AN INNOVATIVE PROTOTYPE OF ADSORPTION CHILLER FOR MOBILE AIR CONDITIONING

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1 Heat Powered Cycles Conference AN INNOVATIVE PROTOTYPE OF ADSORPTION CHILLER FOR MOBILE AIR CONDITIONING Giovanni Restuccia, Angelo Freni, Salvatore Vasta, Alessio Sapienza

2 MAIN GOAL Realization of an innovative prototype of adsorption chiller for mobile air conditioning. The adsorption machine uses the available heat from the engine coolant loop and is designed to deliver about 2.5 kw cooling power for the cabin air conditioning The chiller has been designed and built at CNR ITAE in the framework of the EC project TOPMACS Thermally Operated Mobile Air Conditioning Systems Summary o TOPMACS Project o Design of the on board adsorption air conditioner o Construction of the on board adsorption air conditioner o Performance evaluation in laboratory o Testing in the truck cabin o Conclusions

3 TOPMACS Project The technical challenges: To realize an adsorption system small enough to fit within a car or truck The adsorption system is powered by the engine cooling loop (T<95 C) First phase of the project Four laboratory-scale prototypes were built and tested by project partners Second phase of the project Second phase of the project The ECN adsorption cooling system has been installed in a passenger car (Fiat Grande Punto). The CNR ITAE adsorption cooling system has been installed in a heavy truck (Iveco Stralis).

4 Design of the on board adsorption air conditioner/1 The on-board adsorption chiller was specifically designed for IVECO Stralis truck. System requirements and constraints - Availability of the waste heat in the engine cooling circuit: > 10kW at 90 C. - Cooling power required: >2 kw for Severe European Summer Climate (35 C, 60 % RH) - Maximum temperature drop along the engine cooling circuit: < 5 C. - Mass flow of the cooling fluid: l/min - Auxiliary burner available on the truck for cooling during driver rest in parking areas - Available space for installation: dm 3 - Maximum weight allowed: 35 kg Available space: 689 x 550 x 396 mm

5 Design of the on board adsorption air conditioner/2 Scheme and operating principles radiator radiator Auxiliary Burner Engine The system operates without heat or mass recovery Cycle time Specific Cooling Power

6 Design of the on board adsorption air conditioner/3 547 mm 516 mm 584 mm Volume Weight 170 litres 60 kg Top view

7 On board adsorption air conditioner construction/1 Innovative features Novel double bed adsorber Compact lightweight aluminium finned flat tube heat exchangers, (Valeo Thermique) 2+2 kg of adsorbent material AQSOA Z02 (Mitsubishi Chemical Functional Products Inc.) Compact condenser and evaporator New lay out Detailed characteristics

8 On board adsorption air conditioner construction/2

9 On board adsorption air conditioner construction/3

10 Performance evaluation in laboratory/1 The performance evaluation was carried out by means of a testing facility already installed at the CNR ITAE laboratory T inlet condenser ~ 28 C T inlet condenser ~ 33 C P (kw) COP P (kw) COP Cooling Power COP T outlet evaporator ( C) T outlet evaporator ( C) Cooling Power COP

11 Remarks Performance evaluation in laboratory/2 The adsorption chiller has been tested under the typical EU car air conditioning testing conditions Optimal adsorption/desorption cycle time was 10 minutes. Typical experimental error was 5%. The adsorption cooling system is able to deliver the required cooling power (ACP kw) with a sufficient efficiency (COP C) The adsorption cooling system produces a high Specific Cooling Power (up to 600 W/kg of adsorbent) Reduced performance (cooling COP ~0.25 and ACP ~ 1.3kW) was observed simulating severe climate driving conditions (Tcond=33 C).

12 Testing in the truck cabin/1 The experimental activity continued by installing and testing the adsorption chiller on a truck cabin (Stralis) provided by IVECO. The cabin was located at the ITAE Institute and connected to the adsorption laboratory facilities ITAE ITAE Adsorption laboratory 90 C LPM The adsorption chiller has been connected to the ITAE test bench in order to supply the hot water at 90 C necessary to drive the system.

13 Testing in the truck cabin/2 The adsorption chiller has been installed in the rear part of the cabin, behind the passenger seat 1. A heat exchanger installed in the front part of the truck, allows to cool down both the condenser and the adsorbers by ambient air 2. The cold produced by the adsorption system is delivered to the cabin by means an aluminium exchanger placed behind the dashboard.

14 t ( C) C 30 Testing in the truck cabin/3 Test results 24 C B1 B2 Con Evap Cond AIR outlet Ext TEMP AIR inlet Cabin TEMP Delta 15 C Delta 6 C t (s) T bed 1 T bed 2 T condenser T evaporator T air outlet condenser radiator T ambient T chilled air T of the cabin

15 Testing in the truck cabin/4 Test results remarks The field tests were carried out in winter time, so that the environmental conditions are far from those simulated in laboratory (TOPMACS Project finished in February) The duration of each cycle was about 10 minutes, which confirms the good heat transfer properties of the novel twin beds adsorber The chiller was able to operate automatically for a relevant number of ad/desorption cycles The cooling system delivered continuously cold air at 9 C Considering that the air flow was 600 m 3 /h and that DT = 15 C (recirculation mode), 3 kw of cooling power can be calculated, (target of the project)

16 Testing in the truck cabin/5 Work in progress Available space for condenser and adsorber cooler (air/water exchanger) Vane for adsorption chiller installation

17 Heat Powered Cycles Conference AN INNOVATIVE PROTOTYPE OF ADSORPTION CHILLER FOR MOBILE AIR CONDITIONING Giovanni Restuccia, Angelo Freni, Salvatore Vasta, Alessio Sapienza