An Efficient, Flexible Arrangement to Generate High Quality Process or Domestic Heat in Recuperative Gas Cycle Power Plants: Application to Helium Direct Cycle Nuclear Power Plants

Abstract

The advantages of gas turbine power plants in general and closed cycle systems under gas pressure in particular for waste heat recovery are well known. A satisfactory efficiency for electric power generation and good conditions to obtain a significant amount of hot water above 100°C lead to a high fuel utilization. However, as in most of projects, it is not much possible to produce high temperature steam or water without significantly decreasing the electricity production. A new method for an additional generation of high quality process or domestic heat is proposed. The basic feature of this method lies in arranging one or two steam generators or preheaters in parallel with the low pressure side of the recuperator. The high total efficiency and the noteworthy flexibility of this system are emphasized. This arrangement is suitable for any kind of heat source, but the applications presented in this paper are related to helium direct cycle nuclear power plants the main features of which are a single 600 MW(e) turbomachine, a turbine inlet temperature of 775°C, no or one intermediate cooling and a primary circuit fully integrated in a pre-stressed concrete reactor vessel.

Externally fired gas turbine technology: A review

“…In this period many studies focused on the EFGT-based HTR nuclear reactors. Different large scale EFGT designs were proposed [28,29] and small CHP-EFGT were also investigated [30]. Other aspects such as HTHE designs were elaborately studied [31] and EFGT safety aspects were also investigated [32].…”

Power Generation From a 770°C Heat Source by Means of a Main Steam Cycle, a Topping Closed Gas Cycle and an Ammonia Bottoming Cycle

“…The relatively small topping gas turbine cycle would play a prominent part in this field for the following reasons : -its waste heat is easily available on an extended range of temperature ; -it is a closed cycle,and its load can be changed quite easily, without conversion efficiency penalty, by varying the working gas inventory, i.e. the mean pressure of the circuit ; a further improvement in increasing process heat conditions, performances and operational flexibility can be offered by a recuperator by-pass arrangement as described in (12), (13), (14), and summarily shown in Fig. 8.…”

“…main cycle bypasses, can be used ; the recovery of the waste heat is effected over a significant temperature variation range and without a phase change of fluids ; -another attractive possibility which would be very useful in the case of a change in the heat sink temperature involving a modification of the compressor inlet temperature, consists in using the so-called bypass arrangement on the LP side of the recuperator. Details about this adjustment of recuperative gas cycles can be found in (12), (13), (14), (16). A limited LP gas flow by-pass, effected from an intermediate temperature of the recuperator LP side, as shown in Fig.…”

Improvement in Recuperative Gas Cycles by Means of a Heat Generator Partly By-Passing the Recuperator: Application to Open and Closed Cycles and to Various Kinds of Energy

“…but:t he recovery factor is ig er : etai s a au � t is ar+ angem ent version can be faun� in (2). A par � 1cular app lica tion could concern ammonia (NH 3 ) bottoming {;,)lf;ile;� these conditions propitious to the overall Q• �ti (!iency of the system, a complementary factor has t�;be added, as illustrated by Fig.…”

“…It basically consists of a heat generator, either a steam generator or a heat exchanger, partly by-passing the low pressure side of the recuperator. Preliminary description and appli cation, restricted to gas turbine-high temperature gas cooled nuclear reactors (GT-HTGR) and to combined power and heat generation, were already presented (2).…”