EP1906111A1

EP1906111A1 - Reversible fluid-water heat pump

Info

Publication number: EP1906111A1
Application number: EP07462007A
Authority: EP
Inventors: Zoltàn Fodor
Original assignee: Geowatt Ipari-Szolgaltato Es Kereskedelmi Kft
Current assignee: Geowatt Ipari-Szolgaltato Es Kereskedelmi Kft
Priority date: 2006-09-20
Filing date: 2007-09-14
Publication date: 2008-04-02
Also published as: HU3281U; HU0600213V0

Abstract

The cycle of the reversible fluid-water heat pump according to the invention contains an evaporator, a compressor, an accumulator, a condenser, a fluid collector, and - according to the invention - a tabular steam generator heat exchanger which is connected to the cycle by an expansion valve, a magnetic valve and non-return valves. The expansion valve is a practically modulated electronic expansion valve. Two of the non-return valves is inserted into the steam cycle and the other two into the fluid cycle of the main cycle.

Description

The present invention relates to a reversible fluid-water heat pump, the cycle of which contains an evaporator, a compressor, an accumulator, a condenser and a fluid collector.
It is well known that fossil fuels are not renewable energy sources. Moreover, during burning several undesirable materials arise, such as carbon dioxide or sulfur dioxide. On the other hand, geothermal power utilizes the decay heat of the radioactive elements, a renewable source under the Earth's crust;. As a utilizable and available energy source the geothermal power of the Earth is fiftythousand larger than the present fossil energy sources. The geothermal power can be used for heating, agricultural production and - to an increasing degree - for the utilization of heat pumps.
This way it gets a much larger role among renewable energy sources. The geothermal industry has a growing rate of 3.5 % a year and the fastest grown is the field of heat pumps.
US 2005086969 A and US 2005086970 describe reversible heat pumps (so called split climate systems). To make the cooling cycle reversible two economizer and two expansion valves or a four-channel-valve are used by these - mainly used overseas - setups
In Europe usually traditional fluid heat pumps are used that are designed for general applications the annual average coefficient of performance (COP) of which is between 4,2-4,5 depending on the efficiency of the driving engine.
The object of the present invention is to elaborate a geothermal heat pump that - with special regard to the Hungarian geothermal environment- has higher COP value and cooling temperature (60 °C).
Accordingly, the cycle of the reversible fluid-water heat pump according to the invention contains an evaporator, a compressor, an accumulator, a condenser, a fluid collector, and - according to the invention - a tabular steam generator heat exchanger which is connected to the cycle by an expansion valve, a magnetic valve and non-return valves,.
The expansion valve is a practically modulated electronic expansion valve. Two of the non-return valves is inserted into the steam cycle and the other two into the fluid cycle of the main cycle.
With this steam injection cycle-built heat pump that is optimized to geothermal conditions it is possible to achieve an annual average of 4,9-5,3 COP value,. at a maximum of 45 °C straight-forward temperature and compensated power handling. Furthermore the system is also able to generate a maximum of 60 °C straight-forward fluid temperature. Using this compensated power handling the annual average of COP is approximately 4,5.
According to the invention the heat pump is a reversible cycled, optimized setup especially built up with the use of a special steam injection compressor and designed for geothermal utilization,.
By inserting the steam injection compressor system the setup can be used both in heating and active cooling mode, and it is more efficient than the previous models due to its compressor, and the inner reversible steam cycle developed thereof.
The power improvement is generated by increasing the enthalpy of the system, first of all contrary to the power improvement by increasing the mass flow.
Compared to previous models the efficiency of the setup increases due to the fact that the increase of the transmitted power is higher than the increase of the power taken by the compressor.
The efficiency increases due to the built-in electronic expansion valves and the condenser and the evaporator dimensioned to the tightest possible temperature range of the compressor.
Other details of the invention will be described by way of examples, with reference to drawing. In the drawing

Fig. 1. is a block pattern of a traditional heat pump,
Fig. 2. is the block pattern of the heat pump according to the invention.

The apparatus shown in Fig. 1. contains a compressor 1, a condenser 2, an evaporator 3, a DHW (domestic hot water) heat exchanger 5, a reverse valve 6, an accumulator 7 and a fluid collector holder 8. There are neither inner auxiliary (reversible) steam cycle, nor any steam snag of the compressor 1. Therefore the post-cooling of the coolant and the lack of steam injection do not allow higher COP value. The regulation of the cooling cycle is solved by using exterior thermostatic expansion valves 9, 23 as shown in the figure.
The gas coolant coming out of the compressor 1 with high enthalpy passes through the DHW heat exchanger 5, where it takes off the overheating heat that is transported by the circulation pump to the DHW holder 19, that is not shown in the figure. The coolant having condensation temperature gets into the condenser through the four-channel reverse valve 6. There the heat is transmitted to the heating medium, therefore the phase of the coolant transforms to fluid, but its temperature remains on condensation level. The coolant gets to a thermostatic expansion valve 9 through the non-return valve of the coolant, the fluid storage tank 8 and a filter 21. The expansion valve 9 indicates such a great pressure loss (the drop of the temperature) so that is enables the evaporator 3 to uptake heat from the heat gaining side.
Due to the heat uptake in evaporator 3 the coolant transforms to gas phase and from there the coolant gets to the intake manifold of the compressor 1 through the four-channel reverse valve 6 and the accumulator 7.
In coolant mode the evaporator 3 and the condenser 2 transposes, the fluid coolant flows through the non-return valve and the thermostatic expansion valve 9 to the evaporator.
The block pattern in Fig. 2. shows the heat pump of the invention. The heat pump is made of similar elements as the traditional solution shown in Fig. 1., but here the compressor 1 is made with a connection capable for steam injection and the setup is expanded by an intermediary cooling cycle consisting of a steam cycle A and a fluid cycle B, which contains a four steam generating condenser.
When starting the system and the four channel reverse valve 6 is in heating state the gas-phase coolant, the enthalpy of which is enlarged by compressor 1, gets into the DHW heat exchanger 5. The DHW heat exchanger 5 is dimensioned to use overheating heat of the cycle, so it distracts as much heat from the gas-phase coolant as to gain the planned condensation temperature after the heat exchanger. On the water side of the heat exchanger the distracted heat gets into the DHW tank with the help of DHW circulation pump 19.
The gas-phase coolant having increased enthalpy gets into the four-channel reverse valve 6. The state of the reverse valve 6 is adjusted by the built-in automatic regulator. If the reverse valve 6 is in heating state, the gas-phase coolant having increased enthalpy gets into the condenser 2. In the condenser 2 the coolant gives the heat to the heating water, while its phase transforms into fluid, but its temperature remains on condensation level.
On one way the high-temperatured fluid-phase and enthalpy-less coolant coming out of the condenser 2 goes along the primer side of the tabular steam generator condenser 4 through the non-return 18 valve and fluid storage tank 8. On the other way the "high"-condensation-temperatured coolant fluid coming out of the condenser 2 goes to a expansion valve 10 through a magnetic valve 12 and a non-return valve 11. In this heating mode a built-in non-return valve 14 prevents the high pressure coolant from getting into the low pressure side. The expansion valve 10 is a modulated electronic valve, which helps to keep the overheating rate in a lower value compared to the traditional thermostatic expansion valves, because their deflection is raised by the time dependent vaporization temperature of the heat pumps and causes significant efficiency drop. The modulated electronic expansion valve 10 is adjusted by a microprocessor controlled automation system 20.
While going through the wad and passing through the steam generator's 4 secondary side the reduced pressured and temperatured coolant takes heat from the higher pressured and temeperatured coolant of the primer side and. meanwhile it transforms into steam phase. The expansion valve 10 assures an overheating of 5 °C so as to inhibit the fluid to get into the compressor 1.
The steam-phase coolant having increased enthalpy gets into the compressor 1 through the manufactured steam wad.
Based on the above mentioned process the coolant passing the steam generator's 4 primer side is post-chilled. The post-chilled fluid-phase coolant goes through the filter 21, the glass eyehole 22, a modulated electronic expansion valve 9 and a non-return valve 15 and finally gets into the evaporator 3. The high pressure of the non-return valve's 16 on the closing side ensures that the gas can only go to the direction of the evaporator.
The 9 modulated electronic expansion valve ensures that the coolant gets to lower temperature compared to the primer (heat gaining) side of the evaporator 3.
In virtue of that, the low pressured and temperatured fluid-phase coolant on the secondary side of the evaporator 3 gains heat from the primer side and transforms into gas phase in the meantime. The modulated electronic expansion valve 9 also ensures an overheating of 5 °C as an assurance that the whole coolant that leaves the evaporator 3 is in steam phase.
After going through the four-channel reverse valve 6 and the accumulator 7 the steam-phase coolant having increased enthalpy gets to the intake manifold of the compressor 1.
In the chilling mode of the heat pump the condenser 2 and the evaporator 3 transposes.
When starting the setup and the four-channel reverse valve 6 is in chilling state, the gas-phase coolant having increased enthalpy by the compressor 1 (the heat gained in the evaporator 3 and the heat taken in by the compressor 1 gets into the DHW heat exchanger (desuperheater) 5. On the water side of the heat exchanger the distracted heat gets into the DHW tank with the help of the DHW circulation valve 19.
Thereafter the gas-phase coolant having increased enthalpy passes through the four-channel reverse valve 6. The state of the reverse valve 4 is adjusted by the built-in automatic regulator 20.
If the four-channel reverse valve 6 is in chilling state, the gas-phase coolant having increased enthalpy gets into the condenser 2. In there the coolant gives its heat to the heating water. In the meantime it transforms into fluid phase keeping its temperature at the condensation temperature level.
On one way coming out of the condenser 1 and passing the non-return valve 17 and the fluid collector holder 8 the enthalpy-less, high-temperatured, fluid-phase coolant gets into the primer side of the steam generating heat exchanger 4.
On the other way coming out of the condenser 1 and passing the magnetic valve 13 and the non-return valve 14 the fluid-phase coolant having "high" condensation temperature gets to the modulated electronic expansion valve 10. In this heating mode a built-in non-return valve 11 prevents the high pressured coolant from getting into the low-pressured side.
When going through the wad and passing the tabular steam generating heat exchanger's 4 secondary side the lower-pressured and temperatured coolant gains heat from the higher-pressured and temperatured coolant of the primer side and transforms into steam phase in the meantime. The expansion valve 10 assures an overheating of 5 °C so as to inhibit the fluid getting into the compressor 1.
The steam-phase coolant having increased enthalpy gets into the compressor 1 through the steam wad.
Based on the process mentioned above, going through the primer side of the tabular steam.generating heat exchanger 4 the post-chilling of the coolant occurs. The post-chilled fluid-phase coolant gets through the filter 21, the glass eyehole 22, the modulated electronic expansion valve 9 and the non-return valve 15 and gets to the evaporator 2. The high pressure on the closing side of the non-return valve 16 ensures that the gas can only flow to the direction of the evaporator.
The basic advantage of the heat pump described in the invention is the better power compared to the already known solutions which can be primarily achieved by increasing the enthalpy in the system without increasing the piston displacement. Also the value of the COP of the system also increases, due to the fact that the increase of the transmitted power is higher than the increase of the power gained by the compressor.
The costs and the power-consumption are also more favourable than of traditional solutions, because one can gain equal power with a smaller sized compressor as compared to the larger, traditional model.

LIST OF REFERENCE NUMBERS

1: compressor
2: condenser
3: evaporator
4: steam generating heat exchanger
5: DHW heat exchanger
6: reverse valve
7: accumulator
8: fluid tank
9: expansion valve
10: expansion valve
11: non-return valve
12: magnetic valve
13: magnetic valve
14: non-return valve
15: non-return valve
16: non-return valve
17: non-return valve
18: non-return valve
19: non-return valve
20: automatic regulator
21: filter
22: glass eyehole
23: expansion valve
A: steam cycle
B: fluid cycle

Claims

Reversible fluid-water heat pump, wherein the cycle of said heat pump consists of evaporator, compressor, accumulator, condenser and fluid tank, characterized in that it consists of a tabular steam generating heat exchanger (4), which is inserted into the cycle by an expansion valve (9), a magnetic valve (12) and non-return valves (11, 14, 17, 18)
The heat pump as claimed in claim 1, wherein the expansion valve (9) is a modulated electronic expansion valve.
The heat pump as claimed in claim 1 or 2, characterized in that two non-return valves (11, 14) are inserted into the steam cycle (A) of the cycle.
The heat pump as claimed in claim 1 or 2 or 3, characterized in that two non-return valves (17, 18) are inserted into the fluid cycle (B) of the cycle.