دانلود رایگان ترجمه مقاله آنالیز ویژگی های کنترل دمای راکتور سریع خنک شده سرب با گردش طبیعی (نشریه الزویر 2016)

تجزیه و تحلیل مشخصات کنترل دما برای راکتور سریع خنک شده با سرب با چرخش طبیعی

Temperature control characteristics analysis of lead-cooled fast reactor with natural circulation

Abstract

Lead-cooled Fast Reactor (LFR) with natural circulation in primary system is among the highlights in advance nuclear reactor research, due to its great superiority in reactor safety and reliability. In this work, a transfer function matrix describing coolant temperature dynamic process, obtained by Laplace transform of the one-dimensional system dynamic model is developed in order to investigate the temperature control characteristics of LFR. Based on the transfer function matrix, a close-loop coolant temperature control system without compensator is built. The frequency domain analysis indicates that the stability and steady-state of the temperature control system needs to be improved. Accordingly, a temperature compensator based on Proportion–Integration and feed-forward is designed. The dynamic simulation of the whole system with the temperature compensator for core power step change is performed with SIMULINK and RELAP5-HD. The result shows that the temperature compensator can provide superior coolant temperature control capabilities in LFR with natural circulation due to the efficiency of the frequency domain analysis method.

1 Introduction

The lead cooled fast reactor (LFR) is envisaged as one of the six promising nuclear energy technologies for future advanced systems and is also considered as the system to burn actinides currently (Bianchi et al., 2006). Compared to other kinds of nuclear reactors, LFR has many inherent advantages (Wu et al., 2016):

(a) High boiling temperature and low melting temperature.

(b) Large heat capacity.

(c) No energetic reaction with air and water.

(d) Better shielding against gamma rays and energetic neutrons.

Because of the above advantages, LFR has become the research focus during recent years, several LFRs had been designed in many countries: SVBR (Zrodnikov et al., 2008) and BREST (Orlov et al., 2005) in Russia, MYRRHA (De Bruyn et al., 2007) and ElSY (Cinotti et al., 2008) in Europe, SSTR (Smith et al., 2008) in U.S. In China, series innovative lead-based reactors concepts and some key technology had been developed by FDS Team, such as subcritical system (Wu et al., 2011; Wu and FDS Team, 2008) neutron transport calculation (Wu et al., 1999, 2002; Wu, 2007), liquid metal coolant technology (Wu and FDS Team, 2011), structure materials (Wu and FDS Team, 2009; Huang et al., 2011, 2004), reactor design, etc. However, according to the related published articles, LFRs have rarely been in operation all over the world, except Russia where LFRs were applied in submarines during mid 1960s to 1990s (Alemberti et al., 2014).

In order to study temperature control characteristics, a transfer function model of LFR coolant system is necessary. Since the accurate three-dimensional dynamic model is too complex to be used in derivation of transfer function model, one-dimensional distributed parameter model is employed to be linearized in time domain, and discretized in Spatial Domain for transfer function modeling. A transfer function matrix describing coolant temperature dynamic process is obtained by Laplace transform of the one-dimensional model. This transfer function matrix provides the possibility that the characteristics of the coolant temperature control system can be analyzed by classical frequency domain analysis method of Single-Input–Single-Output System. The frequency domain analysis indicates that the coolant temperature control system without compensator is instable and the steady state error cannot be eliminated completely. Therefore, a temperature compensator based on Proportion–Integration and feedforward is designed for improving the system performance. Proportion term improves the stability, integration eliminates steady state error, and feed-forward improves the response rate. The sim ulation result presents that the temperature compensator could provide superior coolant temperature control capabilities in LFR with natural circulation.