Constant temperature and pressure water supply system

Product Overview

The constant temperature and pressure water supply system is an integrated intelligent water supply device that can simultaneously achieve constant control of water supply pressure and precise regulation of outlet water temperature. It is widely used in industrial cooling water systems, laboratory testing water supply, environmental simulation equipment, precision instrument cooling, and production process water supply—any application requiring strict control over water temperature and pressure.

This system employs fully automatic PLC control with a built-in PID regulation algorithm. Through the coordinated operation of variable frequency speed control technology and a heat exchange temperature control unit, it monitors and dynamically adjusts the water supply pressure and temperature in real time, ensuring that the outlet water pressure fluctuation is no greater than ±0.01MPa and the temperature fluctuation is within ±1℃. The system boasts outstanding advantages such as stable water output, energy efficiency, high automation, and self-diagnosis of faults, meeting various precision water needs.

Working principle

The constant temperature and pressure water supply system is based on the closed-loop PID control principle, achieving dual stable regulation of temperature and pressure.

Constant Pressure Control: A pressure transmitter installed on the outlet water pipeline sends a real-time outlet pressure signal (4-20mA) to the PLC. The PLC compares this signal with the user-set target pressure value, and after PID calculation, outputs a frequency command to the frequency converter. The frequency converter adjusts the speed of the water pump motor, thereby changing the water supply volume and keeping the pressure at the end of the pipeline stable near the set value. When water consumption increases and pressure decreases, the PLC output increases, and the water pump accelerates to compensate for the pressure drop; when water consumption decreases, the water pump slows down or goes into sleep mode, achieving on-demand water supply and high energy efficiency.

Constant Temperature Control: The system uses an indirect temperature control method via heat exchangers to precisely regulate the water temperature in the delivery pipeline. The primary side of the plate heat exchanger (or shell-and-tube heat exchanger) is connected to an external heat source (such as a steam or hot water boiler) or a cold source (such as a chiller or cooling tower), while the secondary side is a circulating water supply pipeline. Temperature sensors monitor the outlet water temperature in real time. The PLC compares the signal with the set temperature and automatically adjusts the flow rate of the primary medium in the heat exchanger (via an electric regulating valve) or switches the cold/heat source supply to stabilize the secondary outlet water temperature within the target range. This heat exchange method avoids direct contact between the heating/cooling elements and the process water, making it particularly suitable for scenarios requiring high water purity (such as pure water or deionized water) or long-distance constant-temperature water delivery. It also enables rapid switching between hot and cold water and large temperature difference regulation.

Closed-loop control: Temperature and pressure sensors continuously collect real-time data. The PLC continuously corrects its output commands based on deviations, forming a closed-loop control system of "detection—calculation—execution—re-detection," ensuring stable and reliable water supply quality.

System Composition

This constant temperature and pressure water supply system consists of the following core units:

Constant Pressure Water Supply Unit: Includes a stainless steel multi-stage centrifugal pump, frequency converter, and pressure stabilizing tank (diaphragm/airbag type). The frequency converter adjusts the pump speed according to PLC commands, and the pressure stabilizing tank acts as a buffer and auxiliary pressure stabilizer, reducing frequent pump start-stops.

Constant Temperature Control Unit:

Heat Exchanger: Employs a high-efficiency plate heat exchanger or shell-and-tube heat exchanger (made of 316L stainless steel or titanium, corrosion-resistant) for heat exchange between the hot and cold media and the process water.

Heat and Cold Source Interfaces: Connects to external heat sources (steam, hot water boilers, heat pumps) and cold sources (chilled water units, cooling towers, deep well water), equipped with electric regulating valves and actuators, with PLC automatically controlling the media flow.

Circulation Pump: Drives the process water to circulate between the heat exchanger and the water usage points, ensuring uniform pipeline temperature.

Detection and Sensing Unit: Includes a pressure transmitter (4-20mA), temperature sensor (PT100 or thermocouple, installed at the pipe outlet and heat exchanger inlet/outlet), level sensor, etc., to collect system operating data in real time with an accuracy class of 0.25.

Control System: An industrial-grade PLC (Programmable Logic Controller) is used as the control core, with a built-in PID control algorithm. Human-machine interaction is achieved through a touchscreen HMI; target temperature and pressure can be set, operating parameters are displayed in real time, and it features fault self-diagnosis, historical data recording, remote monitoring, and alarm functions.

Piping and Accessories: Stainless steel or UPVC piping, equipped with check valves, electric regulating valves, safety valves, air release valves, etc., to ensure safe and stable system operation.

Core advantages

Technical parameters (customizable)

Application areas

Industrial Cooling Water Systems: Provide constant temperature and pressure cooling water for machinery, injection molding machines, extruders, welding equipment, lasers, reaction vessels, etc., ensuring stable equipment operation. Utilizing heat exchange systems allows the use of existing chilled water or cooling tower water resources within the factory, avoiding the need for separate refrigeration units for each piece of equipment.

Laboratory and Scientific Testing: Provides standard-compliant constant temperature and pressure test water for appliance performance testing (water heaters, water purifiers, dishwashers, toilets, etc.), material durability testing, and environmental simulation experiments. Heat exchange systems ensure no additional metal ion precipitation in the test water, preserving test results.

Precision Instrument Cooling: Provides stable circulating cooling water for electron microscopes, spectrometers, X-ray diffractometers, nuclear magnetic resonance equipment, lasers, semiconductor manufacturing equipment, etc., maintaining optimal instrument operating conditions. Heat exchangers isolate cooling water from instrument circulating water, preventing cross-contamination.

Production Process Constant Temperature Water Supply: Used in chemical, pharmaceutical, food processing, and textile printing and dyeing industries for processes such as reaction vessel jacket cooling, constant temperature dissolution of materials, and constant temperature water supply for cleaning lines. By connecting heat exchangers to the plant's heating/cooling network, energy cascade utilization is achieved.

HVAC and Boiler Systems: Provides constant-pressure makeup water for central air conditioning systems, district heating systems, and gas/steam boilers, maintaining stable system pressure and extending equipment lifespan.

Medical Devices and Pharmaceutical Equipment: Provides constant-temperature and constant-pressure circulating cooling water for CT scanners, MRI machines, dialysis equipment, fermenters, drying equipment, etc. The heat exchange method ensures the purity of the cooling medium, complying with GMP standards.

New Energy and New Materials Fields: Constant-temperature control for lithium battery production line injection machines, constant-temperature cooling systems for photovoltaic slicing machines, water supply systems for hydrogen energy testing platforms, etc.

Residential and Commercial Hot Water Systems: Centralized domestic hot water supply, constant-temperature and constant-pressure hot water supply systems for hotels/hospitals/schools, utilizing boilers or solar water heaters as primary heat sources through heat exchangers to solve the problems of water pressure fluctuations and sudden temperature changes during peak water usage periods.

Why Choose Us?

Mature Control Algorithm: PLC-based PID closed-loop control, pressure stability accuracy ≤0.01MPa, high temperature control accuracy, rapid system response, and strong anti-interference capability.

Heat Exchange Temperature Control Technology Expertise: Proficient in designing integrated control schemes for plate/shell-and-tube heat exchangers and automatic regulating valves. Optimized configurations can be tailored to the user's existing heat source conditions (steam, hot water, chilled water, cooling water) to minimize operating energy consumption and equipment investment.

All Stainless Steel Water System: Water tanks, pipes, pump bodies, and heat exchanger flow components are all made of 304/316L stainless steel, corrosion-resistant and rust-free, suitable for various water qualities such as pure water, softened water, and deionized water.

Modular Design, Flexible Customization: Pressure range, temperature range, flow specifications, and installation type (skid-mounted/frame-type/split-type) can be customized according to the user's site conditions.

Comprehensive protection features: Equipped with safety measures such as water shortage shutdown, over-temperature protection, over-pressure protection, anti-freeze protection, and motor overload protection to ensure long-term safe and reliable operation of the equipment.

Remote operation and maintenance support: The system comes standard with a communication interface and can be optionally equipped with a cloud platform for remote monitoring services, enabling real-time viewing of operating parameters, remote fault diagnosis, and data storage and analysis.

Global technical support: Provides factory pre-commissioning, on-site installation guidance, operation training, and long-term spare parts supply services.