# Design and Simulation Analysis of a Temperature Control System for Real-Time Quantitative PCR Instruments Based on Key Hot Air Circulation and Temperature Field Regulation Technologies

## TL;DR

This paper presents a new temperature control system for PCR instruments that improves speed and accuracy, outperforming existing systems.

## Contribution

The study introduces a novel temperature control system using hot air circulation and field regulation for PCR instruments.

## Key findings

- The optimized system achieves up and down ramp rates of 7.5 ± 0.1 °C/s and 13.5 ± 0.1 °C/s, respectively.
- The steady-state temperature deviation is ±0.1 °C, with a nucleic acid amplification efficiency of 98.9 ± 0.2%.
- The system completes 35 PCR cycles in 16.3 ± 0.6 minutes, surpassing mainstream global counterparts.

## Abstract

To address the technical bottlenecks commonly encountered with real-time quantitative PCR instruments, such as insufficient ramp rates and uneven chamber temperature distribution, this study proposes an innovative design scheme for a temperature control system that incorporates key hot air circulation and temperature field regulation technologies. By combining the PCR instruments’ working principles and structural characteristics, the failure mechanisms associated with the temperature control system are systematically analyzed, and a reliability-oriented thermodynamic analysis model is constructed to clarify the functional positioning of core components and to systematically test the airflow uniformity, temperature dynamics, and nucleic acid amplification efficiency. An integrated fixture for airflow rectifier and cruciform frames is designed, which enables precise quantitative characterization of the system temperature uniformity, ramp rates, and amplification efficiency on a multi-condition comparison platform. Through modeling analysis combined with experimental validation, the thermal performance differences among various heating chamber structures are compared, leading to a multidimensional optimization of the temperature control system. The test results demonstrate outstanding core performance metrics for the optimized system: the up ramp reaches 7.5 ± 0.1 °C/s, the down ramp reaches 13.5 ± 0.1 °C/s, and the steady-state temperature deviation is only ±0.1 °C. The total duration for 35 PCR cycles is recorded at 16.3 ± 0.6 min, with a nucleic acid amplification efficiency of 98.9 ± 0.2%. The core performance metrics comprehensively surpass those of mainstream global counterparts. The developed temperature control system is well-suited for practical applications such as rapid detection, providing critical technological support for the iterative upgrade of nucleic acid amplification techniques while laying a solid foundation for the engineering development of high-performance PCR instruments.