CN201607145U - Coaxial mud convection heat exchanger - Google Patents

Abstract

The utility model relates to a coaxial mud convection heat exchanger. The heat exchange tubes of the heat exchanger are arranged in a double-layer or multi-layer arrangement. The inner tube is set inside the outer tube. The annular space between the two tubes is a refrigerant circulation channel, and the inner tube is a mud circulation channel, which circulates mud and refrigeration. The agent flows in the opposite direction to form a countercurrent heat exchange. The inner pipe and the inner pipe are connected through a flange and a U-shaped bellows, and the outer pipe and the outer pipe are connected through a short pipe and a flange. A flange is installed in the middle of the short pipe, and the mud inlet and mud The outlet is set at the same end of the mud convection heat exchanger, the refrigerant inlet and the refrigerant outlet are set at the same side of the coaxial mud convection heat exchanger, and communicated with the outer tube, and the outer wall of the outer tube is coated with thermal insulation material. According to the test, the surface heat transfer coefficient of the heat exchanger is large, the heat exchange effect is good, it can quickly cool the mud, and it can withstand high pressure. It is especially suitable for heat exchange between low-temperature or ultra-low temperature fluids with large flow rates and high flow rates. It has a simple structure and is easy to use. The cost is low.

Description

Coaxial mud convection heat exchanger

technical field

The utility model relates to a heat exchange device suitable for cooling low-temperature mud used in natural gas hydrate drilling and sampling, in particular to a heat exchange device for countercurrent heat exchange.

Background technique

The development and utilization of natural gas hydrate must first obtain natural gas hydrate core samples by means of drilling and sampling, and then evaluate geological parameters such as natural gas hydrate storage capacity, occurrence, scale, and properties of natural gas hydrate deposits through analysis of the cores, so drilling and sampling It is the most direct and main means to develop and utilize natural gas hydrate. Natural gas hydrates exist in formations at 0°C to 10°C and pressures > 10 MPa. As long as the temperature of natural gas hydrate formations increases or formation pressure decreases, natural gas hydrates may decompose. During the drilling and sampling process, the drill bit cuts rocks and generates a lot of heat. At the same time, the friction between the drilling tool and the hole wall also generates heat. The temperature at the bottom of the hole rises. The heat is transferred to the drilling mud, and the mud temperature also rises. The increase in mud temperature will cause the gas hydrate to decompose when the gas hydrate core is drilled, making it impossible to take in-situ fidelity gas hydrate core samples. Cause accidents in the hole and cause damage to drilling equipment, so the mud temperature used in drilling must be controlled to ensure that the mud temperature is basically consistent with the gas hydrate formation temperature.

At present, there is no heat exchanger specially suitable for mud cooling in China. Existing heat exchangers can be divided into direct contact type and partition type according to heat transfer characteristics. Partitioning wall heat exchangers are further divided into: jacketed heat exchangers, submerged coil heat exchangers, spray heat exchangers, tube and tube heat exchangers, and casing heat exchangers. According to the flow direction of the medium, it is divided into: downstream heat exchanger and countercurrent heat exchanger. Direct contact heat exchanger, that is, hot and cold fluids are directly mixed, generally suitable for heat exchange when the hot and cold fluids are the same medium, not suitable for mud cooling; that is, the hot and cold fluids are separated by a metal wall without direct contact . The types of partition heat exchangers are: jacketed heat exchangers, heat exchangers of this structure are mainly used for heating or cooling the reaction process, and are made by installing jackets on the outer wall of the container; immersed coil heat exchangers, This kind of heat exchanger is mostly made of metal pipes, or made into various conditions suitable for the container, and immersed in the liquid in the container; spray heat exchanger, the heat exchanger of this structure is mostly used for cooling The hot fluid in the tube fixes the serpentine tubes in rows on the rigid frame, the cooled fluid flows in the tubes, and the cooling water is evenly poured down from the spray device above the tubes; The heat exchanger is also called the shell-and-tube heat exchanger, mostly a heater; the sleeve-and-tube heat exchanger, the heat exchanger of this structure uses two tubes with different diameters to form a concentric sleeve, so that a fluid One flows through the inner tube, and the other passes through the annular gap between the sleeves. The types of wall heat exchangers generally used in the refrigeration industry are: immersed coil heat exchangers, spray heat exchangers, and casing heat exchangers. For the mud cooling problem, the mud temperature must be cooled to below zero, and the spray heat exchanger is not suitable, and the submerged coil heat exchanger is placed in the mud pool, which occupies a small space, and is not suitable. Most of the existing coaxial countercurrent heat exchangers are coil type with complex structure, small volume and small fluid flow. For mud cooling, large flow rate and high flow rate are required, and mud has wall-building properties, that is, mud skin is easy to form on the pipe wall during the flow of mud. The existing heat exchanger cannot meet the cooling conditions of mud under severe working conditions.

Contents of the invention

The purpose of this utility model is to address the above-mentioned deficiencies in the prior art, to provide a coaxial mud convection converter suitable for the drilling construction of land permafrost and ocean drilling, especially suitable for natural gas hydrate drilling mud cooling heater.

The purpose of this utility model is achieved by the following technical solutions:

Coaxial mud convection heat exchanger, the heat exchange tubes of the heat exchanger are arranged in a double-layer or multi-layer arrangement, the inner tube 1 is set inside the outer tube 3, the inner tube 1 and the outer tube 3 are coaxial, and the The annular space is the refrigerant circulation channel, the two ends of the annular gap are closed, the inner pipe 1 is the mud circulation channel, the circulating mud and the refrigerant flow in opposite directions, forming a countercurrent heat exchange, and the passage between the inner pipe 1 and the inner pipe 1 The flange 7 communicates with the U-shaped corrugated pipe 4, the outer pipe 3 communicates with the outer pipe 3 through the short pipe 5 and the flange 7, the short pipe 5 is equipped with a flange 7, and the outer pipe 3 is welded with a support rod 6 for limiting The distance between the two outer pipes 3, the mud inlet 8 and the mud outlet 11 are arranged on the same end of the mud convection heat exchanger, the refrigerant inlet 9 and the refrigerant outlet 10 are arranged on the same side of the coaxial mud convection heat exchanger, and It communicates with the outer pipe 3, and the outer wall of the outer pipe 3 is coated with an insulating layer 2.

The purpose of this utility model can also be achieved through the following technical solutions:

There are four layers of thermal insulation materials, which are thermal insulation paint, polyurethane foam, hard thermal insulation material and tin foil from the inside to the outside; the thermal insulation paint adopts two-component oil-based thermal insulation primer, oil tank thermal insulation paint or water-based thermal insulation topcoat. The hard insulation material is preferably hard rubber or polyurethane rigid foam plastic tile. The inner wall of the inner pipe 1 is a smooth surface; the refrigerant is ethylene glycol.

Beneficial effects: The coaxial mud convection heat exchanger has a large surface heat transfer coefficient and good heat transfer effect, can quickly cool the mud, and can withstand high pressure. It is especially suitable for heat exchange between low-temperature or ultra-low temperature fluids with large flow rates and high flow rates. Simple, easy to use and low cost.

Description of drawings

Accompanying drawing 1 is the top view diagram of coaxial mud convection heat exchanger;

Accompanying drawing 2 is the schematic diagram of the front view of the coaxial mud convection heat exchanger;

Accompanying drawing 3 is the heat preservation structure schematic diagram of coaxial mud convection heat exchanger;

Accompanying drawing 4 is the schematic diagram of countercurrent heat exchange of coaxial mud convection heat exchanger;

Figure 5 is a schematic diagram of the arrangement of coaxial mud convection heat exchangers.

Accompanying drawing 6 is the sectional view of Fig. 4

1 Inner pipe, 2 Insulation layer, 3 Outer pipe, 4U-shaped bellows, 5 Short pipe, 6 Support, 7 Flange, 8 Mud inlet, 9 Refrigerant outlet, 10 Refrigerant inlet, 11 Mud outlet.

Detailed ways

Below in conjunction with accompanying drawing and embodiment describe in further detail:

Coaxial mud convection heat exchanger, the heat exchange tubes of the heat exchanger are arranged in a double-layer or multi-layer arrangement, the inner tube 1 is set inside the outer tube 3, the inner tube 1 and the outer tube 3 are coaxial, and the The annular space is the refrigerant circulation channel, the two ends of the annular gap are closed, the inner pipe 1 is the mud circulation channel, the circulating mud and the refrigerant flow in opposite directions, forming a countercurrent heat exchange, and the passage between the inner pipe 1 and the inner pipe 1 The flange 7 communicates with the U-shaped corrugated pipe 4, the outer pipe 3 communicates with the outer pipe 3 through the short pipe 5 and the flange 7, the short pipe 5 is equipped with a flange 7, and the outer pipe 3 is welded with a support rod 6 for limiting The distance between the two outer pipes 3, the mud inlet 8 and the mud outlet 11 are arranged on the same end of the mud convection heat exchanger, the refrigerant inlet 9 and the refrigerant outlet 10 are arranged on the same side of the coaxial mud convection heat exchanger, and It communicates with the outer pipe 3, and the outer wall of the outer pipe 3 is coated with an insulating layer 2.

There are four layers of insulation material, which are insulation paint, polyurethane foam, hard insulation material and tin foil from the inside to the outside; the hard insulation material is preferably hard rubber; the inner wall of the inner pipe 1 is a smooth surface; the refrigerant is ethylene glycol.

Example 1

Double-layer arrangement coaxial mud convection heat exchanger

The inner pipe 1 and the outer pipe 3 are straight pipe sections with the same length, the inner pipe 1 is sleeved in the outer pipe 3, and the inner pipe 1 and the outer pipe 3 are coaxial to form a set of coaxial sleeves. The coaxial casings between the groups are arranged in parallel, the inner tubes 1 of the adjacent two groups of coaxial casings are connected through the U-shaped bellows 4 and the flange 7, and the outer tube 3 and the inner tube 1 form a ring The two ends of the annular gap of each group of coaxial sleeves are closed, and a short pipe 5 is welded on one side of the end of the outer tube 3, and the outer tube 3 of the other set of coaxial sleeves is welded through the flange 7 The short tubes 5 are connected; the other ends of the two sets of coaxial sleeves are connected with a support 6, the support 6 is equal to the short tube 5, and the support 6 limits the distance between the two sets of outer tubes 3, so that the two sets of outer tubes 3 remain parallel. The outer surface of the pipe 3 and the outer surface of the short pipe 5 for connecting the outer pipe 3 and the outer surface of the U-shaped corrugated pipe 4 are coated with an insulating layer 2 . The innermost layer of the thermal insulation layer 2 is a two-component oily thermal insulation primer coated on the outer pipe 3, and the polyurethane foam, hard rubber and tin foil are wrapped outwards in sequence. The mud inlet 8 and the mud outlet 11 are installed on the same side, the refrigerant glycol inlet 9 and the refrigerant glycol outlet 10 are installed on the same side, the side of the mud inlet is the refrigerant glycol outlet, and the side of the mud outlet is Refrigerant glycol inlet port. The circulating medium of the inner tube 1 is mud, and the circulating medium flowing in the annular gap formed by the outer tube 3 and the inner tube 1 is the refrigerant ethylene glycol, and the two media flow in opposite directions, forming countercurrent heat exchange. After the heat exchange tubes are connected, they are fixed on the steel structure chassis and transported to the construction site when used. The mud in the mud pool is sent into the heat exchanger through the mud pump, and then returns to the mud pool after cooling, that is, the heat exchanger continuously circulates to cool the mud in the mud pool, and the cooled mud is sent into the drilling hole through the mud pump of the drilling rig. Refrigerant ethylene glycol inlet 10 communicates with ethylene glycol tank through cryogenic liquid pump, and refrigerant ethylene glycol outlet 9 communicates with ethylene glycol tank.

When drilling, a large amount of heat energy will be generated due to the cutting of the rock by the drill bit, and the friction between the drilling tool and the hole wall will also generate heat energy. The mud convection heat exchanger returns to the mud pool after heat exchange and cooling.

The refrigerant ethylene glycol is pumped from the ethylene glycol tank through the low-temperature liquid pump to the refrigerant ethylene glycol inlet 10 of the coaxial mud convection heat exchanger, and then exchanges heat with the mud in the inner pipe in the annular gap of the heat exchanger. After heating, the ethylene glycol temperature rises, and returns to the ethylene glycol box to cool down through the refrigerant ethylene glycol outlet 9.

Example 2

Multi-layer arrangement coaxial mud convection heat exchanger.

The inner tube 1 and the outer tube 3 are straight tube sections with the same length, the inner tube 1 is set inside the outer tube 3, the inner tube 1 and the outer tube 3 are coaxial, the outer tube 3 and the inner tube 1 form an annular gap, forming a set of Coaxial casing. Both ends of the annular gap of each group of coaxial sleeves are closed, and the coaxial sleeves between the groups are arranged in parallel no matter whether they are arranged in a plane or vertically, and two adjacent sets of coaxial sleeves The inner tube 1 of the tube communicates with the flange 7 through a U-shaped bellows 4, and a short tube 5 is welded on one side of the end of the outer tube 3, and the short tube 5 welded with another set of coaxial sleeve outer tube 3 through the flange 7 Connected; at the other ends of the two groups of coaxial sleeves, a support 6 is used to connect, the support 6 is equal to the length of the short tube 5, and the support 6 limits the distance between the two sets of outer tubes 3, so that the two sets of outer tubes 3 remain parallel, and the outer tubes 3 The surface and the outer surface of the short pipe 5 for connecting the outer pipe 3 and the outer surface of the U-shaped corrugated pipe 4 are coated with an insulating layer 2 . The innermost layer of the insulation layer 2 is the oil tank insulation paint coated on the outer pipe 3, which wraps polyurethane foam, polyurethane rigid foam plastic tiles and tinfoil outwards successively. The mud inlet 8 of the third-layer coaxial casing communicates with the mud outlet 11 of the second-layer coaxial casing through the U-shaped bellows 4 and the flange 7, and the refrigerant ethylene glycol inlet 9 of the third-layer coaxial casing is connected to the second-layer coaxial casing mud outlet 11. The refrigerant ethylene glycol outlet 10 of the layer coaxial casing is connected to the short pipe 5 welded to the outer pipe 3 of the third layer through the flange 7, and the fourth layer, the fifth layer, and even the N layer are connected in the same way. The refrigerant ethylene glycol inlet 9 is welded on the side of the outer tube 3 of the last layer of coaxial casing, and the mud outlet 11 is arranged at the same end of the last layer of coaxial casing and the refrigerant ethylene glycol inlet 9 . The side of the mud inlet is the refrigerant glycol outlet, and the side of the mud outlet is the refrigerant glycol inlet. The circulating medium of the inner tube 1 is mud, and the circulating medium flowing in the annular gap formed by the outer tube 3 and the inner tube 1 is the refrigerant ethylene glycol, and the two media flow in opposite directions to form a countercurrent heat exchange. After the heat exchange tubes are connected, they are fixed on the steel structure chassis and transported to the construction site when used. The mud in the mud pool is sent into the heat exchanger through the mud pump, and then returns to the mud pool after cooling, that is, the heat exchanger continuously circulates to cool the mud in the mud pool, and the cooled mud is sent into the drilling hole through the mud pump of the drilling rig. Refrigerant ethylene glycol inlet 10 communicates with ethylene glycol tank through cryogenic liquid pump, and refrigerant ethylene glycol outlet 9 communicates with ethylene glycol tank.

When drilling, a large amount of heat energy will be generated due to the cutting of the rock by the drill bit, and the friction between the drilling tool and the hole wall will also generate heat energy. The mud convection heat exchanger returns to the mud pool after heat exchange and cooling.

The refrigerant ethylene glycol is pumped from the ethylene glycol tank through the low-temperature liquid pump to the refrigerant ethylene glycol inlet 10 of the coaxial mud convection heat exchanger, and then exchanges heat with the mud in the inner pipe in the annular gap of the heat exchanger. After heating, the ethylene glycol temperature rises, and returns to the ethylene glycol box to cool down through the refrigerant ethylene glycol outlet 9.

Claims (5)

1. coaxial mud convection heat exchanger, it is characterized in that, each heat exchanger tube arrangement mode of heat exchanger is that bilayer is arranged or the multilayer arrangement mode, interior pipe (1) is sleeved in the outer tube (3), interior pipe (1) is coaxial with outer tube (3), annulus between two pipes is a refrigerant circulation passage, the annular gap closed at both ends, interior pipe (1) is the mud circulation passage, the relative reverse flow of circulating mud with cold-producing medium, constitute countercurrent flow, in be communicated with by flange (7) and U type bellows (4) between pipe (1) and the interior pipe (1), be communicated with by short tube (5) and flange (7) between outer tube (3) and the outer tube (3), flange (7) is housed in the middle of the short tube (5), outer tube (3) is welded with support bar (6) and is used to limit distance between two outer tubes (3), mud import (8) and mud outlet (11) are located at the same end of mud convection heat exchanger, refrigerant inlet (9) and refrigerant outlet 10 are located at the same side of coaxial mud convection heat exchanger, and are communicated with outer tube (3), and the outer wall of outer tube (3) is coated with heat-insulation layer (2) is housed.

2. according to the described coaxial mud convection heat exchanger of claim 1, it is characterized in that totally four layers of insulation materials are followed successively by insulation lacquer, polyurethane foam, hard insulating material and tinfoil from inside to outside.

3. according to the described coaxial mud convection heat exchanger of claim 2, it is characterized in that the insulation lacquer adopts bi-component oiliness heat-insulation and heat-preservation priming paint, oil tank insulation lacquer or aquosity heat insulating heat preserving finish paint.

4. according to the described coaxial mud convection heat exchanger of claim 2, it is characterized in that preferred hard rubber of hard insulating material or polyurethane rigid foam plastic watt.

5. according to the described coaxial mud convection heat exchanger of claim 1, it is characterized in that interior pipe (1) inwall is a shiny surface, cold-producing medium is an ethylene glycol.

Images