the measured temperature of the temperature measuring body. And the determination means determines adhesion of deposits on the outer surface of the metal tube based on a change in temperature measured by the temperature measuring element when the amount of current supplied to the heating element is changed. It is characterized by being.

Cooling aqueous shape measuring apparatus according to claim 4, in claim 3, wherein after the heating element constant current i ₁ and the predetermined time t ₁ current, or a predetermined time t ₂ only de-energized, or, the predetermined time t ₂ Only a constant current i ₂ smaller than the constant current i ₁ is repeated, and the adhesion of deposits to the outer surface of the metal tube is determined.

Cooling aqueous shape measuring apparatus according to claim 5, in claim 4, the measured temperature T ₁ of the temperature sensing element at the beginning or said predetermined end of constant-time t ₂ of said predetermined constant-time t _1, said predetermined end of constant-time t ₁ or based on temporal change of the temperature difference between the measured temperature T ₂ of the temperature sensing element at the beginning of said predetermined constant-time t _2, is characterized in determining the adhesion of the deposit to the metal tube outer surface .

A cooling tower according to claim 6 is a cooling tower provided with the cooling water state measuring device according to any one of claims 1 to 5 , wherein the water collecting section is a filler installed in the cooling tower. The cooling water which is provided in contact with the water and flows down along the filler is collected.

  In the cooling water state measuring apparatus of the present invention, cooling water from the upper part of the cooling tower is collected in the water collecting part and passed through the water passing part, and the property of the cooling water is measured by a sensor provided in this water passing part. .

  In general, in conjunction with the operation of the refrigerator, the cooling water accumulated in the cooling tower pit by the circulation pump is supplied to the upper part of the cooling tower through the heat exchanger in the refrigerator, and the filler is supplied from the upper part of the cooling tower. It is transmitted and returns to the cooling tower pit again. By collecting the cooling water falling from the upper part of the cooling tower at the water collecting part and supplying it to the water passing part, the cooling water can be passed through the water passing part without power and brought into contact with the sensor. When the water receiving part that receives water from the water collecting part overflows, the cooling water can be passed at a constant flow rate with respect to the water passing part, and the characteristics of the cooling water must be measured accurately. Can do.

  This water collecting part is preferably installed in contact with the filler of the cooling tower. When the circulating pump of the cooling tower starts operation and cooling water is supplied to the upper part of the cooling tower, the cooling water falls through the filler. The water collecting part receives cooling water that flows down the filler wall. If the opening area of the water collection part is sufficiently small, the water receiving part where the falling water from the upper part of the cooling tower during normal cooling tower operation is introduced through the water collection part becomes full or overflowed. The cooling water flows through the water passage at a constant flow rate. Thereby, the property of cooling water can be accurately measured by the sensor.

  As a sensor used for the cooling water state measuring device of the present invention, a sensor in which a heating element and a temperature measuring element are installed inside a metal tube is preferable. The cooling water and the sensor are brought into contact with each other through the water passing portion, and the amount of current supplied to the heating element is increased or decreased at regular intervals. Then, the temperature depending on the water temperature is measured when the energization amount is zero or reduced, and the temperature depending on the heat generation amount is measured when the energization amount is increased. This makes it possible to measure the water temperature and the internal temperature at the time of heat generation with a single sensor, detect the adhesion of the deposit on the probe based on this, and accurately detect the occurrence of slime in the water system. .

  In the present invention, the amount of heat released from the sensor depends only on the temperature of the water and the amount of deposits such as slime on the sensor by passing the cooling water quantitatively through the water passing portion as described above. . For this reason, the internal temperature depending on the water temperature when the energization amount is zero (or reduced) and the internal temperature depending on the heat generation when the energization amount is increased are measured, and the difference between these two temperatures is measured. If calculated, it is possible to accurately detect an increase in internal temperature that increases due to heat transfer inhibition due to slime adhesion.

It is a systematic diagram of a circulating cooling water system. It is a one part enlarged view of FIG. It is sectional drawing of the water flow part containing a measurement chamber. It is sectional drawing of the sensor used for embodiment. It is a circuit block diagram of the measuring apparatus which concerns on embodiment. It is an energization pattern to a sensor, and a detection temperature change pattern figure. It is an energization pattern to a sensor, and a detection temperature change pattern figure. It is a temperature distribution map near a pipe wall. It is a graph which shows the relationship between a sensor output and a flow velocity. It is an output characteristic figure of a sensor. It is a graph which shows a measurement result. It is a systematic diagram of the circulating cooling water system which concerns on a comparative example.

  Hereinafter, embodiments will be described with reference to the drawings.

  FIG. 1 is a schematic longitudinal sectional view of a cooling tower provided with a cooling water state measuring apparatus according to the embodiment and a system diagram of an open circulating cooling water system. FIG. 2 is a side view of the cooling water state measuring device in which a part of FIG. 1 is enlarged, FIG. 3 is a sectional view of a water flow portion, FIG. 4 is a sectional view of a sensor, and FIG. FIG. 6, FIG. 6 and FIG. 7 are explanatory views of the operation of the sensor, and FIG. 8 is a schematic sectional view of the heat transfer wall.

  As shown in FIG. 1, the water in the cooling tower 30 returns to the cooling tower 30 through the pipe 31, the pump 32, the pipe 33, the heat exchanger 34 and the pipe 35, and the filler 40 in the cooling tower 30 passes through the water spray pipe 36. Pour into. The cooling water travels down along the filler 40, during which part of the water evaporates and the cooling water is cooled.

As shown in FIGS. 2 and 3, the water that has fallen down through the filler 40 is collected by the water collecting part 41 having an upper container shape and poured into the water receiving part 43 having an upper container shape through a pipe 42. . The cooling water in the water receiving portion 43 is introduced into the measurement chamber 45 from the pipe 44 and flows out through the pipe 46 at the upper part of the measurement chamber 45. The sensor 1 is installed in the measurement chamber 45 and comes into contact with the cooling water introduced into the measurement chamber 45. The slime generation state in the circulating cooling water system is detected by the detected temperatures T ₁ and T _{2 of the} sensor 1.

  The filler 40 is formed by arranging a large number of plate-like bodies made of a synthetic resin such as polyvinyl chloride in a stacked manner with a gap so that the plate surface is substantially vertical. The water collecting portion 41 is fixed to the filler 40 by a fastening member. The water collection part 41 is a container shape opened upward. In the water collecting portion 41, one side portion of the upper edge is in contact with the plate surface of the filler 40 so as to receive the cooling water that has fallen through the filler 40. The upper end of the pipe 42 is connected to the bottom of the water collecting part 41, and the lower end is located above the water receiving part 43.

  The water receiving portion 43 has a container shape opened upward, and is attached to the filler 40 or the cooling tower 30. The upper end of the pipe 44 is connected to the bottom surface of the water receiving portion 43, and the lower end of the pipe 44 is connected to the middle part in the vertical direction of the side surface of the measurement chamber 45. The measurement chamber 45 has a cylindrical shape with the cylinder axis direction as the vertical direction, and the base end of the pipe 46 is connected to the upper part thereof. The pipe 46 is curved in a downward U-shape or a substantially arc shape, and the distal end side of the pipe 46 is directed downward.

  The sensor 1 has an elongated probe shape, is held by a holder 47, and is inserted into the measurement chamber 45 from below. The holder 47 is held in the chamber 45 by a packing 48 and a nut 49.

  The water receiving part 43, the pipe 44, the measurement chamber 45 and the pipe 46 constitute a water passing part.

  If the opening area of the upper surface of the water collecting part 41 and the cross-sectional area of the pipe 42 are set larger than the cross-sectional area of the pipe 44 or 46, the amount of water poured from the water collecting part 41 into the water receiving part 43 via the pipe 42. Is larger than the amount of water passing through the water passing portion, so that the water receiving portion 43 is in an overflow state. Then, the cooling water is passed through the measurement chamber 45 at a constant flow rate according to the water head difference h between the upper edge of the water receiving portion 43 and the tip of the pipe 46.

  As described above, in this embodiment, the cooling water can be passed through the measurement chamber 45 at a constant flow rate with a simple mechanism that uses a constant water head difference without using a high-functional device such as a metering pump. it can.

  A flow rate adjustment valve may be provided in the pipe 44 or 46 to adjust the flow rate to the measurement chamber 45.

  Next, the structure of the sensor 1 will be described with reference to FIG.

  The sensor 1 includes a metal tube 2 made of a corrosion-resistant metal such as brass or stainless steel whose base end side is open and its distal end side is closed, a heating element 3 and a temperature measuring body 4 disposed in the metal tube 2, and a metal tube 2. It has a filler 5 such as electrically insulating and thermally conductive magnesium oxide (magnesia) particles filled in a space between the inner peripheral surface and the heating element 3 and the temperature measuring element 4. The base end side of the sensor 1 is sealed with a resin 6 such as an epoxy resin.

  The thickness of the metal tube 2 is preferably about 0.05 to 0.5 mm. The diameter of the metal tube 2 is preferably about 2 to 5 mm.

  As the heating element 3, a material in which a platinum thin film is formed on an insulating substrate is suitable. As the temperature measuring element 4, a thermocouple, a thermistor, or the like is suitable. However, the heating element 3 and the temperature measuring element 4 may be other than these.

  The heating element 3 is preferably disposed at the axial center of the metal tube 2. The temperature measuring body 4 is preferably provided so as to be in contact with the inner peripheral surface of the metal tube 2 between the heating element 3 and the inner peripheral surface of the metal tube 2.

  One of the lead wires 3a and 3b for energizing the heating element 3 extends to the outside of the sensor 1, and the other lead wire 3b is connected to the metal tube 2 by soldering or the like. However, the lead wire 3b may also extend to the outside of the sensor 1 similarly to the lead wire 3a. The lead wire 3c is connected to the base end of the metal tube 2 by soldering or the like. Two lead wires 4 a and 4 b from the temperature measuring body 4 are drawn out of the sensor 1. These lead wires are provided with an insulating coating.

  This sensor 1 is attached to the tip of a tubular holder 47. The metal tube 2 of the sensor 1 protrudes from the tip of the holder 47 into the measurement chamber 45.

  As described above, the holder 47 is fixed to the measurement chamber 45 by the packing 48 and the nut 49. The tip of the metal tube 2 of the sensor 1 is located above the connection (inlet) between the pipe 44 and the measurement chamber 45. A holder 47 faces the inlet of the cooling water from the pipe 44.

  The apparatus for detecting an adhering matter to the sensor 1 has an energization control means for the heating element 3 and a judging means for processing the output signal of the temperature measuring element 4 and judging the adhering state of the adhering substance. The circuit configuration of the attached matter detection apparatus will be described with reference to FIG.

  The attached matter detection device includes a current output unit 21 that outputs a current to the heating element 3, a temperature input unit 22 that inputs a temperature signal from the temperature measuring body 4 and converts it into a digital signal, and a temperature input unit 22 A signal is input to calculate a current value to be output by the current output unit 21 based on temperature information of the temperature measuring element, and a calculation unit 23 that performs slime adhesion determination. The arithmetic unit 23 is an arithmetic processing circuit configured by a microcomputer (μ-CPU) or a large scale integrated circuit (LSI). The calculation unit 23 periodically increases the value of the energization current to the heating element 3, and based on the temperature data from the temperature measuring element 4, the increase in the heat transfer resistance generated by the deposits attached to the surface of the sensor 1. Judgment status of deposits is determined

  In order to observe the occurrence of water-based slime using this deposit detection apparatus, the cooling water collected by the water collection unit 41 is passed through the measurement chamber 45 at a constant flow rate. Then, as shown in FIG. 6, the heating element 3 is energized in pulses, the measured temperature of the temperature measuring element 4 is detected, the amount of slime attached to the sensor 1 is determined based on this result, and the slime in the water system The occurrence status (ease of occurrence) of the event is determined.

As in FIG. 6, when starting the energization of the heating element 3, by heat transfer within temperature sensing element 4 heating of the heating element 3, the detected temperature of the temperature sensing element 4 starts to rise from T _1. The detected temperature of the temperature measuring element 4 rises until the amount of heat generated from the heating element 3 and the amount of heat released from the surface of the sensor 1 are balanced.

The energization time t ₁ is selected so that the temperature detected by the temperature measuring element 4 is sufficient to reach the equilibrium temperature T ₂ . The time t ₁ may be determined by performing a pre-operation test. However, if t ₁ is excessively long, the real-time property of the measurement becomes poor, so the temperature rises to a temperature that can be substantially regarded as an equilibrium temperature (for example, a temperature at which the difference from the final equilibrium temperature is within 0.1 ° C.). the time required for temperature may be set as t _1. For normal, _{t 1} is preferably about 5 to 60 seconds, especially 5 to 20 seconds.

When energization of the heating element 3 is stopped, the temperature detected by the temperature measuring element 4 starts to decrease by radiating heat from the sensor 1 to the surrounding water. The energization-stopping time period t _2, the detected temperature of the temperature sensing element 4 even if the slime is attached to the sensor 1 is kept reduced to at sufficient time to reach approximately equal equilibrium temperature T ₁ of the ambient temperature . The time t ₂ may be determined by performing a pre-operation test. However, if too long a t _2, since the real-time measurement becomes poor, required to decrease to a temperature which can be regarded as substantially equilibrium temperature (e.g., temperature difference between the water temperature is within 0.1 ° C.) time may be set as t _2. Usually, t2 is preferably about ₂₀ to 300 seconds, particularly about 60 to 300 seconds.

In the FIG. 6 is a zero energization amount at t ₂ hours period, but may be energized a constant current i ₂ traces than the current amount i ₁ of t ₁ hour period. However, i ₂ = 0 is preferable.

If the water temperature of the cooling water collecting in the water collecting part 41 does not vary, in a state in which slime sensor 1 is not attached, one energization time t ₁ before the start measurement temperature T _1, the energization time t both ₁ and the measured temperature T ₂ of the end which is constant over time. It is preferable to set the amount of current supplied to the heating element 3 so that the difference between T ₂ and T ₁ is of the order of 5 to 20 ° C..

In a state where slime adheres to the sensor 1, the measured temperature T _{2 at the} end of the energization time t ₁ is higher than when the slime does not adhere to the sensor 1. This is because heat transfer from the sensor 1 to the water is inhibited by slime, and the detailed mechanism will be described next.

Accordingly, the temperatures T ₁ and T ₂ are measured over time while the pulse energization shown in FIG. 6 is repeatedly performed, and the change from T ₁ and T ₂ (T ₂ −T ₁ ) over time to the sensor 1 is measured. It is possible to detect the presence and amount of slime adhesion.

A calculation formula for obtaining the adhesion thickness of the slime from the above temperatures T ₁ and T ₂ is as follows. This equation is based on the heat transfer model shown in FIG.

In Figure 8, Tw (water temperature) is _{T 1.} Ts (sensor surface temperature), when the thermal conductivity of the internal sensor is smaller in negligible compared to k _f can be a value equal to T _2. The items on the right side other than Tw and Ts are constants obtained from the shape of the sensor, the resistance value of the heating element, the energization amount, and the like.

For example, for the heat flux q, the electrical resistance value R of the heating element 3, the current value i applied to the heating element 3, the length L of the heating element 3 in the longitudinal direction of the sensor, and the radius r ₁ of the metal tube 2 are Can be calculated.

Thus, by measuring the T ₁ and T _2, it is possible to measure the thickness of the slime (sensor surface deposits).

  However, in order to consider the laminar boundary film heat transfer coefficient as a constant, it is necessary to make the thickness of the laminar boundary film constant, and therefore water is passed through the measurement chamber 45 at a constant flow rate. In addition, it is good also considering the flow rate as the speed value which can ignore the fluctuation | variation of a laminar boundary film heat transfer coefficient.

  When the pump 32 for circulating the cooling water is stopped, the inflow of cooling water into the measurement chamber 45 is stopped and the output temperature of the sensor 1 is increased.

That is, the air-conditioning refrigerator or the like may stop at night or in winter, and the circulation pump 32 may be stopped. When the water supply (sprinkling) from the upper part of the cooling tower 30 is stopped by stopping the circulation pump 32, the supply of water to the water collecting section 41 is stopped, so the supply of cooling water to the measurement chamber 45 is stopped. The water flow inside stops. As a result, the amount of heat released from the sensor 1 decreases, and the output temperature of the sensor 1 rapidly increases during heating (time zone t ₁ ) as shown in FIG. In addition, when the circulating pump 32 once stopped is restarted, the cooling water is supplied again from the water collecting section 41 to the measurement chamber 45, so that a flow velocity is generated in the measurement chamber 45. As a result, the heat radiation amount of the sensor 1 increases, so that the sensor output temperature at the time of heating is drastically lowered as compared to when the pump 32 is stopped. Accordingly, by monitoring the temperature rise rate during heating that is repeated periodically, it is determined whether or not a flow velocity is generated in the measurement chamber 45, and the operation state (ON / OFF) of the circulation pump of the cooling tower is detected. It becomes possible. That is, it is possible to set a threshold value for the heating rise rate and perform control to turn off the power supply to the heating element 3 when a heating rise rate exceeding the threshold value is detected.

  As described above, it is possible to detect the operation state of the circulation pump 32 from the output of the sensor 1 and to automatically control the energization amount to the sensor in the heating process, thereby reducing wasteful power consumption and cooling towers. It is possible to monitor the state of slime adhesion that is not easily affected by the operating conditions.

[Example 1]
A metal film resistance 120Ω of φ1.7 × 4.0 mm was installed as a heating element 3 at the tip of a stainless steel metal tube 2 having a diameter of 3.0 mm, a wall thickness of 0.1 mm, and a length of 35 mm. Further, in the vicinity of the heating element 3, a thermocouple as a temperature measuring body 4 was disposed so as to contact the inner peripheral surface of the metal tube 2. A magnesium oxide powder having an average particle size of about 100 μm was filled between the inner peripheral surface of the metal tube 2 and the heating element 3 and the temperature measuring element 4. The base end of the metal tube 2 was sealed with an epoxy resin 6. This sensor 1 was attached to the tip of the holder 47. The protruding length of the sensor 1 from the holder 47 is 18 mm.

The holder 47 was attached to the measurement chamber 45 as shown in FIG. 3 and connected as shown in FIG. The inner diameter of the measurement chamber 45 is 20 mm, the length in the vertical direction is 120 mm, and the outer diameter of the holder 47 is 18 mm. Pilot steers the cooling water in the measurement chamber 41, to the heating element 3 of the sensor 1 _was energized at _{t 1 = 60sec, t 2 =} 60sec, the current value i = 40 mA during energization. FIG. 9 shows the relationship between the water flow rate and T ₂ -T ₁ . FIG. 10 shows the relationship between slime thickness and T ₂ -T ₁ when slime gradually adheres to the sensor 1.

The measurement chamber 45 and the water collecting part 41 were installed in the cooling tower 30 as shown in FIG. As the water collection part 41, the thing of the opening area of 200 cm < ² > of an upper surface was used. The inner diameter of the pipe 42 is 20 mm, the inner diameter of the pipe 44 is 8 mm, and the inner diameter of the pipe 46 is 8 mm. As a result, the amount of water flow through the measurement chamber 45 was a constant flow rate of 300 cm ³ / min. At this water flow velocity, the flow of the test water along the surface of the metal tube 2 of the sensor 1 becomes a turbulent flow, and heat is uniformly transferred from the surface of the metal tube 2 to the water.

The heating element 3 of the sensor 1 was energized at t ₁ = 60 sec, t ₂ = 60 sec, and a current value i = 40 mA during energization. FIG. 11 shows the change with time of T ₂ -T ₁ .

  From this Example 1, it was confirmed that the slime adhesion thickness can be detected from the output temperature of the sensor 1 as shown in FIG. Further, as shown in FIG. 11, it was confirmed that ON / OFF of the circulation pump 32 could be detected based on the output temperature of the sensor 1.

[Comparative Example 1]
As shown in FIG. 12, a measurement-dedicated circulation line including a pipe 36, a pump 37, a flow cell 11 and a pipe 38 was provided, and the sensor 1 was installed in the flow cell 11. The water in the pit of the cooling tower 30 is introduced into the flow cell 11 via the sampling pipe 36 and the metering pump 37, contacts the probe 1 installed in the flow cell 11, and then returned to the pit via the pipe 38. . The detection temperatures T ₁ and T ₂ of the probe 1 were measured and shown in FIG.

  As shown in FIG. 11, in Comparative Example 1, water is passed through the measurement chamber 45 using the metering pump 37, so that the output of the sensor 1 hardly fluctuates even when the circulation pump 42 is stopped.

DESCRIPTION OF SYMBOLS 1 Probe 2 Metal pipe 3 Heating element 4 Temperature measuring body 5 Packing thing 10 Adhering matter detection unit 11 Flow cell 21 Current output part 22 Temperature input part 23 Calculation part 30 Cooling tower 32 Circulation pump 34 Heat exchanger 37 Metering pump 40 Filling material 41 Water collecting part 42, 44, 46 Piping 43 Water receiving part 45 Measuring chamber

Claims (6)

A water collecting section for collecting cooling water flowing down the cooling tower;
A water flow section through which cooling water from the water collection section passes;
A sensor installed in the water flow section for measuring the properties of cooling water;
A cooling water state measuring device comprising :
The water flow section includes a water receiving section having an upper opening that receives the cooling water from the water collecting section while maintaining a full or overflow state, and a measurement chamber through which the cooling water from the water receiving section passes. A cooling water state measuring apparatus, wherein the sensor is installed in the measuring chamber. Oite to claim 1, wherein the sensor includes a metal tube, which is filled between the heating element and the temperature sensing element is inserted into the metal tube, the inner surface of the heat generating member and the temperature sensing element and the metal tube A cooling water state measuring device comprising a filler. In claim 2 ,
Energization control means to the heating element;
A determination means for performing adhesion determination of the deposit on the outer surface of the metal tube from the measured temperature of the temperature measuring body,
The determination means determines adhesion of an adhering substance to the outer surface of the metal pipe based on a change in temperature measured by the temperature measuring element when the energization amount to the heating element is changed. A cooling water quality measuring device. The constant current i according to claim 3 , wherein a constant current i ₁ is energized to the heating element for a predetermined time t _{1 and then} de-energized for a predetermined time t ₂ , or a constant current i smaller than the constant current i _{1 for} a predetermined time t _{2. The} cooling water state measuring apparatus is configured to repeatedly perform a cycle of ₂ and determine adhesion of an adhering substance to the outer surface of the metal pipe. In claim 4, the measured temperature T ₁ of the temperature sensing element at the beginning or said predetermined end of constant-time t ₂ of said predetermined constant-time t _1, measuring at the start of the end or said predetermined constant-time t ₂ of said predetermined constant-time t ₁ based on the temporal change of the temperature difference between the measured temperature T ₂ of the temperature sensing element, the cooling water like measuring apparatus characterized by determining the adhesion of the deposit to the metal tube outer surface. A cooling tower comprising the cooling water state measuring device according to any one of claims 1 to 5 ,
The said water collection part is provided in contact with the filler installed in the cooling tower, and collects the cooling water which flows down along a filler, The cooling tower characterized by the above-mentioned.

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