JPS6117865A - Heat pump device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention (a) Industrial Application Field The present invention relates to a heat pump device that extracts a high temperature fluid from a low temperature heat source fluid, and particularly relates to a heat pump device that extracts a high temperature fluid from a low temperature heat source fluid. The present invention relates to a heat pump device that is airtightly connected to form a closed circulation cycle of working fluid.

(b) Conventional technology Heat pump devices include gas compression type, absorption type, magnet type, and other types, but the ones currently in practical use are gas compression type and absorption type heat pumps. The compressor of the gas compression heat pump uses a reciprocating type, single-screw turbo type compressor, and the gas compressed by such a gas compressor is guided to the condensing section to supply heated heat to the outside. On the other hand, by replenishing heat to the gas circulation cycle system from the evaporator, a high temperature fluid can be obtained from a low temperature heat source fluid.

In order to obtain a fluid at a higher temperature level in a heat pump with such a configuration, for example,
As shown in Figure 2 of No. 6280, a compressor (1),
A refrigerant circulation cycle (3) on the low temperature side with an evaporator (2) etc.
) refrigerant condensing section (4), compressor (5), and condenser (6)
, a refrigerant circulation cycle on the high temperature side having an expansion valve (7), etc.
A device having a configuration in which the evaporator section (8) and the evaporator section (9) are connected in a heat exchange manner is also known as a cascade type heat pump device. By increasing the number of connections in this cascade, theoretically it should be possible to raise the temperature to a considerably high temperature using a heat pump device, but in general,
The substances used as working fluids in heat pumps are:
In the coexistence of copper and iron-based metals, which are the forming materials of the devices that make up the refrigerant circulation cycle, thermal decomposition begins at a temperature of more than 100 degrees Celsius, making it difficult to use as a working fluid for heat pumps over long periods of time. Furthermore, when fluorocarbons are used as the working fluid, the critical temperature of fluorocarbons is between 100°C and 100°C.
Since the temperature was 50°C, operation as a vapor compression cycle could not be expected in a higher temperature range.

For this reason, conventionally, the temperature of the fluid taken out by a gas compression type heat pump device was generally about 70°C, and even when the temperature was raised at the expense of the coefficient of performance, the practical drawing temperature limit was about 100°C.

p→ Problems to be Solved by the Invention In view of these points, the present invention uses a gas compression heat pump to take out a fluid heated to a higher temperature than before, for example, a fluid at a temperature of 100°C to 150°C. The purpose of this is to obtain a heat pump device that can be taken out even if it is removed.

(b) Means for solving the problem To this end, in the present invention, in a plurality of independent closed circulation cycles connected in cascade as described above, Freon is used as the working fluid in the low-temperature side cycle, and fluorocarbon is used as the working fluid in the high-temperature side cycle. Tetraalkyl 7 run, such as tetramethylsilane, is used as the working fluid, and the heat raised to an intermediate temperature in the low-temperature cycle is transferred to the high-temperature cycle, where the temperature is further raised to a higher temperature and the machine is heated. It was designed to be supplied outside.

(e) In a working gas compression type heat pump, the compressor section that pressurizes the working fluid used in the heat pump becomes higher in temperature than the condenser section that heats the fluid to be heated, which tends to cause deterioration of the working fluid. However, in the present invention, by using tetraa/l/kylsilane as the working fluid in this high temperature side cycle,
Chemical reactions between the compressor parts exposed to high temperatures, metal members from the compressor to the condenser, and the working fluid are minimized to prevent deterioration of heat pump function due to deterioration of the working fluid. On the other hand, in the low-temperature cycle, Freon, which is widely used in compression heat pump equipment, is used as the working fluid, and in the high-temperature cycle, only tetraalkylsilane, which is the working fluid, is used in the heat pump equipment. We are trying to suppress the increase and decrease in efficiency.

(f) Example The present invention will be described in detail below with reference to the drawings.

FIG. 1 is a cycle configuration diagram conceptually showing an example of the embodiment of the heat pump device according to the present invention, and (3)
Gas compressor flL as shown in the figure, condenser (4), expansion valve (1)
The working fluid circulation cycle on the low temperature side is formed by airtightly connecting 01, evaporator (2), etc. with pipe α1), (8) is a gas compressor (5), condenser (6), expansion valve (7). ) and evaporator (9) etc. are connected airtight with pipe α2, and the low temperature side cycle (
3) is a high-temperature working fluid circulation cycle that forms an independent working fluid circulation cycle, with a condenser (4) serving as a gas condensation part in the low-temperature cycle and a gas evaporation part in the high-temperature cycle. It is connected to the evaporator (9) in such a manner that heat is exchanged with each other, and both cycles constitute one heat pump device as a whole.

Therefore, in the present invention, Freon such as R12, R114, R133a, etc. is used as the working fluid in the cycle (3) on the low temperature side, and tetrafluorocarbons such as tetramethylsilane are used as the working fluid in the cycle (8) on the high temperature side. Alkylsilanes are used.

Among these, for example, the low temperature side cycle (31KR12 (
When TMS (tetramethylsilane) is used in cycle (8) on the high temperature side, the physical properties of R12 and TMS are as shown in Table 1. Therefore, as an example of suitable usage conditions within that range, the temperature of the evaporator (2) in the low-temperature side cycle is set to 0°C (the temperature of the fluid serving as the heat source is approximately 7°C), and the temperature of the condenser ( The condensation temperature of R12 in 4) was set to about 90°C, and the evaporation temperature of TMS, which is the working fluid of the high temperature side cycle, in the evaporator (9) was set to 80°C1.
Similarly, assuming that the condensation temperature in the condenser (6) is 170°C, the fluid to be heated supplied from the condenser (6) to the load 03) can be heated to about 150°C.

In this case, looking at the pressure conditions applied to the compressor in each cycle, the low temperature side is the temperature and pressure conditions used in general air conditioners and refrigerators, and even in the high temperature side cycle, the evaporator side is 4. .6 to 9 / crd A b
s, 26.3 ky/ff1Ab s on the condenser side
Therefore, even in the high-temperature side cycle, the conventionally used fluorocarbon refrigerant compressor can be used under almost the same conditions.

Next, Table 2 shows the results of measuring the heat resistance and corrosiveness of TMS in comparison with a general fluorocarbon refrigerant R114.

In this test, TMS and R114 were degassed and sealed in a pipe made of iron and copper with an internal volume of about 50 mm, and then placed in a constant temperature bath and heated at 250°C for 200 hours.The amount of decomposed products produced was measured using a gas chromatograph. Corrosion was determined by cutting the pipe and inspecting the inside surface.

As can be seen from the test results, TMS has better heat resistance and corrosion resistance than common fluorocarbon refrigerants.

(G) Effects of the Invention As described above, the present invention integrates two independent gas compression type working fluid circulation cycles in such a way that the condensing section of the low-temperature cycle exchanges heat with the evaporating section of the high-temperature cycle. At the same time, we used fluorocarbons as the working fluid in the low-temperature cycle and tetraalkylsilane as the working fluid in the high-temperature cycle, which reduced the temperature by several tens of degrees Celsius compared to heat pumps that use only fluorocarbon-based working fluids. ) can also provide a heat pump device that can stably supply a fluid heated to a high temperature under load.

[Brief explanation of the drawing]

FIG. 1 is a block diagram for explaining a heat pump device according to the present invention, and FIG. 2 is a refrigerant circuit diagram showing an example of a cascade type refrigeration device. fllf5)...Gas compressor, +21 (9)...
・Evaporator, (3)...Low temperature side cycle, (41(
6)... Condenser, f7) (101... Expansion valve, (
8)...High temperature side cycle, (111(12...tube, 03)...load.

Claims (1)

[Claims] (1) In multiple closed circulation cycles formed by airtightly connecting gas compressors, condensers, expansion valves, evaporators, etc. with piping, the condensation section of the working fluid circulation cycle on the low temperature side is connected to the condensation section of the circulation cycle on the high temperature side. In a device that exchanges heat with a gas evaporation section and extracts heated fluid from a gas condenser in a high-temperature cycle, CFC is used as the working fluid in the low-temperature cycle, and tetraalkylsilane is used as the working fluid in the high-temperature cycle. A heat pump device characterized by using.