How to detect leaks or faults in capillary tube mat network systems

I. Leak detection
1. Visual inspection method
Principle: By observing the surface of the system and the surrounding environment, look for direct signs of leakage.
Operation:
Appearance Inspection: Look carefully at the walls, ceilings, floors and other areas where the capillary network is laid to check for water seepage, water stains, bulging, deformation or paint peeling. For example, if water stains are found somewhere on the wall and gradually expanding, there may be a leak in the nearby capillary tube.
Connection parts inspection: focus on checking the connection between capillary tube and water supply and return collector pipe, as well as collector pipe and other piping, equipment connection parts, to see whether there are signs of loosening, leakage. If there are drops of water seeping out of the connection parts, it indicates that there may be leakage.

Applicable scenarios: For leaks that are more obvious and can be directly observed, but cannot detect leaks that are hidden inside or have very small leaks.

2. Pressure detection method
Principle: Use the pressure change to determine whether there is a leak in the system. When there is a leak in the system, the pressure will gradually decrease.
Operation:
Preparation: Close the system's inlet and return valves, connect a pressure gauge to the system's water supply line, and make sure the system is closed.
Pressurization: Use the pump to inject water at a certain pressure into the system (generally pressurized to about 1.5 times the working pressure, such as the system's working pressure of 0.3MPa, then pressurized to 0.45MPa), and record the initial pressure value.
Observe the pressure change: wait for a period of time (usually 30 minutes - 1 hour), observe the pressure gauge reading changes. If the pressure drops significantly, there is a leak in the system.
Locate leaks: After the pressure has dropped, the leaks can be further located by applying pressure in sections. Divide the system into a number of segments, respectively, for each segment of the pressure test, according to the pressure drop to determine the approximate location of the leak.

Applicable scenarios: It can accurately detect whether there is a leak in the system and locate the leak point roughly, but the accuracy of locating the tiny leak point is limited.

3. Gas Detection Method
Principle: Fill the system with a certain pressure of gas (such as nitrogen), and use the gas detector to detect whether there is gas leakage around the system, so as to determine whether there is a leak in the system.
Operation:
Filling: Close the system valve, connect the nitrogen bottle to the system's water supply line through a pressure reducing valve, and fill the system with a certain pressure of gas (generally filled to 0.2 - 0.3MPa).
Detection: Use the gas detector to scan and detect the area where the capillary network is laid, focusing on the connection parts, pipe bends and other easy-to-leak parts. When the detector sends out an alarm signal, it indicates that there is gas leakage at the place, i.e. there is a leakage point in the system.

Applicable scenarios: the detection of small leaks is more effective, but requires specialized gas detection equipment and nitrogen source, the operation is relatively complex, high cost.

4. Infrared thermal imaging detection method
Principle: the use of infrared thermography to detect the surface temperature distribution of the system, when there is a leak in the system, the temperature around the leakage point will be abnormal due to the evaporation or flow of water, thus showing a clear temperature difference on the infrared thermal imaging map.
Operation:
Preparation: Ensure that the system is in operation (cooling or heating) so that the surface temperature of the system is somewhat different from the ambient temperature.
Detection: Use the infrared thermal imager to scan and detect the area where the capillary network is laid, and observe the temperature distribution on the infrared thermographic map. If you find that the temperature in a certain place is significantly different from other areas, it may be the location of the leakage point.

Applicable scenarios: can quickly and intuitively detect the leakage point, especially suitable for hidden in the decorative layer of the capillary network leakage detection, but infrared thermal imager price is more expensive, the operator's technical requirements are higher.

Fault detection
1. Flow detection method
Principle: By measuring the flow of water in the system, to determine whether the system is clogged or flow abnormalities and other faults. When there is a blockage in the system, the flow rate will be reduced; when there is a leak or other faults lead to poor water circulation, the flow rate will also change.
Operation:
Installation of flowmeter: Install the flowmeter in the system's water supply pipeline or return pipeline to ensure that the measurement accuracy of the flowmeter meets the requirements.
Measure the flow rate: When the system is in normal operation, record the reading of the flow meter and compare it with the designed flow rate of the system. If the actual flow rate is significantly less than the design flow rate, the system may be blocked or other faults.
Locate the point of failure: If the flow rate is found to be abnormal, segmented measurement can be used to further locate the point of failure. Divide the system into several segments, measure the flow rate of each segment, and determine the approximate location of the fault according to the flow rate changes.
Applicable scenarios: It can accurately detect whether the system flow is normal or not, and can roughly locate the fault point, but the judgment of the cause of the fault needs to be combined with other detection methods.

2. Temperature detection method
Principle: Measure the temperature of the water in the system and the temperature of the indoor environment to determine whether there is a fault in the system, such as poor cooling or heating effect. When there is a fault in the system, the water supply temperature, return water temperature or indoor ambient temperature may not meet the design requirements.
Operation:
Measurement of water temperature: using a temperature measuring instrument, measure the water supply temperature and return water temperature of the system respectively, and compare them with the system design temperature. For example, in summer cooling, the water supply temperature should be maintained at around 16 - 18°C and the return water temperature will be slightly higher; in winter heating, the water supply temperature should be around 30 - 35°C and the return water temperature slightly lower. If the water temperature deviates from the normal range, the system may be faulty.
Measurement of indoor temperature: Place temperature measuring instruments at different locations in the room to measure the indoor ambient temperature and determine whether the system is able to reach the indoor temperature required by the design. If the indoor temperature cannot reach the set value, the system may have insufficient cooling or heating capacity.
Scenario: It can quickly determine whether the cooling or heating effect of the system is normal or not, but the further diagnosis of the cause of the failure needs to be combined with other testing methods.

3. Electrical detection method (for systems with electrical equipment)
Principle: Check the electrical parameters of the electrical equipment in the system (such as pumps, refrigeration units, heating equipment, etc.) to determine whether the equipment is faulty. When the electrical equipment is faulty, its voltage, current, power and other electrical parameters will change.
Operation:
Use electrical testing instruments: use electrical testing instruments such as multimeters and clamp-on ammeters to measure the voltage, current, resistance and other parameters of electrical equipment. For example, measure the resistance of the motor winding of the pump to determine whether there is a short-circuit or circuit-breaking fault in the motor winding; measure the operating current of the pump and compare it with the rated current to determine whether the pump is overloaded or underloaded operation.
Check the control circuit: check the control circuit of the system to see whether the control switch, relay, contactor and other components are working properly and whether the line connection is firm. For example, check whether the control switch can connect and disconnect the circuit normally, and whether the contacts of the relay and contactor are in good contact.
Applicable Scenario: It is suitable for detecting electrical equipment faults in the system, but has limited effect on detecting non-electrical faults.

4. Running sound detection method
Principle: By listening to the sound of the system operation, determine whether the system is abnormal. When there is a fault in the system, such as damaged pump bearings, foreign objects in the pipeline, etc., abnormal sounds will be produced.
Operation:
Quiet environment listening: when the system is running, keep the surrounding environment quiet and listen carefully to the sound of the pump, piping and other parts. Under normal circumstances, the sound of pump operation should be smooth and even, and the sound of water flow in the pipeline should be normal. If you hear abnormal noise, such as sharp friction, impact sound, humming, etc., that the system may be faulty.
Locate the fault part: according to the source and characteristics of the sound, roughly locate the fault part. For example, if you hear an abnormal friction sound at the water pump, it may be that the pump bearing is damaged; if you hear a crashing sound in the pipeline, it may be that there is a foreign object in the pipeline or the pipeline bracket is loose.
Applicable scenarios: simple operation, can quickly find some obvious faults, but the detection of minor faults or faults that do not produce abnormal sounds is not effective.