Temperature Control Unit - Model TCU
Mechanical refrigeration and/or heating unit which controls final sample temperature to 77º ± 1°F (25º ± 0.5°C)
A temperature control unit (TCU) provides controlled temperature water (coolant) to a group of secondary sample coolers in order to ensure closely controlled sample temperatures.
Sentry temperature control unit (TCU) systems are pre-designed, pre-piped packages available in sizes from 3 to 15 tons, air or water-cooled. All components are easily accessible for service (see resources to the right for detailed information).
Hot gas bypass provides heat capacity
Closed loop system eliminates corrosion problems
Designed for the high service water temperatures in power plant water chemistry
Cooling water at a precisely-controlled temperature with ± 1°F (0.5°C) accuracy
Self-contained with all necessary controls, pumping and refrigeration systems
Optional heater for additional warming capacity for subcooled samples.
Local display provides quick operational snapshot.
About Sentry Cooling Water Systems
Cooling water is a primary resource in many areas of power plant operation. The chemical quality of this water varies measurably from plant to plant, and from season to season within a particular plant. In addition, other characteristics can affect operational effectiveness. These include temperature, supply pressure and the presence of undissolved impurities such as silt, corrosion products and organic matter.
High quality cooling water is of particular importance for proper operation of the sample conditioning system. However, if cooling water is not of desirable quality, it is usually not feasible to upgrade the entire plant service water system solely to provide good water for the sample conditioning system. To address these special needs of the water chemist, Sentry has developed a comprehensive package of cooling systems which provide a dedicated loop of clean, temperature controlled water for the sample system.
Cooling water concerns related to sample systems fall into several categories:
Chemical Purity - if the water contains any hardness, exposure to the high temperatures in the sample cooler can result in scaling and loss of cooling capacity. Also, other chemical contaminants can cause corrosion (such as the effect of chlorides on stainless steel).
Physical Purity - undissolved material in the cooling water - e.g. silt, clams, organic matter, corrosion products - can foul the sample coolers and piping to inhibit heat transfer and flow.
Pressure - the flow of cooling water may be insufficient due to low source pressure or excess pressure drop in the supply piping.
Temperature - analyzers used to monitor water chemistry can be affected by temperature. Some compensation can be built into the instrument, but to achieve maximum accuracy, it is necessary to maintain the sample temperature at precisely 77°F (25°C). Short of this, it is desirable to maintain a constant temperature, even though it may not be 77°F (25°C). This at least assures that changes in readings are due to chemical deviations and not variations in sample temperature.