Preferred choice for temperature control of high-power phased array radar: Why is the air conditioning cooling and heating solution the core choice?

The high power, high precision, and high reliability requirements of high-power array controlled array radar determine that the temperature control system must simultaneously meet the four major requirements of "precise temperature control, environmental adaptation, long-term stability, and controllable cost". The cooling and heating scheme of air conditioning, especially industrial grade precision air conditioning, has become the "optimal solution" under current technological conditions through its extremely high temperature control accuracy, full scene adaptability, high reliability, and controllable full life cycle cost. It is not only the "basic engineering" to ensure radar performance, but also the core supporting technology to support the "practical deployment and efficient operation" of radar equipment.

Why are there extreme requirements for "temperature control"?

1. The huge amount of heat generated by high power loss

Radar transmission power usually reaches the "kilowatt level" or even the "megawatt level", but the energy conversion efficiency of T/R modules is limited (mainstream GaN devices have an efficiency of about 30% -60%), and the remaining 40% -70% of energy will be directly converted into heat. For example, a radar with a transmission power of 100kW may generate more than 50kW of heat per hour - equivalent to 50 household induction cookers working simultaneously. If the heat cannot be dissipated in time, it will cause a sudden rise in component temperature.

2. The "sensitive dependence" of precision electronic devices on temperature
Chips (such as power amplifiers, phase shifters), antenna array feeding networks, etc. in T/R modules are all high-precision electronic components:

For every 10 ℃ increase in temperature, the lifespan of semiconductor devices may shorten by 50% (in accordance with Arrhenius' law);

Temperature fluctuations exceeding ± 2 ℃ may lead to phase deviation of phase shifters and output power drift of power amplifiers, directly affecting the detection range, angle accuracy, and anti-interference ability of the radar (for example, a phase deviation of 1 ° may cause the radar beam pointing error to exceed 0.1 °, which has a fatal impact on long-distance target tracking).

Why can it match the extreme demand of radar?

The air conditioning solution (specifically referring to "industrial grade precision air conditioning", non household air conditioning) combines "compression refrigeration+electric heating/heat pump heating".

1.  Extremely high temperature control accuracy: meeting the implicit requirement of radar's "micrometer level accuracy"

2.  Temperature control accuracy reaches ± 0.5 ℃: Through "PID closed-loop control" (real-time monitoring of array temperature → dynamic adjustment of cooling/heating power), the influence of temperature fluctuations on electronic components is avoided;

Humidity collaborative control: The high-frequency feeding network of the radar array is easily affected by humidity (humidity may cause leakage and corrosion), and the air conditioner can synchronously control the humidity at 40% -60% RH (relative humidity), solving the limitations of "single temperature control".

Compared with other solutions (such as liquid cooling: although it has high heat dissipation efficiency, the local temperature difference can easily reach ± 3 ℃; natural heat dissipation: completely uncontrollable accuracy), the air conditioning solution is the only technical path that can simultaneously meet the dual precision control of "temperature+humidity".

1.  Strong environmental adaptability: meeting the "full scenario deployment requirements" of radar

2.  High power array controlled array radar is often deployed in complex environments such as wilderness, shipborne, and airborne. The air conditioning scheme can be adapted to extreme conditions through structural design:

Field deployment: The air conditioner has the ability to operate in a wide temperature range of -30 ℃~55 ℃. In winter, it uses a heat pump for heating (no additional electric heating required, saving 30% energy), and in summer, it uses enhanced heat dissipation (such as anti dust design of the condenser) to cope with high temperatures;

Shipborne/airborne: adopting a "vibration and impact resistant" structure (such as suspended installation of compressors and flexible connection of pipelines) to avoid damage to the system caused by ship shaking and aircraft takeoff and landing;

Anti electromagnetic interference (EMC): The radar operates in high frequency bands (such as S-band and X-band), and the electrical system of the air conditioner must meet the "EMC Class A" standard to avoid electromagnetic radiation interference with radar signal reception.

1.  High system reliability: ensuring the radar operates continuously 24/7

2.  As a core equipment in national defense, air traffic control and other fields, radar needs to have "high availability" (MTBF ≥ 10000 hours per year), and the air conditioning scheme ensures reliability through three major designs:

Redundancy design: Key components (such as compressors and fans) adopt "N+1 redundancy" (for example, two compressors, one automatically replenishes energy when the other fails) to avoid temperature control failure caused by single point failure;

Low maintenance requirements: The filters, condensers, and other components of industrial grade air conditioners are designed to be "easy to disassemble and clean", with a maintenance cycle of up to 6 months (liquid cooling solutions require monthly replacement of coolant, resulting in high maintenance costs);

Intelligent diagnosis: Built in sensors monitor the real-time operation status of the air conditioner (such as compressor pressure, fan speed), and can provide early warning of faults (such as filter blockage, refrigerant leakage), reducing the risk of sudden shutdown.

According to industry data, the radar array using air conditioning temperature control has an average annual downtime of ≤ 2 hours due to temperature control issues, which is much lower than the ≤ 10 hours for liquid cooling solutions.

1.  Controllable Engineering Cost: Balancing "Performance" and "Feasibility of Implementation"

2.  Although the initial investment in air conditioning solutions is slightly higher than that of air cooling, the cost advantage is significant over the entire lifecycle (10-20 years):

Initial cost: The unit cooling capacity cost of industrial grade precision air conditioning is about 800 yuan/kW (liquid cooling scheme is about 1500 yuan/kW). For a radar with a heat dissipation requirement of 100kW, an initial savings of 700000 yuan can be achieved;

Operating costs: Air conditioning; The COP (energy efficiency ratio, i.e. cooling capacity/power consumption) can reach 3.5-4.0 (the COP of liquid cooling scheme is about 2.0-2.5), which can save about 50% of electricity bills annually;

Installation complexity: The air conditioning system does not require complex pipeline pre embedding (liquid cooling requires laying coolant channels inside the radar array, with a long installation cycle), and can be constructed synchronously with the radar body, shortening the overall delivery cycle by 30%.

From "technology adaptation" to "strategic support"

1. Directly guarantee the core combat performance of the radar

2.  The core indicators of radar, such as detection range and anti-interference ability, essentially depend on the stable operation of T/R components;

When the temperature stabilizes at 25 ℃± 0.5 ℃, the output power fluctuation of GaN power amplifier is ≤ 1%, which can ensure that the radar detection distance reaches the design value (such as 500km);

If the temperature fluctuation exceeds ± 3 ℃, the output power of the power amplifier may decrease by 10%, and the detection distance will be shortened to below 450km, directly affecting the early warning capability for distant targets such as stealth aircraft and ballistic missiles.

The air conditioning solution, through precise temperature control, has become the core guarantee for the radar's "performance not compromised".

1.  Enhance the deployment flexibility and environmental adaptability of radar

2.  Modern radar needs to have the ability of "rapid deployment and full coverage" (such as emergency air defense radar, border monitoring radar):

The radar with air conditioning temperature control can be designed as a "modular cabin" (air conditioning and radar integrated in the same cabin), without the need to build complex heat dissipation facilities on site, achieving "out of the box use" (deployment time shortened from 72 hours to 24 hours);

For high-altitude (such as over 5000 meters) and high salt spray (coastal) environments, air conditioning can be customized with designs such as "high-altitude compressors" and "anti-corrosion coatings" to ensure the continuous operation capability of radar in extreme environments, expanding the application scenarios of radar.

1.     Reduce the full lifecycle cost of radar and improve equipment cost-effectiveness

2.  As a high-value equipment (a high-power array controlled radar often costs hundreds of millions of yuan), the full lifecycle cost (procurement, operation, and maintenance) is a key consideration for radar:

Operating cost: The low energy consumption feature of the air conditioning solution can reduce the annual electricity cost of the radar by 50% -60% (taking 100kW heat dissipation demand as an example, saving about 200000 yuan in electricity cost per year, and saving 4 million yuan in 20-year life cycle);

Maintenance cost: The low maintenance requirement of air conditioning (maintenance once every 6 months) can reduce maintenance personnel investment and avoid damage to radar components caused by "coolant leakage" in liquid cooling solutions (the cost of repairing a single leak may reach millions of yuan).

This "low-cost, high reliability" feature allows limited equipment budgets to support more radar deployments, enhancing the overall coverage density of the air defense/monitoring system.