JPH02500997A - heat pump - 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] heat pump The present invention provides a heat pump having a refrigerant circulation system including a compressor, a condenser, an expansion valve, and an evaporator. In this case, the evaporator is essentially vertically arranged and the cooling The refrigerant circuit forming the refrigerant circuit and the subsequent upwardly leading refrigerant circuit is advantageously buried underground. It consists of a conduit.

Since the compressor requires oiling, there is always a certain amount of oil in the heat pump refrigerant. or similar lubricants, which are equipped with an oil separator immediately after the compressor. Despite this, at least a portion of the refrigerant will circulate with the refrigerant. The refrigerant It is difficult to install the evaporator vertically in a heat pump device due to the presence of oil. become. This is because when the refrigerant evaporates, the oil settles in a particularly long and narrow evaporator. This is because it is deposited and accumulated at the bottom of the evaporator. The pressure ratio is that the separated oil is the refrigerant can be absorbed to an insufficient extent from the evaporator along with the vapor, resulting in evaporation Operation failure due to oil accumulation inside the compressor or failure of the compressor due to insufficient oil supply. There is a risk of dry operation. Therefore, in conventional large heat pump equipment, the evaporator is arranged horizontally. Higher temperatures in deeper geological formations can be achieved by direct evaporation buried underground. When using a secondary circulatory system that cannot be used depending on the device and is expensive and has a lot of loss. It is only available for

The present invention therefore aims to eliminate these drawbacks and also to use a large vertical evaporator. Guaranteed to function and operate economically without failure even when , the fundamental task is to provide a heat pump of the type described at the beginning.

The invention incorporates at least one oil separator in the refrigerant circuit leading above the evaporator. This is the refrigerant passage area that exists above the oil tank and is related to the filling state of the oil tank. The above-mentioned problem is solved by having a direction changing part equipped with. That number is higher Depending on the length of the refrigerant circuit leading to the oil separator and other operating conditions, the oil separator entraining the separated or separable oil droplets in stages, thus reducing the oil residue in the evaporator and The risks associated with this are eliminated. The oil is passed from the oil separator to the oil separator along with the refrigerant vapor. The excess oil is then collected in the respective oil separators by overcoming the corresponding altitude. He is then sent onwards little by little. The refrigerant flow increases due to the increase in the amount of oil in the oil tank. The region narrows, which accelerates the refrigerant flow in the redirection region and also reduces the pressure. Therefore, a change in the flow ratio that promotes oil removal always entrains more oil.

Prevents complete separation of oil components from the refrigerant circulation system and is independent of its height. A certain equilibrium condition is obtained which ensures sufficient flow of oil through the evaporator. So No additional pumping equipment or similar costly piping equipment is required and they are compatible with each other. Simple oil separators placed at appropriate intervals are sufficient.・ The oil separator itself can be configured in an appropriate format each time, but the oil separator The intermediate bottom of the conduit forms an overflow nozzle that projects in the axial direction, and the overflow nozzle is covered with and a direction-changing hood whose edge extends below the nozzle outlet. This results in a particularly advantageous structure. In this case, the intermediate bottom and direction can be changed using a simple construction method. The exchange hood provides an oil tank and a direction change area. Concentrates on the hood edge and mid-bottom. The small cross section remaining between the piled oil determines the respective passage zone for the refrigerant flow. The entrainment of the resulting oil droplets is determined by the coolant flow.

The expansion valve located in front of the evaporator operates in conjunction with the pressure difference between the two refrigerant circuits. If possible, the refrigerant circulation system starts from the beginning with a regular flow through the evaporator at the evaporator outlet. It is possible to control the amount of oil in the refrigerant flow to ensure that it does not fluctuate significantly. can.

The object of the invention is illustrated by way of example in the drawing.

FIG. 1 is a schematic diagram showing the structure of a heat pump according to the present invention, and FIG. FIG. 2 is an enlarged vertical cross-sectional view of a part of the evaporator of the evaporator of the evaporator.

A geothermal heat pump 1 essentially includes at least one compressor 2 and a condenser. 3, an expansion valve 4 and one or several evaporators 5, the conduit 6 being a closed refrigerant circuit. Construct a ring system. The vapor collected directly from the earth is transferred to the evaporable refrigerant in the evaporator 5. The heat generated is pumped up by the compressor 2, and is transferred from the condensed refrigerant as heat of condensation in the condenser 3. It is provided to a consumer (not shown) via a heat exchanger 3a. The refrigerant condensate is then It reaches the expansion valve 4'' through the liquid receiving tank 7 and the refrigerant dryer 8, where it is depressurized, and then It flows into the evaporator 5 again.

Compressor 2 needs to be lubricated, so lubricant is present in the refrigerant circulation system, but this This is removed from the refrigerant by the oil separator 9 immediately after the compressor 2, and the oil is removed from the refrigerant by the oil regulating tank 10f: Then, it is guided to the compressor 2 again. Complete oil separation is not possible, and only a certain amount of oil or Lubricants are present throughout the entire refrigerant circuit.

To take advantage of the increasing and uniform temperature with increasing depth underground. In order to (One leg leads the refrigerant circuit 11a downward and the other leg leads upward. (constitutes the refrigerant circuit 11b). Because the specific volume of the refrigerant changes when it evaporates. , the cross section of the refrigerant circuit 11b leading upward is similar to the cross section of the refrigerant circuit 11& leading downward. is correspondingly large, so that its flow ratio is adapted to changing conditions of the refrigerant.

Vertically arranged evaporators have a height difference that must be overcome if they exceed a certain length. This represents an insurmountable obstacle in itself for the oil contained in the refrigerant circulation system, and Oil that precipitates during refrigerant evaporation can accumulate at the bottom of the evaporator 5, resulting in short There is a risk that the heat pump will malfunction over time and the operation of the heat pump will have to be interrupted. Ru. Therefore, in order to easily ensure the conveyance of oil even within the evaporator 5, the coolant is guided upward. The oil separators 12 are stacked at appropriate intervals in the medium circuit 11b, and thereby The oil rises in the refrigerant circuit 1ib which leads the oil upward from the oil separator to the oil separator in stages. This can prevent oil from remaining in the evaporator 5.

As is particularly clear from FIG. The intermediate bottom portion constitutes an overflow nozzle 13a projecting in the axial direction, and this nozzle 13 The peripheral area surrounding a is used together with the wall surface of the conduit 11 as an oil receiving tank 13b.

The overflow nozzle 13a is covered by a direction changing hood 14, which The edge 14a of the nozzle 13a reaches below the outlet of the nozzle 13a, and the cooling process inevitably accompanies oil drop. Forms a medial direction conversion site. The refrigerant flowing upward through the overflow nozzle 13a is The direction is changed by the direction changing hood 14, and the wall of the direction changing hood 14 and the conduit 11 further flows through the remaining space between. Excess oil is separated during direction changes. The oil is accumulated in the oil receiving tank 13b, and the oil receiving tank has a free passage area 14b for the refrigerant. Control. As the amount of oil separated increases, the filling position in the oil receiving tank 13b becomes higher and higher. The passage area 14b becomes smaller. As a result, the flow rate increases and the pressure decreases. to this The separated oil is increased in volume again and transported further. This means self-controllable conveyance bring about the process. In other words, the oil is carried upward little by little into the refrigerant circuit 11b. This prevents oil separation from increasing in the evaporator, regardless of the actual altitude difference that must be overcome. be done. For example, it extends to a depth of 60m underground, and oil deposits are distributed at 12m height intervals. An underground evaporator with a separator has already been tested. This evaporator is Precisely maintains the amount of oil present in the medium circulation system and prevents oil from accumulating in the evaporator do.

In order to maintain the safety of the refrigerant circulation system, a pressure monitoring device 15 is installed in the conduit 6. An expansion valve is used to adjust the flow ratio and pressure ratio in the evaporator 5 to conditions suitable for oil entrainment. 4 is operated in conjunction with the pressure difference across the evaporator 50. Of course heat The pump 1 is also equipped with other control devices for monitoring the refrigerant circulation system and its efficiency. Additional devices may also be used to improve the reservoir.

The evaporator 5 itself and the oil separator 12 are not limited to this special structure either.

international search report 1111 Yuichimu Pass---mp(τ/Entry 8ε/QC・Cji2 International Investigation Report

Claims (3)

[Claims] 1. The evaporator (5) is actually arranged vertically, and the refrigerant circuit leading downwards and its The refrigerant circuit (11a, 11b) which follows is preferably buried underground. A compressor (2), a condenser (3), an expansion valve ( 4) and a heat pump (1) having a refrigerant circulation system including an evaporator (5), At least one oil separator ( 12) is incorporated, which is located above the oil tank (13b) and located above the oil tank (13b). having a redirection section with a refrigerant passage area (14b) associated with the filling state of the refrigerant; A heat pump characterized by. 2. The oil separator (12) forms an axially projecting overflow nozzle (13a). The intermediate bottom (13) of the pipe (11) and the overflow nozzle (13a) are covered and the edge thereof A direction changing hood (14) in which the portion (14a) extends below the nozzle outlet. The heat pump according to claim 1, comprising: 3. The expansion valve (4) disposed in front of the evaporator (5) connects both refrigerant circuits (11a, 3. The heater according to claim 1 or 2, operable in connection with a pressure difference between Topomp.