The Institute for Fluid Dynamics operates high-pressure systems for the investigation of thermofluid-dynamic phenomena. A system for the investigation of supercritical CO 2 built. For this purpose, a recuperator is used to internally transfer the heat from the CO 2 Mass flow of 4 kg / s of the warm system area to the mass flow of 4 kg / s of the colder system area is required. Furthermore, a heat exchanger is required, which further reduces the temperature of the cooled mass flow of 4 kg / s from the recuperator with the help of cooling water. For this purpose, cooling water is provided by the operator, which has a controllable mass flow between 0.1 kg / s and 4.3 kg / s, an inlet temperature of 35 oC and a pressure of 95 bar (g). Both components should be designed as compact diffusion-welded plate heat exchangers (PrintedCircuitHeatExchanger or microchannel heat exchangers). The pressure equipment directive must be met.

The CO 2 Countercurrent recuperator must meet the following minimum requirements:

- Compact diffusion-welded plate heat exchanger with counterflow according to the Pressure Equipment Directive (2014/68 / EU),

- Operating point 1:

—— Side A: Medium: CO 2 , Mass flow: 4 kg / s, inlet temperature: 200 O C, outlet temperature: 531 O C, pressure: 300 bar,

—— Side B: Medium: CO 2 , Mass flow: 4 kg / s, inlet temperature: 560 O C, exit temperature: 224.6 O C, pressure: 300 bar.

- Operating point 2:

—— Side A: Medium: CO 2 , Mass flow: 4 kg / s, inlet temperature: 170 O C, outlet temperature: 493 O C, pressure: 300 bar,

—— Side B: Medium: CO 2 , Mass flow: 4 kg / s, inlet temperature: 570 O C, exit temperature: 193.1 O C, pressure: 75 bar.

- Operation of the recuperator up to 300 bar and 570 O C at the same time,

- Design pressure: -1 bar (g) (evacuation of the system; at the same time -10 O C to 30 O C) up to 315 bar (g) (at the same time 590 O C),

- Design temperature: -10 O C (at 315 bar (g) and -1 bar (g) at the same time) to 600 O C (at the same time 315 bar (g)),

- Delivery of the recuperator after acceptance of the entire device by an approved monitoring body (ZÜS), issue of a declaration of conformity for the heat exchanger and evidence of the certificate of conformity,

- Design for at least a service life of 10,000 h and number of load cycles 1,000,

- Design, manufacture, testing and documentation in accordance with the Pressure Equipment Directive (2014/68 / EU), issuing of a CE mark required,

- Maximum pressure loss for all operating points for side A: 1.5 bar and for side B: 4 bar,

- Materials: pressure device and flange:

a) 2.4663 (NiCr23Co12Mo, Inconel 617) according to VdTÜV material sheet 485,

b) 2.4856 (NiCr22Mo9Nb, Inconel 625),

c) 1.4401 (X5CrNiMo17-12-2, 316),

d) 1.4404 (X2CrNiMo17-12-2, 316L).

- Pipeline connections are DN 100 PN 400 on both sides at all 4 points. The associated connection flanges are to be dimensioned by the bidder.

The cooling water driven countercurrent CO 2 The cooler must meet the following minimum requirements:

- Compact diffusion-welded plate heat exchanger with counterflow according to the Pressure Equipment Directive (2014/68 / EU),

- Operating point 1:

—— Side A: Medium: CO 2 , Mass flow: 4 kg / s, inlet temperature: 224 O C, outlet temperature: 181 O C, pressure: 300 bar,

—— Side B: Medium: water, mass flow: adjustable between 0.1 kg / s and 4.2 kg / s, inlet temperature: 35 O C, outlet temperature: to be determined, pressure: 95 bar (g)

- Operating point 2:

Side A: Medium: CO 2 , Mass flow: 4 kg / s, inlet temperature: 195 O C, outlet temperature: 140 O C, pressure: 75bar.

Side B: Medium: water, mass flow: adjustable between 0.1 kg / s and 4.2 kg / s, inlet temperature: 35 O C, outlet temperature: to be determined, pressure: 95 bar (g)

- Operation of the liquid cooler up to 300 bar and 300 O C at the same time,

- Design pressure: -1 bar (g) (evacuation of the system; at the same time -10 O C to 30 O C) up to 315 bar (g) (at the same time 300 O C),

- Design temperature: -10 O C (at 315 bar (g) and -1 bar (g) at the same time) to 300 O C (at the same time 315 bar (g)),

- Delivery of the liquid cooler after acceptance of the entire device by an approved monitoring body (ZÜS), issue of a declaration of conformity for the heat exchanger and evidence of the certificate of conformity,

- Design for at least a service life of 10,000 h and number of load cycles 1,000,

- Design, manufacture, testing and documentation in accordance with the Pressure Equipment Directive (2014/68 / EU), a CE mark required,

- Maximum pressure loss on the CO 2 Side: 1.7 bar for operating point 1 and on the CO 2 Side: 4.5 bar for operating point 2. And on the water side: 5 bar for both operating points,

- Materials: pressure device and flange:

a) 1.4401 (X5CrNiMo17-12-2, 316),

b) 1.4404 (X2CrNiMo17-12-2, 316L),

c) 1.4410 (UNS S32750).

- Pipe connections are CO 2 side: DN 50 PN 400 and cooling water side: DN50 PN160. The associated connection flanges are to be dimensioned by the bidder.

The offer price includes:

- Delivery according to DDP Dresden (Incoterms 2020),

- Acceptance of the recuperator by a central monitoring point and issuing of a CE mark before delivery,

- Acceptance of the liquid cooler by a central monitoring point and issuing of a CE mark before delivery,

- Complete documentation, documentation language German, including:

a) operating and assembly instructions,

b) acceptance test certificates,

c) Calculation of the heat exchanger surface with regard to the given thermal output and the operating points:

- Descriptive files and lists in MS Office, drawings in Auto-CAD,

- Issuing a declaration of conformity for the entire heat exchanger system, proof of the certificate of conformity and complete delivery including documentation within a maximum of 32 weeks after placing the order,

- Warranty of at least 24 months.