Summary of technology
At the heart of the HTHP, there is a novel double hinged arc vane compressor (Fig.1) driven by a vertically placed electrical motor. Main features are listed below.

• Closed loop HTHP is equipped with oil-to-refrigerant evaporator and condenser (Fig.2);
• Compressor eccentric shaft (5mm) allows for low torque arm and as such, ensures the lowest input shaft power in its class,
• Double hinges of the arc vane compressor fully eliminate sliding frictions that are inherently present in swing-vane type and other spring-vane type commercial rolling piston compressors;
• HTHP part load capabilities range from 20% up to 100% thanks to electrical inverter motor;
• The HTHP cycle is charging a high temperature thermal energy storage tank for commercial applications;
• We provide low-cost decarbonization solution for revalorization of low-grade heat from:
  • Air heat source (-10°C to 100°C)
  • Geothermal heat sources (10°C to 130°C),
• Each HTHP has a maximum installed thermal power of 1 MW. Each rack is combining standard compressors in series, each contributing to a rated heat pump power of 25kWth, 75kWth, and 125kWth;
• Lubrication oil is PAG68 and oil quantity is 0.75 Lt;
• No oil pump is needed;

• Development status has now reached TRL6 at the factory test bench;
• The Heat Transfer Fluid (HTF) on the sink and source sides is mineral-based Renotherm 320. Refrigerant-to-HTF heat transfer in the evaporator and condenser are achieved through 13.05 m2 of heat transfer surfaces and 29 m of finned copper piping. Hot oil circulation pumps move 100 liters of HTF within the condenser to the Thermal Energy Storage (TES).

Figure 2: Operational HTHP+TES prototype configuration

Table 1: Measured performance on factory test bench.

Project example
InnoSolPower project has been supported under the
umbrella of CSP-ERA.NET (Cofound ERA-NET Action, G.A. N°
838311). The project is now completed. This technology is
highly flexible for different industrial operations and heat
needs. Pars Makina Ltd (PML) has designed, developed,
manufactured and tested a double hinged arc vane
compressor for a high temperature heat pump (HTHP) with
a discharge temperature well over 130°C. Closed volume
compression allows the pumping of a nominal mass flow
rate around 0.14 kg/s of R1233zd(E) with very high
volumetric efficiencies.

Main thermodynamic performance indicators are:
Volumetric efficiency: the smaller the internal leakage, the
more the volumetric efficiency increases. Volumetric
efficiency is over 90%,
Compressor pressure ratio: 1.58 for R1233zd(E),
Compressor volume ratio: 1.72 for R1233zd(E),
Compressor discharge pressure: 19.55Bar for R1233zd(E),
Volumetric flow rate: 2.9Lt/s for R1233zd(E),
Reliability & Operating Life Expectancy: roll-cake topology of
hinged-vane rolling piston compressor and oil film prevent
direct contact with the internal surface of the cylindrical
housing. The compressor can operate for over 100,000
hours (2 to 3 times that of rotary screw compressors)
without wear.
Main economic performance indicator: to provide low cost
and very efficient high temperature industrial heat pump
compressors. Our potential customers are heat pump
manufacturers, heat pump installers and repair shops,
HTHP technology extensions: supercritical CO2 (R744)
compressors and expanders.
Installation and test start date: January 2024

Contact information
Dr. Sinan Akmandor, Pars Makina Ltd

Product is a hybrid electrical/thermal energy storage composed by a novel high temperature heat pump and the thermal energy storage tank. Integration of heat pump and storage is optimized as operating temperatures and pressure ratios are specifically chosen for highest operational efficiency. Calculated COP is around 9.67. Working fluid: R1233zd(E)

• Standard and modular units HTHF-15 and HTHF-30 (15kW-30kW)
• Offered with three different non-pressurized TES configurations:
• µTES-PCM, µTES-HTF and µTES-C (modular approach)
• Heat exchangers (HXs): evaporator and condenser have each 13.05 m2 heat transfer surfaces. 29m finned copper piping. Hot oil circulation pumps move 100 Lt HTF within HXs
• Flexible operation: heat pumps operate most efficiently at 100% compressor capacity and with a TES. Thus, it is easy to follow “plant heat-load demand” mode of operation.

• Application: homes, schools and Industrial waste heat and processes
• Low-cost decarbonization solution for lower heat grades such as; heat from micro-size concentrated solar blocks (up-to 100°C); Underground/geothermal heat sources (up-to 100°C); excess electrical power heaters from roof-top PVs stored as heat inside TES (PV charges TES in 5 hours)
• 100 kWh modules of µTES charge and discharge in 6 hours
• Up to 120°C: µTES-PCM contains PCM encapsulated tubes
• Up to 150°C: µTES-HTF contains heat transfer fluid (HTF)
• Up to 150°C Concrete filled µTES-C
• HTHP-15 (15 kW) charges a minimum of 4 µTES-PCM modules with a total weight less than 2.5 t. Nominal compressor input is 1.75 kWe.
• HTHP power units (15kW-30kW) are modular (parallel assembly)
• HTHP-15 footprint LxW: 1m x 1m, HTHP weight-alone: 250 kg
• µTES-PCM footprint LxW: 4m x 2m (modules of 25 kWh)
• HTHP-15 charges the TES tank at a rate of 16.67 kWth
• Modular capacity installations from 15 kW to 480 kW up to 8 compressors per unit. Highly flexible industrial operations,
• HCFO-1233zd(E) working fluid is harmless. Class A1, no toxicity and no flammability. ODP = 0, GWP < 5.
• Leak-proof pressure seals on the shaft side
• Compressor driven by a 2kWe open motor with controller
• Compressor technology: patented double hinged arc vane rolling piston
• Lubrication: POE-SL-68
• HTHP pilot plant at TRL6 as the technology is demonstrated in industrially relevant environment.
• Heat Transfer Fluid (HTF) on sink and source side is mineral based Renotherm 320 with high thermal stability up to 320°C.

Project: HTHP-15 is demonstrated at full scale in the context of InnoSolPower (CSP ERA-NET grant agreement No. 838311).

• Tested operating temperature are between 100°C-130°C and pressures are between 12.4 bar-19.6 bar.

Results are presented to InnoSolPower Advisory Group Members.

• Key Performance Indicators (KPIs) ar: high density, high latent heat of fusion, high specific heat, melting point near the required operational temperature (120°C), high thermal conductivity, low vapor pressure, high thermal stability, high chemical stability, low cost, high market availability and low tank size.

Heat supply capacity: Modules of 15kW-30kW-60kW, combined units up to 480 kW

Temperature range: maximum supply temperatures 150°C. HTHP can supply maximum supply heat up to 150°C, such as maximum temperature lift of 20°C. Maximum temperature glides in source is 20°C and at the sink, 25°C

Specific investment cost for installed system without integration: Combined HTHP-15 + µTES-PCM cost: 1500 €/kW

TRL level: TRL6

Expected lifetime: 25 years with regular yearly maintenance

• Rotor, housing and end plates are manufactured from high performance stainless steel
• Material can be magnetized and hardened for near-perfect grind finish.
• Low thermal expansion coefficient.
• 51HRC hardness is conserved up to 450°C
• Primary and secondary balances are achieved with two identical stages, placed 180 degrees out of phase to each-other.

• Low local cavitation risk (low speed, very strong rotor architecture) compared to centrifugal compressors
• Clearances much lower than screw compressors
• Manufacturing cost down (No need for 5-axis CNC (only 3-axis needed), high tolerances are obtained through cost effective grinding and EDM wire technology (electrical discharge machining)
• No reed valves at inlet and outlet of compressor
• Balanced and quiet operation (because no valves)

Stae-of-the-Art technology: Dyadaxis Ltd. double hinged arc vane: compact, no leakage, no friction, suction: blue, discharge: red

• Semi-hermetic architecture.
• Electrical motor is operating at expander outlet temperature (35°C) and pressure (40.7bar),

Direct coupling allows ease of compressor-expander alignment

Current technologies:
Left: Spring loaded vane: leakage and friction,
Right: Swing vane: no leakage but vane-swing vane friction