Math & Numbers
Heat Exchanger LMTD Calculator (Log Mean Temperature Difference)
Compute the Log Mean Temperature Difference (LMTD) of a heat exchanger for parallel or counter flow. Parallel flow: ΔT₁ = T_h,in - T_c,in and ΔT₂ = T_h,out - T_c,out; counter flow: ΔT₁ = T_h,in - T_c,out and ΔT₂ = T_h,out - T_c,in. LMTD = (ΔT₁ - ΔT₂)/ln(ΔT₁/ΔT₂), or ΔT₁ when ΔT₁ = ΔT₂. A non-positive terminal difference (temperature cross) is physically impossible and is rejected. Optionally, with the overall heat transfer coefficient U (W/(m²·K)) and the heat transfer area A (m²), the heat transfer rate Q = U·A·LMTD (W) is returned. Temperatures are used only as differences: Δ°C = ΔK and Δ°F ×5/9 = ΔK; the LMTD is reported in K.
Quick start
Call this tool from your code in three languages.
curl -X POST 'https://api.elysiatools.com/en/api/tools/heat-exchanger-lmtd' \
-H 'Content-Type: application/json' \
-d '{"flowType":"counter","hotInletTemp":100,"hotOutletTemp":60,"coldInletTemp":20,"coldOutletTemp":50,"tempUnit":"°C","heatTransferCoeff":0,"area":0,"decimalPlaces":4}'API reference
Send a POST request with your inputs as JSON. File parameters require a separate upload first.
Endpoint
POST https://api.elysiatools.com/en/api/tools/heat-exchanger-lmtdParameters
| Name | Type | Required | Description |
|---|---|---|---|
| flowType | select | No | Flow arrangement: Parallel Flow (both streams in the same direction) or Counter Flow (opposite directions). |
| hotInletTemp | number | Yes | Hot-stream inlet temperature T_h,in, in the selected Temperature Unit. |
| hotOutletTemp | number | Yes | Hot-stream outlet temperature T_h,out, in the selected Temperature Unit. |
| coldInletTemp | number | Yes | Cold-stream inlet temperature T_c,in, in the selected Temperature Unit. |
| coldOutletTemp |
MCP integration
Add this tool to your Model Context Protocol server so AI agents can list and call it.
Server configuration
Add this block to your MCP client configuration:
{
"mcpServers": {
"elysiatools-heat-exchanger-lmtd": {
"name": "heat-exchanger-lmtd",
"description": "Compute the Log Mean Temperature Difference (LMTD) of a heat exchanger for parallel or counter flow. Parallel flow: ΔT₁ = T_h,in - T_c,in and ΔT₂ = T_h,out - T_c,out; counter flow: ΔT₁ = T_h,in - T_c,out and ΔT₂ = T_h,out - T_c,in. LMTD = (ΔT₁ - ΔT₂)/ln(ΔT₁/ΔT₂), or ΔT₁ when ΔT₁ = ΔT₂. A non-positive terminal difference (temperature cross) is physically impossible and is rejected. Optionally, with the overall heat transfer coefficient U (W/(m²·K)) and the heat transfer area A (m²), the heat transfer rate Q = U·A·LMTD (W) is returned. Temperatures are used only as differences: Δ°C = ΔK and Δ°F ×5/9 = ΔK; the LMTD is reported in K.",
"baseUrl": "https://api.elysiatools.com/mcp/sse?toolId=heat-exchanger-lmtd",
"command": "",
"args": [],
"env": {},
"isActive": true,
"type": "sse"
}
}
}List available tools
After connecting to the SSE endpoint, list the exposed tools:
{
"jsonrpc": "2.0",
"id": 1,
"method": "tools/list"
}Call this tool
Invoke the tool by its id, passing arguments built from its parameters:
{
"jsonrpc": "2.0",
"id": 2,
"method": "tools/call",
"params": {
"name": "heat-exchanger-lmtd",
"arguments": {
"flowType": "counter",
"hotInletTemp": 100,
"hotOutletTemp": 60,
"coldInletTemp": 20,
"coldOutletTemp": 50,
"tempUnit": "°C",
"heatTransferCoeff": 0,
"area": 0,
"decimalPlaces": 4
}
}
}